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Transcriptome analysis of MENX‑associated rat pituitary adenomas identifies novel molecular mechanisms involved in the pathogenesis of human pituitary gonadotroph adenomas

ABSTRACT: Gonadotroph adenomas comprise 15–40 % of all pituitary tumors, are usually non-functioning and are often large and invasive at presentation. Surgery is the first-choice treatment, but complete resection is not always achieved, leading to high recurrence rates. As gonadotroph adenomas poorly respond to conventional pharmacological therapies, novel treatment strategies are needed. Their identification has been hampered by our incomplete understanding of the molecular pathogenesis of these tumors. Recently, we dem¬onstrated that MENX-affected rats develop gonadotroph adenomas closely resembling their human counterparts. To discover new genes/pathways involved in gonadotroph cells tumorigenesis, we performed transcriptome profiling of rat tumors versus normal pituitary. Adenomas showed overrep¬resentation of genes involved in cell cycle, development, cell differentiation/proliferation, and lipid metabolism. Bioinfor¬matic analysis identified downstream targets of the transcrip¬tion factor SF-1 as being up-regulated in rat (and human) adenomas. Meta-analyses demonstrated remarkable similari¬ties between gonadotroph adenomas in rats and humans, and highlighted common dysregulated genes, several of which were not previously implicated in pituitary tumorigenesis. Two such genes, CYP11A1 and NUSAP1, were analyzed in 39 human gonadotroph adenomas by qRT-PCR and found to be up-regulated in 77 and 95 % of cases, respectively. Immunohistochemistry detected high P450scc (encoded by CYP11A1) and NuSAP expression in 18 human gonado¬troph tumors. In vitro studies demonstrated for the first time that Cyp11a1 is a target of SF-1 in gonadotroph cells and promotes proliferation/survival of rat pituitary adenoma pri¬mary cells and cell lines. Our studies reveal clues about the molecular mechanisms driving rat and human gonadotroph adenomas development, and may help identify previously unexplored biomarkers for clinical use.

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE23207 | GEO | 2013/07/10

SECONDARY ACCESSION(S): PRJNA131639

REPOSITORIES: GEO

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Project description:Gonadotroph adenomas comprise 15M-bM-^@M-^S40 % of all pituitary tumors, are usually non-functioning and are often large and invasive at presentation. Surgery is the first-choice treatment, but complete resection is not always achieved, leading to high recurrence rates. As gonadotroph adenomas poorly respond to conventional pharmacological therapies, novel treatment strategies are needed. Their identification has been hampered by our incomplete understanding of the molecular pathogenesis of these tumors. Recently, we demM-BM-,onstrated that MENX-affected rats develop gonadotroph adenomas closely resembling their human counterparts. To discover new genes/pathways involved in gonadotroph cells tumorigenesis, we performed transcriptome profiling of rat tumors versus normal pituitary. Adenomas showed overrepM-BM-,resentation of genes involved in cell cycle, development, cell differentiation/proliferation, and lipid metabolism. BioinforM-BM-,matic analysis identified downstream targets of the transcripM-BM-,tion factor SF-1 as being up-regulated in rat (and human) adenomas. Meta-analyses demonstrated remarkable similariM-BM-,ties between gonadotroph adenomas in rats and humans, and highlighted common dysregulated genes, several of which were not previously implicated in pituitary tumorigenesis. Two such genes, CYP11A1 and NUSAP1, were analyzed in 39 human gonadotroph adenomas by qRT-PCR and found to be up-regulated in 77 and 95 % of cases, respectively. Immunohistochemistry detected high P450scc (encoded by CYP11A1) and NuSAP expression in 18 human gonadoM-BM-,troph tumors. In vitro studies demonstrated for the first time that Cyp11a1 is a target of SF-1 in gonadotroph cells and promotes proliferation/survival of rat pituitary adenoma priM-BM-,mary cells and cell lines. Our studies reveal clues about the molecular mechanisms driving rat and human gonadotroph adenomas development, and may help identify previously unexplored biomarkers for clinical use. We compared five control animals and 16 homozygous mutants (p27Kip1/Cdknb1)

Project description:Context : Non Functioning Pituitary Adenomas (NFPAs), although typically benign, may be locally invasive. Few datas are currently available related to the molecular process of invasion in sporadic pituitary adenomas. Markers of invasiveness, important for helping the clinician in the therapeutic strategy particularly in the decision for adjuvant radiotherapy, are currently lacking. Objective: Evaluate if invasive NFPAs display a specific expression profile compared with non invasive tumors. Methods: To address this issue, we selected 40 NFPAs (38 of the gonadotroph type) and classified them as invasive (n=22) or non invasive (n=18) on the basis of MRI and surgical findings. Then we performed pangenomic analysis based on Agilent Human Whole genome Gene Expression oligonucleotide microarray (44k) Expression in order to identify genes differentially expressed between invasive and non invasive NFPA. Experiements are made in dual color with tumor samples labelled in cyanine 5 and a pool of all tumors labelled in cyanine 3.The expressions of some genes identified by microarray screening were confirmed by real-time quantitative RT-PCR. The selection of genes was made on the basis of Ingenuity networks and degree of upregulation between invasive and non invasive tumors. Moreover, some genes of interest already described in the literature were added to the analysis. Results: Prediction class analysis showed that 346 genes discriminated between invasive and non invasive NFPAs (p<0.001); 233 were up- and 113 were down-regulated between the two groups. We then tested On the basis of Ingenuity networks and degree of upregulation between invasive and non invasive tumors, a set of eight genes, including MYO5A, IGFBP5, FLT3, NFE2L1, PTTG, MMP9, NCAM and NR1H3, was tested in quantitative PCR analysis and. Results confirmed those obtained in microarrays results.analysis. At the protein level, Myosin 5A (MYO5A) demonstrated stronger immunostaining in invasive NFPAs compared to non invasive NFPAs. Conclusions: We propose a molecular signature of eight genes of grossly invasive NFPAs as compared with non invasive tumors: The product of one of these genes, MYO5A, may be a useful marker of invasive process in tumoral specimens. The role of these genes in the invasiveness process and as prognostic markers of pituitary adenomas needs to be confirmedinvestigated. Method: Microarray analyses the transcriptome of 22 invasive Non Functional Pituitary Adenomas (NFPAs) and 18 non invasive NFPAs in dual color (each sample labelled in cyanine 5 and a pool of all tumors labelled in cyanine 3).

Project description:Pituitary adenomas are common benign neoplasms giving rise to disorders of growth, reproductive function and cortisol production. Although recently determined to be monoclonal, very little is known about the mechanisms regulating the development of pituitary hyperplasia and neoplasia in humans. Surgical resection is the treatment of choice for most symptomatic pituitary adenomas. The goal of surgery is the complete removal of the tumor and the success of surgery is strongly affected by the presence of local invasion. However, complete tumor removal is unlikely when there is extensive local invasion. Identifying genes that control the invasiveness and recurrence of this class of tumors will provide therapeutic targets for this class of tumors. We will determine the expression pattern of genes in recurrent and invasive and pituitary adenomas and compare those to non-invasive and non-recurrent tumors. We hypothesize that the differential expression and activation of a number of genes affect pituitary adenoma recurrence and invasiveness. Rationale: Preliminary result showed a differential expression of novel PKC isozymes in non-invasive and invasive pituitary adenomas. PMA, an activator of both novel and classical PKC isozymes increased the expression of gelatinase A (MMP-2) mRNA in human pituitary adenoma cell line. This result raises a fundamental question as to the functional role of novel PKC isozymes and proteases in the invasive phenotype of pituitary adenomas. The primary component of this Specific Aim is to determine whether specific genes are differentially expressed in recurrent or invasive adenomas when compared with control non-invasive tumors. Tissue specimens from non-invasive and invasive (dural invasion based microscopic examination) and recurrent vs non-recurrent tumors will be used for microarray analysis. Frozen pituitaryspecimens will be collected and total RNA extracted with TriZol reagent. We will provide total RNA (10 ug) from non-invasive, invasive, reoccurred and non-occurrent pituitary adenomas.

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Transcriptome analysis of MENX‑associated rat pituitary adenomas identifies novel molecular mechanisms involved in the pathogenesis of human pituitary gonadotroph adenomas

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