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Srirangam Nadhamuni V, Korbonits M. Novel Insights into Pituitary Tumorigenesis: Genetic and Epigenetic Mechanisms. Endocr Rev 2020; 41:bnaa006. [PMID: 32201880 PMCID: PMC7441741 DOI: 10.1210/endrev/bnaa006] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/19/2020] [Indexed: 02/08/2023]
Abstract
Substantial advances have been made recently in the pathobiology of pituitary tumors. Similar to many other endocrine tumors, over the last few years we have recognized the role of germline and somatic mutations in a number of syndromic or nonsyndromic conditions with pituitary tumor predisposition. These include the identification of novel germline variants in patients with familial or simplex pituitary tumors and establishment of novel somatic variants identified through next generation sequencing. Advanced techniques have allowed the exploration of epigenetic mechanisms mediated through DNA methylation, histone modifications and noncoding RNAs, such as microRNA, long noncoding RNAs and circular RNAs. These mechanisms can influence tumor formation, growth, and invasion. While genetic and epigenetic mechanisms often disrupt similar pathways, such as cell cycle regulation, in pituitary tumors there is little overlap between genes altered by germline, somatic, and epigenetic mechanisms. The interplay between these complex mechanisms driving tumorigenesis are best studied in the emerging multiomics studies. Here, we summarize insights from the recent developments in the regulation of pituitary tumorigenesis.
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Affiliation(s)
- Vinaya Srirangam Nadhamuni
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Márta Korbonits
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
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Cassarino MF, Ambrogio AG, Cassarino A, Terreni MR, Gentilini D, Sesta A, Cavagnini F, Losa M, Pecori Giraldi F. Gene expression profiling in human corticotroph tumours reveals distinct, neuroendocrine profiles. J Neuroendocrinol 2018; 30:e12628. [PMID: 29920815 PMCID: PMC6175113 DOI: 10.1111/jne.12628] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 12/15/2022]
Abstract
Adrenocorticotrophic hormone (ACTH)-secreting pituitary adenomas give rise to a severe endocrinological disorder, comprising Cushing's disease, with multifaceted clinical presentation and treatment outcomes. Experimental studies suggest that the disease variability is inherent to the pituitary tumour, thus indicating the need for further studies into tumour biology. The present study evaluated transcriptome expression pattern in a large series of ACTH-secreting pituitary adenoma specimens in order to identify molecular signatures of these tumours. Gene expression profiling of formalin-fixed, paraffin-embedded specimens from 40 human ACTH-secreting pituitary adenomas revealed the significant expression of genes involved in protein biosynthesis and ribosomal function, in keeping with the neuroendocrine cell profile. Unsupervised cluster analysis identified 3 distinct gene profile clusters and several genes were uniquely overexpressed in a given cluster, accounting for different molecular signatures. Of note, gene expression profiles were associated with clinical features, such as the age and size of the tumour. Altogether, the findings of the present study show that corticotroph tumours are characterised by a neuroendocrine gene expression profile and present subgroup-specific molecular features.
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Affiliation(s)
| | - Alberto G. Ambrogio
- Neuroendocrinology Research LaboratoryIstituto Auxologico Italiano IRCCSCusano MilaninoItaly
- Department of Clinical Sciences & Community HealthUniversity of MilanMilanItaly
| | - Andrea Cassarino
- Neuroendocrinology Research LaboratoryIstituto Auxologico Italiano IRCCSCusano MilaninoItaly
| | | | - Davide Gentilini
- Molecular Biology LaboratoryIstituto Auxologico Italiano IRCCSCusano MilaninoItaly
| | - Antonella Sesta
- Neuroendocrinology Research LaboratoryIstituto Auxologico Italiano IRCCSCusano MilaninoItaly
| | - Francesco Cavagnini
- Neuroendocrinology Research LaboratoryIstituto Auxologico Italiano IRCCSCusano MilaninoItaly
| | - Marco Losa
- Department of NeurosurgeryOspedale San RaffaeleMilanItaly
| | - Francesca Pecori Giraldi
- Neuroendocrinology Research LaboratoryIstituto Auxologico Italiano IRCCSCusano MilaninoItaly
- Department of Clinical Sciences & Community HealthUniversity of MilanMilanItaly
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Abstract
Pituitary adenomas (PA) represent the largest group of intracranial neoplasms and yet the molecular mechanisms driving this disease remain largely unknown. The aim of this study was to use a high-throughput screening method to identify molecular pathways that may be playing a significant and consistent role in PA. RNA profiling using microarrays on eight local PAs identified the aryl hydrocarbon receptor (AHR) signalling pathway as a key canonical pathway downregulated in all PA types. This was confirmed by real-time PCR in 31 tumours. The AHR has been shown to regulate cell cycle progression in various cell types; however, its role in pituitary tissue has never been investigated. In order to validate the role of AHR in PA behaviour, further functional studies were undertaken. Over-expression of AHR in GH3 cells revealed a tumour suppressor potential independent of exogenous ligand activation by benzo α-pyrene (BαP). Cell cycle analysis and quantitative PCR of cell cycle regulator genes revealed that both unstimulated and BαP-stimulated AHR reduced E2F-driven transcription and altered expression of cell cycle regulator genes, thus increasing the percentage of cells in G0/G1 phase and slowing the proliferation rate of GH3 cells. Co-immunoprecipitation confirmed the interaction between AHR and retinoblastoma (Rb1) protein supporting this as a functional mechanism for the observed reduction. Endogenous Ahr reduction using silencing RNA confirmed the tumour suppressive function of the Ahr. These data support a mechanistic pathway for the putative tumour suppressive role of AHR specifically in PA, possibly through its role as a cell cycle co-regulator, even in the absence of exogenous ligands.
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Affiliation(s)
- R Formosa
- Department of MedicineFaculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - J Borg
- Department of Applied Biomedical ScienceFaculty of Health Sciences, University of Malta, Msida, Malta
| | - J Vassallo
- Department of MedicineFaculty of Medicine and Surgery, University of Malta, Msida, Malta
- Department of MedicineNeuroendocrine Clinic, Mater Dei Hospital, Msida, Malta
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Melo FM, Couto PP, Bale AE, Bastos-Rodrigues L, Passos FM, Lisboa RGC, Ng JMY, Curran T, Dias EP, Friedman E, De Marco L. Whole-exome identifies RXRG and TH germline variants in familial isolated prolactinoma. Cancer Genet 2016; 209:251-7. [PMID: 27245436 DOI: 10.1016/j.cancergen.2016.05.065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/26/2016] [Accepted: 05/03/2016] [Indexed: 11/19/2022]
Abstract
Familial isolated pituitary adenoma (FIPA) is a rare genetic disorder. In a subset of FIPA families AIP germline mutations have been reported, but in most FIPA cases the exact genetic defect remains unknown. The present study aimed to determine the genetic basis of FIPA in a Brazilian family. Three siblings presented with isolated prolactin genes. Further mutation screening was performed using whole-exome sequencing and all likely causative mutations were validated by Sanger sequencing. In silico analysis and secreting pituitary adenoma diagnosed through clinical, biochemical and imaging testing. Sanger sequencing was used to genotype candidate prolactinoma-mutated additional predictive algorithms were applied to prioritize likely pathogenic variants. No mutations in the coding and flanking intronic regions in the MEN1, AIP and PRLR genes were detected. Whole-exome sequencing of three affected siblings revealed novel, predicted damaging, heterozygous variants in three different genes: RXRG, REXO4 and TH. In conclusion, the RXRG and TH possibly pathogenic variants may be associated with isolated prolactinoma in the studied family. The possible contribution of these genes to additional FIPA families should be explored.
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Affiliation(s)
- Flavia M Melo
- Department of Surgery, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Patrícia P Couto
- Department of Surgery, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Allen E Bale
- Department of Genetics, Yale University School of Medicine, New Haven, USA
| | - Luciana Bastos-Rodrigues
- Department of Basic Sciences, Universidade Federal de Juiz de Fora, Governador Valadares, Brazil
| | - Flavia M Passos
- Department of Surgery, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Raony G C Lisboa
- Laboratory of Clinical Genomics, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Jessica M Y Ng
- Dept. of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, USA
| | - Tom Curran
- Children's Mercy Hospital Research Institute, Kansas City, MO, USA
| | - Eduardo P Dias
- Department of Endocrinology, Hospital Felício Rocho, Belo Horizonte, Brazil
| | - Eitan Friedman
- The Susanne Levy Gertner Oncogenetics Unit, Chaim Sheba Medical Center, Tel-Hashomer, and the Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Luiz De Marco
- Department of Surgery, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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Abstract
INTRODUCTION Prolactinomas are the most common functional pituitary adenomas. Current classification systems rely on phenotypic elements and have few molecular markers for complementary classification. Treatment protocols for prolactinomas are also devoid of molecular targets, leaving those refractory to standard treatments without many options. METHODS A systematic literature review was performed utilizing the PRISMA guidelines. We aimed to summarize prior research exploring gene and protein expression in prolactinomas in order to highlight molecular variations associated with tumor development, growth, and prolactin secretion. A PubMed search of select MeSH terms was performed to identify all studies reporting gene and protein expression findings in prolactinomas from 1990 to 2014. RESULTS 1392 abstracts were screened and 51 manuscripts were included in the analysis, yielding 54 upregulated and 95 downregulated genes measured by various direct and indirect analytical methods. Of the many genes identified, three upregulated (HMGA2, HST, SNAP25), and three downregulated (UGT2B7, Let7, miR-493) genes were selected for further analysis based on our subjective identification of strong potential targets. CONCLUSIONS Many significant genes have been identified and validated in prolactinomas and most have not been fully analyzed for therapeutic and diagnostic potential. These genes could become candidate molecular targets for biomarker development and precision drug targeting as well as catalyze deeper research efforts utilizing next generation profiling/sequencing techniques, particularly genome scale expression and epigenomic analyses.
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Affiliation(s)
- Justin Seltzer
- Department of Neurosurgery, Keck School of Medicine of USC, 1200 North State St., Los Angeles, CA, 90033, USA.
| | - Thomas C Scotton
- Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Keiko Kang
- Department of Neurosurgery, Keck School of Medicine of USC, 1200 North State St., Los Angeles, CA, 90033, USA
| | - Gabriel Zada
- Department of Neurosurgery, Keck School of Medicine of USC, 1200 North State St., Los Angeles, CA, 90033, USA
- USC Pituitary Center, Keck School of Medicine of USC, Los Angeles, CA, USA
- Zilka Neurogenetics Institute, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - John D Carmichael
- Division of Endocrinology, Department of Medicine, Keck School of Medicine of USC, Los Angeles, CA, USA
- USC Pituitary Center, Keck School of Medicine of USC, Los Angeles, CA, USA
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Suppression of MMQ cells by fulvestrant: possible mechanism of action and potential application for bromocriptine-resistant prolactinomas. J Clin Neurosci 2013; 20:721-5. [DOI: 10.1016/j.jocn.2012.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 06/20/2012] [Accepted: 07/04/2012] [Indexed: 11/21/2022]
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Formosa R, Gruppetta M, Falzon S, Santillo G, DeGaetano J, Xuereb-Anastasi A, Vassallo J. Expression and clinical significance of Wnt players and survivin in pituitary tumours. Endocr Pathol 2012; 23:123-31. [PMID: 22327960 DOI: 10.1007/s12022-012-9197-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Deregulation of the Wnt pathway has been implicated in oncogenesis of numerous tissues including the pituitary gland. Immunohistochemical localization and quantification of β-catenin, Cyclin D1, c-MYC and Survivin expression in 47 pituitary adenomas (35 non-functioning, seven GH-secreting, three prolactinomas, two ACTH-secreting tumour) and six normal controls was undertaken in this study and correlation of protein expression to patient and tumour characteristics analysed. β-catenin was strictly membrane-bound with no difference observed between normal and tumour tissue. In contrast, Cyclin D1 and c-MYC localization was nuclear and significantly higher in tumour versus normal tissue (p < 0.05). c-MYC expression correlated negatively with age at diagnosis (p = 0.006, R = -0.395) while Cyclin D1 expression correlated positively with age (p = 0.036, R = 0.306) and was higher in males than in females (p = 0.036). c-MYC expression was significantly lower in patients with functional tumours requiring octreotide treatment and in patients with non-functioning tumours suffering from hypopituitarism. Survivin expression was extremely low in tumours and absent in normal controls. Involvement of the canonical Wnt pathway appears to be minimal, given the segregation of β-catenin to the membrane. Our data suggest that c-MYC may have an important role in early pituitary tumorigenesis while Cyclin D1 is likely to promote tumour growth at a later stage. We also report a novel gender difference in Cyclin D1 expression, the biological significance of which merits further analysis. The reported reduction of c-MYC in functional tumours subsequently treated with octreotide further supports a role of c-MYC in early tumorigenesis and not in recurrence. The decrease in c-MYC in patients with hypopituitarism provides the first in vivo evidence for hormonal regulation of c-MYC expression.
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Affiliation(s)
- Robert Formosa
- Department of Medicine, Faculty of Medicine and Surgery, Mater Dei Hospital, University of Malta, Msida, Malta.
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Facile backbone structure determination of human membrane proteins by NMR spectroscopy. Nat Methods 2012; 9:834-9. [PMID: 22609626 DOI: 10.1038/nmeth.2033] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 04/25/2012] [Indexed: 12/31/2022]
Abstract
Although nearly half of today's major pharmaceutical drugs target human integral membrane proteins (hIMPs), only 30 hIMP structures are currently available in the Protein Data Bank, largely owing to inefficiencies in protein production. Here we describe a strategy for the rapid structure determination of hIMPs, using solution NMR spectroscopy with systematically labeled proteins produced via cell-free expression. We report new backbone structures of six hIMPs, solved in only 18 months from 15 initial targets. Application of our protocols to an additional 135 hIMPs with molecular weight <30 kDa yielded 38 hIMPs suitable for structural characterization by solution NMR spectroscopy without additional optimization.
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Bai JW, Wang Z, Gui SB, Zhang YZ. Loss of 15-hydroxyprostaglandin dehydrogenase indicates a tumor suppressor role in pituitary adenomas. Oncol Rep 2012; 28:714-20. [PMID: 22580984 DOI: 10.3892/or.2012.1806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 04/13/2012] [Indexed: 11/06/2022] Open
Abstract
15-hydroxyprostaglandin dehydrogenase (15-PGDH) may function as a tumor suppressor that antagonizes the action of the cyclooxygenase-2 (COX-2) oncogene in several types of tumors. However, it is unknown if it has a role in the pituitary. Recently, our group found that 15-PGDH expression was low in prolactin (PRL) secreting adenomas (prolactinomas) and growth hormone (GH) secreting adenomas (GHomas) using fiber-optic BeadArray technology. In this study, we examined the relative expression of 15-PGDH and COX-2 mRNA in clinical specimens and examined the effects of 15-PGDH on GH3 rat pituitary tumor cell proliferation, apoptosis and hormone secretion. 15-PGDH expression was lower and COX-2 expression was higher in prolactinomas and GHomas compared with normal controls. Overexpressed 15-PGDH inhibited tumor cell proliferation and induced apoptosis. It had a significant suppressive effect on mRNA levels and on the secretion of PRL and GH in GH3 cells. The inhibition of cell proliferation was accompanied by the decreased expression of cox-2, matrix metalloproteinase-9 (MMP-9) and B cell leukemia/lymphoma-2 (Bcl-2). These data are suggestive of a previously unrecognized pathway in pituitary tumorigenesis, and this novel observation may shed light on therapeutic strategies for pituitary tumors.
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Affiliation(s)
- Ji-Wei Bai
- Beijing Neurosurgical Institute, Capital Medical University, and Neurosurgical Department, Beijing Tiantan Hospital, Dongcheng District, Beijing 100050, PR China
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