1
|
Fares J, Wan Y, Mair R, Price SJ. Molecular diversity in isocitrate dehydrogenase-wild-type glioblastoma. Brain Commun 2024; 6:fcae108. [PMID: 38646145 PMCID: PMC11032202 DOI: 10.1093/braincomms/fcae108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/15/2024] [Accepted: 03/26/2024] [Indexed: 04/23/2024] Open
Abstract
In the dynamic landscape of glioblastoma, the 2021 World Health Organization Classification of Central Nervous System tumours endeavoured to establish biological homogeneity, yet isocitrate dehydrogenase-wild-type (IDH-wt) glioblastoma persists as a tapestry of clinical and molecular diversity. Intertumoural heterogeneity in IDH-wt glioblastoma presents a formidable challenge in treatment strategies. Recent strides in genetics and molecular biology have enhanced diagnostic precision, revealing distinct subtypes and invasive patterns that influence survival in patients with IDH-wt glioblastoma. Genetic and molecular biomarkers, such as the overexpression of neurofibromin 1, phosphatase and tensin homolog and/or cyclin-dependent kinase inhibitor 2A, along with specific immune cell abundance and neurotransmitters, correlate with favourable outcomes. Conversely, increased expression of epidermal growth factor receptor tyrosine kinase, platelet-derived growth factor receptor alpha and/or vascular endothelial growth factor receptor, coupled with the prevalence of glioma stem cells, tumour-associated myeloid cells, regulatory T cells and exhausted effector cells, signifies an unfavourable prognosis. The methylation status of O6-methylguanine-DNA methyltransferase and the influence of microenvironmental factors and neurotransmitters further shape treatment responses. Understanding intertumoural heterogeneity is complemented by insights into intratumoural dynamics and cellular interactions within the tumour microenvironment. Glioma stem cells and immune cell composition significantly impact progression and outcomes, emphasizing the need for personalized therapies targeting pro-tumoural signalling pathways and resistance mechanisms. A successful glioblastoma management demands biomarker identification, combination therapies and a nuanced approach considering intratumoural variability. These advancements herald a transformative era in glioblastoma comprehension and treatment.
Collapse
Affiliation(s)
- Jawad Fares
- Academic Neurosurgery Division, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
- Cambridge Brain Tumour Imaging Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
- Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Yizhou Wan
- Academic Neurosurgery Division, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
- Cambridge Brain Tumour Imaging Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Richard Mair
- Academic Neurosurgery Division, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Stephen J Price
- Academic Neurosurgery Division, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
- Cambridge Brain Tumour Imaging Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
| |
Collapse
|
2
|
Bomsztyk K, Mar D, Denisenko O, Powell S, Vishnoi M, Delegard J, Patel A, Ellenbogen RG, Ramakrishna R, Rostomily R. Analysis of gliomas DNA methylation: Assessment of pre-analytical variables. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586350. [PMID: 38586048 PMCID: PMC10996653 DOI: 10.1101/2024.03.26.586350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Precision oncology is driven by molecular biomarkers. For glioblastoma multiforme (GBM), the most common malignant adult primary brain tumor, O6-methylguanine-DNA methyltransferase ( MGMT ) gene DNA promoter methylation is an important prognostic and treatment clinical biomarker. Time consuming pre-analytical steps such as biospecimen storage before fixing, sampling, and processing are major sources of errors and batch effects, that are further confounded by intra-tumor heterogeneity of MGMT promoter methylation. To assess the effect of pre-analytical variables on GBM DNA methylation, tissue storage/sampling (CryoGrid), sample preparation multi-sonicator (PIXUL) and 5-methylcytosine (5mC) DNA immunoprecipitation (Matrix MeDIP-qPCR/seq) platforms were used. MGMT promoter CpG methylation was examined in 173 surgical samples from 90 individuals, 50 of these were used for intra-tumor heterogeneity studies. MGMT promoter methylation levels in paired frozen and formalin fixed paraffin embedded (FFPE) samples were very close, confirming suitability of FFPE for MGMT promoter methylation analysis in clinical settings. Matrix MeDIP-qPCR yielded similar results to methylation specific PCR (MS-PCR). Warm ex-vivo ischemia (37°C up to 4hrs) and 3 cycles of repeated sample thawing and freezing did not alter 5mC levels at MGMT promoter, exon and upstream enhancer regions, demonstrating the resistance of DNA methylation to the most common variations in sample processing conditions that might be encountered in research and clinical settings. 20-30% of specimens exhibited intratumor heterogeneity in the MGMT DNA promoter methylation. Collectively these data demonstrate that variations in sample fixation, ischemia duration and temperature, and DNA methylation assay technique do not have significant impact on assessment of MGMT promoter methylation status. However, intratumor methylation heterogeneity underscores the need for histologic verification and value of multiple biopsies at different GBM geographic tumor sites in assessment of MGMT promoter methylation. Matrix-MeDIP-seq analysis revealed that MGMT promoter methylation status clustered with other differentially methylated genomic loci (e.g. HOXA and lncRNAs), that are likewise resilient to variation in above post-resection pre-analytical conditions. These MGMT -associated global DNA methylation patterns offer new opportunities to validate more granular data-based epigenetic GBM clinical biomarkers where the CryoGrid-PIXUL-Matrix toolbox could prove to be useful.
Collapse
|
3
|
Gibson D, Vo AH, Lambing H, Bhattacharya P, Tahir P, Chehab FF, Butowski N. A systematic review of high impact CpG sites and regions for MGMT methylation in glioblastoma [A systematic review of MGMT methylation in GBM]. BMC Neurol 2024; 24:103. [PMID: 38521933 PMCID: PMC10960428 DOI: 10.1186/s12883-024-03605-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 03/17/2024] [Indexed: 03/25/2024] Open
Abstract
BACKGROUND MGMT (O 6 -methylguanine-DNA methyltransferase) promoter methylation is a commonly assessed prognostic marker in glioblastoma (GBM). Epigenetic silencing of the MGMT gene by promoter methylation is associated with greater overall and progression free survival with alkylating agent regimens. To date, there is marked heterogeneity in how MGMT promoter methylation is tested and which CpG sites are interrogated. METHODS To further elucidate which MGMT promoter CpG sites are of greatest interest, we performed comprehensive searches in PubMed, Web of Science, and Embase and reviewed 2,925 article abstracts. We followed the GRADE scoring system to assess risk of bias and the quality of the studies we included. RESULTS We included articles on adult glioblastoma that examined significant sites or regions within MGMT promoter for the outcomes: overall survival, progression free survival, and/or MGMT expression. We excluded systemic reviews and articles on lower grade glioma. fifteen articles met inclusion criteria with variable overlap in laboratory and statistical methods employed, as well as CpG sites interrogated. Pyrosequencing or BeadChip arrays were the most popular methods utilized, and CpG sites between CpG's 70-90 were most frequently investigated. Overall, there was moderate concordance between the CpG sites that the studies reported to be highly predictive of prognosis. Combinations or means of sites between CpG's 73-89 were associated with improved OS and PFS. Six studies identified CpG sites associated with prognosis that were closer to the transcription start site: CpG's 8, 19, 22, 25, 27, 32,38, and CpG sites 21-37, as well as low methylation level of the enhancer regions. CONCLUSION The following systematic review details a comprehensive investigation of the current literature and highlights several potential key CpG sites that demonstrate significant association with OS, PFS, and MGMT expression. However, the relationship between extent of MGMT promoter methylation and survival may be non-linear and could be influenced by potential CpG hotspots, the extent of methylation at each CpG site, and MGMT enhancer methylation status. There were several limitations within the studies such as smaller sample sizes, variance between methylation testing methods, and differences in the various statistical methods to test for association to outcome. Further studies of high impact CpG sites in MGMT methylation is warranted.
Collapse
Affiliation(s)
- David Gibson
- Department of Neuro-Oncology, University of California, San Francisco, 400 Parnassus Ave, San Francisco, CA, USA
- Department of Bioinformatics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Anh Huan Vo
- Department of Neuro-Oncology, University of California, San Francisco, 400 Parnassus Ave, San Francisco, CA, USA.
| | - Hannah Lambing
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Prithanjan Bhattacharya
- Department of Neuro-Oncology, University of California, San Francisco, 400 Parnassus Ave, San Francisco, CA, USA
| | - Peggy Tahir
- University of California, San Francisco Library, San Francisco, CA, USA
| | - Farid F Chehab
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Nicholas Butowski
- Department of Neuro-Oncology, University of California, San Francisco, 400 Parnassus Ave, San Francisco, CA, USA
| |
Collapse
|
4
|
Shaw R, Basu M, Karmakar S, Ghosh MK. MGMT in TMZ-based glioma therapy: Multifaceted insights and clinical trial perspectives. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119673. [PMID: 38242327 DOI: 10.1016/j.bbamcr.2024.119673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 01/21/2024]
Abstract
Temozolomide (TMZ) is the most preferred and approved chemotherapeutic drug for either first- or second-line chemotherapy for glioma patients across the globe. In glioma patients, resistance to treatment with alkylating drugs like TMZ is known to be conferred by exalted levels of MGMT gene expression. On the contrary, epigenetic silencing through MGMT gene promoter methylation leading to subsequent reduction in MGMT transcription and protein expression, is predicted to have a response favoring TMZ treatment. Thus, MGMT protein level in cancer cells is a crucial determining factor in indicating and predicting the choice of alkylating agents in chemotherapy or choosing glioma patients directly for a second line of treatment. Thus, in-depth research is necessary to achieve insights into MGMT gene regulation that has recently enticed a fascinating interest in epigenetic, transcriptional, post-transcriptional, and post-translational levels. Furthermore, MGMT promoter methylation, stability of MGMT protein, and related subsequent adaptive responses are also important contributors to strategic developments in glioma therapy. With applications to its identification as a prognostic biomarker, thus predicting response to advanced glioma therapy, this review aims to concentrate on the mechanistic role and regulation of MGMT gene expression at epigenetic, transcriptional, post-transcriptional, and post-translational levels functioning under the control of multiple signaling dynamics.
Collapse
Affiliation(s)
- Rajni Shaw
- Cancer Biology and Inflammatory Disorder Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology (CSIR-IICB), TRUE Campus, CN-6, Sector-V, Salt Lake, Kolkata-700091 & 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Malini Basu
- Department of Microbiology, Dhruba Chand Halder College, Dakshin Barasat, South 24, Paraganas 743372, India
| | - Subhajit Karmakar
- Cancer Biology and Inflammatory Disorder Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology (CSIR-IICB), TRUE Campus, CN-6, Sector-V, Salt Lake, Kolkata-700091 & 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Mrinal K Ghosh
- Cancer Biology and Inflammatory Disorder Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology (CSIR-IICB), TRUE Campus, CN-6, Sector-V, Salt Lake, Kolkata-700091 & 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India.
| |
Collapse
|
5
|
Kushihara Y, Tanaka S, Kobayashi Y, Nagaoka K, Kikuchi M, Nejo T, Yamazawa E, Nambu S, Kugasawa K, Takami H, Takayanagi S, Saito N, Kakimi K. Glioblastoma with high O6-methyl-guanine DNA methyltransferase expression are more immunologically active than tumors with low MGMT expression. Front Immunol 2024; 15:1328375. [PMID: 38288307 PMCID: PMC10824125 DOI: 10.3389/fimmu.2024.1328375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/02/2024] [Indexed: 01/31/2024] Open
Abstract
Background Glioblastoma (GBM) is a highly lethal brain tumor. The effectiveness of temozolomide (TMZ) treatment in GBM is linked to the methylation status of O6-methyl-guanine DNA methyltransferase (MGMT) promoter. Patients with unmethylated MGMT promoter have limited treatment options available. Consequently, there is a pressing need for alternative therapeutic strategies for such patients. Methods Data, including transcriptomic and clinical information, as well as information on MGMT promoter methylation status in primary GBM, were obtained from The Cancer Genome Atlas (TCGA) (n=121) and Chinese Glioma Genome Atlas (CGGA) (n=83) datasets. Samples were categorized into high and low MGMT expression groups, MGMT-high (MGMT-H) and MGMT-low (MGMT-L) tumors. A comprehensive transcriptome analysis was conducted to explore the tumor-immune microenvironment. Furthermore, we integrated transcriptome data from 13 GBM patients operated at our institution with findings from tumor-infiltrating lymphocyte (TIL) cultures, specifically investigating their response to autologous tumors. Results Gene signatures associated with various immune cells, including CD8 T cells, helper T cells, B cells, and macrophages, were noted in MGMT-H tumors. Pathway analysis confirmed the enrichment of immune cell-related pathways. Additionally, biological processes involved in the activation of monocytes and lymphocytes were observed in MGMT-H tumors. Furthermore, TIL culture experiments showed a greater presence of tumor-reactive T cells in MGMT-H tumors compared to MGMT-L tumors. These findings suggest that MGMT-H tumors has a potential for enhanced immune response against tumors mediated by CD8 T cells. Conclusion Our study provides novel insights into the immune cell composition of MGMT-H tumors, which is characterized by the infiltration of type 1 helper T cells and activated B cells, and also the presence of tumor-reactive T cells evidenced by TIL culture. These findings contribute to a better understanding of the immune response in MGMT-H tumors, emphasizing their potential for immunotherapy. Further studies are warranted to investigate on the mechanisms of MGMT expression and antitumor immunity.
Collapse
Affiliation(s)
- Yoshihiro Kushihara
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Immunotherapeutics, The University of Tokyo Hospital, Tokyo, Japan
| | - Shota Tanaka
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yukari Kobayashi
- Department of Immunotherapeutics, The University of Tokyo Hospital, Tokyo, Japan
| | - Koji Nagaoka
- Department of Immunotherapeutics, The University of Tokyo Hospital, Tokyo, Japan
| | - Miyu Kikuchi
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takahide Nejo
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Erika Yamazawa
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Genome Science and Medicine, Research center for Advanced Science and technology, The University of Tokyo, Tokyo, Japan
| | - Shohei Nambu
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazuha Kugasawa
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hirokazu Takami
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shunsaku Takayanagi
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Nobuhito Saito
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazuhiro Kakimi
- Department of Immunotherapeutics, The University of Tokyo Hospital, Tokyo, Japan
- Department of Immunology, Kindai University Faculty of Medicine, Osakasayama, Osaka, Japan
| |
Collapse
|
6
|
Di Salle G, Tumminello L, Laino ME, Shalaby S, Aghakhanyan G, Fanni SC, Febi M, Shortrede JE, Miccoli M, Faggioni L, Cosottini M, Neri E. Accuracy of Radiomics in Predicting IDH Mutation Status in Diffuse Gliomas: A Bivariate Meta-Analysis. Radiol Artif Intell 2024; 6:e220257. [PMID: 38231039 PMCID: PMC10831518 DOI: 10.1148/ryai.220257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 09/12/2023] [Accepted: 10/24/2023] [Indexed: 01/18/2024]
Abstract
Purpose To perform a systematic review and meta-analysis assessing the predictive accuracy of radiomics in the noninvasive determination of isocitrate dehydrogenase (IDH) status in grade 4 and lower-grade diffuse gliomas. Materials and Methods A systematic search was performed in the PubMed, Scopus, Embase, Web of Science, and Cochrane Library databases for relevant articles published between January 1, 2010, and July 7, 2021. Pooled sensitivity and specificity across studies were estimated. Risk of bias was evaluated using Quality Assessment of Diagnostic Accuracy Studies-2, and methods were evaluated using the radiomics quality score (RQS). Additional subgroup analyses were performed according to tumor grade, RQS, and number of sequences used (PROSPERO ID: CRD42021268958). Results Twenty-six studies that included 3280 patients were included for analysis. The pooled sensitivity and specificity of radiomics for the detection of IDH mutation were 79% (95% CI: 76, 83) and 80% (95% CI: 76, 83), respectively. Low RQS scores were found overall for the included works. Subgroup analyses showed lower false-positive rates in very low RQS studies (RQS < 6) (meta-regression, z = -1.9; P = .02) compared with adequate RQS studies. No substantial differences were found in pooled sensitivity and specificity for the pure grade 4 gliomas group compared with the all-grade gliomas group (81% and 86% vs 79% and 79%, respectively) and for studies using single versus multiple sequences (80% and 77% vs 79% and 82%, respectively). Conclusion The pooled data showed that radiomics achieved good accuracy performance in distinguishing IDH mutation status in patients with grade 4 and lower-grade diffuse gliomas. The overall methodologic quality (RQS) was low and introduced potential bias. Keywords: Neuro-Oncology, Radiomics, Integration, Application Domain, Glioblastoma, IDH Mutation, Radiomics Quality Scoring Supplemental material is available for this article. Published under a CC BY 4.0 license.
Collapse
Affiliation(s)
- Gianfranco Di Salle
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Lorenzo Tumminello
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Maria Elena Laino
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Sherif Shalaby
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Gayane Aghakhanyan
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Salvatore Claudio Fanni
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Maria Febi
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Jorge Eduardo Shortrede
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Mario Miccoli
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Lorenzo Faggioni
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Mirco Cosottini
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| | - Emanuele Neri
- From Academic Radiology, Department of Translational Research on New
Technologies in Medicine and Surgery (G.D.S., L.T., G.A., S.C.F., M.F., J.E.S.,
L.F., E.N.), Department of Clinical and Experimental Medicine (M.M.), and
Neuroradiology Unit, Department of Translational Research on New Technologies in
Medicine and Surgery (M.C.), University of Pisa, Via Roma 67, 56126 Pisa, Italy;
Artificial Intelligence Center, IRCCS Humanitas Research Hospital, Rozzano,
Milan, Italy (M.E.L.); The Shrewsbury and Telford Hospital NHS Trust,
Shrewsbury, England (S.S.); and Italian Society of Medical and Interventional
Radiology, SIRM Foundation, Milan, Italy (E.N.)
| |
Collapse
|
7
|
Mohammad AH, Jatana S, Ruiz-Barerra MA, Khalaf R, Al-Saadi T, Diaz RJ. Metformin use is associated with longer survival in glioblastoma patients with MGMT gene silencing. J Neurooncol 2023; 165:209-218. [PMID: 37889443 DOI: 10.1007/s11060-023-04485-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 10/19/2023] [Indexed: 10/28/2023]
Abstract
PURPOSE New treatments are needed to improve the overall survival of patients with glioblastoma Metformin is known for anti-tumorigenic effects in cancers, including breast and pancreas cancers. In this study, we assessed the association between metformin use and overall survival in glioblastoma patients. METHODS We retrospectively studied 241 patients who underwent surgery at diagnosis of glioblastoma between 2014 and 2018. Metformin was used for pre-existing type 2 diabetes mellitus or in the prevention or management of glucocorticoid induced hyperglycemia. Kaplan-Meier curves and log-rank p test were used for univariate analysis. Cox-proportional hazards model was used to generate adjusted hazard ratios for multivariate analysis. RESULTS Metformin use was associated with longer survival in patients with tumors that had a methylated O6-methylguanine DNA methyltransferase gene (MGMT) promoter (484 days 95% CI: 56-911 vs. 394 days 95% CI: 249-538, Log-Rank test: 6.5, p = 0.01). Cox regression analysis shows that metformin associates with lower risk of death at 2 years in patients with glioblastoma containing a methylated MGMT promoter (aHR = 0.497, 95% CI 0.26-0.93, p = 0.028). CONCLUSION Our findings suggest a survival benefit with metformin use in patients with glioblastomas having methylation of the MGMT promoter.
Collapse
Affiliation(s)
| | | | - Miguel Angel Ruiz-Barerra
- Neuro-Oncology Research Group, National Institute of Cancer, Bogotá, Colombia
- Department of Neurosurgery, National Institute of Cancer, Bogotá, Colombia
| | - Roy Khalaf
- Faculty of Medicine, McGill University, Montreal, Canada
| | - Tariq Al-Saadi
- Faculty of Medicine, McGill University, Montreal, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute - McGill University Health Centre, Montreal, Canada
| | - Roberto J Diaz
- Faculty of Medicine, McGill University, Montreal, Canada.
- Department of Neurology and Neurosurgery, Montreal Neurological Institute - McGill University Health Centre, Montreal, Canada.
- Neurosurgical Oncology, Department of Neurology and Neurosurgery, Montreal Neurological Hospital - McGill University Health Centre, Montreal, Canada.
- Neurosurgical Oncology, Department of Neurology and Neurosurgery, Montreal Neurological Hospital, Faculty of Medicine, Faculty of Medicine, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
| |
Collapse
|
8
|
Leske H, Camenisch Gross U, Hofer S, Neidert MC, Leske S, Weller M, Lehnick D, Rushing EJ. MGMT methylation pattern of long-term and short-term survivors of glioblastoma reveals CpGs of the enhancer region to be of high prognostic value. Acta Neuropathol Commun 2023; 11:139. [PMID: 37641156 PMCID: PMC10463744 DOI: 10.1186/s40478-023-01622-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/11/2023] [Indexed: 08/31/2023] Open
Abstract
Treatment with the alkylating agent temozolomide is known to be prognostically beneficial in a subset of glioblastoma patients. Response to such chemotherapeutic treatment and the prognostic benefit have been linked to the methylation status of O6-methylguanine-DNA methyltransferase (MGMT). To date, it has not been entirely resolved which methylation pattern of MGMT is most relevant to predict response to temozolomide treatment and outcome. In this retrospective study, we compared the methylation patterns, analyzed by Sanger sequencing, of 27 isocitrate dehydrogenase (IDH)-wildtype glioblastoma patients that survived more than 3 years (long-term survivors) with those of 24 patients who survived less than a year after initial surgery (short-term survivors). Random Forest-, Correlation-, and ROC-curve analyses were performed. The data showed that MGMT is typically methylated in long-term survivors, whereas no prominent methylation is observed in short-term survivors. The methylation status of CpGs, especially in the promoter and exon1/enhancer region correlated highly with outcome. In addition, age and temozolomide treatment were strongly associated with overall survival. Some CpGs in the enhancer region, in particular CpG 86 (bp + 154), demonstrated high values associated with overall survival in the Random Forest analysis. Our data confirm previously published prognostic factors in IDH-wildtype glioblastoma patients, including age and temozolomide treatment as well as the global MGMT methylation status. The area frequently used for decision making to administer temozolomide at the end of exon1 of MGMT, was associated with outcome. However, our data also suggest that the enhancer region, especially CpG 86 (bp + 154) is of strong prognostic value. Therefore, we propose further investigation of the enhancer region in a large prospective study in order to confirm our findings, which might result in an optimized prediction of survival in glioblastoma patients, likely linked to response to temozolomide treatment.
Collapse
Affiliation(s)
- Henning Leske
- Department of Pathology, Oslo University Hospital, Oslo, Norway.
- University of Oslo (UiO), Oslo, Norway.
- Department of Neuropathology, University Hospital of Zurich, Zurich, Switzerland.
| | | | - Silvia Hofer
- Department of Neurology, University Hospital and University of Zurich, Zurich, Switzerland
| | - Marian Christoph Neidert
- Department of Neurosurgery, University Hospital of Zurich, Zurich, Switzerland
- Department of Neurosurgery, Cantonal Hospital of St. Gallen, St. Gallen, Switzerland
| | | | - Michael Weller
- Department of Neurology, University Hospital and University of Zurich, Zurich, Switzerland
| | - Dirk Lehnick
- Department of Health Sciences and Medicine, Head Biostatistics and Methodology, University of Lucerne, Lucerne, Switzerland
| | - Elisabeth Jane Rushing
- Department of Neuropathology, University Hospital of Zurich, Zurich, Switzerland
- Department of Pathology/ Neuropathology, Lucerne, Switzerland
| |
Collapse
|
9
|
Smith J, Field M, Sugaya K. Suppression of NANOG Expression Reduces Drug Resistance of Cancer Stem Cells in Glioblastoma. Genes (Basel) 2023; 14:1276. [PMID: 37372456 DOI: 10.3390/genes14061276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/06/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Glioblastoma (GBM) is an aggressive and incurable primary brain tumor that harbors therapy-resistant cancer stem cells (CSCs). Due to the limited effectiveness of conventional chemotherapies and radiation treatments against CSCs, there is a critical need for the development of innovative therapeutic approaches. Our previous research revealed the significant expression of embryonic stemness genes, NANOG and OCT4, in CSCs, suggesting their role in enhancing cancer-specific stemness and drug resistance. In our current study, we employed RNA interference (RNAi) to suppress the expression of these genes and observed an increased susceptibility of CSCs to the anticancer drug, temozolomide (TMZ). Suppression of NANOG expression induced cell cycle arrest in CSCs, specifically in the G0 phase, and it concomitantly decreased the expression of PDK1. Since PDK1 activates the PI3K/AKT pathway to promote cell proliferation and survival, our findings suggest that NANOG contributes to chemotherapy resistance in CSCs through PI3K/AKT pathway activation. Therefore, the combination of TMZ treatment with RNAi targeting NANOG holds promise as a therapeutic strategy for GBM.
Collapse
Affiliation(s)
- Jonhoi Smith
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
| | - Melvin Field
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
- Orlando Neurosurgery, AdventHealth Neuroscience Institute, Orlando, FL 32803, USA
| | - Kiminobu Sugaya
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA
| |
Collapse
|
10
|
MGMT and Whole-Genome DNA Methylation Impacts on Diagnosis, Prognosis and Therapy of Glioblastoma Multiforme. Int J Mol Sci 2022; 23:ijms23137148. [PMID: 35806153 PMCID: PMC9266959 DOI: 10.3390/ijms23137148] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 12/15/2022] Open
Abstract
Epigenetic changes in DNA methylation contribute to the development of many diseases, including cancer. In glioblastoma multiforme, the most prevalent primary brain cancer and an incurable tumor with a median survival time of 15 months, a single epigenetic modification, the methylation of the O6-Methylguanine-DNA Methyltransferase (MGMT) gene, is a valid biomarker for predicting response to therapy with alkylating agents and also, independently, prognosis. More recently, the progress from single gene to whole-genome analysis of DNA methylation has allowed a better subclassification of glioblastomas. Here, we review the clinically relevant information that can be obtained by studying MGMT gene and whole-genome DNA methylation changes in glioblastomas, also highlighting benefits, including those of liquid biopsy, and pitfalls of the different detection methods. Finally, we discuss how changes in DNA methylation, especially in glioblastomas bearing mutations in the Isocitrate Dehydrogenase (IDH) 1 and 2 genes, can be exploited as targets for tailoring therapy.
Collapse
|
11
|
Xiao Z, Zhang W, Li G, Li W, Li L, Sun T, He Y, Liu G, Wang L, Han X, Wen H, Liu Y, Chen Y, Wang H, Li J, Fan Y, Zhang J. Multiomics Analysis Reveals the Prognostic Non-tumor Cell Landscape in Glioblastoma Niches. Front Genet 2021; 12:741325. [PMID: 34603399 PMCID: PMC8481948 DOI: 10.3389/fgene.2021.741325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/11/2021] [Indexed: 11/21/2022] Open
Abstract
A comprehensive characterization of non-tumor cells in the niches of primary glioblastoma is not fully established yet. This study aims to present an overview of non-malignant cells in the complex microenvironment of glioblastoma with detailed characterizations of their prognostic effects. We curate 540 gene signatures covering a total of 64 non-tumor cell types. Cell type-specific expression patterns are interrogated by normalized enrichment score across four large gene expression profiling cohorts of glioblastoma with a total number of 967 cases. The glioblastoma multiforms (GBMs) in each cohort are hierarchically clustered into negative or positive immune response classes with significantly different overall survival. Our results show that astrocytes, macrophages, monocytes, NKTs, and MSC are risk factors, while CD8 T cells, CD8 naive T cells, and plasma cells are protective factors. Moreover, we find that the immune system and organogenesis are uniformly enriched in negative immune response clusters, in contrast to the enrichment of nervous system in positive immune response clusters. Mesenchymal differentiation is also observed in the negative immune response clusters. High enrichment status of macrophages in negative immune response clusters is independently validated by analyzing scRNA-seq data from eight high-grade gliomas, revealing that negative immune response samples comprised 46.63 to 55.12% of macrophages, whereas positive immune response samples comprised only 1.70 to 8.12%, with IHC staining of samples from six short-term and six long-term survivors of GBMs confirming the results.
Collapse
Affiliation(s)
- Zixuan Xiao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Wei Zhang
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Guanzhang Li
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Wendong Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Lin Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Ting Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yufei He
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Guang Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Lu Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xiaohan Han
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Hao Wen
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yong Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yifan Chen
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Haoyu Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Jing Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Jing Zhang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| |
Collapse
|
12
|
Śledzińska P, Bebyn MG, Furtak J, Kowalewski J, Lewandowska MA. Prognostic and Predictive Biomarkers in Gliomas. Int J Mol Sci 2021; 22:ijms221910373. [PMID: 34638714 PMCID: PMC8508830 DOI: 10.3390/ijms221910373] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/14/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022] Open
Abstract
Gliomas are the most common central nervous system tumors. New technologies, including genetic research and advanced statistical methods, revolutionize the therapeutic approach to the patient and reveal new points of treatment options. Moreover, the 2021 World Health Organization Classification of Tumors of the Central Nervous System has fundamentally changed the classification of gliomas and incorporated many molecular biomarkers. Given the rapid progress in neuro-oncology, here we compile the latest research on prognostic and predictive biomarkers in gliomas. In adult patients, IDH mutations are positive prognostic markers and have the greatest prognostic significance. However, CDKN2A deletion, in IDH-mutant astrocytomas, is a marker of the highest malignancy grade. Moreover, the presence of TERT promoter mutations, EGFR alterations, or a combination of chromosome 7 gain and 10 loss upgrade IDH-wildtype astrocytoma to glioblastoma. In pediatric patients, H3F3A alterations are the most important markers which predict the worse outcome. MGMT promoter methylation has the greatest clinical significance in predicting responses to temozolomide (TMZ). Conversely, mismatch repair defects cause hypermutation phenotype predicting poor response to TMZ. Finally, we discussed liquid biopsies, which are promising diagnostic, prognostic, and predictive techniques, but further work is needed to implement these novel technologies in clinical practice.
Collapse
Affiliation(s)
- Paulina Śledzińska
- Department of Thoracic Surgery and Tumors, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, 85-067 Torun, Poland
- The F. Lukaszczyk Oncology Center, Molecular Oncology and Genetics Department, Innovative Medical Forum, 85-796 Bydgoszcz, Poland
| | - Marek G Bebyn
- The F. Lukaszczyk Oncology Center, Molecular Oncology and Genetics Department, Innovative Medical Forum, 85-796 Bydgoszcz, Poland
- Faculty of Medicine, Medical University of Gdańsk, 80-210 Gdańsk, Poland
| | - Jacek Furtak
- Department of Neurosurgery, 10th Military Research Hospital and Polyclinic, 85-681 Bydgoszcz, Poland
- Franciszek Lukaszczyk Oncology Center, Department of Neurooncology and Radiosurgery, 85-796 Bydgoszcz, Poland
| | - Janusz Kowalewski
- Department of Thoracic Surgery and Tumors, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, 85-067 Torun, Poland
| | - Marzena A Lewandowska
- Department of Thoracic Surgery and Tumors, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, 85-067 Torun, Poland
- The F. Lukaszczyk Oncology Center, Molecular Oncology and Genetics Department, Innovative Medical Forum, 85-796 Bydgoszcz, Poland
| |
Collapse
|
13
|
Tomar MS, Kumar A, Srivastava C, Shrivastava A. Elucidating the mechanisms of Temozolomide resistance in gliomas and the strategies to overcome the resistance. Biochim Biophys Acta Rev Cancer 2021; 1876:188616. [PMID: 34419533 DOI: 10.1016/j.bbcan.2021.188616] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 07/25/2021] [Accepted: 08/15/2021] [Indexed: 02/06/2023]
Abstract
Temozolomide (TMZ) is a first-choice alkylating agent inducted as a gold standard therapy for glioblastoma multiforme (GBM) and astrocytoma. A majority of patients do not respond to TMZ during the course of their treatment. Activation of DNA repair pathways is the principal mechanism for this phenomenon that detaches TMZ-induced O-6-methylguanine adducts and restores genomic integrity. Current understanding in the domain of oncology adds several other novel mechanisms of resistance such as the involvement of miRNAs, drug efflux transporters, gap junction's activity, the advent of glioma stem cells as well as upregulation of cell survival autophagy. This review describes a multifaceted account of different mechanisms responsible for the intrinsic and acquired TMZ-resistance. Here, we summarize different strategies that intensify the TMZ effect such as MGMT inhibition, development of novel imidazotetrazine analog, and combination therapy; with an aim to incorporate a successful treatment and increased overall survival in GBM patients.
Collapse
Affiliation(s)
- Manendra Singh Tomar
- Center for Advance Research, Faculty of Medicine, King George's Medical University, Lucknow 226003, Uttar Pradesh, India
| | - Ashok Kumar
- Department of Biochemistry, All India Institute of Medical Sciences (AIIMS) Bhopal, Saket Nagar, Bhopal 462020, Madhya Pradesh, India
| | - Chhitij Srivastava
- Department of Neurosurgery, King George's Medical University, Lucknow 226003, Uttar Pradesh, India
| | - Ashutosh Shrivastava
- Center for Advance Research, Faculty of Medicine, King George's Medical University, Lucknow 226003, Uttar Pradesh, India.
| |
Collapse
|
14
|
Bacolod MD, Barany F. MGMT Epigenetics: The Influence of Gene Body Methylation and Other Insights Derived from Integrated Methylomic, Transcriptomic, and Chromatin Analyses in Various Cancer Types. Curr Cancer Drug Targets 2021; 21:360-374. [PMID: 33535955 DOI: 10.2174/1568009621666210203111620] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/03/2020] [Accepted: 12/03/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND MGMT (O6-methylguanine-DNA methyltransferase) is primarily responsible for limiting the activity of some widely used chemotherapeutic agents, including temozolomide (TMZ) and carmustine (BCNU). The gene encoding this protein is epigenetically regulated, and assessment of methylation at its promoter region is used to predict glioma patients' response to TMZ. METHODS In this report, we employed a bioinformatic approach to elucidate MGMT's epigenetic regulation. Integrated for the analysis were genome-wide methylation and transcription datasets for > 8,600 human tissue (representing 31 distinct cancer types) and 500 human cancer cell line samples. Also crucial to the interpretation of results were publicly available data from the ENCODE Project: tracks for histone modifications (via ChIP-seq) and DNase I hypersensitivity (via DNaseseq), as well as methylation and transcription data for representative cell lines (HeLa-S3, HMEC, K562). RESULTS AND DISCUSSION We were able to validate (perhaps more comprehensively) the contrasting influences of CpG methylation at promoter region and at gene body on MGMT transcription. While the MGMT promoter is populated by CpG sites whose methylation levels displayed high negative correlation (R) with MGMT mRNA counts, the gene body harbors CpG sites exhibiting high positive R values. The promoter CpG sites with very high negative R's across cancer types include cg12981137, cg12434587, and cg00618725. Among the notable gene body CpG sites (high positive R's across cancer types) are cg00198994 (Intron 1), cg04473030 (Intron 2), and cg07367735 (Intron 4). For certain cancer types, such as melanoma, gene body methylation appears to be a better predictor of MGMT transcription (compared to promoter methylation). In general, the CpG methylation v. MGMT expression R values are higher in cell lines relative to tissues. Also, these correlations are noticeably more prominent in certain cancer types such as colorectal, adrenocortical, esophageal, skin, and head and neck cancers, as well as glioblastoma. As expected, hypomethylation at the promoter region is associated with more open chromatin, and enrichment of histone marks H3K4m1, H3K4m2, H3K4m3, and H3K9ac. CONCLUSION Overall, our analysis illustrated the contrasting influence of promoter and gene body methylation on MGMT expression. These observations may help improve diagnostic assays for MGMT.
Collapse
Affiliation(s)
- Manny D Bacolod
- Department of Microbiology and Immunology, Weill Cornell Medicine, 1300 York Ave, New York, NY 10065, United States
| | - Francis Barany
- Department of Microbiology and Immunology, Weill Cornell Medicine, 1300 York Ave, New York, NY 10065, United States
| |
Collapse
|
15
|
Ahmed M, Bayoumi B, Abdallah S, Elserafy M. MGMT Immunohistochemical Expression in Colorectal Carcinoma and its Correlation with Tumor Progression. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.5879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Introduction: There is an urgent need to identify predictive features and markers for colorectal carcinoma (CRC) progression and treatment. This study aimed to assess O6-methylguanine DNA methyltransferase (MGMT) expression in CRC and correlate with the clinico-pathological aspects of the tumor, also to evaluate the relationship between different histopathologic parameters and tumor progression.
Material and Methods: The study was carried on 70 colectomy using formalin fixed paraffin embedded tumor tissue. Immunohistochemistry was used to detect MGMT expression, and clinico-pathologic aspects as well as Tumor budding, type of desmoplastic reaction, inflammatory lymphocytic milieu, pattern of invasive front and necrosis were assessed Then correlated with MGMT expression and tumor progression, using parametric and nonparametric statistical methods.
Results: MGMT Loss of expression was detected in 42.9% of CRC cases. MGMT expression status was significantly correlated with tumor stage and metastatic status (p<0.05), while it was not correlated with other clinic-pathologic features, (p>0.05). Desmoplastic reaction (DR), tumor budding, stromal tumor infiltrating lymphocytes (TIL-S) and necrosis were correlated with tumor stage (p<0.05). DR correlated with tumor budding (p<0.05). Both types of TIL and Crohn’s-like lymphoid reaction (CLR) showed a mutual correlation (p<0.05).
Conclusion: MGMT high expression and histopathologic parameters as DR, tumor budding, inflammatory lymphocytic milieu and necrosis could be correlated with CRC progression.
Collapse
|
16
|
The number of methylated CpG sites within the MGMT promoter region linearly correlates with outcome in glioblastoma receiving alkylating agents. Acta Neuropathol Commun 2021; 9:35. [PMID: 33663593 PMCID: PMC7934240 DOI: 10.1186/s40478-021-01134-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 02/21/2021] [Indexed: 12/11/2022] Open
Abstract
MGMT-promoter methylation is associated with favorable outcome in glioblastoma. The aim of this study was to determine whether the absolute number of methylated Cytosine-Guanine-dinucleotide-(CpG-)sites within the DMR-2 island of the MGMT-promoter may correlate with outcome in a qualitative or quantitative fashion. In a cohort of newly diagnosed glioblastoma patients treated with stereotactic biopsy or open tumor resection plus concomitant chemoradiotherapy, we assessed MGMT-promoter methylation by methylation-specific polymerase-chain-reaction (MSP). Methylation of the CpG-sites 74–98 within the MGMT-promoter region was additionally analysed by Sanger sequencing, and the total number of methylated CpG-sites was correlated with outcome using proportional hazards models. 215 patients with glioblastoma were identified and stratified per MSP (positive: 53%, negative: 47%). Among MSP-positive tumors, hierarchical clustering identified three subgroups with different methylation rates (median: 80% vs. 52% vs. 47%), indicating a site-dependent methylation propagation. The methylation status of a given CpG-site indicated a neighborhood-dependent methylation propagation. Survival was linearly associated with the cumulative number of methylated CpG-sites. This was particularly true in patients who received at least one adjuvant cycle of temozolomide. Notably, all CpG-sites analyzed contributed similarly to effect size; this enabled a further predictive substratification of MSP-positive tumors with median OS ranging from as low as 17.1 months (< 18 methylated CpG-sites) to as high as 26.2 months (≥ 18 methylated CpG-sites) in the overall cohort. All in all, total number of methylated CpG-sites may correlate with outcome in a linear fashion. Such analysis may therefore add further predictive value to conventional methods of determining the MGMT-promoter status.
Collapse
|
17
|
Low MGMT digital expression is associated with a better outcome of IDH1 wildtype glioblastomas treated with temozolomide. J Neurooncol 2021; 151:135-144. [PMID: 33400009 DOI: 10.1007/s11060-020-03675-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/10/2020] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Glioblastoma (GBM) is the deadliest primary brain tumor. The standard treatment consists of surgery, radiotherapy, and temozolomide (TMZ). TMZ response is heterogeneous, and MGMT promoter (MGMTp) methylation has been the major predictive biomarker. We aimed to describe the clinical and molecular data of GBMs treated with TMZ, compare MGMT methylation with MGMT expression, and further associate with patient's outcome. METHODS We evaluate 112 FFPE adult GBM cases. IDH1 and ATRX expression was analyzed by immunohistochemistry, hotspot TERT promoter (TERTp) mutations were evaluated by Sanger or pyrosequencing, and MGMTp methylation was assessed by pyrosequencing and MGMT mRNA expression using the nCounter® Vantage 3D™ DNA damage and repair panel. RESULTS Of the 112 GBMs, 96 were IDH1WT, and 16 were IDH1MUT. Positive ATRX expression was found in 91.6% (88/96) of IDHWT and 43.7% (7/16) of IDHMUT. TERTp mutations were detected in 70.4% (50/71) of IDHWT. MGMTp methylation was found in 55.5% (35/63) of IDHWT and 84.6% (11/13) of IDHMUT, and as expected, MGMTp methylation was significantly associated with a better response to TMZ. MGMT expression was inversely correlated with MGMTp methylation levels (- 0.506, p < 0.0001), and MGMT low expression were significantly associated with better patient survival. It was also observed that integrating MGMTp methylation and expression, significantly improved the prognostication value. CONCLUSIONS MGMT mRNA levels evaluated by digital expression were associated with the outcome of TMZ-treated GBM patients. The combination of MGMT methylation and mRNA expression may provide a more accurate prediction of TMZ response in GBM patients.
Collapse
|
18
|
Hanihara M, Miyake K, Watanabe A, Yamada Y, Oishi N, Kawataki T, Inukai T, Kondo T, Kinouchi H. Assessment of MGMT methylation status using high-performance liquid chromatography in newly diagnosed glioblastoma. Clin Epigenetics 2020; 12:174. [PMID: 33203454 PMCID: PMC7672949 DOI: 10.1186/s13148-020-00968-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 11/03/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The utility of O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation status as a prognostic marker in patients with glioblastoma (GBM) has been established. However, the number of CpG sites that must be methylated to cause transcriptional silencing remains unclear, and no significant consensus exists on the optimal method of assessing MGMT methylation. We developed a new high-performance liquid chromatography (HPLC) method that enables accurate analysis of DNA methylation levels using long PCR products. In the present study, we analyzed the MGMT methylation status of 28 isocitrate dehydrogenase-wild-type GBMs treated with temozolomide using ion-exchange HPLC and set the optimal cutoff values. RESULTS We designed three primers for separate regions (regions 1-3) that had 21 to 38 CpGs for PCR and validated the MGMT promoter methylation status using frozen samples. There was a strong correlation between HPLC and bisulfite sequencing results (R = 0.794). The optimal cutoff values for MGMT methylation in HPLC were determined to allow differentiation of patient prognosis by receiver operating characteristic curve analysis. The cutoff values were 34.15% for region 1, 8.84% for region 2, and 36.72% for region 3. Kaplan-Meyer curve analysis estimated that the most differentiated prognosis was enabled in the setting of 8.84% methylation of MGMT in region 2. Progression-free survival and overall survival were significantly longer for patients in this setting of region 2 methylation (p = 0.00365 and p = 0.00258, respectively). CONCLUSIONS The combination of our HPLC method and the original primer setting provides a new standard method for determination of MGMT methylation status in patients with GBM and is useful for refining MGMT-based drug selection.
Collapse
Affiliation(s)
- Mitsuto Hanihara
- Departments of Neurosurgery, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Kunio Miyake
- Department of Health Sciences, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
| | - Atsushi Watanabe
- Department of Pediatrics, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Yuriko Yamada
- Tsukuba Research Institute, Research and Development Division, Sekisui Medical Co., Ltd., Ryugasaki, Japan
| | - Naoki Oishi
- Department of Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Tomoyuki Kawataki
- Departments of Neurosurgery, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Takeshi Inukai
- Tsukuba Research Institute, Research and Development Division, Sekisui Medical Co., Ltd., Ryugasaki, Japan
| | - Tetsuo Kondo
- Department of Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Hiroyuki Kinouchi
- Departments of Neurosurgery, University of Yamanashi, Chuo, Yamanashi, Japan
| |
Collapse
|
19
|
Oughourlian TC, Yao J, Hagiwara A, Nathanson DA, Raymond C, Pope WB, Salamon N, Lai A, Ji M, Nghiemphu PL, Liau LM, Cloughesy TF, Ellingson BM. Relative oxygen extraction fraction (rOEF) MR imaging reveals higher hypoxia in human epidermal growth factor receptor (EGFR) amplified compared with non-amplified gliomas. Neuroradiology 2020; 63:857-868. [PMID: 33106922 DOI: 10.1007/s00234-020-02585-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/13/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE Epidermal growth factor receptor (EGFR) amplification promotes gliomagenesis and is linked to lack of oxygen within the tumor microenvironment. Using hypoxia-sensitive spin-and-gradient echo echo-planar imaging and perfusion MRI, we investigated the influence of EGFR amplification on tissue oxygen availability and utilization in human gliomas. METHODS This study included 72 histologically confirmed EGFR-amplified and non-amplified glioma patients. Reversible transverse relaxation rate (R2'), relative cerebral blood volume (rCBV), and relative oxygen extraction fraction (rOEF) were calculated for the contrast-enhancing and non-enhancing tumor regions. Using Student t test or Wilcoxon rank-sum test, median R2', rCBV, and rOEF were compared between EGFR-amplified and non-amplified gliomas. ROC analysis was performed to assess the ability of imaging characteristics to discriminate EGFR amplification status. Overall survival (OS) was determined using univariate and multivariate cox models. Kaplan-Meier survival curves were plotted and compared using the log-rank test. RESULTS EGFR amplified gliomas exhibited significantly higher median R2' and rOEF than non-amplified gliomas. ROC analysis suggested that R2' (AUC = 0.7190; P = 0.0048) and rOEF (AUC = 0.6959; P = 0.0156) could separate EGFR status. Patients with EGFR-amplified gliomas had a significantly shorter OS than non-amplified patients. Univariate cox regression analysis determined both R2' and rOEF significantly influence OS. No significant difference was observed in rCBV between patient cohorts nor was rCBV found to be an effective differentiator of EGFR status. CONCLUSION Imaging of tumor oxygen characteristics revealed EGFR-amplified gliomas to be more hypoxic and contribute to shorter patient survival than EGFR non-amplified gliomas.
Collapse
Affiliation(s)
- Talia C Oughourlian
- UCLA Brain Tumor Imaging Laboratory (BTIL), Center for Computer Vision and Imaging Biomarkers, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Neuroscience Interdepartmental Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Jingwen Yao
- UCLA Brain Tumor Imaging Laboratory (BTIL), Center for Computer Vision and Imaging Biomarkers, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Bioengineering, Henry Samueli School of Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Akifumi Hagiwara
- UCLA Brain Tumor Imaging Laboratory (BTIL), Center for Computer Vision and Imaging Biomarkers, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 615, Los Angeles, CA, 90024, USA
| | - David A Nathanson
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Catalina Raymond
- UCLA Brain Tumor Imaging Laboratory (BTIL), Center for Computer Vision and Imaging Biomarkers, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 615, Los Angeles, CA, 90024, USA
| | - Whitney B Pope
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 615, Los Angeles, CA, 90024, USA
| | - Noriko Salamon
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 615, Los Angeles, CA, 90024, USA
| | - Albert Lai
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Matthew Ji
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Phioanh L Nghiemphu
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Linda M Liau
- Department of Neurosurgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Timothy F Cloughesy
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.,Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Benjamin M Ellingson
- UCLA Brain Tumor Imaging Laboratory (BTIL), Center for Computer Vision and Imaging Biomarkers, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA. .,Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 615, Los Angeles, CA, 90024, USA.
| |
Collapse
|
20
|
The Effects of O 6-methyl Guanine DNA-methyl Transferase Promotor Methylation and CpG1, CpG2, CpG3 and CpG4 Methylation on Treatment Response and their Prognostic Significance in Patients with Glioblastoma. Balkan J Med Genet 2020; 23:33-41. [PMID: 32953407 PMCID: PMC7474218 DOI: 10.2478/bjmg-2020-0015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
This retrospective study examined the prognostic significance and treatment effect of promoter methylation of O6- methyl guanine methyl transferase (MGMT) and meth-ylation of CpG 1, CpG2, CpG3 and CpG4 in glioblastoma (GB) patients received postoperative radiotherapy (PORT), with or without adjuvant temozolomide (TMZ). One hundred patients with GB who received PORT with concomitant TMZ plus adjuvant TMZ or PORT alone, were included. The MGMT promoter methylation of CpG1, CpG2, CpG3 and CpG4 islands were examined. Overall, MGMT-methylation emerged as a significant prognostic factor for better overall survival (OS) and progression-free survival (PFS) [odds ratio (OR): 0.609, 95% confidence interval (95% CI): 0.395-0.939, p = 0.02; OR: 0.662,95% CI: 0.430-1019, p = 0.5, respectively]. The methylation of each CpG1, CpG2, CpG3 and CpG4 islands was found to have no significant effects on OS and the methylation of each CpGl, CpG2 and CpG4 islands had no significant effect on PFS (p <0.05 for all). On the other hand, the methylation of CpG3 had a positive prognostic effect on PFS (OR: 2.1, 95% CI: 0.99-4.67, p = 0.04). In the group that only received radiotherapy (RT), CpG1 and CpC3 methylations were found to have a positive prognostic significance in terms of PFS (OR: 266, 95% CI: 1.05-6.75, p -0.03 for CpG1; OR: 2.4, 95% CI: 1.01-5.92, p = 0.04 for CpG3). The MGMT promoter methylation represents an important biomarker for predicting response to therapy. Individual islands, particularly CpG3, deserves further investigation as a prognostic marker. Further studies need to be done with larger sample sizes to clarify the results.
Collapse
|
21
|
Dahlrot RH, Larsen P, Boldt HB, Kreutzfeldt MS, Hansen S, Hjelmborg JB, Kristensen BW. Posttreatment Effect of MGMT Methylation Level on Glioblastoma Survival. J Neuropathol Exp Neurol 2020; 78:633-640. [PMID: 31058280 DOI: 10.1093/jnen/nlz032] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) removes temozolomide-induced alkylation, thereby preventing DNA damage and cytotoxicity. We investigated the prognostic effect of different MGMT methylation levels on overall and progression-free survival in 327 patients with primary glioblastoma undergoing standard treatment. We obtained MGMT methylation level in 4 CpG sites using pyrosequencing. The association between MGMT methylation level and survival was investigated using Cox proportional hazards model and an extension to detect time-varying effects. We found an association between MGMT methylation level and overall survival (OS) from around 9 months after the diagnosis, with no association between MGMT methylation level and OS before that. For patients surviving at least 9 months even small increases in MGMT methylation level are significantly beneficial (HR = 0.97, 95% CI [0.96, 0.98]). The predictive ability of MGMT methylation level on OS from 9 months after diagnosis has a Harrel's C of 66%. We conclude that the MGMT methylation level is strongly associated with survival only for patients surviving beyond 9 months with considerable effects for levels much lower than previously reported. Prognostic evaluation of cut-points of MGMT methylation levels and of CpG island site selection should take the time-varying effect on overall survival into account.
Collapse
Affiliation(s)
| | - Pia Larsen
- Department of Epidemiology, Biostatistics and Biodemography, University of Southern Denmark
| | | | | | | | - Jacob B Hjelmborg
- Department of Epidemiology, Biostatistics and Biodemography, University of Southern Denmark
| | - Bjarne Winther Kristensen
- Department of Pathology, Odense University Hospital.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
22
|
Mansouri A, Hachem LD, Mansouri S, Nassiri F, Laperriere NJ, Xia D, Lindeman NI, Wen PY, Chakravarti A, Mehta MP, Hegi ME, Stupp R, Aldape KD, Zadeh G. MGMT promoter methylation status testing to guide therapy for glioblastoma: refining the approach based on emerging evidence and current challenges. Neuro Oncol 2020; 21:167-178. [PMID: 30189035 DOI: 10.1093/neuonc/noy132] [Citation(s) in RCA: 160] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/11/2018] [Accepted: 08/29/2018] [Indexed: 12/12/2022] Open
Abstract
Glioblastoma (GBM) is the most common primary malignant brain tumor, with a universally poor prognosis. The emergence of molecular biomarkers has had a significant impact on histological typing and diagnosis, as well as predicting patient survival and response to treatment. The methylation status of the O6-methylguanine-DNA methyl-transferase (MGMT) gene promoter is one such molecular biomarker. Despite the strong evidence supporting the role of MGMT methylation status in prognostication, its routine implementation in clinical practice has been challenging. The methods and optimal cutoff definitions for MGMT status determination remain controversial. Variation in detection methods between laboratories presents a major challenge for consensus. Moreover, consideration of other clinical and genetic/epigenetic factors must also be incorporated into treatment decision making. In this review, we distill the available evidence to summarize our position on the optimal use of available assays, and propose strategies for resolving cases with equivocal methylation status and a framework for incorporating this important assay into research and clinical practice.
Collapse
Affiliation(s)
- Alireza Mansouri
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Laureen D Hachem
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Sheila Mansouri
- MacFeeters Hamilton Centre for Neuro-Oncology Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Farshad Nassiri
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
- MacFeeters Hamilton Centre for Neuro-Oncology Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Normand J Laperriere
- Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Daniel Xia
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Neal I Lindeman
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Patrick Y Wen
- Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Arnab Chakravarti
- Radiation Oncology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Minesh P Mehta
- Department of Radiation Oncology, Miami Cancer Institute, Miami, Florida, USA
| | - Monika E Hegi
- Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland
| | - Roger Stupp
- Malnati Brain Tumor Institute of the Lurie Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Kenneth D Aldape
- Department of Laboratory Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Gelareh Zadeh
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
- MacFeeters Hamilton Centre for Neuro-Oncology Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| |
Collapse
|
23
|
Butler M, Pongor L, Su YT, Xi L, Raffeld M, Quezado M, Trepel J, Aldape K, Pommier Y, Wu J. MGMT Status as a Clinical Biomarker in Glioblastoma. Trends Cancer 2020; 6:380-391. [PMID: 32348734 DOI: 10.1016/j.trecan.2020.02.010] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 12/27/2022]
Abstract
Glioblastoma is the most common primary malignant brain tumor. Although current standard therapy extends median survival to ~15 months, most patients do not have a sustained response to treatment. While O6-methylguanine (O6-MeG)-DNA methyltransferase (MGMT) promoter methylation status is accepted as a prognostic and promising predictive biomarker in glioblastoma, its value in informing treatment decisions for glioblastoma patients remains debatable. Discrepancies between MGMT promoter methylation status and treatment response in some patients may stem from inconsistencies between MGMT methylation and expression levels in glioblastoma. Here, we discuss MGMT as a biomarker and elucidate the discordance between MGMT methylation, expression, and patient outcome, which currently challenges the implementation of this biomarker in clinical practice.
Collapse
Affiliation(s)
- Madison Butler
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Lorinc Pongor
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Yu-Ting Su
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Liqiang Xi
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Mark Raffeld
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Martha Quezado
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Jane Trepel
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Kenneth Aldape
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Yves Pommier
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA.
| | - Jing Wu
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA.
| |
Collapse
|
24
|
Pan Y, Zhang JH, Zhao L, Guo JC, Wang S, Zhao Y, Tao S, Wang H, Zhu YB. A robust two-gene signature for glioblastoma survival prediction. J Cell Biochem 2020; 121:3593-3605. [PMID: 31960992 DOI: 10.1002/jcb.29653] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 12/11/2019] [Indexed: 12/21/2022]
Abstract
Glioblastoma multiforme (GBM) is a highly malignant brain tumor. We explored the prognostic gene signature in 443 GBM samples by systematic bioinformatics analysis, using GSE16011 with microarray expression and corresponding clinical data from Gene Expression Omnibus as the training set. Meanwhile, patients from The Chinese Glioma Genome Atlas database (CGGA) were used as the test set and The Cancer Genome Atlas database (TCGA) as the validation set. Through Cox regression analysis, Kaplan-Meier analysis, t-distributed Stochastic Neighbor Embedding algorithm, clustering, and receiver operating characteristic analysis, a two-gene signature (GRIA2 and RYR3) associated with survival was selected in the GSE16011 dataset. The GRIA2-RYR3 signature divided patients into two risk groups with significantly different survival in the GSE16011 dataset (median: 0.72, 95% confidence interval [CI]: 0.64-0.98, vs median: 0.98, 95% CI: 0.65-1.61 years, logrank test P < .001), the CGGA dataset (median: 0.84, 95% CI: 0.70-1.18, vs median: 1.21, 95% CI: 0.95-2.94 years, logrank test P = .0017), and the TCGA dataset (median: 1.03, 95% CI: 0.86-1.24, vs median: 1.23, 95% CI: 1.04-1.85 years, logrank test P = .0064), validating the predictive value of the signature. And the survival predictive potency of the signature was independent from clinicopathological prognostic features in multivariable Cox analysis. We found that after transfection of U87 cells with small interfering RNA, GRIA2 and RYR3 influenced the biological behaviors of proliferation, migration, and invasion of glioblastoma cells. In conclusion, the two-gene signature was a robust prognostic model to predict GBM survival.
Collapse
Affiliation(s)
- Yuhualei Pan
- Experimental and Translational Research Center, Beijing Friendship Hospital, Affiliated to the Capital University of Medical Sciences, Beijing, China
| | - Jian-Hua Zhang
- Department of Blood Transfusion, Peking University People's Hospital, Peking university, Beijing, China
| | - Lianhe Zhao
- Key Laboratory of Intelligent Information Processing, Advanced Computer Research Center, Institute of Computing Technology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jin-Cheng Guo
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Song Wang
- Experimental and Translational Research Center, Beijing Friendship Hospital, Affiliated to the Capital University of Medical Sciences, Beijing, China
| | - Yushang Zhao
- Experimental and Translational Research Center, Beijing Friendship Hospital, Affiliated to the Capital University of Medical Sciences, Beijing, China
| | - Shaoxin Tao
- Experimental and Translational Research Center, Beijing Friendship Hospital, Affiliated to the Capital University of Medical Sciences, Beijing, China
| | - Huan Wang
- Experimental and Translational Research Center, Beijing Friendship Hospital, Affiliated to the Capital University of Medical Sciences, Beijing, China
| | - Yan-Bing Zhu
- Experimental and Translational Research Center, Beijing Friendship Hospital, Affiliated to the Capital University of Medical Sciences, Beijing, China
| |
Collapse
|
25
|
Montgomery M, Srinivasan A. Epigenetic Gene Regulation by Dietary Compounds in Cancer Prevention. Adv Nutr 2019; 10:1012-1028. [PMID: 31100104 PMCID: PMC6855955 DOI: 10.1093/advances/nmz046] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/07/2019] [Accepted: 04/03/2019] [Indexed: 02/06/2023] Open
Abstract
Traditionally, cancer has been viewed as a set of diseases that are driven by the accumulation of genetic mutations, but we now understand that disruptions in epigenetic regulatory mechanisms are prevalent in cancer as well. Unlike genetic mutations, however, epigenetic alterations are reversible, making them desirable therapeutic targets. The potential for diet, and bioactive dietary components, to target epigenetic pathways in cancer is now widely appreciated, but our understanding of how to utilize these compounds for effective chemopreventive strategies in humans is in its infancy. This review provides a brief overview of epigenetic regulation and the clinical applications of epigenetics in cancer. It then describes the capacity for dietary components to contribute to epigenetic regulation, with a focus on the efficacy of dietary epigenetic regulators as secondary cancer prevention strategies in humans. Lastly, it discusses the necessary precautions and challenges that will need to be overcome before the chemopreventive power of dietary-based intervention strategies can be fully harnessed.
Collapse
Affiliation(s)
- McKale Montgomery
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK,Address correspondence to MM (E-mail: )
| | | |
Collapse
|
26
|
Malmström A, Łysiak M, Kristensen BW, Hovey E, Henriksson R, Söderkvist P. Do we really know who has an MGMT methylated glioma? Results of an international survey regarding use of MGMT analyses for glioma. Neurooncol Pract 2019; 7:68-76. [PMID: 32025325 PMCID: PMC6993038 DOI: 10.1093/nop/npz039] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Glioma O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status informs clinical decision making. Worldwide different methods and cutoff levels are used, which can lead to discordant methylation results. Methods We conducted an international survey to clarify which methods are regularly used and why. We also explored opinions regarding international consensus on methods and cutoff. Results The survey had 152 respondents from 25 countries. MGMT methylation status is determined for all glioblastomas in 37% of laboratories. The most common methods are methylation-specific polymerase chain reaction (msPCR) (37%) and pyrosequencing (34%). A method is selected for simplicity (56%), cost-effectiveness (50%), and reproducibility of results (52%). For sequencing, the number of CpG sites analyzed varies from 1–3 up to more than 16. For 50% of laboratories, the company producing the kit determines which CpG sites are examined, whereas 33% select the sites themselves. Selection of cutoff is equally distributed among a cutoff defined in the literature, by the local laboratory, or by the outside laboratory performing the analysis. This cutoff varies, reported from 1% to 30%, and in 1 laboratory tumor is determined as methylated in case of 1 methylated CpG site of 17 analyzed. Some report tumors as unmethylated or weakly vs highly methylated. An international consensus on MGMT methylation method and cutoff is warranted by 66% and 76% of respondents, respectively. The method preferred would be msPCR (45%) or pyrosequencing (42%), whereas 18% suggest next-generation sequencing. Conclusion Although analysis of MGMT methylation status is routine, there is controversy regarding laboratory methods and cutoff level. Most respondents favor development of international consensus guidelines.
Collapse
Affiliation(s)
- Annika Malmström
- Department of Advanced Home Care, Linköping University, Sweden.,Department of Clinical and Experimental Medicine, Linköping University, Sweden
| | - Małgorzata Łysiak
- Department of Clinical and Experimental Medicine, Linköping University, Sweden
| | - Bjarne Winther Kristensen
- Department of Pathology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark
| | - Elizabeth Hovey
- Department of Medical Oncology, Nelune Comprehensive Cancer Centre, Prince of Wales Hospital, Randwick, Sydney, NSW, Australia.,University of New South Wales, Sydney, Australia
| | | | | |
Collapse
|
27
|
Johannessen LE, Brandal P, Myklebust TÅ, Heim S, Micci F, Panagopoulos I. MGMT Gene Promoter Methylation Status - Assessment of Two Pyrosequencing Kits and Three Methylation-specific PCR Methods for their Predictive Capacity in Glioblastomas. Cancer Genomics Proteomics 2018; 15:437-446. [PMID: 30343277 DOI: 10.21873/cgp.20102] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/13/2018] [Accepted: 08/21/2018] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Although methylation of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter predicts response to temozolomide in patients with glioblastoma, no consensus exists as to which assay is best for its detection. MATERIALS AND METHODS Methylation of MGMT promoter was examined by methylation-specific polymerase chain reaction (MSP), quantitative real-time MSP, methylation-sensitive high-resolution melting analysis, and two commercial pyrosequencing (PSQ) kits. Survival was compared among 48 patients with glioblastoma according to assay results. RESULTS Only PSQ and MSP significantly separated patients who benefited from temozolomide, with PSQ being the superior method. For PSQ analysis, the cut-off value that best correlated with prognostic outcome was 7% methylation of MGMT. Median survival in patients with MGMT promoter methylation above this cut-off value was 7.8 months longer compared to those with less than 7% methylation. Two-year overall survival for the two groups was 42% and 7.4%, respectively. CONCLUSION PSQ is the method of choice for MGMT promoter methylation analysis in routine clinical practice.
Collapse
Affiliation(s)
- Lene E Johannessen
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Petter Brandal
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Tor Åge Myklebust
- Department of Research and Innovation, Møre and Romsdal Hospital Trust, Ålesund, Norway.,Cancer Registry of Norway, Institute of Population-based Cancer Research, Oslo, Norway
| | - Sverre Heim
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Francesca Micci
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Ioannis Panagopoulos
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| |
Collapse
|
28
|
Romani M, Pistillo MP, Banelli B. Epigenetic Targeting of Glioblastoma. Front Oncol 2018; 8:448. [PMID: 30386738 PMCID: PMC6198064 DOI: 10.3389/fonc.2018.00448] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/24/2018] [Indexed: 12/17/2022] Open
Abstract
Glioblastoma is one of the first tumors where the biological changes accompanying a single epigenetic modification, the methylation of the MGMT gene, were found to be of clinical relevance. The exploration of the epigenomic landscape of glioblastoma has allowed to identify patients carrying a diffuse hypermethylation at gene promoters and with better outcome. Epigenetic and genetic data have led to the definition of major subgroups of glioma and were the basis of the current WHO classification of CNS tumors and of a novel classification based solely on DNA methylation data that shows a remarkable diagnostic precision.The reversibility of epigenetic modifications is considered a therapeutic opportunity in many tumors also because these alterations have been mechanistically linked to the biological characteristics of glioblastoma. Several alterations like IDH1/2 mutations that interfere with "epigenetic modifier" enzymes, the mutations of the histone 3 variants H3.1 and H3.3 that alter the global H3K27me3 levels and the altered expression of histone methyltransferases and demethylases are considered potentially druggable targets in glioma and molecules targeting these alterations are being tested in preclinical and clinical trials. The recent advances on the knowledge of the players of the "epigenetic orchestra" and of their mutual interactions are indicating new paths that may eventually open new therapeutic options for this invariably lethal cancer.
Collapse
Affiliation(s)
- Massimo Romani
- Laboratory of Tumor Epigenetics, IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Maria Pia Pistillo
- Laboratory of Tumor Epigenetics, IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Barbara Banelli
- Laboratory of Tumor Epigenetics, IRCCS Ospedale Policlinico San Martino, Genova, Italy
- Department of Health Sciences, University of Genoa, Genova, Italy
| |
Collapse
|
29
|
Dahlrot RH, Dowsett J, Fosmark S, Malmström A, Henriksson R, Boldt H, de Stricker K, Sørensen MD, Poulsen HS, Lysiak M, Söderkvist P, Rosell J, Hansen S, Kristensen BW. Prognostic value of O-6-methylguanine-DNA methyltransferase (MGMT) protein expression in glioblastoma excluding nontumour cells from the analysis. Neuropathol Appl Neurobiol 2018; 44:172-184. [PMID: 28574607 DOI: 10.1111/nan.12415] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 05/26/2017] [Accepted: 06/02/2017] [Indexed: 01/20/2023]
Abstract
AIMS It is important to predict response to treatment with temozolomide (TMZ) in glioblastoma (GBM) patients. Both MGMT protein expression and MGMT promoter methylation status have been reported to predict the response to TMZ. We investigated the prognostic value of quantified MGMT protein levels in tumour cells and the prognostic importance of combining information of MGMT protein level and MGMT promoter methylation status. METHODS MGMT protein expression was quantified in tumour cells in 171 GBMs from the population-based Region of Southern Denmark (RSD)-cohort using a double immunofluorescence approach. Pyrosequencing was performed in 157 patients. For validation we used GBM-patients from a Nordic Study (NS) investigating the effect of radiotherapy and different TMZ schedules. RESULTS When divided at the median, patients with low expression of MGMT protein (AF-low) had the best prognosis (HR = 1.5, P = 0.01). Similar results were observed in the subgroup of patients receiving the Stupp regimen (HR = 2.0, P = 0.001). In the NS-cohort a trend towards superior survival (HR = 1.6, P = 0.08) was seen in patients with AF-low. Including MGMT promoter methylation status, we found for both cohorts that patients with methylated MGMT promoter and AF-low had the best outcome; median OS 23.1 and 20.0 months, respectively. CONCLUSION Our data indicate that MGMT protein expression in tumour cells has an independent prognostic significance. Exclusion of nontumour cells contributed to a more exact analysis of tumour-specific MGMT protein expression. This should be incorporated in future studies evaluating MGMT status before potential integration into clinical practice.
Collapse
Affiliation(s)
- R H Dahlrot
- Department of Oncology, Odense University Hospital, Odense, Denmark
| | - J Dowsett
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - S Fosmark
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - A Malmström
- Department of Advanced Home Care, Linköping University, Linköping, Sweden
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - R Henriksson
- Department of Radiation Sciences & Oncology, Umeå University, Umeå, Sweden
- Regional Cancer Center Stockholm Gotland, Stockholm, Sweden
| | - H Boldt
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - K de Stricker
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - M D Sørensen
- Department of Pathology, Odense University Hospital, Odense, Denmark
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - H S Poulsen
- Department of Radiation Biology & Oncology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | - M Lysiak
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - P Söderkvist
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - J Rosell
- Regional Cancer Center South East Sweden and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - S Hansen
- Department of Oncology, Odense University Hospital, Odense, Denmark
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - B W Kristensen
- Department of Pathology, Odense University Hospital, Odense, Denmark
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
30
|
Ida CM, Butz ML, Jenkins RB, Sarkaria JN, Kitange GJ, Giannini C, Kipp BR. Real-Time Methylation-Specific Polymerase Chain Reaction for MGMT Promoter Methylation Clinical Testing in Glioblastoma: An Alternative Detection Method for a Heterogeneous Process. Am J Clin Pathol 2017; 148:296-307. [PMID: 28967952 DOI: 10.1093/ajcp/aqx073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES To develop and evaluate a real-time methylation-specific polymerase chain reaction (RT-MSP) MGMT assay, with a particular focus on small biopsies and indeterminate testing results. METHODS We assessed formalin-fixed paraffin-embedded glioblastoma or gliosarcoma specimens (n = 641). A test-validation group (n = 51) with previously obtained reference laboratory (RL) results was used to determine performance characteristics of the RT-MSP assay. An indeterminate (equivocal) category was established for cases that could not be clearly classified as positive or negative. RESULTS Overall agreement of RT-MSP and RL results was 91% (41/45 nonindeterminate cases). Discordant cases were tested by pyrosequencing, and results were most concordant with RT-MSP. Among cases with limited amounts of tissue (n = 7), six yielded valid results by RT-MSP (all negative); the single invalid result consisted of a stereotactic biopsy specimen obtained 14 years prior. A subset of indeterminate cases obtained during clinical testing (n = 18/575 [3%]) was also evaluated by pyrosequencing and showed a heterogeneous pattern of methylation across the eight interrogated CpG sites. CONCLUSIONS The RT-MSP assay that we developed in-house is a robust clinical detection method for the heterogeneous process of MGMT promoter methylation in glioblastoma.
Collapse
Affiliation(s)
| | | | - Robert B Jenkins
- Departments of Laboratory Medicine and Pathology
- Biochemistry and Molecular Biology
| | | | | | | | - Benjamin R Kipp
- Departments of Laboratory Medicine and Pathology
- Clinical Genomics
| |
Collapse
|
31
|
Assessing alternative base substitutions at primer CpG sites to optimise unbiased PCR amplification of methylated sequences. Clin Epigenetics 2017; 9:31. [PMID: 28392841 PMCID: PMC5379501 DOI: 10.1186/s13148-017-0328-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/20/2017] [Indexed: 11/20/2022] Open
Abstract
Background Determining the role of DNA methylation in various biological processes is dependent on the accurate representation of often highly complex patterns. Accurate representation is dependent on unbiased PCR amplification post bisulfite modification, regardless of methylation status of any given epiallele. This is highly dependent on primer design. Particular difficulties are raised by the analysis of CpG-rich regions, which are the usual regions of interest. Here, it is often difficult or impossible to avoid placing primers in CpG-free regions, particularly if one wants to target a specific part of a CpG-rich region. This can cause biased amplification of methylated sequences if the C is placed at those positions or to unmethylated sequences if a T is placed at those positions. Methods We examined the effect of various base substitutions at the cytosine position of primer CpGs on the representational amplification of templates and also examined the role of the annealing temperature during PCR. These were evaluated using methylation-sensitive high-resolution melting and Pyrosequencing. Results For a mixture of fully methylated and unmethylated templates, amplification using the C-, C/T (Y-) and inosine-containing primers was biased towards amplification of methylated DNA. The bias towards methylated sequences increased with annealing temperature. Amplification using primers with an A/C/G/T (N) degeneracy at the cytosine positions was not biased at the lowest temperature used but became increasingly biased towards methylated DNA with increased annealing temperature. Using primers matching neither C nor T was in the main unbiased but at the cost of poor PCR amplification efficiency. Primers with abasic sites were also unbiased but could only amplify DNA for one out of the two assays tested. However, with heterogeneous methylation, it appeared that both the primer type and stringency used have a minimal influence on PCR bias. Conclusions This is the first comprehensive analysis of base substitutions at CpG sites in primers and their effect on PCR bias for the analysis of DNA methylation. Our findings are relevant to the appropriate design of a wide range of assays, including amplicon-based next-generation sequencing approaches that need to measure DNA methylation. Electronic supplementary material The online version of this article (doi:10.1186/s13148-017-0328-4) contains supplementary material, which is available to authorized users.
Collapse
|
32
|
Alireza M, Amelot A, Chauvet D, Terrier LM, Lot G, Bekaert O. Poor Prognosis and Challenging Treatment of Optic Nerve Malignant Gliomas: Literature Review and Case Report Series. World Neurosurg 2017; 97:751.e1-751.e6. [DOI: 10.1016/j.wneu.2016.10.083] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 10/14/2016] [Accepted: 10/15/2016] [Indexed: 10/20/2022]
|
33
|
Frontal glioblastoma multiforme may be biologically distinct from non-frontal and multilobar tumors. J Clin Neurosci 2016; 34:128-132. [PMID: 27593971 DOI: 10.1016/j.jocn.2016.05.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 05/20/2016] [Indexed: 11/21/2022]
Abstract
Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults and carries a grim prognosis. Lobar GBM, notably those localized to the frontal lobe, are generally more amenable to complete surgical resection, and may carry a better prognosis. The biology of differently localized GBM has been reported scarcely in terms of prognostic markers, including isocitrate dehydrogenase 1 (IDH1) mutation and O(6)-methylguanine-methyltransferase (MGMT) methylation. To our knowledge, there has been no evaluation in the literature of different proliferation indexes in different GBM locations in the brain. We performed a retrospective evaluation of our prospectively collected database to assess the rate of IDH1 positivity, MGMT methylation and Ki67 index for GBM located in the frontal lobes alone, lobar GBM in other supra-tentorial lobes and multilobar GBM. IDH1 mutated tumors were localized in the frontal lobes in 50.0%, whereas only 20.3% of IDH1 wild-type tumors were localized in the frontal lobe (p=0.006); MGMT methylated tumors were localized in the frontal lobe in 32.0% of the cases. Only 13.75% of the MGMT unmethylated tumors were localized to the frontal lobe (p=0.005); Tumors with higher Ki67 proliferation index were more likely to be localized in the frontal lobe (40.6% vs. 19.5%, p=0.019). This is the largest cohort of GBM assessed for these purposes in the literature. Frontal lobe GBMs may be intrinsically biologically distinct from GBM in other lobes and from multilobar tumors.
Collapse
|
34
|
Zhang J, Yang JH, Quan J, Kang X, Wang HJ, Dai PG. Identification of MGMT promoter methylation sites correlating with gene expression and IDH1 mutation in gliomas. Tumour Biol 2016; 37:13571-13579. [PMID: 27468718 DOI: 10.1007/s13277-016-5153-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 07/12/2016] [Indexed: 12/30/2022] Open
Abstract
O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation was reported to be an independent prognostic and predictive factor in glioma patients who received temozolomide treatment. However, the predictive value of MGMT methylation was recently questioned by several large clinical studies. The purpose of this study is to identify MGMT gene promoter CpG sites or region whose methylation were closely correlated with its gene expression to elucidate this contradictory clinical observations. The methylation status for all CpG dinucleotides in MGMT promoter and first exon region were determined in 42 Chinese glioma patients, which were then correlated with MGMT gene expression, IDH1 mutation, and tumor grade. In whole 87 CpG dinucleotides analyzed, three distinct CpG regions covering 28 CpG dinucleotides were significantly correlated with MGMT gene expression; 10 CpG dinucleotides were significantly correlated with glioma classification (p < 0.05). Isocitrate dehydrogenase 1 (IDH1) mutation and MGMT gene hypermethylation significantly co-existed, but not for MGMT gene expression. The validation cohort of gliomas treated with standard of care and comparison of the CpGs we identified with the current CpGs used in clinical setting will be very important for gliomas individual medicine in the future.
Collapse
Affiliation(s)
- Jie Zhang
- National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, Xi'an, China
| | - Jian-Hui Yang
- National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, Xi'an, China
| | - Jia Quan
- National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, Xi'an, China
| | - Xing Kang
- National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, Xi'an, China
| | - Hui-Juan Wang
- National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, Xi'an, China
| | - Peng-Gao Dai
- National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, Xi'an, China.
| |
Collapse
|
35
|
McCarthy D, Pulverer W, Weinhaeusel A, Diago OR, Hogan DJ, Ostertag D, Hanna MM. MethylMeter(®): bisulfite-free quantitative and sensitive DNA methylation profiling and mutation detection in FFPE samples. Epigenomics 2016; 8:747-65. [PMID: 27337298 DOI: 10.2217/epi-2016-0004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Development of a sensitive method for DNA methylation profiling and associated mutation detection in clinical samples. MATERIALS & METHODS Formalin-fixed and paraffin-embedded tumors received by clinical laboratories often contain insufficient DNA for analysis with bisulfite or methylation sensitive restriction enzymes-based methods. To increase sensitivity, methyl-CpG DNA capture and Coupled Abscription PCR Signaling detection were combined in a new assay, MethylMeter(®). Gliomas were analyzed for MGMT methylation, glioma CpG island methylator phenotype and IDH1 R132H. RESULTS MethylMeter had 100% assay success rate measuring all five biomarkers in formalin-fixed and paraffin-embedded tissue. MGMT methylation results were supported by survival and mRNA expression data. CONCLUSION MethylMeter is a sensitive and quantitative method for multitarget DNA methylation profiling and associated mutation detection. The MethylMeter-based GliomaSTRAT assay measures methylation of four targets and one mutation to simultaneously grade gliomas and predict their response to temozolomide. This information is clinically valuable in management of gliomas.
Collapse
Affiliation(s)
- David McCarthy
- Ribomed Biotechnologies Inc., 3469 Kurtz St., San Diego, CA 92110, USA
| | - Walter Pulverer
- Molecular Diagnostics, Health & Environment Department, Austrian Institute of Technology, Muthgasse 11, 1190 Vienna, Austria
| | - Andreas Weinhaeusel
- Molecular Diagnostics, Health & Environment Department, Austrian Institute of Technology, Muthgasse 11, 1190 Vienna, Austria
| | - Oscar R Diago
- Tocagen Inc., 3030 Bunker Hill Street, Suite 230; San Diego, CA 92109, USA
| | - Daniel J Hogan
- Tocagen Inc., 3030 Bunker Hill Street, Suite 230; San Diego, CA 92109, USA
| | - Derek Ostertag
- Tocagen Inc., 3030 Bunker Hill Street, Suite 230; San Diego, CA 92109, USA
| | - Michelle M Hanna
- Ribomed Biotechnologies Inc., 3469 Kurtz St., San Diego, CA 92110, USA
| |
Collapse
|
36
|
Defining the cutoff value of MGMT gene promoter methylation and its predictive capacity in glioblastoma. J Neurooncol 2016; 128:333-9. [DOI: 10.1007/s11060-016-2116-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 03/22/2016] [Indexed: 10/22/2022]
|
37
|
Chen YP, Hou XY, Yang CS, Jiang XX, Yang M, Xu XF, Feng SX, Liu YQ, Jiang G. DNA methylation and histone acetylation regulate the expression of MGMT and chemosensitivity to temozolomide in malignant melanoma cell lines. Tumour Biol 2016; 37:11209-18. [PMID: 26943799 DOI: 10.1007/s13277-016-4994-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/28/2015] [Indexed: 12/31/2022] Open
Abstract
Malignant melanoma is an aggressive, highly lethal dermatological malignancy. Chemoresistance and rapid metastasis limit the curative effect of multimodal therapies like surgery or chemotherapy. The suicide enzyme O6-methylguanine-DNA methyltransferase (MGMT) removes adducts from the O6-position of guanine to repair DNA damage. High MGMT expression is associated with resistance to therapy in melanoma. However, it is unknown if MGMT is regulated by DNA methylation or histone acetylation in melanoma. We examined the effects of the DNA methylation inhibitor 5-Aza-2'-deoxycytidine and histone deacetylase inhibitor Trichostatin A alone or in combination on MGMT expression and promoter methylation and histone acetylation in A375, MV3, and M14 melanoma cells. This study demonstrates that MGMT expression, CpG island methylation, and histone acetylation vary between melanoma cell lines. Combined treatment with 5-Aza-2'-deoxycytidine and Trichostatin A led to reexpression of MGMT, indicating that DNA methylation and histone deacetylation are associated with silencing of MGMT in melanoma. This study provides information on the role of epigenetic modifications in malignant melanoma that may enable the development of new strategies for treating malignant melanoma.
Collapse
Affiliation(s)
- Ya-Ping Chen
- Department of Dermatology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
- Department of Stereotactic Radiosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
| | - Xiao-Yang Hou
- Department of Dermatology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
| | - Chun-Sheng Yang
- Department of Dermatology, Affiliated Huai'an Hospital of Xuzhou Medical College, Huai'an, 223002, China
| | - Xiao-Xiao Jiang
- Department of Stereotactic Radiosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
| | - Ming Yang
- Department of Stereotactic Radiosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
| | - Xi-Feng Xu
- Department of Stereotactic Radiosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
| | - Shou-Xin Feng
- Department of Dermatology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
| | - Yan-Qun Liu
- Department of Dermatology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China
| | - Guan Jiang
- Department of Dermatology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, 221002, China.
| |
Collapse
|
38
|
Fogli A, Chautard E, Vaurs-Barrière C, Pereira B, Müller-Barthélémy M, Court F, Biau J, Pinto AA, Kémény JL, Khalil T, Karayan-Tapon L, Verrelle P, Costa BM, Arnaud P. The tumoral A genotype of the MGMT rs34180180 single-nucleotide polymorphism in aggressive gliomas is associated with shorter patients' survival. Carcinogenesis 2015; 37:169-176. [PMID: 26717998 DOI: 10.1093/carcin/bgv251] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/19/2015] [Indexed: 01/09/2023] Open
Abstract
Malignant gliomas are the most common primary brain tumors. Grade III and IV gliomas harboring wild-type IDH1/2 are the most aggressive. In addition to surgery and radiotherapy, concomitant and adjuvant chemotherapy with temozolomide (TMZ) significantly improves overall survival (OS). The methylation status of the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter is predictive of TMZ response and a prognostic marker of cancer outcome. However, the promoter regions the methylation of which correlates best with survival in aggressive glioma and whether the promoter methylation status predictive value could be refined or improved by other MGMT-associated molecular markers are not precisely known. In a cohort of 87 malignant gliomas treated with radiotherapy and TMZ-based chemotherapy, we retrospectively determined the MGMT promoter methylation status, genotyped single nucleotide polymorphisms (SNPs) in the promoter region and quantified MGMT mRNA expression level. Each of these variables was correlated with each other and with the patients' OS. We found that methylation of the CpG sites within MGMT exon 1 best correlated with OS and MGMT expression levels, and confirmed MGMT methylation as a stronger independent prognostic factor compared to MGMT transcription levels. Our main finding is that the presence of only the A allele at the rs34180180 SNP in the tumor was significantly associated with shorter OS, independently of the MGMT methylation status. In conclusion, in the clinic, rs34180180 SNP genotyping could improve the prognostic value of the MGMT promoter methylation assay in patients with aggressive glioma treated with TMZ.
Collapse
Affiliation(s)
- Anne Fogli
- INSERM-U1103 and.,CNRS-UMR 6293, Clermont-Ferrand 63001, France.,GReD Laboratory, Clermont Auvergne University, Clermont-Ferrand 63000, France.,Biochemistry and Molecular Biology Department, Clermont-Ferrand Hospital, Clermont-Ferrand 63003, France
| | - Emmanuel Chautard
- Clermont Auvergne University, EA 7283 CREaT, Clermont-Ferrand 63000, France.,Radiotherapy Department, Jean Perrin Center, Clermont-Ferrand 63011, France
| | - Catherine Vaurs-Barrière
- INSERM-U1103 and.,CNRS-UMR 6293, Clermont-Ferrand 63001, France.,GReD Laboratory, Clermont Auvergne University, Clermont-Ferrand 63000, France
| | - Bruno Pereira
- Biostatistics Department , DRCI, Clermont-Ferrand Hospital , Clermont-Ferrand 63003 , France
| | | | - Franck Court
- INSERM-U1103 and.,CNRS-UMR 6293, Clermont-Ferrand 63001, France.,GReD Laboratory, Clermont Auvergne University, Clermont-Ferrand 63000, France
| | - Julian Biau
- Clermont Auvergne University, EA 7283 CREaT, Clermont-Ferrand 63000, France.,Radiotherapy Department, Jean Perrin Center, Clermont-Ferrand 63011, France
| | - Afonso Almeida Pinto
- Department of Neurosurgery , Braga Hospital , Braga 4710-243 São Victor , Portugal
| | - Jean-Louis Kémény
- Department of Anatomopathology , Clermont-Ferrand Hospital , Clermont-Ferrand 63003 , France
| | - Toufic Khalil
- Department of Neurosurgery, Clermont-Ferrand Hospital, Clermont-Ferrand 63003, France.,Clermont Auvergne University, EA 7282 IGCNC, Clermont-Ferrand 63000, France
| | - Lucie Karayan-Tapon
- INSERM-U935, Poitiers 86021, France.,Poitiers University, Poitiers 86000, France.,Cancer Biology Laboratory, Poitiers Hospital, Poitiers 86021, France
| | - Pierre Verrelle
- Clermont Auvergne University, EA 7283 CREaT, Clermont-Ferrand 63000, France.,Radiotherapy Department, Jean Perrin Center, Clermont-Ferrand 63011, France.,INSERM U2021 CNRS UMR3347, Curie Institute, Orsay 91405, France
| | - Bruno Marques Costa
- School of Health Sciences, Life and Health Sciences Research Institute (ICVS), Braga 4710-057, Portugal and.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Braga 4710-057, Portugal
| | - Philippe Arnaud
- INSERM-U1103 and.,CNRS-UMR 6293, Clermont-Ferrand 63001, France.,GReD Laboratory, Clermont Auvergne University, Clermont-Ferrand 63000, France
| |
Collapse
|
39
|
Barbagallo GMV, Paratore S, Caltabiano R, Palmucci S, Parra HS, Privitera G, Motta F, Lanzafame S, Scaglione G, Longo A, Albanese V, Certo F. Long-term therapy with temozolomide is a feasible option for newly diagnosed glioblastoma: a single-institution experience with as many as 101 temozolomide cycles. Neurosurg Focus 2015; 37:E4. [PMID: 25434389 DOI: 10.3171/2014.9.focus14502] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The objective of this study was to report the authors' experience with the long-term administration of temozolomide (TMZ; > 6 cycles, up to 101) in patients with newly diagnosed glioblastoma and to analyze its feasibility and safety as well as its impact on survival. The authors also compared data obtained from the group of patients undergoing long-term TMZ treatment with data from patients treated with a standard TMZ protocol. METHODS A retrospective analysis was conducted of 37 patients who underwent operations for glioblastoma between 2004 and 2012. Volumetric analysis of postoperative Gd-enhanced MR images, obtained within 48 hours, confirmed tumor gross-total resection (GTR) in all but 2 patients. All patients received the first cycle of TMZ at a dosage of 150 mg/m(2) starting on the second or third postsurgical day. Afterward, patients received concomitant radiochemotherapy according to the Stupp protocol. With regard to adjuvant TMZ therapy, the 19 patients in Group A, aged 30-72 years (mean 56.1 years), received 150 mg/m(2) for 5 days every 28 days for more than 6 cycles (range 7-101 cycles). The 18 patients in Group B, aged 46-82 years (mean 64.8 years), received the same dose, but for no more than 6 cycles. O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status was analyzed for both groups and correlated with overall survival (OS) and progression-free survival (PFS). The impact of age, sex, Karnofsky Performance Scale score, and Ki 67 staining were also considered. RESULTS All patients but 1 in Group A survived at least 18 months (range 18-101 months), and patients in Group B survived no more than 17 months (range 2-17 months). The long-term survivors (Group A), defined as patients who survived at least 12 months after diagnosis, were 51.3% of the total (19/37). Kaplan-Meier curve analysis showed that patients treated with more than 6 TMZ cycles had OS and PFS that was significantly longer than patients receiving standard treatment (median OS 28 months vs 8 months, respectively; p = 0.0001; median PFS 20 months vs 4 months, respectively; p = 0.0002). By univariate and multivariate Cox proportional hazard regression analysis, MGMT methylation status and number of TMZ cycles appeared to be survival prognostic factors in patients with glioblastoma. After controlling for MGMT status, highly significant differences related to OS and PFS between patients with standard and long-term TMZ treatment were still detected. Furthermore, in Group A and B, the statistical correlation of MGMT status to the number of TMZ cycles showed a significant difference only in Group A patients, suggesting that MGMT promoter methylation was predictive of response for long-term TMZ treatment. Prolonged therapy did not confer hematological toxicity or opportunistic infections in either patient group. CONCLUSIONS This study describes the longest experience so far reported with TMZ in patients with newly diagnosed glioblastomas, with as many as 101 cycles, who were treated using GTR. Statistically significant data confirm that median survival correlates with MGMT promoter methylation status as well as with the number of TMZ cycles administered. Long-term TMZ therapy appears feasible and safe.
Collapse
|
40
|
Amelot A, De Cremoux P, Quillien V, Polivka M, Adle-Biassette H, Lehmann-Che J, Françoise L, Carpentier AF, George B, Mandonnet E, Froelich S. IDH-Mutation Is a Weak Predictor of Long-Term Survival in Glioblastoma Patients. PLoS One 2015; 10:e0130596. [PMID: 26158269 PMCID: PMC4497660 DOI: 10.1371/journal.pone.0130596] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 05/21/2015] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND A very small proportion of patients diagnosed with glioblastoma (GBM) survive more than 3 years. Isocitrate dehydrogenase 1 or 2 (IDH1/2) mutations define a small subgroup of GBM patients with favourable prognosis. However, it remains controversial whether long-term survivors (LTS) are found among those IDH1/2 mutated patients. METHODS We retrospectively analyzed 207 GBM patients followed at Lariboisière Hospital (Paris) between 2005 and 2010. Clinical parameters were obtained from medical records. Mutations of IDH1/2 were analyzed in these patients, by immunohistochemistry for the R132H mutation of IDH1 and by high-resolution melting-curve analysis, followed by Sanger sequencing for IDH1 and IDH2 exon 4 mutations. Mutation rates in LTS and non-LTS groups were compared by Chi square Pearson test. RESULTS Seventeen patients with survival >3 years were identified (8.2% of the total series). The median overall survival in long-term survivors was 4.6 years. Subgroup analysis found that the median age at diagnosis was significantly higher for non long-term survivors (non-LTS) compared to LTS (60 versus 51 years, p <0.03). The difference in the rate of IDH mutation between non-LTS and LTS was statistically not significant (1.16% versus 5.9%, p = 0.144). Among LTS, 10 out of 16 tumors presented a methylation of MGMT promoter. CONCLUSIONS This study confirms that long-term survival in GBM patients is if at all only weakly correlated to IDH-mutation.
Collapse
Affiliation(s)
- Aymeric Amelot
- Assistance Publique-Hôpitaux de Paris (AP-HP), Lariboisière Hospital, Department of Neurosurgery, Paris, France
| | - Patricia De Cremoux
- Assistance Publique-Hôpitaux de Paris (AP-HP), St-Louis Hospital, Department of Biochemistry, Molecular Oncology Unit, Paris, France
| | - Véronique Quillien
- Département de Biologie, Centre Eugène Marquis, CS 44229, Rue de la Bataille Flandres Dunkerque, 35042, Rennes Cedex, France
| | - Marc Polivka
- Assistance Publique-Hôpitaux de Paris (AP-HP), Lariboisière Hospital, Department of pathology, Paris, France
| | - Homa Adle-Biassette
- Assistance Publique-Hôpitaux de Paris (AP-HP), Lariboisière Hospital, Department of pathology, Paris, France
| | - Jacqueline Lehmann-Che
- Assistance Publique-Hôpitaux de Paris (AP-HP), St-Louis Hospital, Department of Biochemistry, Molecular Oncology Unit, Paris, France
| | - Laurence Françoise
- Assistance Publique-Hôpitaux de Paris (AP-HP), St-Louis Hospital, Department of Biochemistry, Molecular Oncology Unit, Paris, France
| | - Antoine F. Carpentier
- Assistance Publique-Hôpitaux de Paris (AP-HP), Avicennes Hospital, Department of Neurology, Bobigny, France
| | - Bernard George
- Assistance Publique-Hôpitaux de Paris (AP-HP), Lariboisière Hospital, Department of Neurosurgery, Paris, France
- University Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Emmanuel Mandonnet
- Assistance Publique-Hôpitaux de Paris (AP-HP), Lariboisière Hospital, Department of Neurosurgery, Paris, France
- University Paris Diderot, Sorbonne Paris Cité, Paris, France
- IMNC, UMR 8165, Orsay, France
| | - Sébastien Froelich
- Assistance Publique-Hôpitaux de Paris (AP-HP), Lariboisière Hospital, Department of Neurosurgery, Paris, France
- University Paris Diderot, Sorbonne Paris Cité, Paris, France
| |
Collapse
|
41
|
Cabrini G, Fabbri E, Lo Nigro C, Dechecchi MC, Gambari R. Regulation of expression of O6-methylguanine-DNA methyltransferase and the treatment of glioblastoma (Review). Int J Oncol 2015; 47:417-28. [PMID: 26035292 PMCID: PMC4501657 DOI: 10.3892/ijo.2015.3026] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/09/2015] [Indexed: 12/22/2022] Open
Abstract
O-6-methylguanine-DNA methyltransferase (MGMT) is an abundantly expressed nuclear protein dealkylating O6-methylguanine (O6-MG) DNA residue, thus correcting the mismatches of O6-MG with a thymine residue during DNA replication. The dealkylating effect of MGMT is relevant not only in repairing DNA mismatches produced by environmental alkylating agents promoting tumor pathogenesis, but also when alkylating molecules are applied in the chemotherapy of different cancers, including glioma, the most common primary tumor of the central nervous system. Elevated MGMT gene expression is known to confer resistance to the treatment with the alkylating drug temozolomide in patients affected by gliomas and, on the contrary, methylation of MGMT gene promoter, which causes reduction of MGMT protein expression, is known to predict a favourable response to temozolomide. Thus, detecting expression levels of MGMT gene is crucial to indicate the option of alkylating agents or to select patients directly for a second line targeted therapy. Further study is required to gain insights into MGMT expression regulation, that has attracted growing interest recently in MGMT promoter methylation, histone acetylation and microRNAs expression. The review will focus on the epigenetic regulation of MGMT gene, with translational applications to the identification of biomarkers predicting response to therapy and prognosis.
Collapse
Affiliation(s)
- Giulio Cabrini
- Department of Pathology and Diagnostics, University Hospital, Verona, Italy
| | - Enrica Fabbri
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Cristiana Lo Nigro
- Department of Oncology, S. Croce and Carle Teaching Hospital, Cuneo, Italy
| | | | - Roberto Gambari
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| |
Collapse
|
42
|
Xavier-Magalhães A, Nandhabalan M, Jones C, Costa BM. Molecular prognostic factors in glioblastoma: state of the art and future challenges. CNS Oncol 2015; 2:495-510. [PMID: 25054820 DOI: 10.2217/cns.13.48] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Gliomas account for the majority of primary tumors of the CNS, of which glioblastoma (GBM) is the most common and malignant, and for which survival is very poor. Despite significant inter- and intra-tumor heterogeneity, all patients are treated with a standardized therapeutic approach. While some clinical features of GBM patients have already been established as classic prognostic factors (e.g., patient age at diagnosis and Karnofsky performance status), one of the most important research fields in neuro-oncology today is the identification of novel molecular determinants of patient survival and tumor response to therapy. Here, we aim to review and discuss some of the most relevant and novel prognostic biomarkers in adult and pediatric GBM patients that may aid in stratifying subgroups of GBMs and rationalizing treatment decisions.
Collapse
Affiliation(s)
- Ana Xavier-Magalhães
- Life & Health Sciences Research Institute, School of Health Sciences, University of Minho, Braga, Portugal
| | | | | | | |
Collapse
|
43
|
Shah N, Schroeder B, Cobbs C. MGMT methylation in glioblastoma: tale of the tail. Neuro Oncol 2014; 17:167-8. [PMID: 25395464 DOI: 10.1093/neuonc/nou319] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Nameeta Shah
- The Ben and Catherine Ivy Center for Advanced Brain Tumor Treatment, Swedish Neuroscience Institute, Seattle, Washington
| | - Brett Schroeder
- The Ben and Catherine Ivy Center for Advanced Brain Tumor Treatment, Swedish Neuroscience Institute, Seattle, Washington
| | - Charles Cobbs
- The Ben and Catherine Ivy Center for Advanced Brain Tumor Treatment, Swedish Neuroscience Institute, Seattle, Washington
| |
Collapse
|
44
|
Shilpa V, Bhagat R, Premalata C, Pallavi V, Ramesh G, Krishnamoorthy L. Relationship between promoter methylation & tissue expression of MGMT gene in ovarian cancer. Indian J Med Res 2014; 140:616-23. [PMID: 25579142 PMCID: PMC4311314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND & OBJECTIVES Epigenetic alterations, in addition to multiple gene abnormalities, are involved in the genesis and progression of human cancers. Aberrant methylation of CpG islands within promoter regions is associated with transcriptional inactivation of various tumour suppressor genes. O 6-methyguanine-DNA methyltransferase (MGMT) is a DNA repair gene that removes mutagenic and cytotoxic adducts from the O 6 -position of guanine induced by alkylating agents. MGMT promoter hypermethylation and reduced expression has been found in some primary human carcinomas. We studied DNA methylation of CpG islands of the MGMT gene and its relation with MGMT protein expression in human epithelial ovarian carcinoma. METHODS A total of 88 epithelial ovarian cancer (EOC) tissue samples, 14 low malignant potential (LMP) tumours and 20 benign ovarian tissue samples were analysed for MGMT promoter methylation by nested methylation-specific polymerase chain reaction (MSP) after bisulphite modification of DNA. A subset of 64 EOC samples, 10 LMP and benign tumours and five normal ovarian tissue samples were analysed for protein expression by immunohistochemistry. RESULTS The methylation frequencies of the MGMT gene promoter were found to be 29.5, 28.6 and 20 per cent for EOC samples, LMP tumours and benign cases, respectively. Positive protein expression was observed in 93.8 per cent of EOC and 100 per cent in LMP, benign tumours and normal ovarian tissue samples. Promoter hypermethylation with loss of protein expression was seen only in one case of EOC. INTERPRETATION & CONCLUSIONS Our results suggest that MGMT promoter hypermethylation does not always reflect gene expression.
Collapse
Affiliation(s)
- V. Shilpa
- Department of Biochemistry, Kidwai Memorial Institute of Oncology, Bangalore, India
| | - Rahul Bhagat
- Department of Biochemistry, Kidwai Memorial Institute of Oncology, Bangalore, India
| | - C.S. Premalata
- Department of Pathology, Kidwai Memorial Institute of Oncology, Bangalore, India
| | - V.R. Pallavi
- Department of Gynaecologic Oncology, Kidwai Memorial Institute of Oncology, Bangalore, India
| | - G. Ramesh
- Department of Biochemistry, Kidwai Memorial Institute of Oncology, Bangalore, India
| | - Lakshmi Krishnamoorthy
- Department of Biochemistry, Kidwai Memorial Institute of Oncology, Bangalore, India,Reprint requests: Dr Lakshmi Krishnamoorthy, Department of Biochemistry, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore 560 029, Karnataka, India e-mail:
| |
Collapse
|
45
|
DNA methylation biomarkers: cancer and beyond. Genes (Basel) 2014; 5:821-64. [PMID: 25229548 PMCID: PMC4198933 DOI: 10.3390/genes5030821] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 08/17/2014] [Accepted: 09/01/2014] [Indexed: 12/23/2022] Open
Abstract
Biomarkers are naturally-occurring characteristics by which a particular pathological process or disease can be identified or monitored. They can reflect past environmental exposures, predict disease onset or course, or determine a patient's response to therapy. Epigenetic changes are such characteristics, with most epigenetic biomarkers discovered to date based on the epigenetic mark of DNA methylation. Many tissue types are suitable for the discovery of DNA methylation biomarkers including cell-based samples such as blood and tumor material and cell-free DNA samples such as plasma. DNA methylation biomarkers with diagnostic, prognostic and predictive power are already in clinical trials or in a clinical setting for cancer. Outside cancer, strong evidence that complex disease originates in early life is opening up exciting new avenues for the detection of DNA methylation biomarkers for adverse early life environment and for estimation of future disease risk. However, there are a number of limitations to overcome before such biomarkers reach the clinic. Nevertheless, DNA methylation biomarkers have great potential to contribute to personalized medicine throughout life. We review the current state of play for DNA methylation biomarkers, discuss the barriers that must be crossed on the way to implementation in a clinical setting, and predict their future use for human disease.
Collapse
|
46
|
Kanemoto M, Shirahata M, Nakauma A, Nakanishi K, Taniguchi K, Kukita Y, Arakawa Y, Miyamoto S, Kato K. Prognostic prediction of glioblastoma by quantitative assessment of the methylation status of the entire MGMT promoter region. BMC Cancer 2014; 14:641. [PMID: 25175833 PMCID: PMC4161852 DOI: 10.1186/1471-2407-14-641] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 08/27/2014] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation is reported to be a prognostic and predictive factor of alkylating chemotherapy for glioblastoma patients. Methylation specific PCR (MSP) has been most commonly used when the methylation status of MGMT is assessed. However, technical obstacles have hampered the implementation of MSP-based diagnostic tests. We quantitatively analyzed the methylation status of the entire MGMT promoter region and applied this information for prognostic prediction using sequencing technology. METHODS Between 1998 and 2012, the genomic DNA of 85 tumor samples from newly diagnosed glioblastoma patients was subjected to bisulfite treatment and subdivided into a training set, consisting of fifty-three samples, and a test set, consisting of thirty-two samples. The training set was analyzed by deep Sanger sequencing with a sequencing coverage of up to 96 clones per sample. This analysis quantitatively revealed the degree of methylation of each cytidine phosphate guanosine (CpG) site. Based on these data, we constructed a prognostic prediction system for glioblastoma patients using a supervised learning method. We then validated this prediction system by deep sequencing with a next-generation sequencer using a test set of 32 samples. RESULTS The methylation status of the MGMT promoter was correlated with progression-free survival (PFS) in our patient population in the training set. The degree of correlation differed among the CpG sites. Using the data from the top twenty CpG sites, we constructed a prediction system for overall survival (OS) and PFS. The system successfully classified patients into good and poor prognosis groups in both the training set (OS, p = 0.0381; PFS, p = 0.00122) and the test set (OS, p = 0.0476; PFS, p = 0.0376). Conventional MSP could not predict the prognosis in either of our sets. (training set: OS; p = 0.993 PFS; p = 0.113, test set: OS; p = 0.326 PFS; p = 0.342). CONCLUSIONS The prognostic ability of our prediction system using sequencing data was better than that of methylation-specific PCR (MSP). Advances in sequencing technologies will make this approach a plausible option for diagnoses based on MGMT promotor methylation.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Kikuya Kato
- Research Institute, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-3 Nakamichi, Higashinari-ku, Osaka, Japan.
| |
Collapse
|
47
|
Tabouret E, Chinot O, Sanson M, Loundou A, Hoang-Xuan K, Delattre JY, Idbaih A. Predictive biomarkers investigated in glioblastoma. Expert Rev Mol Diagn 2014; 14:883-93. [PMID: 25096963 DOI: 10.1586/14737159.2014.945436] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Glioblastoma is the most aggressive primary brain tumor in adults. Consequently, new therapeutic strategies are needed. Tumor response to cytotoxic chemotherapy is heterogeneous across patients. Interestingly, predictive biomarkers of response to these classic chemotherapeutic agents have been identified in neuro-oncology (i.e., 1p/19q co-deletion, IDH mutation and O6-methylguanine DNA-methyltransferase promoter methylation). The most emblematic biomarker in glioblastoma is O6-methylguanine DNA-methyltransferase promoter methylation that predicts response to temozolomide. In parallel, innovative drugs are emerging. Some of these agents have shown some activity but in a limited number of glioblastoma patients. One of the major challenges is to identify molecular predictors of response to these smart drugs for an efficient personalized medicine. These novel agents have been tested in clinical trials enrolling glioblastoma patients. Although none of them has been validated prospectively in Phase III clinical trials, interesting molecular predictors of response to these drugs have been investigated and are presented in this review, which also reports more advanced biomarkers.
Collapse
Affiliation(s)
- Emeline Tabouret
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2-Mazarin, 47-83, Boulevard de l'Hôpital, 75013 Paris, France
| | | | | | | | | | | | | |
Collapse
|
48
|
Tsankova NM, Canoll P. Advances in genetic and epigenetic analyses of gliomas: a neuropathological perspective. J Neurooncol 2014; 119:481-90. [PMID: 24962200 DOI: 10.1007/s11060-014-1499-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 06/02/2014] [Indexed: 01/08/2023]
Abstract
Gliomas, the most common malignant primary brain tumors, are universally fatal once they progress from low-grade into high-grade neoplasms. In recent years, we have accumulated unprecedented data about the genetic and epigenetic abnormalities in gliomas; yet, our appreciation of how these deadly tumors arise is still rudimentary. One of the major deterrents in understanding gliomagenesis is the remarkably complex and heterogeneous molecular composition of gliomas, as well as their ability to change phenotypically as they progress and recur. In the past decade, several monumental studies have begun to define better glioma heterogeneity. Four distinct molecular subgroups have emerged: proneural, classical, mesenchymal, and neural; which have unique gene expression signatures and prognostic significance. Of these, gliomas of the proneural subtype, which encompass most grade II/III diffuse gliomas and secondary glioblastomas and often carry isocitrate dehydrogenase (IDH) mutations, have emerged as a distinct tumor subclass with a notably superior prognosis. Important molecular markers with prognostic relevance, such as mutant IDH1/2, have already been incorporated into clinical neuropathological practice. The recent molecular discoveries in gliomas have also emphasized the intimate link between epigenetics and genetics in gliomagenesis. Several of the novel genetic mutations described are responsible for distinct epigenetic remodeling in gliomas, the mechanisms of which are currently being elucidated. Importantly, these epigenetic and genomic alterations represent new and exciting drug targets for future therapeutic interventions in our continuous fight with this fatal malignancy.
Collapse
Affiliation(s)
- Nadejda M Tsankova
- Division of Neuropathology, Department of Pathology and Cell Biology, Columbia University, New York, NY, USA,
| | | |
Collapse
|
49
|
Smalley S, Chalmers AJ, Morley SJ. mTOR inhibition and levels of the DNA repair protein MGMT in T98G glioblastoma cells. Mol Cancer 2014; 13:144. [PMID: 24909675 PMCID: PMC4061125 DOI: 10.1186/1476-4598-13-144] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/30/2014] [Indexed: 01/11/2023] Open
Abstract
Background Glioblastoma multiforme (GBM), the most common and most aggressive type of primary adult brain tumour, responds poorly to conventional treatment. Temozolomide (TMZ) chemotherapy remains the most commonly used treatment, despite a large proportion of tumours displaying TMZ resistance. 60% of GBM tumours have unmethylated MGMT promoter regions, resulting in an overexpression of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT), which is responsible for tumour resistance to TMZ chemotherapy. Tumours also often exhibit hyperactive PI3-kinase/mTOR signalling, which enables them to resynthesise proteins quickly. Since MGMT is a suicide protein that is degraded upon binding to and repairing TMZ-induced O6-methylguanine adducts, it has been hypothesized that inhibition of translation via the mTOR signalling pathway could generate a tumour-specific reduction in MGMT protein and increase TMZ sensitivity. Methods MGMT was monitored at the post-transcriptional, translational and protein levels, to determine what effect mTOR inhibition was having on MGMT protein expression in vitro. Results We show that inhibiting mTOR signalling is indeed associated with acute inhibition of protein synthesis. Western blots show that despite this, relative to loading control proteins, steady state levels of MGMT protein increased and MGMT mRNA was retained in heavy polysomes. Whilst TMZ treatment resulted in maintained MGMT protein levels, concomitant treatment of T98G cells with TMZ and KU0063794 resulted in increased MGMT protein levels without changes in total mRNA levels. Conclusions These in vitro data suggest that, counterintuitively, mTOR inhibition may not be a useful adjunct to TMZ therapy and that more investigation is needed before applying mTOR inhibitors in a clinical setting.
Collapse
Affiliation(s)
- Sarah Smalley
- Department of Biochemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
| | | | | |
Collapse
|
50
|
Promoter region hypermethylation and mRNA expression of MGMT and p16 genes in tissue and blood samples of human premalignant oral lesions and oral squamous cell carcinoma. BIOMED RESEARCH INTERNATIONAL 2014; 2014:248419. [PMID: 24991542 PMCID: PMC4058681 DOI: 10.1155/2014/248419] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/23/2014] [Accepted: 05/13/2014] [Indexed: 01/09/2023]
Abstract
Promoter methylation and relative gene expression of O(6)-methyguanine-DNA-methyltransferase (MGMT) and p16 genes were examined in tissue and blood samples of patients with premalignant oral lesions (PMOLs) and oral squamous cell carcinoma (OSCC). Methylation-specific PCR and reverse transcriptase PCR were performed in 146 tissue and blood samples from controls and patients with PMOLs and OSCC. In PMOL group, significant promoter methylation of MGMT and p16 genes was observed in 59% (P = 0.0010) and 57% (P = 0.0016) of tissue samples, respectively, and 39% (P = 0.0135) and 33% (P = 0.0074) of blood samples, respectively. Promoter methylation of both genes was more frequent in patients with OSCC, that is, 76% (P = 0.0001) and 82% (P = 0.0001) in tissue and 57% (P = 0.0002) and 70% (P = 0.0001) in blood, respectively. Significant downregulation of MGMT and p16 mRNA expression was observed in both tissue and blood samples from patients with PMOLs and OSCC. Hypermethylation-induced transcriptional silencing of MGMT and p16 genes in both precancer and cancer suggests important role of these changes in progression of premalignant state to malignancy. Results support use of blood as potential surrogate to tissue samples for screening or diagnosing PMOLs and early OSCC.
Collapse
|