1
|
Amilca-Seba K, Sabbah M, Larsen AK, Denis JA. Osteopontin as a Regulator of Colorectal Cancer Progression and Its Clinical Applications. Cancers (Basel) 2021; 13:cancers13153793. [PMID: 34359694 PMCID: PMC8345080 DOI: 10.3390/cancers13153793] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 12/29/2022] Open
Abstract
Simple Summary The mortality of colorectal cancer is principally related to metastatic disease at the time of diagnosis or to the growth of initially undetectable micro-metastasis. Current therapeutic strategies are efficient in patients with locally advanced cancer, but are rarely able to cure patients with metastatic disease. Therapeutic failure is mainly associated with drug resistance and an aggressive phenotype. The identification of new biomarkers for micro-metastasis and tumor progression remains an unmet clinical need that should allow for improved patient stratification for optimal treatment and may lead to the identification of novel therapeutic targets. Osteopontin (OPN), a multifunctional protein, has emerged as a potentially valuable biomarker in several cancer types. This review principally describes the molecular mechanisms of OPN that are associated with colorectal cancer (CRC) progression and metastasis, as well as the use of OPN as a clinical biomarker. This review identifies a role for OPN as a biomarker ready for extended clinical application and discusses its use as a therapeutic target. Abstract A high expression of the phosphoprotein osteopontin (OPN) has been associated with cancer progression in several tumor types, including breast cancer, hepatocarcinoma, ovarian cancer, and colorectal cancer (CRC). Interestingly, OPN is overexpressed in CRC and is associated with a poor prognosis linked to invasion and metastasis. Here, we review the regulation and functions of OPN with an emphasis on CRC. We examine how epigenetic and genetic regulators interact with the key signaling pathways involved in this disease. Then, we describe the role of OPN in cancer progression, including proliferation, survival, migration, invasion, and angiogenesis. Furthermore, we outline the interest of using OPN as a clinical biomarker, and discuss if and how osteopontin can be implemented as a routine assay in clinical laboratories for monitoring CRC patients. Finally, we discuss the use of OPN an attractive, but challenging, therapeutic target.
Collapse
Affiliation(s)
- Katyana Amilca-Seba
- Cancer Biology and Therapeutics, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France; (K.A.-S.); (M.S.); (A.K.L.)
- Institut National de la Santé et de la Recherche Médicale (INSERM) U938, 75012 Paris, France
- Institut Universitaire de Cancérologie (IUC), Faculté de Médecine, Sorbonne Université, 75005 Paris, France
| | - Michèle Sabbah
- Cancer Biology and Therapeutics, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France; (K.A.-S.); (M.S.); (A.K.L.)
- Institut National de la Santé et de la Recherche Médicale (INSERM) U938, 75012 Paris, France
- Institut Universitaire de Cancérologie (IUC), Faculté de Médecine, Sorbonne Université, 75005 Paris, France
- Centre National de la Recherche Scientifique (CNRS), 75016 Paris, France
| | - Annette K. Larsen
- Cancer Biology and Therapeutics, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France; (K.A.-S.); (M.S.); (A.K.L.)
- Institut National de la Santé et de la Recherche Médicale (INSERM) U938, 75012 Paris, France
- Institut Universitaire de Cancérologie (IUC), Faculté de Médecine, Sorbonne Université, 75005 Paris, France
- Centre National de la Recherche Scientifique (CNRS), 75016 Paris, France
| | - Jérôme A. Denis
- Cancer Biology and Therapeutics, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France; (K.A.-S.); (M.S.); (A.K.L.)
- Institut National de la Santé et de la Recherche Médicale (INSERM) U938, 75012 Paris, France
- Institut Universitaire de Cancérologie (IUC), Faculté de Médecine, Sorbonne Université, 75005 Paris, France
- Department of Endocrinology and Oncology Biochemistry, Pitié-Salpetrière Hospital, 75013 Paris, France
- Correspondence: ; Tel.: +33-(0)1-42-16-20-39
| |
Collapse
|
2
|
Enhancer of zeste homolog 2-mediated paired box 8 methylation promotes gastrointestinal stromal tumor progression through Wnt4 downregulation. Cancer Gene Ther 2021; 28:1162-1174. [PMID: 33479444 DOI: 10.1038/s41417-020-00266-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 11/17/2020] [Indexed: 01/03/2023]
Abstract
Gastrointestinal stromal tumor (GIST) is a refractory malignant tumor without satisfactory therapy. In recent years, aberrant gene methylation has been highlighted as an inducer for tumor progression. In this study, we explored whether enhancer of zeste homolog 2 (EZH2)-mediated paired box 8 (PAX8) methylation affects GIST development through regulation of Wnt4. A total of 50 cases of GIST tissues were collected and the human GIST cell lines were cultured. PAX8 methylation was examined using MS-PCR. Following loss- and gain-function approaches, GIST cell proliferation, migration, invasion, and apoptosis were examined by CCK-8 assay, Transwell assay and flow cytometry. The expression of proliferation related factors and apoptosis related factors was determined. Finally, xenograft tumors in nude mice were observed to examine in vivo tumorigenicity of GIST cells. Downregulated PAX8 and upregulated EZH2 expression was found in GIST tissues. Overexpression of PAX8 or suppression of PAX8 methylation using DNA methyltransferase inhibitor 5-Aza-dC inhibited the proliferation, migration, and invasion of GIST cells while promoting their apoptosis (diminished PCNA, Ki67 and Bcl-2, elevated Bax, and cleaved caspase-3). EZH2 promoted PAX8 methylation to inhibit its expression. Downregulated PAX8 decreased Wnt4 expression to accelerate GIST progression both in vitro and in vivo. Collectively, EZH2 inhibits PAX8 expression by promoting its methylation, which thus downregulates Wnt4 expression, thereby promoting the development of GIST.
Collapse
|
3
|
Žlajpah M, Boštjančič E, Zidar N. (Epi)genetic regulation of osteopontin in colorectal cancerogenesis. Epigenomics 2020; 12:1389-1403. [PMID: 32921164 DOI: 10.2217/epi-2020-0032] [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] [Indexed: 12/13/2022] Open
Abstract
Aim: To identify (epi)genetic regulators of osteopontin (OPN, encoded by SPP1 gene) from normal colon mucosa to adenoma, adenoma with early carcinoma and advanced carcinoma. Patients & methods: Biopsy samples of 41 patients with different patohistologic diagnosis were used. Using qPCR, pyrosequencing and statistical analysis, we determined the expression level of osteopontin regulatory miRNAs, its copy number and methylation status. Results & conclusion: We showed that hsa-miR-146a-5p expression is inversely proportional to the expression level of SPP1 and that expression might be also controlled by copy number and methylation. These results suggest that not only expression of SPP1 but also its copy number, methylation status and expression of its regulators might be used as a potential biomarker of colorectal cancer.
Collapse
Affiliation(s)
- Margareta Žlajpah
- Institute of Pathology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Emanuela Boštjančič
- Institute of Pathology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Nina Zidar
- Institute of Pathology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| |
Collapse
|
4
|
Sang L, Yu Z, Wang A, Li H, Dai X, Sun L, Liu H, Yuan Y. Identification of methylated-differentially expressed genes and pathways in esophageal squamous cell carcinoma. Pathol Res Pract 2020; 216:153050. [PMID: 32825936 PMCID: PMC7283077 DOI: 10.1016/j.prp.2020.153050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/26/2020] [Accepted: 06/07/2020] [Indexed: 12/19/2022]
Abstract
Methylation, as an epigenetic modification, can affect gene expression and play a role in the occurrence and development of cancer. This research is devoted to discover methylated-differentially expressed genes (MDEGs) in esophageal squamous cell carcinoma (ESCC) and explore special associated pathways. We downloaded GSE51287 methylation profiles and GSE26886 expression profiles from GEO DataSets, and performed a comprehensive bioinformatics analysis. Totally, 19 hypermethylated, lowly expressed genes (Hyper-LGs) were identified, and involved in regulation of cell proliferation, phosphorus metabolic process and protein kinase activity. Meanwhile, 17 hypomethylated, highly expressed genes (Hypo-HGs) were participated in collagen catabolic process, metallopeptidase and cytokine activity. Pathway analysis determined that Hyper-LGs were enriched in arachidonic acid metabolism pathway, while Hypo-HGs were primarily associated with the cytokine-cytokine receptor interaction pathway. IL 6, MMP3, MMP9, SPP1 were identified as hub genes based on the PPI network that combined 7 ranked methods included in cytoHubba, and verification was performed in human tissues. Our integrated analysis identified many novel genetic lesions in ESCC and provides a crucial molecular foundation to improve our understanding of ESCC. Hub genes, including IL 6, MMP3, MMP9 and SPP1, could be considered for use as aberrant methylation-based biomarkers to facilitate the accurate diagnosis and therapy of ESCC.
Collapse
Affiliation(s)
- Liang Sang
- Cancer Etiology and Screening Department of Cancer Institute and General Surgery, the First Hospital of China Medical University, Shenyang 110001, China; Ultrasound Department, the First Hospital of China Medical University, Shenyang 110001, China
| | - Zhanwu Yu
- Department of Thoracic Surgery, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, No. 44 Xiaoheyan Road, Shenyang, Liaoning 110042, China
| | - Ang Wang
- Cancer Etiology and Screening Department of Cancer Institute and General Surgery, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, the First Hospital of China Medical University, Shenyang 110001, China
| | - Hao Li
- Cancer Etiology and Screening Department of Cancer Institute and General Surgery, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, the First Hospital of China Medical University, Shenyang 110001, China
| | - Xiantong Dai
- Cancer Etiology and Screening Department of Cancer Institute and General Surgery, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, the First Hospital of China Medical University, Shenyang 110001, China
| | - Liping Sun
- Cancer Etiology and Screening Department of Cancer Institute and General Surgery, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, the First Hospital of China Medical University, Shenyang 110001, China
| | - Hongxu Liu
- Department of Thoracic Surgery, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, No. 44 Xiaoheyan Road, Shenyang, Liaoning 110042, China.
| | - Yuan Yuan
- Cancer Etiology and Screening Department of Cancer Institute and General Surgery, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of Cancer Etiology and Prevention in Liaoning Education Department, the First Hospital of China Medical University, Shenyang 110001, China; Key Laboratory of GI Cancer Etiology and Prevention in Liaoning Province, the First Hospital of China Medical University, Shenyang 110001, China.
| |
Collapse
|
5
|
Identification of low-density lipoprotein receptor class A domain containing 4 (LDLRAD4) as a prognostic indicator in primary gastrointestinal stromal tumors. Curr Probl Cancer 2020; 44:100593. [PMID: 32507364 DOI: 10.1016/j.currproblcancer.2020.100593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 02/11/2020] [Accepted: 04/23/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND There is an urgent clinical need to select the patients with resectable gastrointestinal stromal tumors (GISTs) who can benefit from adjuvant treatment after complete resection based on disease recurrence risk stratification. We hypothesized that integrating biomarkers into available risk assessment tools may improve the precision of GIST prognostic predictions. METHODS Candidate genes that may cause GIST progression were identified using the Gene Expression Omnibus dataset GSE20708. Quantitative Real-time was used to confirm the prognostic value of the candidate genes for recurrence-free survival (RFS) in a cohort of 94 patients. RESULTS Thirty-seven differentially expressed genes between localized tumors and metastatic primary tumors were found; 14 (37.8%) were upregulated and 23 (62.2%) were downregulated in the latter tumors. Low-density lipoprotein receptor class A domain containing 4 (LDLRAD4) was selected for further prognostic analysis. Although LDLRAD4 mRNA expression was not associated with recurrence risk grades as determined by the revised NIH consensus criteria, multivariate Cox regression analysis showed that LDLRAD4 expression (hazard ratio [HR] = 4.403, 95% confidence interval [CI]: 1.822-10.641, P = 0.001), tumor size (HR = 1.174, 95% CI: 1.027-1.342, P = 0.019) and tumor location (HR = 6.291, 95% CI: 1.128-35.080, P = 0.036) were independent prognostic factors for RFS in patients with resectable GISTs. Moreover, the RFS model constructed by these three factors may effectively predict GIST prognosis within the first 2 postsurgical years. CONCLUSION Our study identifies LDLRAD4 as a suitable prognostic marker for GISTs. The integration of biomarkers into risk assessment tools may improve the precision of GIST prognostic predictions.
Collapse
|
6
|
Bure I, Geer S, Knopf J, Roas M, Henze S, Ströbel P, Agaimy A, Wiemann S, Hoheisel JD, Hartmann A, Haller F, Moskalev EA. Long noncoding RNA HOTAIR is upregulated in an aggressive subgroup of gastrointestinal stromal tumors (GIST) and mediates the establishment of gene-specific DNA methylation patterns. Genes Chromosomes Cancer 2018; 57:584-597. [PMID: 30248209 DOI: 10.1002/gcc.22672] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 01/17/2023] Open
Abstract
Aberrant alterations of DNA methylation are common events in oncogenesis. The origin of cancer-associated epigenetic defects is of interest for mechanistic understanding of malignant transformation and-in the long run-therapeutic modulation of DNA methylation in a locus-specific manner. Given the ability of certain long noncoding RNAs to operate as an interface between DNA and the epigenetic modification machinery which can interact with DNA methyltransferases, we hypothesized-considering HOTAIR as an example-that this transcript may contribute to gene specificity of DNA methylation. Using gastrointestinal stromal tumors (GISTs, n = 67) as a model, we confirmed upregulation of HOTAIR in tumors with high risk of recurrence and showed high abundance of the transcript in GIST cell lines. HOTAIR knockdown in GIST-T1 cells triggered transcriptional response of genes involved in the organization and disassembly of the extracellular matrix and, notably, induced global locus-specific alterations of DNA methylation patterns. Hypomethylation was induced at a total of 507 CpG sites, whereas 382 CpG dinucleotides underwent gain of methylation upon HOTAIR depletion. Importantly, orchestrated gain or loss of methylation at multiple individual CpG sites was shown for cancer-related DPP4, RASSF1, ALDH1A3, and other targets. Collectively, our data indicate that HOTAIR enables target specificity of DNA methylation in GIST and is capable of dual (hypo- and hypermethylation) regulation by a yet to be defined mechanism. The results further suggest the feasibility of manipulating DNA methylation in a targeted manner and are of interest in the context of epigenetic cancer therapy.
Collapse
Affiliation(s)
- Irina Bure
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Sandra Geer
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Jasmin Knopf
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Maike Roas
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Sabine Henze
- Genomics and Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Philipp Ströbel
- Institute of Pathology, Georg August University, Göttingen, Germany
| | - Abbas Agaimy
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Stefan Wiemann
- Genomics and Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jörg D Hoheisel
- Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Arndt Hartmann
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Florian Haller
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Evgeny A Moskalev
- Diagnostic Molecular Pathology, Institute of Pathology, Friedrich Alexander University, Erlangen, Germany
| |
Collapse
|
7
|
Settas N, Faucz FR, Stratakis CA. Succinate dehydrogenase (SDH) deficiency, Carney triad and the epigenome. Mol Cell Endocrinol 2018; 469:107-111. [PMID: 28739378 PMCID: PMC5776069 DOI: 10.1016/j.mce.2017.07.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 07/13/2017] [Accepted: 07/20/2017] [Indexed: 12/29/2022]
Abstract
In this report, we review the relationship between succinate dehydrogenase (SDH) deficiency and the epigenome, especially with regards to two clinical conditions. Carney triad (CT) is a very rare disease with synchronous or metachronous occurrence of at least three different tumor entities; gastric gastrointestinal stromal tumor (GIST), paraganglioma (PGL), and pulmonary chondroma. This condition affects mostly females and it is never inherited. Another disease that shares two of the tumor components of CT, namely GIST and PGL is the Carney-Stratakis syndrome (CSS) or dyad. CSS affects both genders during childhood and adolescence. We review herein the main clinical features and molecular mechanisms behind those two syndromes that share quite a bit of similarities, but one is non-hereditary (CT) whereas the other shows an autosomal-dominant, with incomplete penetrance, inheritance pattern (CSS). Both CT and CSS are caused by the deficiency of the succinate dehydrogenase (SDH) enzyme. The key difference between the two syndromes is the molecular mechanism that causes the SDH deficiency. Most cases of CT show down-regulation of SDH through site-specific hyper-methylation of the SDHC gene, whereas CSS cases carry inactivating germline mutations within one of the genes coding for the SDH subunits A, B, C, or D (SDHA, SDHB, SDHC, and SDHD). There is only partial overlap between the two conditions (there are a few patients with CT that have SDH subunit mutations) but both lead to increased methylation of the entire genome in the tumors associated with them. Other tumors (outside CT and CSS) that have SDH deficiency are associated with increased methylation of the entire genome, but only in CT there is site-specific methylation of the SDHC gene. These findings have implications for diagnostics and the treatment of patients with these, often metastatic tumors.
Collapse
Affiliation(s)
- Nikolaos Settas
- Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, USA.
| | - Fabio R Faucz
- Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, USA
| | - Constantine A Stratakis
- Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, USA
| |
Collapse
|
8
|
Liu F, Zhang H, Lu S, Wu Z, Zhou L, Cheng Z, Bai Y, Zhao J, Zhang Q, Mao H. Quantitative assessment of gene promoter methylation in non-small cell lung cancer using methylation-sensitive high-resolution melting. Oncol Lett 2018; 15:7639-7648. [PMID: 29725463 PMCID: PMC5920472 DOI: 10.3892/ol.2018.8321] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 02/08/2018] [Indexed: 12/12/2022] Open
Abstract
DNA methylation is closely associated with aberrant epigenetic changes. Previous studies have identified various genes associated with non-small cell lung cancer (NSCLC), but the precise combination responsible for its etiology is still debated. The aim of the present study was to select a new set of NSCLC-related genes using methylation-sensitive high-resolution melting. The promoter methylation status of six selected genes, consisting of protocadherin γ subfamily B, 6 (PCDHGB6), homeobox A9 (HOXA9), O6-methylguanine-DNA methyltransferase (MGMT), microRNA (miR)-126, suppressor of cytokine signaling 3 (SOCS3) and Ras association domain family member 5, also termed NORE1A, was evaluated in 54 NSCLC patients. From these samples, genome-wide DNA was extracted and bisulfite conversion was performed along with fluorogenic quantitative polymerase chain reaction to detect methylation values of the six selected promoters. The present results revealed frequent methylation on PCDHGB6, HOXA9 and miR-126, which contrasted with infrequent methylation on MGMT. The results indicated no methylation on either SOCS3 or NORE1A. The sensitivity and specificity of the methylation assessment were 85.2 and 81.5%, respectively, and the analysis results were validated by pyrosequencing. Furthermore, minute comparison of the association between DNA methylation and clinical features was performed. Overall, these results may provide potential information for the development of better clinical diagnostics and more targeted and effective therapies for NSCLC.
Collapse
Affiliation(s)
- Fangming Liu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, P.R. China.,Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou, Fujian 350002, P.R. China
| | - Honglian Zhang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, P.R. China
| | - Shaohua Lu
- Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai 200032, P.R. China
| | - Zhenhua Wu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, P.R. China
| | - Lin Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, P.R. China
| | - Zule Cheng
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, P.R. China
| | - Yanan Bai
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, P.R. China
| | - Jianlong Zhao
- Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou, Fujian 350002, P.R. China
| | - Qiqing Zhang
- Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou, Fujian 350002, P.R. China.,Institute of Biomedical Engineering, Chinese Academy of Medical Science and Peking Union Medical College, The Key Laboratory of Biomaterials of Tianjin, Tianjin 300192, P.R. China
| | - Hongju Mao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai 200050, P.R. China
| |
Collapse
|
9
|
Fang G, Zhang QH, Tang Q, Jiang Z, Xing S, Li J, Pang Y. Comprehensive analysis of gene expression and DNA methylation datasets identify valuable biomarkers for rheumatoid arthritis progression. Oncotarget 2017; 9:2977-2983. [PMID: 29423022 PMCID: PMC5790439 DOI: 10.18632/oncotarget.22918] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/03/2017] [Indexed: 11/29/2022] Open
Abstract
Rheumatoid arthritis (RA) represents a common systemic autoimmune disease which lays chronic and persistent pain on patients. The purpose of our study is to identify novel RA-related genes and biological processes/pathways. All the datasets of this study, including gene expression and DNA methylation datasets of RA and OA samples, were obtained from the free available database, i.e. Gene Expression Omnibus (GEO). We firstly identified the differentially expressed genes (DEGs) between RA and OA samples through the limma package of R programming software followed by the functional enrichment analysis in the Database for Annotation, Visualization and Integrated Discovery (DAVID) for the exploring of potential involved biological processes/pathways of DEGs. For DNA methylation datasets, we used the IMA package for their normalization and identification of differential methylation genes (DMGs) in RA compared with OA samples. Comprehensive analysis of DEGs and DMGs was also conducted for the identification of valuable RA-related biomarkers. As a result, we obtained 394 DEGs and 363 DMGs in RA samples with the thresholds of |log2fold change|> 1 and p-value < 0.05, and |delta beta|> 0.2 and p-value < 0.05 respectively. Functional analysis of DEGs obtained immune and inflammation associated biological processes/pathways. Besides, several valuable biomarkers of RA, including BCL11B, CCDC88C, FCRLA and APOL6, were identified through the integrated analysis of gene expression and DNA methylation datasets. Our study should be helpful for the development of novel drugs and therapeutic methods for RA.
Collapse
Affiliation(s)
- Gang Fang
- Laboratory of Zhuang Medicine Prescriptions Basis and Application Research, Guangxi University of Chinese Medicine, Nanning, China
| | - Qing Huai Zhang
- Laboratory of Zhuang Medicine Prescriptions Basis and Application Research, Guangxi University of Chinese Medicine, Nanning, China
| | - Qianqian Tang
- Department of Rheumatism, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Zuling Jiang
- Department of Zhuang Medicine, The First Affiliated of Guangxi University of Chinese Medicine, Nanning, China
| | - Shasha Xing
- Department of Rheumatism, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Jianying Li
- Laboratory of Zhuang Medicine Prescriptions Basis and Application Research, Guangxi University of Chinese Medicine, Nanning, China
| | - Yuzhou Pang
- Laboratory of Zhuang Medicine Prescriptions Basis and Application Research, Guangxi University of Chinese Medicine, Nanning, China
| |
Collapse
|
10
|
Bure I, Braun A, Kayser C, Geddert H, Schaefer I, Cameron S, Ghadimi MB, Ströbel P, Werner M, Hartmann A, Wiemann S, Agaimy A, Haller F, Moskalev EA. The expression of hematopoietic progenitor cell antigen CD34 is regulated by DNA methylation in a site‐dependent manner in gastrointestinal stromal tumours. Int J Cancer 2017; 141:2296-2304. [DOI: 10.1002/ijc.30905] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/22/2017] [Accepted: 06/26/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Irina Bure
- Institute of Pathology, Friedrich Alexander UniversityErlangen Germany
| | - Alexander Braun
- Institute for Surgical Pathology, University Medical Center Freiburg Germany
- German Cancer Consortium (DKTK) and Cancer Research Center (DKFZ)Heidelberg Germany
| | - Claudia Kayser
- Institute for Surgical Pathology, University Medical Center Freiburg Germany
- German Cancer Consortium (DKTK) and Cancer Research Center (DKFZ)Heidelberg Germany
| | - Helene Geddert
- Institute of Pathology, St. Vincentius HospitalKarlsruhe Germany
| | | | - Silke Cameron
- Department of Gastroenterology and EndocrinologyGeorg August UniversityGöttingen Germany
| | - Michael B. Ghadimi
- Department of General and Visceral SurgeryGeorg August UniversityGöttingen Germany
| | - Philipp Ströbel
- Institute of Pathology, Georg August UniversityGöttingen Germany
| | - Martin Werner
- Institute for Surgical Pathology, University Medical Center Freiburg Germany
- German Cancer Consortium (DKTK) and Cancer Research Center (DKFZ)Heidelberg Germany
| | - Arndt Hartmann
- Institute of Pathology, Friedrich Alexander UniversityErlangen Germany
| | - Stefan Wiemann
- Division Molecular Genome AnalysisGerman Cancer Research Center (DKFZ)Heidelberg Germany
| | - Abbas Agaimy
- Institute of Pathology, Friedrich Alexander UniversityErlangen Germany
| | - Florian Haller
- Institute of Pathology, Friedrich Alexander UniversityErlangen Germany
| | | |
Collapse
|
11
|
Geddert H, Braun A, Kayser C, Dimmler A, Faller G, Agaimy A, Haller F, Moskalev EA. Epigenetic Regulation of CD133 in Gastrointestinal Stromal Tumors. Am J Clin Pathol 2017; 147:515-524. [PMID: 28398518 DOI: 10.1093/ajcp/aqx028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES This study ascertained the regulation of the stem cell marker CD133 and its potential applicability for prognostication of gastrointestinal stromal tumors (GISTs). METHODS A total of 95 resected GISTs were included in the study. CD133 protein expression was assessed immunohistochemically on tissue microarrays. Methylation percentage was quantified by pyrosequencing. Gene expression in cell lines GIST48b and GIST882 upon treatment with DNA demethylation agent 5-aza-2'-deoxycytidine was analyzed by quantitative polymerase chain reaction. RESULTS The expression of hypermethylated CD133 could be reactivated in the GIST cell line upon hypomethylation with the drug. Similarly, in patient material, CD133 methylation percentage correlated inversely with the protein expression and reflected tumor size with hypermethylation in small (<2 cm) tumors and virtually no methylation in large (>10 cm) GISTs. The gene's methylation percentage and expression level were clearly specific to anatomic sites and distinct driver mutations. KIT -mutant gastric GISTs exhibited significantly lower methylation degrees and concomitant high CD133 protein abundance compared with KIT -mutant GISTs from the small intestine. CD133 hypermethylation was documented in PDGFRA -mutant gastric GISTs along with low CD133 expression compared with KIT -mutant gastric GISTs. High CD133 expression was a prognosticator of shorter disease-free survival in all patients. In a subgroup of KIT -mutant gastric GISTs, low CD133 methylation degree was correlated with a shorter disease-free survival. CONCLUSIONS Our results strongly suggest epigenetic regulation of CD133 expression by promoter methylation in GISTs. Pending further validation studies, high abundance of the protein can serve as a marker for malignant GISTs.
Collapse
Affiliation(s)
- Helene Geddert
- Institute for Pathology, St Vincentius Hospital, Karlsruhe, Germany
| | - Alexander Braun
- Institute for Pathology, Albert Ludwigs University, Freiburg, Germany
| | - Claudia Kayser
- Institute for Pathology, Albert Ludwigs University, Freiburg, Germany
| | - Arno Dimmler
- Institute for Pathology, St Vincentius Hospital, Karlsruhe, Germany
| | - Gerhard Faller
- Institute for Pathology, St Vincentius Hospital, Karlsruhe, Germany
| | - Abbas Agaimy
- Institute for Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Florian Haller
- Institute for Pathology, Friedrich Alexander University, Erlangen, Germany
| | - Evgeny A Moskalev
- Institute for Pathology, Friedrich Alexander University, Erlangen, Germany
| |
Collapse
|
12
|
Xu Y, Gao X, Zhang L, Chen D, Dai Z, Zou X. Simultaneous detection of double gene-specific methylation loci based on hairpin probes tagged with electrochemical quantum dots barcodes. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2016.06.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
13
|
Kondo T. Proteogenomics for the Study of Gastrointestinal Stromal Tumors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 926:139-151. [DOI: 10.1007/978-3-319-42316-6_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
14
|
Zhang R, Zhao J, Xu J, Liu F, Xu Y, Bu X, Dai C, Song C. Genetic variations in the TERT and CLPTM1L gene region and gastrointestinal stromal tumors risk. Oncotarget 2016; 6:31360-7. [PMID: 26372813 PMCID: PMC4741611 DOI: 10.18632/oncotarget.5153] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 08/27/2015] [Indexed: 12/03/2022] Open
Abstract
Recent studies have suggested polymorphisms in the TERT and CLPTM1L region are associated with carcinogenesis of many distinct cancer types, including gastrointestinal cancers. However, the contribution of polymorphisms in the TERT and CLPTM1L gene region to gastrointestinal stromal tumors (GISTs) risk is still unknown. We tested the six tagSNPs on TERT and CLPTM1L region with GIST risk, using a population-based, two-stage, case-control study in 2,000 subjects. Functional validation was conducted to validate our findings of TERT rs2736098 and explore its influence on relative telomere length (RTL) in GIST cells. It showed that variant rs2736098 was significantly associated with increased risk of GIST (per allele OR = 1.29, 95% CI: 1.14–1.47, P = 7.03 × 10−5). The difference remain significant after Bonferroni correction (P = 7.03 × 10−5 * 6 = 4.2 × 10−4). Real-time PCR showed carriers of genotype CC have the longest RTL, following by carriers of genotype CT, while carriers of genotype TT have the shortest RTL in GIST tissues (P < 0.001). Our data provide evidence to implicate TERT rs2736098 polymorphism as a novel susceptibility factor for GIST risk.
Collapse
Affiliation(s)
- Rui Zhang
- Department of Colorectal Surgery, Liaoning Cancer Hospital & Institute, Shenyang 110042, Liaoning Province, P.R. China
| | - Jian Zhao
- Department of Colorectal Surgery, Liaoning Cancer Hospital & Institute, Shenyang 110042, Liaoning Province, P.R. China
| | - Jian Xu
- Department of Colorectal Surgery, Liaoning Cancer Hospital & Institute, Shenyang 110042, Liaoning Province, P.R. China
| | - Fang Liu
- Department of Colorectal Surgery, Liaoning Cancer Hospital & Institute, Shenyang 110042, Liaoning Province, P.R. China
| | - Yongqing Xu
- Department of Hepatobiliary and Splenic Surgery, Shengjing Hospital, China Medical University, Shenyang 110004, Liaoning Province, P.R. China
| | - Xianmin Bu
- Department of Hepatobiliary and Splenic Surgery, Shengjing Hospital, China Medical University, Shenyang 110004, Liaoning Province, P.R. China
| | - Chaoliu Dai
- Department of Hepatobiliary and Splenic Surgery, Shengjing Hospital, China Medical University, Shenyang 110004, Liaoning Province, P.R. China
| | - Chun Song
- Department of Colorectal Surgery, Liaoning Cancer Hospital & Institute, Shenyang 110042, Liaoning Province, P.R. China
| |
Collapse
|
15
|
Zhang L, Liu Y, Li Y, Zhao Y, Wei W, Liu S. Sensitive electrochemical assaying of DNA methyltransferase activity based on mimic-hybridization chain reaction amplified strategy. Anal Chim Acta 2016; 933:75-81. [DOI: 10.1016/j.aca.2016.05.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/16/2016] [Accepted: 05/23/2016] [Indexed: 11/29/2022]
|
16
|
Discovery and Validation of Hypermethylated Markers for Colorectal Cancer. DISEASE MARKERS 2016; 2016:2192853. [PMID: 27493446 PMCID: PMC4963574 DOI: 10.1155/2016/2192853] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/06/2016] [Accepted: 06/15/2016] [Indexed: 12/31/2022]
Abstract
Colorectal carcinoma (CRC) is one of the most prevalent malignant tumors worldwide. Screening and early diagnosis are critical for the clinical management of this disease. DNA methylation changes have been regarded as promising biomarkers for CRC diagnosis. Here, we map DNA methylation profiling on CRC in six CRCs and paired normal samples using a 450 K bead array. Further analysis confirms the methylation status of candidates in two data sets from the Gene Expression Omnibus. Receiver operating characteristic (ROC) curves are calculated to determine the diagnostic performances. We identify 1549 differentially methylated regions (DMRs) showing differences in methylation between CRC and normal tissue. Two genes (ADD2 and AKR1B1), related to the DMRs, are selected for further validation. ROC curves show that the areas under the curves of ADD2 and AKR1B1 are higher than that of SEPT9, which has been clinically used as a screening biomarker of CRC. Our data suggests that aberrant DNA methylation of ADD2 and AKR1B1 could be potential screening markers of CRC.
Collapse
|
17
|
Brahmi M, Alberti L, Dufresne A, Ray-Coquard I, Cassier P, Meeus P, Decouvelaere AV, Ranchère-Vince D, Blay JY. KIT exon 10 variant (c.1621 A > C) single nucleotide polymorphism as predictor of GIST patient outcome. BMC Cancer 2015; 15:780. [PMID: 26498480 PMCID: PMC4619434 DOI: 10.1186/s12885-015-1817-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 10/16/2015] [Indexed: 11/25/2022] Open
Abstract
Background Tumor genotype plays a crucial role in clinical management of GIST. Whether genetic polymorphism of KIT may influence GIST patient outcome is unclear. Methods We investigated the biological and clinical significance of the presence of KIT exon 10 variant (c.1621 A > C), KITL541, in a transfected cell line (3 T3 L541) and in two retrospectively collected series of 109 GIST patients in total. The control group consisted of 60 healthy donors collected at the French department of blood transfusion. Results In the 3 T3 L541 cell line, KITL541 protein exhibited a spontaneous phosphorylation status comparable to that of wild-type KIT but displayed a phosphorylation pattern of AKT and ERK1/2 that was found similar to that of the classical mutated forms of the KIT receptor. Of 109 patients enrolled in this retrospective translational research study, 24 (22 %) harboured KITL541, similarly to the control group of healthy donors (n = 10 of 60, 17 %). A higher prevalence of the variant KITL541 was observed in patients with metastatic status at diagnosis (KITL541 correlated nine of 22 versus 15 of 87, p = 0.02). In addition, patients with KITL541 and localized GIST had a higher rate of relapse at 5 years and lower relapse free survival at 5 years in univariate, as well as in multivariate analysis. Response rate and duration of response to imatinib was similar in KITL541 and KITM541 patients. Conclusion KITL541 genotype is associated with a higher risk of metastasis at diagnosis and a higher risk of relapse in GIST patients. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1817-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Mehdi Brahmi
- Department of medical oncology, Centre Leon Berard, 28 rue Laennec, Lyon, France.
| | - Laurent Alberti
- Cancer Research Center of Lyon, INSERM UMR 1052, CNRS UMR 5286, Centre Leon Berard, 28 rue Laennec, Lyon, France.
| | - Armelle Dufresne
- Cancer Research Center of Lyon, INSERM UMR 1052, CNRS UMR 5286, Centre Leon Berard, 28 rue Laennec, Lyon, France.
| | - Isabelle Ray-Coquard
- Department of medical oncology, Centre Leon Berard, 28 rue Laennec, Lyon, France.
| | - Philippe Cassier
- Department of medical oncology, Centre Leon Berard, 28 rue Laennec, Lyon, France.
| | - Pierre Meeus
- Department of medical oncology, Centre Leon Berard, 28 rue Laennec, Lyon, France.
| | | | | | - Jean-Yves Blay
- Department of medical oncology, Centre Leon Berard, 28 rue Laennec, Lyon, France.
| |
Collapse
|
18
|
Duan ZH, Wang HC, Zhao DM, Ji XX, Song M, Yang XJ, Cui W. Cooperatively transcriptional and epigenetic regulation of sonic hedgehog overexpression drives malignant potential of breast cancer. Cancer Sci 2015; 106:1084-91. [PMID: 25990213 PMCID: PMC4556399 DOI: 10.1111/cas.12697] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 05/12/2015] [Accepted: 05/14/2015] [Indexed: 01/24/2023] Open
Abstract
Sonic hedgehog (Shh), a ligand of Hedgehog signaling pathway, is considered an important oncogene and an exciting potential therapeutic target in several cancers. Comprehensive understanding of the regulation mechanism of Shh in cancer cells is necessary to find an effective approach to selectively block its tumorigenic function. We and others previously demonstrated that nuclear factor-kappa B (NF-κB) activation and promoter hypomethylation contributed to the overexpression of Shh. However, the relationship between transcriptional and epigenetic regulation of Shh, and their roles in the malignant phenotype of cancer cells are still not clearly elucidated. In the present study, our data showed that the level of Shh was higher in breast cancer tissues with positive NF-κB nuclear staining and promoter hypomethylation. In addition, survival analysis revealed that Shh overexpression, but not hypomethylation and NF-κB nuclear staining, was a poor prognosis indicator for breast cancers. Moreover, in vitro data demonstrated that both NF-κB activation and hypomethylation in promoter region were positively associated with the overexpression of Shh. Mechanistically, the hypomethylation in Shh promoter could facilitate NF-κB binding to its site, and subsequently cooperate to induce transcription of Shh. Furthermore, the biological function data indicated that overexpressed Shh enhanced the self-renewal capacity and migration ability of breast cancer cells, which could be augmented by promoter demethylation and NF-κB activation. Overall, our findings reveal multiple and cooperative mechanisms of Shh upregulation in cancer cells, and the roles of Shh in tumor malignant behavior, thus suggesting a new strategy for therapeutic interventions to reduce Shh in tumors and improve patients’ prognosis.
Collapse
Affiliation(s)
- Zhao-Heng Duan
- Department of Pharmacology, College of Life Science and Biopharmaceutical of Shenyang Pharmaceutical University, Shenyang, China
| | - Hao-Chuan Wang
- Department of Pharmacology, College of Life Science and Biopharmaceutical of Shenyang Pharmaceutical University, Shenyang, China
| | - Dong-Mei Zhao
- Department of Pharmacology, College of Life Science and Biopharmaceutical of Shenyang Pharmaceutical University, Shenyang, China
| | - Xiao-Xin Ji
- Department of Pharmacology, College of Life Science and Biopharmaceutical of Shenyang Pharmaceutical University, Shenyang, China
| | - Min Song
- Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, Shenyang, China
| | - Xiao-Jun Yang
- Center for Neuroscience, Medical College of Shantou University, Shantou, China
| | - Wei Cui
- Department of Pharmacology, College of Life Science and Biopharmaceutical of Shenyang Pharmaceutical University, Shenyang, China
| |
Collapse
|
19
|
Alturkmani HJ, Pessetto ZY, Godwin AK. Beyond standard therapy: drugs under investigation for the treatment of gastrointestinal stromal tumor. Expert Opin Investig Drugs 2015; 24:1045-58. [PMID: 26098203 DOI: 10.1517/13543784.2015.1046594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Gastrointestinal stromal tumor (GIST) is the most common nonepithelial malignancy of the GI tract. With the discovery of KIT and later platelet-derived growth factor α (PDGFRA) gain-of-function mutations as factors in the pathogenesis of the disease, GIST was the quintessential model for targeted therapy. Despite the successful clinical use of imatinib mesylate, a selective receptor tyrosine kinase (RTK) inhibitor that targets KIT, PDGFRA and BCR-ABL, we still do not have treatment for the long-term control of advanced GIST. AREAS COVERED This review summarizes the drugs that are under investigation or have been assessed in trials for GIST treatment. The article focuses on their mechanisms of actions, the preclinical evidence of efficacy, and the clinical trials concerning safety and efficacy in humans. EXPERT OPINION It is known that KIT and PDGFRA mutations in GIST patients influence the response to treatment. This observation should be taken into consideration when investigating new drugs. RECIST was developed to help uniformly report efficacy trials in oncology. Despite the usefulness of this system, many questions are being addressed about its validity in evaluating the true efficacy of drugs knowing that new targeted therapies do not affect the tumor size as much as they halt progression and prolong survival.
Collapse
Affiliation(s)
- Hani J Alturkmani
- University of Kansas Medical Center, Department of Pathology and Laboratory Medicine , Kansas City, Kansas , USA
| | | | | |
Collapse
|