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Whyte E, Nezu M, Chik C, Tateno T. Update on Current Evidence for the Diagnosis and Management of Nonfunctioning Pituitary Neuroendocrine Tumors. Endocrinol Metab (Seoul) 2023; 38:631-654. [PMID: 37964483 PMCID: PMC10764990 DOI: 10.3803/enm.2023.1838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/29/2023] [Accepted: 11/01/2023] [Indexed: 11/16/2023] Open
Abstract
Pituitary neuroendocrine tumors (PitNETs) are the third most frequently diagnosed intracranial tumors, with nonfunctioning PitNETs (nfPitNETs) accounting for 30% of all pituitary tumors and representing the most common type of macroPitNETs. NfPitNETs are usually benign tumors with no evidence of hormone oversecretion except for hyperprolactinemia secondary to pituitary stalk compression. Due to this, they do not typically present with clinical syndromes like acromegaly, Cushing's disease or hyperthyroidism and instead are identified incidentally on imaging or from symptoms of mass effects (headache, vision changes, apoplexy). With the lack of effective medical interventions, first-line treatment is transsphenoidal surgical resection, however, nfPitNETs often have supra- or parasellar extension, and total resection of the tumor is often not possible, resulting in residual tumor regrowth or reoccurrence. While functional PitNETs can be easily followed for recurrence using hormonal biomarkers, there is no similar parameter to predict recurrence in nfPitNETs, hence delaying early recognition and timely management. Therefore, there is a need to identify prognostic biomarkers that can be used for patient surveillance and as therapeutic targets. This review focuses on summarizing the current evidence on nfPitNETs, with a special focus on potential new biomarkers and therapeutics.
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Affiliation(s)
- Elizabeth Whyte
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Masahiro Nezu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Constance Chik
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Toru Tateno
- Division of Endocrinology and Metabolism, Department of Medicine, University of Alberta, Edmonton, AB, Canada
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Targeting the Tumor Immune Microenvironment Could Become a Potential Therapeutic Modality for Aggressive Pituitary Adenoma. Brain Sci 2023; 13:brainsci13020164. [PMID: 36831707 PMCID: PMC9954754 DOI: 10.3390/brainsci13020164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/14/2022] [Accepted: 01/03/2023] [Indexed: 01/20/2023] Open
Abstract
OBJECT This study aimed to explore the relationship between the aggressiveness and immune cell infiltration in pituitary adenoma (PA) and to provide the basis for immuno-targeting therapies. METHODS One hundred and three patients with PA who underwent surgery at a single institution were retrospectively identified. The infiltration of macrophages and T-lymphocytes was quantitatively assessed. RESULTS The number of CD68+ macrophages was positively correlated with Knosp (p = 0.003) and MMP-9 expression grades (p = 0.00). The infiltration of CD163+ macrophages differed among Knosp (p = 0.022) and MMP-9 grades (p = 0.04). CD8+ tumor-infiltrating lymphocytes (TILs) were also positively associated with Knosp (p = 0.002) and MMP-9 grades (p = 0.01). Interestingly, MGMT expression was positively correlated with MMP-9 staining extent (p = 0.000). The quantities of CD8+ TILs (p = 0.016), CD68+ macrophages (p = 0.000), and CD163+ macrophages (p = 0.043) were negatively associated with MGMT expression levels. The number of CD68+ macrophages in the PD-L1 negative group was significantly more than that in the PD-L1 positive group (p = 0.01). The rate of PD-L1 positivity was positively correlated with the Ki-67 index (p = 0.046) and p53 expression (p = 0.029). CONCLUSION Targeted therapy for macrophages and CD8+ TILs could be a helpful treatment in the future for aggressive PA. Anti-PD-L1 therapy may better respond to PAs with higher Ki-67 and p53 expression and more infiltrating CD68+ macrophages. Multiple treatment modalities, especially combined with immunotherapy could become a novel therapeutic strategy for aggressive PA.
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Lenders NF, Inder WJ, McCormack AI. Towards precision medicine for clinically non-functioning pituitary tumours. Clin Endocrinol (Oxf) 2021; 95:398-409. [PMID: 33774854 DOI: 10.1111/cen.14472] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/21/2021] [Accepted: 03/17/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Clinically non-functioning pituitary tumours (NFPT) are a heterogenous group of neoplasms with diverse outcomes. The purpose of this narrative review was to summarize available data on predictive factors, both in routine practice and research settings. DESIGN A literature review was conducted for papers published in peer-reviewed journals, investigating clinical, radiological, pathological and genetic predictive factors in NFPT. RESULTS Several clinical and radiological factors have been associated with NFPT recurrence and/or aggressiveness, including larger size and pre-/post-operative growth rates. Application of transcription factor immunohistochemistry has given rise to improved subtype identification, including 'higher-risk' subtypes, in routine clinical practice. Numerous other pathological and genetic biomarkers have demonstrated promise for prognostication in the research setting. CONCLUSION NFPT are a heterogenous group of tumours, characterized by diverse presentation, pathogenesis and outcomes. Ongoing refinements in understanding of tumour biology are likely to pave the way to improved integrative prognostication and precision medicine for NFPT.
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Affiliation(s)
- Nèle F Lenders
- Department of Endocrinology, St Vincent's Hospital, Sydney, New South Wales, Australia
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW, Sydney, New South Wales, Australia
| | - Warrick J Inder
- Department of Diabetes and Endocrinology, Princess Alexandra Hospital, Brisbane, Queensland, Australia
- Faculty of Medicine, the University of Queensland, Brisbane, Queensland, Australia
| | - Ann I McCormack
- Department of Endocrinology, St Vincent's Hospital, Sydney, New South Wales, Australia
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW, Sydney, New South Wales, Australia
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Manojlovic-Gacic E, Bollerslev J, Casar-Borota O. Invited Review: Pathology of pituitary neuroendocrine tumours: present status, modern diagnostic approach, controversies and future perspectives from a neuropathological and clinical standpoint. Neuropathol Appl Neurobiol 2019; 46:89-110. [PMID: 31112312 DOI: 10.1111/nan.12568] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 05/08/2019] [Indexed: 12/21/2022]
Abstract
Neuroendocrine tumours of the adenohypophysis have traditionally been designated as pituitary adenomas to underline their usually indolent growth and lack of metastatic potential. However, they may demonstrate a huge spectrum of growth patterns and endocrine disturbances, some of them significantly affecting health and quality of life. To predict tumour growth, risk of postoperative recurrence and response to medical therapy in patients with pituitary neuroendocrine tumours is challenging. A thorough histopathological and immunohistochemical diagnostic work-up is an obligatory part of a multidisciplinary effort to precisely define the tumour type and assess prognostic and predictive factors on an individual basis. In this review, we have summarized the current status in the pathology in pituitary neuroendocrine tumours based on the selection of references from the PubMed database. We have presented possible diagnostic approaches according to the current pituitary cell lineage-based classification. The importance of recognizing histological subtypes with potentially aggressive behaviour and identification of prognostic and predictive tissue biomarkers have been highlighted. Controversies related to particular subtypes of pituitary tumours and a still limited prognostic impact of the current classification indicate the need for further refinement. Multidisciplinary approach including clinical, pathological and molecular genetic characterization will be essential for improved personalized therapy and the search for novel therapeutic targets in patients with pituitary neuroendocrine tumours.
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Affiliation(s)
- E Manojlovic-Gacic
- Institute of Pathology, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - J Bollerslev
- Section of Specialized Endocrinology, Department of Endocrinology, Oslo University Hospital Rikshospitalet, Oslo, Norway.,Faculty of Medicine, University of Oslo, Oslo, Norway
| | - O Casar-Borota
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Department of Clinical Pathology, Uppsala University Hospital, Uppsala, Sweden
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Micko ASG, Höftberger R, Wöhrer A, Millesi M, Knosp E, Wolfsberger S. MGMT assessment in pituitary adenomas: comparison of different immunohistochemistry fixation chemicals. Pituitary 2018; 21:266-273. [PMID: 29344904 PMCID: PMC5942339 DOI: 10.1007/s11102-018-0862-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Despite the established role of O6-methyl-guanine-DNA methyltransferase (MGMT) as a marker for temozolomide response, consensus of the most reliable method to assess MGMT expression in pituitary adenomas is still missing. Currently, immunohistochemistry (IHC) assessment of formaldehyde fixed tissue samples is most widely used in a semiquantitative description. As formaldehyde fails to completely preserve nucleic acids, RCL2, an alcohol-based formaldehyde-free fixative, has been proposed as a more reliable alternative in terms of cell stability. Furthermore, as the current method of IHC is semiquantitative and observer-dependent, pyrosequencing, an objective tool to evaluate the methylation status of the MGMT promoter, has emerged as a reliable and accurate alternative. The aim of this study was to validate the current IHC method for assessment of MGMT protein expression in pituitary adenomas. METHODS The tissue samples of 8 macroadenomas with positive IHC MGMT expression (> 50%) were investigated: first, we compared the time dependent stability of MGMT protein expression after pituitary adenoma removal between formaldehyde vs. RCL2. Then, we compared positive IHC MGMT expression with methylated promoter status using pyrosequencing. RESULTS In the first 12 h after adenoma removal, tissue samples remained MGMT positive in significantly more samples when fixated with formaldehyde than with RCL2, respectively (96 vs. 81%, p = 0.025). CONCLUSION Our data confirm that the current method using formaldehyde tissue fixation and IHC reveals stable and reliable results of MGMT assessment in pituitary adenomas.
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Affiliation(s)
- Alexander S G Micko
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Romana Höftberger
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Adelheid Wöhrer
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matthias Millesi
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
| | - Engelbert Knosp
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria.
| | - Stefan Wolfsberger
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
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Micko ASG, Wöhrer A, Höftberger R, Vila G, Marosi C, Knosp E, Wolfsberger S. MGMT and MSH6 immunoexpression for functioning pituitary macroadenomas. Pituitary 2017; 20:643-653. [PMID: 28900805 PMCID: PMC5655586 DOI: 10.1007/s11102-017-0829-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE Knowledge of biological behavior is crucial for clinical management of functioning pituitary macroadenomas. For recurrent cases unresponsive to standard treatment, temozolomide (TMZ) has been used as a therapeutic alternative. MGMT (O6-methyl-guanine-DNA methyltransferase) and MSH6 (mutS homolog 6) immunoexpression have been linked to the response to TMZ treatment and MGMT immunoexpression has been additionally linked to early recurrence of non-functioning pituitary adenomas. The aim of this study was to assess the prognostic value of MGMT and MSH6 immunoexpression for aggressive functioning pituitary adenomas. METHODS The study cohort comprised a single center series of 76 patients who underwent an operation for functioning pituitary macroadenoma. We retrospectively compared 38 patients with postoperative persistent or recurrent disease with another set of 38 patients who were in endocrine remission. RESULTS Low-to-moderate MGMT immunoexpression (<50%) was significantly more frequent in the group with persistent/recurrent disease than in cases of endocrine remission (66 vs. 21%, p < 0.001). Furthermore, adenomas with low-to-moderate MGMT immunoexpression were significantly more often recurrent (76 vs. 30%, p < 0.001) and invasive (64 vs. 28%, p = 0.002). CONCLUSION In our series, low-to-moderate MGMT immunoexpression was the only marker that significantly correlated with surgical invasiveness and recurrence in functioning pituitary macroadenomas. Therefore, in the future, MGMT status may be considered an additional marker for understanding the biological behavior of pituitary adenomas.
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Affiliation(s)
- Alexander S G Micko
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
| | - Adelheid Wöhrer
- Institute of Neurology, Medical University Vienna, Vienna, Austria
| | | | - Greisa Vila
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University Vienna, Vienna, Austria
| | - Christine Marosi
- Division of Oncology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - Engelbert Knosp
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria.
| | - Stefan Wolfsberger
- Department of Neurosurgery, Medical University Vienna, Waehringer Guertel 18-20, 1097, Vienna, Austria
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O-6-Methylguanine-DNA methyltransferase expression is associated with pituitary adenoma tumor recurrence: a systematic meta-analysis. Oncotarget 2017; 8:19674-19683. [PMID: 28152515 PMCID: PMC5386713 DOI: 10.18632/oncotarget.14936] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/01/2016] [Indexed: 11/25/2022] Open
Abstract
O-6-methylguanine-DNA methyltransferase (MGMT) reportedly counteracts the cytotoxic effects of the alkylating agent temozolomide. MGMT expression is often low in aggressive pituitary adenomas (PAs) and recurrent PAs. However, because these associations are controversial, we performed this meta-analysis to clarify the involvement of MGMT in the prognosis and clinicopathology of PA. We searched for relevant studies in electronic databases (MEDLINE, the Cochrane Library Database, EMBASE, CINAHL, Web of Science and the Chinese Biomedical Database (CBD)) and calculated/pooled the odds ratios (ORs) or standard mean differences (SMDs) with 95% confidence intervals (95% CIs). Eleven case-control studies with a total of 454 PA patients were included. Our meta-analysis revealed that lower expression of MGMT was associated with PA recurrence (OR=2.09, 95% CI=1.09-4.02; p=0.026). On the other hand, MGMT expression was not associated with PA invasiveness (OR=1.112, 95% CI=0.706-1.753; p=0.646), Unexpectedly, MGMT expression could not be used to distinguish functional from non-functional PA patients (OR=1.766, 95% CI=0.938-3.324; p=0.078). The MGMT expression was not found to be related to other clinicopathological indicators of PA including age, gender or tumor size. No publication bias was detected in this meta-analysis (p>0.05). This meta-analysis suggests that MGMT expression may be associated with PA tumor recurrence, but not be related to invasiveness or other clinicopathological indicators. Thus, detection of MGMT expression may facilitate outcome prediction and guide clinical therapy for PA patients.
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Li ZY, Huang GD, Chen L, Zhang C, Chen BD, Li QZ, Wang X, Zhang XJ, Li WP. Tanshinone IIA induces apoptosis via inhibition of Wnt/β‑catenin/MGMT signaling in AtT‑20 cells. Mol Med Rep 2017; 16:5908-5914. [PMID: 28849207 PMCID: PMC5865768 DOI: 10.3892/mmr.2017.7325] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 03/24/2017] [Indexed: 12/25/2022] Open
Abstract
A strategy to suppress the expression of the DNA repair enzyme O6‑methylguanine‑DNA methyltransferase (MGMT) by inhibition of Wnt/β‑catenin signaling may be useful as a novel treatment for pituitary adenoma. Previous studies have reported that Tanshinone IIA (TSA), a major quinone compound isolated from Salvia miltiorrhiza, had antitumor effects. However, whether TSA has antitumor effects against pituitary adenoma and whether the mechanisms are associated with the Wnt/β‑catenin/MGMT pathway remains to be clarified. In the present study, TSA treatment caused apoptosis in AtT‑20 cells in a concentration‑dependent manner, as demonstrated by cell viability reduction, phophatidylserine externalization detected by Annexin V staining and mitochondrial membrane potential disruption detected by JC‑1 staining, which were associated with activation of caspase‑3 and DNA fragmentation detected by TUNEL in AtT‑20 cells. T‑cell factor (TCF)‑lymphoid‑enhancing factor (LEF) reporter activity was determined by dual luciferase reporter assay and the interaction between β‑catenin and TCF‑4 were detected using a co‑immunoprecipitation kit. The results indicated TSA treatment increased β‑catenin phosphorylation, inhibited β‑catenin nuclear translocation, reduced β‑catenin/TCF‑4 complex formation and TCF‑LEF luciferase reporter activity, and subsequently reduced the expression of cyclin D1 and MGMT. Notably, overexpression of MGMT in β‑catenin knock down AtT‑20 cells abrogated the TSA‑mediated effects in AtT‑20 cells. In conclusion, TSA induced apoptosis via inhibition of Wnt/β‑catenin‑dependent MGMT expression, which may provide novel insights into the understanding of the mechanism of the antitumor effects of Salvia miltiorrhiza.
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Affiliation(s)
- Zong-Yang Li
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Guo-Dong Huang
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Lei Chen
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Ce Zhang
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Bao-Dong Chen
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Qing-Zhong Li
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Xiang Wang
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Xie-Jun Zhang
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
| | - Wei-Ping Li
- Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen, Guangdong 518035, P.R. China
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Ji Y, Vogel RI, Lou E. Temozolomide treatment of pituitary carcinomas and atypical adenomas: systematic review of case reports. Neurooncol Pract 2015; 3:188-195. [PMID: 27551432 DOI: 10.1093/nop/npv059] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Pituitary carcinomas (PC) and atypical pituitary adenomas (APA) are rare variants of pituitary tumors for which no evidence-based treatment currently exists. We sought to determine whether temozolomide represents an effective chemotherapeutic option for patients with PC and APA. METHODS A systematic review was performed using all published cases of PC and APA treated with temozolomide, and for which information on treatment regimen, clinical response, and survival could be identified. The primary goal of this analysis was to describe overall survival and progression-free survival among PC and APA patients after temozolomide treatment. Secondary goals included assessment of response rate and biomarkers of response. RESULTS We identified 57 cases and obtained follow-up data on 54 patients (31 APA and 23 PC) for analysis. Estimates of 5-year progression-free survival and overall survival were 21.9% and 57.4% for patients with APA and 36.1% and 56.2% for patients with PC. Among those who responded to temozolomide, overall survival was marginally statistically significantly greater for patients on long-term temozolomide therapy compared with those who were not (5-year overall survival 91.7% vs 54.1%, P = .08); Progression-free survival results were similar but not statistically significant. The objective response rate was 48.4% for patients with APA and 65.2% for patients with PC. Stable disease occurred in 29% of APA and 17.4% of PC patients. Neither histology nor expression of Ki-67 correlated with response; however, negative O6-methylguanine-DNA methyltransferase staining was strongly related to response to temozolomide in patients with APA (P < .001). CONCLUSIONS Temozolomide is an effective treatment of both PC and APA, and long-term treatment can be considered for particularly aggressive cases.
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Affiliation(s)
- Yan Ji
- Division of Hematology, Oncology and Transplantation , University of Minnesota , Minneapolis, MN (Y.J., E.L.); Masonic Cancer Center, Biostatistics and Bioinformatics , University of Minnesota , Minneapolis, MN (R.I.V.)
| | - Rachel Isaksson Vogel
- Division of Hematology, Oncology and Transplantation , University of Minnesota , Minneapolis, MN (Y.J., E.L.); Masonic Cancer Center, Biostatistics and Bioinformatics , University of Minnesota , Minneapolis, MN (R.I.V.)
| | - Emil Lou
- Division of Hematology, Oncology and Transplantation , University of Minnesota , Minneapolis, MN (Y.J., E.L.); Masonic Cancer Center, Biostatistics and Bioinformatics , University of Minnesota , Minneapolis, MN (R.I.V.)
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Ge N, Guo L, Zhang J, Lin Z, Li Y, Liu Y, Kong F, Fang X, Zhao S. Impact of O6-methylguanine-DNA methyltransferase expression on the drug resistance of clear cell renal cell carcinoma. Jpn J Clin Oncol 2015; 45:860-6. [PMID: 26185135 DOI: 10.1093/jjco/hyv095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 06/01/2015] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE The deoxyribonucleic acid-repair protein O(6)-methylguanine-deoxyribonucleic acid methyltransferase is a major determinant of resistance of cells to various alkylating drugs. Its expression profile is different in different cancer types. Here, we studied the expression and function of O(6)-methylguanine-deoxyribonucleic acid methyltransferase in clear cell renal cell carcinoma. METHODS The expression of O(6)-methylguanine-deoxyribonucleic acid methyltransferase was evaluated in clear cell renal cell carcinoma tissues and cell lines by quantitative real-time polymerase chain reaction and immunohistochemistry. The relationship between O(6)-methylguanine-deoxyribonucleic acid methyltransferase expression and clinicopathological characteristics was analyzed. To further investigate the function of O(6)-methylguanine-deoxyribonucleic acid methyltransferase in clear cell renal cell carcinoma resistance to alkylating agents, siRNA targeting O(6)-methylguanine-deoxyribonucleic acid methyltransferase were used to silence the O(6)-methylguanine-deoxyribonucleic acid methyltransferase expression. RESULTS We found that O(6)-methylguanine-deoxyribonucleic acid methyltransferase is over-expressed in clear cell renal cell carcinoma tissues and cell lines. O(6)-methylguanine-deoxyribonucleic acid methyltransferase expression is related with tumor progression in clear cell renal cell carcinoma patients. Up-regulation of O(6)-methylguanine-deoxyribonucleic acid methyltransferase plays a critical role in primary resistance to alkylating agents. CONCLUSIONS The overexpression of O(6)-methylguanine-deoxyribonucleic acid methyltransferase contributes to resistance of clear cell renal cell carcinoma to standard chemotherapy. Our results have significance for understanding a new pathway of the development of drug resistance of clear cell renal cell carcinoma.
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Affiliation(s)
- Nan Ge
- Department of Urology Surgery, The Second Hospital, Shandong University, Jinan
| | - Liqiang Guo
- Department of Urology Surgery, The Second Hospital, Shandong University, Jinan
| | - Jie Zhang
- Department of Urology Surgery, The Second Hospital, Shandong University, Jinan
| | - Zhaomin Lin
- Central Research Laboratory, The Second Hospital, Shandong University, Jinan
| | - Yan Li
- Department of Radiology, The Affiliated Hospital, Shandong University of Traditional Chinese Medicine, Jinan, PR China
| | - Yuqiang Liu
- Department of Urology Surgery, The Second Hospital, Shandong University, Jinan
| | - Feng Kong
- Central Research Laboratory, The Second Hospital, Shandong University, Jinan
| | - Xiaolei Fang
- Department of Urology Surgery, The Second Hospital, Shandong University, Jinan
| | - Shengtian Zhao
- Department of Urology Surgery, The Second Hospital, Shandong University, Jinan
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11
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Syro LV, Rotondo F, Cusimano MD, Di Ieva A, Horvath E, Restrepo LM, Wong M, Killinger DW, Smyth H, Kovacs K. Current status on histological classification in Cushing's disease. Pituitary 2015; 18:217-24. [PMID: 25501318 DOI: 10.1007/s11102-014-0619-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Managing Cushing's disease remains a challenge. Surgery is the first option of treatment and it offers a high success rate. Even in cases where biochemical remission is not achieved, it is crucial to obtain surgical tissue for morphological diagnosis because the therapeutic approach can be modified according to the findings. MATERIALS AND METHODS A literature search was performed using PubMed for information regarding pathology and Cushing's disease. RESULTS The histopathological features found in the pituitary gland of patients with Cushing's disease are presented. CONCLUSION Different subtypes of ACTH-producing pituitary tumors are recognized and characterized. The significance of finding a normal pituitary gland with or without Crooke's changes is also discussed.
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Affiliation(s)
- Luis V Syro
- Department of Neurosurgery, Hospital Pablo Tobon Uribe, Clinica Medellin and Group of Genetics, Regeneration and Cancer, Universidad de Antioquia, Medellín, Colombia,
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Liu JK, Patel J, Eloy JA. The role of temozolomide in the treatment of aggressive pituitary tumors. J Clin Neurosci 2015; 22:923-9. [PMID: 25772801 DOI: 10.1016/j.jocn.2014.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 12/24/2014] [Indexed: 01/09/2023]
Abstract
Pituitary tumors are amongst the most common intracranial neoplasms and are generally benign. However, some pituitary tumors exhibit clinically aggressive behavior that is characterized by tumor recurrence and continued progression despite repeated treatments with conventional surgical, radiation and medical therapies. More recently, temozolomide, a second generation oral alkylating agent, has shown therapeutic promise for aggressive pituitary adenomas and carcinomas with favorable clinical and radiographic responses. Temozolomide causes DNA damage by methylation of the O(6) position of guanine, which results in potent cytotoxic DNA adducts and consequently, tumor cell apoptosis. The degree of MGMT expression appears to be inversely related to therapeutic responsiveness to temozolomide with a significant number of temozolomide-sensitive pituitary tumors exhibiting low MGMT expression. The presence of high MGMT expression appears to mitigate the effectiveness of temozolomide and this has been used as a marker in several studies to predict the efficacy of temozolomide. Recent evidence also suggests that mutations in mismatch repair proteins such as MSH6 could render pituitary tumors resistant to temozolomide. In this article, the authors review the development of temozolomide, its biochemistry and interaction with O(6)-methylguanine-DNA methyltransferase (MGMT), its role in adjuvant treatment of aggressive pituitary neoplasms, and future works that could influence the efficacy of temozolomide therapy.
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Affiliation(s)
- James K Liu
- Center for Skull Base and Pituitary Surgery, Neurological Institute of New Jersey, Department of Neurological Surgery, Rutgers University, New Jersey Medical School, Suite 8100, 90 Bergen Street, Newark, NJ 07103, USA; Department of Neurological Surgery, Rutgers University, New Jersey Medical School, Newark, NJ, USA; Department of Otolaryngology-Head and Neck Surgery, Rutgers University, New Jersey Medical School, Newark, NJ, USA.
| | - Jimmy Patel
- Department of Neurological Surgery, Rutgers University, New Jersey Medical School, Newark, NJ, USA
| | - Jean Anderson Eloy
- Center for Skull Base and Pituitary Surgery, Neurological Institute of New Jersey, Department of Neurological Surgery, Rutgers University, New Jersey Medical School, Suite 8100, 90 Bergen Street, Newark, NJ 07103, USA; Department of Neurological Surgery, Rutgers University, New Jersey Medical School, Newark, NJ, USA; Department of Otolaryngology-Head and Neck Surgery, Rutgers University, New Jersey Medical School, Newark, NJ, USA
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Abstract
The genetic mutations underlying familial syndromes that include pituitary tumors are rarely noted in the majority of sporadic adenohypophyseal adenomas. In contrast, epigenetic dysregulation is common, resulting in differential expression of cell cycle and apoptosis regulators, adhesion molecules, growth factors, and metabolic determinants of cell function. Here, we discuss the diagnostic and therapeutic implications of these findings as the landscape of pituitary tumor defects unfolds.
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Affiliation(s)
- Sylvia L Asa
- Department of Pathology, University Health Network, 200 Elizabeth Street, 11th floor, Toronto, Ontario, Canada, M5G 2C4,
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