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Angelousi A, Koumarianou A, Chatzellis E, Kaltsas G. Resistance of neuroendocrine tumours to somatostatin analogs. Expert Rev Endocrinol Metab 2023; 18:33-52. [PMID: 36651768 DOI: 10.1080/17446651.2023.2166488] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/05/2023] [Indexed: 01/13/2023]
Abstract
INTRODUCTION A common feature shared by most neuroendocrine tumors (NETs) is the expression on their surface of somatostatin receptors (SSTRs) that are essential for their pathophysiological regulation, diagnosis, and management. The first-generation synthetic somatostatin analogs (SSAs), octreotide and lanreotide, constitute the cornerstone of treatment for growth hormone secreting pituitary adenomas and functioning, progressive functioning, and non-functioning gastro-entero-pancreatic (GEP-NETs). SSAs exert their mechanism of action through binding to the SSTRs; however, their therapeutic response is frequently attenuated or diminished by the development of resistance. The phenomenon of resistance is complex implicating the presence of additional epigenetic and genetic mechanisms. AREAS COVERED We aim to analyze the molecular, genetic, and epigenetic mechanisms of resistance to SSA treatment. We also summarize recent clinical data related to the development of resistance on conventional and non-conventional modes of administration of the first-generation SSAs and the second-generation SSA pasireotide. We explore mechanisms used to counteract the resistance to SSAs using higher doses or more frequent mode of administration of SSAs and/or combination treatments. EXPERT OPINION There is considerable heterogeneity in the development of resistance to SSAs that is tumor-specific necessitating the delineation of the underlying pathophysiological processes to further expand their therapeutic applications.
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Affiliation(s)
- Anna Angelousi
- First Department of Internal Medicine, Unit of Endocrinology, Laikon General hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Anna Koumarianou
- Hematology Oncology Unit, Fourth Department of Internal Medicine, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Eleftherios Chatzellis
- Endocrinology Diabetes and Metabolism Department, 251 Hellenic Air Force and VA General Hospital, Athens, Greece
| | - Gregory Kaltsas
- First Propaedeutic Department of Internal Medicine, Endocrine Unit, National and Kapodistrian University of Athens, Athens, Greece
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Ozkaya HM, Sayitoglu M, Comunoglu N, Sun E, Keskin FE, Ozata D, Hocaoglu RH, Khodzaev K, Firtina S, Tanriover N, Gazioglu N, Oz B, Kadioglu P. G-protein Coupled Estrogen Receptor Expression in Growth Hormone Secreting and Non-Functioning Adenomas. Exp Clin Endocrinol Diabetes 2020; 129:634-643. [PMID: 33091936 DOI: 10.1055/a-1274-1330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the expression of G-protein coupled estrogen receptor (GPER1), aromatase, estrogen receptor α (ERα), estrogen receptor β (ERβ), pituitary tumor transforming gene (PTTG), and fibroblast growth factor 2 (FGF2) in GH-secreting and non-functioning adenomas (NFA). METHODS Thirty patients with acromegaly and 27 patients with NFA were included. Gene expression was determined via quantitative reverse transcription polymerase chain reaction (QRT-PCR). Protein expression was determined via immunohistochemistry. RESULTS There was no difference, in terms of gene expression of aromatase, ERα, PTTG, and FGF2 between the two groups (p>0.05 for all). ERβ gene expression was higher and GPER1 gene expression was lower in GH-secreting adenomas than NFAs (p<0.05 for all). Aromatase and ERβ protein expression was higher in GH-secreting adenomas than NFAs (p=0.01). None of the tumors expressed ERα. GPER1 expression was detected in 62.2% of the GH-secreting adenomas and 45% of NFAs. There was no difference in terms of GPER1, PTTG, FGF2 H scores between the two groups (p>0.05 for all). GPER1 gene expression was positively correlated to ERα, ERβ, PTTG, and FGF2 gene expression (p<0.05 for all). There was a positive correlation between aromatase and GPER1 protein expression (r=0.31; p=0.04). CONCLUSIONS GPER1 is expressed at both gene and protein level in a substantial portion of GH-secreting adenomas and NFAs. The finding of a positive correlation between GPER1 and ERα, ERβ, PTTG, and FGF2 gene expression and aromatase and GPER1 protein expression suggests GPER1 along with aromatase and classical ERs might mediate the effects of estrogen through upregulation of PTTG and FGF2.
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Affiliation(s)
- Hande Mefkure Ozkaya
- Department of Endocrinology and Metabolism, Cerrahpasa Medical School, Istanbul University-Cerrahpasa, Istanbul
| | - Muge Sayitoglu
- Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul
| | - Nil Comunoglu
- Department of Pathology, Cerrahpasa Medical School, Istanbul University-Cerrahpasa, Istanbul
| | - Eda Sun
- Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul
| | - Fatma Ela Keskin
- Department of Endocrinology and Metabolism, Demiroglu Bilim University, Istanbul
| | - Duygu Ozata
- Department of Internal Medicine, Cerrahpasa Medical School, Istanbul University-Cerrahpasa, Istanbul
| | - Rabia Hacer Hocaoglu
- Department of Internal Medicine, Cerrahpasa Medical School, Istanbul University-Cerrahpasa, Istanbul
| | - Khusan Khodzaev
- Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul
| | - Sinem Firtina
- Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul
| | - Necmettin Tanriover
- Department of Neurosurgery, Cerrahpasa Medical School, Istanbul University-Cerrahpasa, Istanbul.,Pituitary Center, Istanbul University-Cerrahpasa, Istanbul
| | - Nurperi Gazioglu
- Department of Neurosurgery, Demiroglu Bilim University, Istanbul
| | - Buge Oz
- Department of Pathology, Cerrahpasa Medical School, Istanbul University-Cerrahpasa, Istanbul
| | - Pinar Kadioglu
- Department of Endocrinology and Metabolism, Cerrahpasa Medical School, Istanbul University-Cerrahpasa, Istanbul.,Pituitary Center, Istanbul University-Cerrahpasa, Istanbul
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Trott G, Ongaratti BR, de Oliveira Silva CB, Abech GD, Haag T, Rech CGSL, Ferreira NP, da Costa Oliveira M, Pereira-Lima JFS. PTTG overexpression in non-functioning pituitary adenomas: Correlation with invasiveness, female gender and younger age. Ann Diagn Pathol 2019; 41:83-89. [DOI: 10.1016/j.anndiagpath.2019.04.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/11/2019] [Accepted: 04/28/2019] [Indexed: 12/27/2022]
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Proliferaton index in pituitary adenomas from a black African population. ALEXANDRIA JOURNAL OF MEDICINE 2017. [DOI: 10.1016/j.ajme.2016.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Ozkaya HM, Comunoglu N, Keskin FE, Oz B, Haliloglu OA, Tanriover N, Gazioglu N, Kadioglu P. Locally produced estrogen through aromatization might enhance tissue expression of pituitary tumor transforming gene and fibroblast growth factor 2 in growth hormone-secreting adenomas. Endocrine 2016; 52:632-40. [PMID: 26578364 DOI: 10.1007/s12020-015-0802-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 11/05/2015] [Indexed: 01/05/2023]
Abstract
Aromatase, a key enzyme in local estrogen synthesis, is expressed in different pituitary tumors including growth hormone (GH)-secreting adenomas. We aimed to evaluate aromatase, estrogen receptor α (ERα), estrogen receptor β (ERβ), pituitary tumor transforming gene (PTTG), and fibroblast growth factor 2 (FGF2) expressions in GH-secreting adenomas, and investigate their correlation with clinical, pathologic, and radiologic parameters. This cross-sectional study was conducted in a tertiary center in Turkey. Protein expressions were determined via immunohistochemical staining in ex vivo tumor samples of 62 patients with acromegaly and ten normal pituitary tissues. Concordantly increased aromatase, PTTG, and FGF2 expressions were detected in the tumor samples as compared with controls (p < 0.001 for all). None of the tumors expressed ERα while ERβ was detected only in mixed somatotroph adenomas. Aromatase, ERβ, PTTG expressions were not significantly different between patients with and without remission (p > 0.05 for all). FGF2 expression was significantly higher in patients without postoperative and late remission (p = 0.002 and p = 0.012, respectively), with sphenoid bone invasion, optic chiasm compression, and somatostatin analog resistance (p = 0.005, p = 0.033, and p = 0.013, respectively). Aromatase, PTTG and FGF2 expressions were positively correlated with each other (r = 0,311, p = 0.008 for aromatase, FGF2; r = 0.380, p = 0.001 for aromatase, PTTG; r = 0.400, p = 0.001 for FGF2, PTTG). PTTG-mediated FGF2 upregulation is associated with more aggressive tumor features in patients with acromegaly. Also, locally produced estrogen through aromatization might have a role in this phenomenon.
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Affiliation(s)
- Hande Mefkure Ozkaya
- Department of Endocrinology and Metabolism, Cerrahpasa Medical School, University of Istanbul, Cerrahpasa, 34303, Istanbul, Turkey
| | - Nil Comunoglu
- Department of Pathology, Cerrahpasa Medical School, University of Istanbul, Istanbul, Turkey
| | - Fatma Ela Keskin
- Department of Endocrinology and Metabolism, Cerrahpasa Medical School, University of Istanbul, Cerrahpasa, 34303, Istanbul, Turkey
| | - Buge Oz
- Department of Pathology, Cerrahpasa Medical School, University of Istanbul, Istanbul, Turkey
| | - Ozlem Asmaz Haliloglu
- Department of Endocrinology and Metabolism, Cerrahpasa Medical School, University of Istanbul, Cerrahpasa, 34303, Istanbul, Turkey
| | - Necmettin Tanriover
- Department of Neurosurgery, Cerrahpasa Medical School, University of Istanbul, Istanbul, Turkey
| | - Nurperi Gazioglu
- Department of Neurosurgery, Cerrahpasa Medical School, University of Istanbul, Istanbul, Turkey
| | - Pinar Kadioglu
- Department of Endocrinology and Metabolism, Cerrahpasa Medical School, University of Istanbul, Cerrahpasa, 34303, Istanbul, Turkey.
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Gonzales PH, Mezzomo LC, Ferreira NP, Roehe AV, Kohek MBF, Oliveira MDC. Aromatase P450 expression in human pituitary adenomas. Neuropathology 2014; 35:16-23. [DOI: 10.1111/neup.12145] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 06/18/2014] [Accepted: 06/19/2014] [Indexed: 01/05/2023]
Affiliation(s)
| | - Lisiane Cervieri Mezzomo
- Post-Graduation Program of Pathology; UFCSPA; Porto Alegre RS Brazil
- Laboratory of Molecular Biology; UFCSPA; Porto Alegre RS Brazil
| | - Nelson Pires Ferreira
- Neuroendocrinology Center; Irmandade Santa Casa de Misericórdia de Porto Alegre (ISCMPA); Porto Alegre RS Brazil
| | | | - Maria Beatriz Fonte Kohek
- Post-Graduation Program of Pathology; UFCSPA; Porto Alegre RS Brazil
- Laboratory of Molecular Biology; UFCSPA; Porto Alegre RS Brazil
| | - Miriam da Costa Oliveira
- Post-Graduation Program of Pathology; UFCSPA; Porto Alegre RS Brazil
- Neuroendocrinology Center; Irmandade Santa Casa de Misericórdia de Porto Alegre (ISCMPA); Porto Alegre RS Brazil
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Zhang H, Du R, Huang YH, She L, Dong L, Wang X, Kwan AL. Characterization of pituitary tumor transforming gene in meningiomas. Clin Neurol Neurosurg 2014; 122:120-3. [PMID: 24908230 DOI: 10.1016/j.clineuro.2014.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 04/23/2014] [Accepted: 04/28/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Pituitary tumor transforming gene (PTTG) is an oncogene and has been detected in several tumors of unrelated histological origin. However, its role in meningiomas is unknown so far. We aim to investigate PTTG expression in intracranial meningiomas, and clarify the relationship between PTTG and the histopathological types of tumors. MATERIALS AND METHODS Over a 7-year period, 195 meningioma specimens were collected from 195 patients. Seventeen nonneoplastic meningeal tissues were used as controls. We analyze PTTG expression by tissue microarray with immunohistochemistry. RESULTS Immunoexpression of PTTG was identified in 172 of 195 meningiomas, accounting for 88.2%. All of immunoexpression of tumors were found to be cytoplasmic, and no nuclear expression was observed. In the control group, there were 3 of 17 specimens (17.6%) with positive PTTG expression. The percentage of high expression WHO subtypes of meningiomas ranged from 0% to 95.7%. We further stratified the tumors into 3 subgroups based on pathological grading (WHO grade I, WHO grade II and III, control), and there was significant intergroup difference in PTTG expression (p<0.001). CONCLUSION This study demonstrated that PTTG was expressed in most of meningioma tissues, and the degree of PTTG immunostaining was variable in the subtypes of tumors. Further investigations into PTTG expression are required to broaden the pathogenesis research of meningiomas.
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Affiliation(s)
- Hengzhu Zhang
- Department of Neurosurgery, Yangzhou Medical College, Yangzhou University, Yangzhou, China
| | - Renfei Du
- Department of Neurosurgery, Yangzhou Medical College, Yangzhou University, Yangzhou, China
| | - Yu-Hua Huang
- Department of Neurosurgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Lei She
- Department of Neurosurgery, Yangzhou Medical College, Yangzhou University, Yangzhou, China
| | - Lun Dong
- Department of Neurosurgery, Yangzhou Medical College, Yangzhou University, Yangzhou, China
| | - Xiaodong Wang
- Department of Neurosurgery, Yangzhou Medical College, Yangzhou University, Yangzhou, China
| | - Aij-Lie Kwan
- Department of Surgery, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
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Correlations of pituitary tumor transforming gene expression with human pituitary adenomas: a meta-analysis. PLoS One 2014; 9:e90396. [PMID: 24594688 PMCID: PMC3942425 DOI: 10.1371/journal.pone.0090396] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 01/29/2014] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE Pituitary tumor transforming gene (PTTG) is an important paracrine growth factor involved in early lactotrope transformation and early onset of angiogenesis in pituitary hyperplasia. Emerging evidences have shown that PTTG expression may contribute to the etiology of pituitary adenomas; but individually published studies showed inconclusive results. This meta-analysis aimed to derive a more precise estimation of the correlations of PTTG expression with human pituitary adenomas. METHODS A range of electronic databases were searched: MEDLINE (1966∼2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980∼2013), CINAHL (1982∼2013), Web of Science (1945∼2013) and the Chinese Biomedical Database (CBM) (1982∼2013) without language restrictions. Meta-analysis was performed using the STATA 12.0 software. Crude odds ratio (OR) or standard mean difference (SMD) with its corresponding 95% confidence interval (95%CI) were calculated. RESULTS Twenty-four clinical cohort studies were included with a total of 1,464 pituitary adenomas patients. The meta-analysis results revealed that patients with invasive pituitary adenomas had higher positive expression of PTTG than those of non-invasive patients (OR = 6.68, 95%CI = 3.72-11.99, P<0.001). We also found a significant difference in microvessel density between invasive and non-invasive patients (SMD = 1.81, 95%CI = 0.39-3.23, P = 0.013). However, there were no significant difference in PTTG expression between functional and non-functional patients with pituitary adenomas (OR = 1.11, 95%CI = 0.58-2.10, P = 0.753). No publication bias was detected in this meta-analysis (all P>0.05). CONCLUSION This present meta-analysis suggests that PTTG expression may be associated with tumor invasiveness and microvessel density of pituitary adenomas, while no correlations with functional status was found.
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Sajjad EA, Zieliński G, Maksymowicz M, Hutnik Ł, Bednarczuk T, Włodarski P. mTOR is frequently active in GH-secreting pituitary adenomas without influencing their morphopathological features. Endocr Pathol 2013; 24:11-9. [PMID: 23296986 DOI: 10.1007/s12022-012-9230-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Initiating factors and mechanisms of tumor formation are poorly understood in nonfamilial pituitary adenomas. Alteration of intracellular pathways is an underlying event in numerous neoplasms. Among them, excessive activation of mammalian target of rapamycin (mTOR) pathway and its two main regulators, Akt and Erk, has been detected frequently in solid tumors. This study tests the activation of mTOR pathway in pituitary adenomas and its influence on their morphopathological features. Fifty-three pituitary adenomas were fresh frozen after surgery and analyzed by western blotting using phospho-specific antibodies. The impact of Akt and Erk activation on mTOR pathway was assessed in five primary cultures derived from the excised adenomas using selective kinase inhibitors. Statistical correlations of size, volume, Ki-67 %, Knosp's grading, and somatostatin receptor (SSTR) expression with the activation of mentioned kinases was performed. GHomas showed the highest frequency (71 %) and level of mTOR pathway activity comparing to other adenomas (33 %). No significant correlation was found between mTOR activation and any of the morphopathological features in the studied samples. mTOR kinase phosphorylation was independent of Erk and Akt in primary cultures. Erk activity was significant in all types of adenomas but was the highest in control samples. Its phosphorylation correlated inversely with the Knosp's grading in nonfunctional pituitary adenomas and directly with somatostatin receptor subtype 2 A expression in GHomas. Presented data point to the noteworthy mTOR activity in GHomas. However, the lack of correlation with morphopathological features, its independence of Erk and Akt phosphorylation, and high level of Erk activity in control pituitary necessitate further research for clarifying the role of these pathways in pituitary adenomas.
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Affiliation(s)
- Emir Ahmed Sajjad
- Department of Histology and Embryology, Center for Biostructure Research, Medical University of Warsaw, Chałubińskiego 5, 02-004, Warszawa, Poland
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Expression of pituitary tumor transforming gene (PTTG) in human pituitary macroadenomas. Tumour Biol 2013; 34:1559-67. [DOI: 10.1007/s13277-013-0686-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/03/2013] [Indexed: 11/27/2022] Open
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Davis SW, Ellsworth BS, Peréz Millan MI, Gergics P, Schade V, Foyouzi N, Brinkmeier ML, Mortensen AH, Camper SA. Pituitary gland development and disease: from stem cell to hormone production. Curr Top Dev Biol 2013; 106:1-47. [PMID: 24290346 DOI: 10.1016/b978-0-12-416021-7.00001-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Many aspects of pituitary development have become better understood in the past two decades. The signaling pathways regulating pituitary growth and shape have emerged, and the balancing interactions between the pathways are now appreciated. Markers for multipotent progenitor cells are being identified, and signature transcription factors have been discovered for most hormone-producing cell types. We now realize that pulsatile hormone secretion involves a 3D integration of cellular networks. About a dozen genes are known to cause pituitary hypoplasia when mutated due to their essential roles in pituitary development. Similarly, a few genes are known that predispose to familial endocrine neoplasia, and several genes mutated in sporadic pituitary adenomas are documented. In the next decade, we anticipate gleaning a deeper appreciation of these processes at the molecular level, insight into the development of the hypophyseal portal blood system, and evolution of better therapeutics for congenital and acquired hormone deficiencies and for common craniopharyngiomas and pituitary adenomas.
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Affiliation(s)
- Shannon W Davis
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, USA
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Abstract
BACKGROUND The pathogenesis of tumour formation in the anterior pituitary including adrenocorticotropic hormone (ACTH)-secreting tumours has been intensively studied, but the causative mechanisms involved in pituitary cell transformation and tumourigenesis remain unclear. MATERIALS AND METHODS We searched PubMed on any paper related with molecular pathology of pituitary corticotroph adenomas and have included to this review all relevant references published up to June 2011. RESULTS Current studies increased our knowledge on the genetic basis of McCune-Albright syndrome (MAS), multiple endocrine neoplasia type 1 (MEN1), Carney complex (CNC), pituitary adenoma predisposition syndromes and tuberous sclerosis, but they have performed little to elucidate the causes of sporadic pituitary tumours including Cushing disease. DISCUSSION The aim of this review was to focus on the most recently published advances in the molecular pathology of corticotroph adenomas, which are presented in the context of changes seen in all types of pituitary adenomas, as well as in terms of corticotrophin-releasing hormone/ACTH/cortisol-specific pathways. CONCLUSIONS We would expect that over the next 5 years, more detailed analysis of inter-cellular communication pathways between pituitary cells, including the cadherins and integrins, and their interactions with other signalling pathways such as the β-catenin cascade will help elucidate what exactly goes awry in the formation of a benign corticotroph adenoma. This should in turn predict novel forms of pharmacological tumour control.
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Affiliation(s)
- Dorota Dworakowska
- Department of Endocrinology, Kings College Hospital, Denmark Hill, London, UK
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Shen XL, Wei W, Xu HL, Zhang MX, Qin XQ, Shi WZ, Jiang ZP, Chen YJ, Chen FP. JAK2V617F/STAT5 signaling pathway promotes cell proliferation through activation of Pituitary Tumor Transforming Gene 1 expression. Biochem Biophys Res Commun 2010; 398:707-12. [PMID: 20621061 DOI: 10.1016/j.bbrc.2010.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Accepted: 07/02/2010] [Indexed: 11/25/2022]
Abstract
Gain-of-function mutations of JAK2 play crucial roles in the development of myeloproliferative neoplasms; however, the underlying downstream events of this activated signaling pathway are not fully understood. Our experiment was designed and performed to address one aspect of this issue. Here we report that AG490, a potent JAK2V617F kinase inhibitor, effectively inhibits the proliferation of HEL cells. Interestingly, AG490 also decreases the expression of PTTG1, a possible target gene of the aberrant signaling pathway, in a dose- and time-dependent manner. Furthermore, the promoter activity analyses reveal that the inhibition of the PTTG1 expression is affected at the transcriptional level. Thus, our results suggest that the JAK2V617F/STAT5 signaling pathway promotes cell proliferation through the transcriptional activation of PTTG1.
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Affiliation(s)
- Xu-Liang Shen
- Department of Hematology, Heping Hospital of Changzhi Medical College, Changzhi 046000, China
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Vandeva S, Jaffrain-Rea ML, Daly AF, Tichomirowa M, Zacharieva S, Beckers A. The genetics of pituitary adenomas. Best Pract Res Clin Endocrinol Metab 2010; 24:461-76. [PMID: 20833337 DOI: 10.1016/j.beem.2010.03.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Pituitary adenomas are one of the most frequent intracranial tumors with a prevalence of clinically-apparent tumors close to 1:1000 of the general population. They are clinically significant because of hormone overproduction and/or tumor mass effects in addition to the need for neurosurgery, medical therapies and radiotherapy. The majority of pituitary adenomas have a sporadic origin with recognized genetic mutations seldom being found; somatotropinomas are an exception, presenting frequent somatic GNAS mutations. In this and other phenotypes, tumorigenesis could possibly be explained by altered function of genes implicated in cell cycle regulation, growth factors or their receptors, cell-signaling pathways, specific hormonal factors or other molecules with still unclear mechanisms of action. Genetic changes, such as allelic loss or gene amplification, and epigenetic changes, usually by promoter methylation, have been implicated in abnormal gene expression, but alternative mechanisms may be present. Familial cases of pituitary adenomas represent 5% of all pituitary tumors. MEN1 mutations cause multiple endocrine neoplasia type 1 (MEN1), while the Carney complex (CNC) is characterized by mutations in the protein kinase A regulatory subunit-1alpha (PRKAR1A) gene or changes in a locus at 2p16. Recently, a MEN1-like condition, MEN4, was found to be related to mutations in the CDKN1B gene. The clinical entity of familial isolated pituitary adenomas (FIPA) is characterized by genetic defects in the aryl hydrocarbon receptor interacting protein (AIP) gene in about 15% of all kindreds and 50% of homogenous somatotropinoma families. Identification of familial cases of pituitary adenomas is important as these tumors may be more aggressive than their sporadic counterparts.
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Affiliation(s)
- Silvia Vandeva
- Department of Endocrinology, University of Liège, Domaine Universitaire du Sart-Tilman, 4000 Liège, Belgium
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