ABSTRACT: ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a clinically and genetically heterogeneous disorder that can be associated with aberrant hormone receptors. Whole-genome expression profiling was analyzed in samples of different nodules from a patient with AIMAH.
Project description:ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a clinically and genetically heterogeneous disorder that can be associated with aberrant hormone receptors. Whole-genome expression profiling was analyzed in samples of different nodules from a patient with AIMAH. Total RNA obtained from adrenal nodules were compared to those samples obtained normal adrenal pools
Project description:AIMAH is an ACTH-independent bilateral enlargement of the adrenal cortex occuring during adulthood. The enlargment is related to the growth of multiple benign nodules. This condition is associated with various degrees of cortisol hypersecretion. The occurence of several nodules in both adrenals, and the existence of familial forms, suggest the existence of a germline genetic predisposition. To find the gene(s), the aim of the project was to look for recurrent chromosomal alterations in the AIMAH nodules. Extensive mapping of somatic gains, losses and copy-neutral loss of heterozygosity (LOH) was performed with Affymetrix SNP6 arrays. A copy neutral LOH of 16p, occuring in 7 of 26 patients, was one of the only recurrent alterations, pointing towards a candidate gene in this region. Of note this condition differs from the congenital adrenal hyperplasias, related to genetic alterations of steroidogenesis (the latter is an ACTH dependent adrenal hyperplasia). Affymetrix SNP6 arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved tumor samples or peripheral blood samples. Copy number and LOH analysis of Affymetrix SNP6 arrays was performed for AIMAH nodules from 26 patients, including 18 with paired leucocyte and nodules (1 to 4 nodules per patient), and 8 with a single nodule (no paired leucocyte available)
Project description:AIMAH is an ACTH-independent bilateral enlargement of the adrenal cortex occuring during adulthood. The enlargment is related to the growth of multiple benign nodules. This condition is associated with various degrees of cortisol hypersecretion. The occurence of several nodules in both adrenals, and the existence of familial forms, suggest the existence of a germline genetic predisposition. To find the gene(s), the aim of the project was to look for recurrent chromosomal alterations in the AIMAH nodules. Extensive mapping of somatic gains, losses and copy-neutral loss of heterozygosity (LOH) was performed with Affymetrix SNP6 arrays. A copy neutral LOH of 16p, occuring in 7 of 26 patients, was one of the only recurrent alterations, pointing towards a candidate gene in this region. Of note this condition differs from the congenital adrenal hyperplasias, related to genetic alterations of steroidogenesis (the latter is an ACTH dependent adrenal hyperplasia). Affymetrix SNP6 arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved tumor samples or peripheral blood samples.
Project description:A ""Cartes d'Identite des Tumeurs"" (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net). 92 samples on Affymetrix HG-U133 Plus 2.0 GeneChips arrays for 92 patients with Adrenocortical Tumors (ACT). 4 normal adrenal samples from the same batch are also included. 10 ACTH-independant Macronodular Adrenal Hyperplasia (AIMAH) from the same batch are also included.
Project description:The mechanisms responsible for the ectopic adrenal expression of glucose-dependent insulinotropic peptide (GIP) receptor (GIPR) in GIP-dependent Cushing's syndrome (CS) are unknown. Chronic adrenal stimulation by ACTH in Cushing's disease or GIP in GIP-dependent ACTH-independent macronodular adrenal hyperplasia both lead to the induction of genes implicated in adrenal proliferation and steroidogenesis. OBJECTIVE: The objective of the study was to identify genes differentially expressed specifically in GIP-dependent CS that could be implicated in the ectopic expression of GIPR. METHODS: We used the Affymetrix U133 plus 2.0 microarray oligochips to compare the whole genome expression profile of adrenal tissues from five cases of GIP-dependent bilateral ACTH-independent macronodular adrenal hyperplasia with CS, one case of GIP-dependent unilateral adenoma with CS, five cases of ACTH-dependent hyperplasias, and a pool of adrenals from 62 normal individuals. RESULTS: After data normalization and statistical filtering, 723 genes with differential expression were identified, including 461 genes or sequences with a known functional implication, classified in eight dominant functional classes. Specific findings include repression of perilipin, the overexpression of 13 G protein-coupled receptors, and the potential involvement of Rho-GTPases. We also isolated 94 probe sets potentially linked to the formation of GIP-dependent nodules adjacent to the diffuse hyperplasia. These included probe sets related to the linker histone H1 and repression of RXRa and CCND2. The expression profiles for eight genes were confirmed by real-time RT-PCR. CONCLUSION: This study identified an extensive series of potentially novel target candidate genes that could be implicated in the molecular mechanisms of ectopic expression of the GIPR as well as in the multistep progression of GIP-dependent CS.
Project description:Abstract submitted to the Journal of clinical encodcrinology and metabolism: The molecular mechanisms responsible for the ectopic expression of the GIP receptor in the adrenal cortex of patients with GIP-dependent Cushing’s syndrome (CS) are unknown. Chronic adrenal stimulation by ACTH in Cushing’s disease (CD) or by GIP in GIP-dependent AIMAH both lead to induction of a set of genes which stimulate adrenal proliferation and steroidogenesis. The objective of this study was to compare the whole genome expression profile of adrenal glands of five cases of GIP-dependent bilateral macronodular adrenal hyperplasia with CS, one case of GIP-dependent adenoma, compared to five cases of ACTH-dependant hyperplasias (CD) and a pool of adrenals from 62 normal individuals. We used the genome-spanning Affymetrix U133 plus 2.0 microarray oligochips to identify genes differentially expressed specifically in GIP-dependent CS and which would be candidate genes implicated in the ectopic expression of the GIP receptor in the adrenal cortex. After data normalization and filtering, genes with differential expression were identified with a multi-step statistical analysis involving a student’s t-test, a filter on flags and a SAM analysis. A total of 721 probesets were thus isolated with intensity levels robustly related to the presence of a GIP-dependent hyperplasia. We performed a functional classification to further define potentially important biological processes and signaling mechanism for the formation of GIP-dependent AIMAH. Various probesets were related to metabolic processes, cell-surface and intracellular signaling, tumorigenesis, transport and transcription factors. The most relevant genes had their expression profile confirmed by real-time RT-PCR. This study reports an extensive series of potentially novel targets in the identification of the molecular mechanisms of ectopic expression of the GIP-receptor in this pathology. Keywords: Comparative genomic analysis
Project description:Analysis of ACTH-regulation on adrenocortical cells at gene expression level. The hypothesis tested in the present study was that ACTH increases chronic cell growth and steroidogenesis in adrenal glands by changing the gene expression profile. Results provide important information of the response of adrenocortical cells gene expression to chronic ACTH treatment. Total RNA obtained from primary cultured adult adrenal cells subjected to 48 hours in vitro treatment of ACTH compared to untreated control cell.
Project description:Analysis of ACTH-regulation on adrenocortical cells at gene expression level. The hypothesis tested in the present study was that ACTH increases chronic cell growth and steroidogenesis in adrenal glands by changing the gene expression profile. Results provide important information on the changes of gene expression of adrenocortical cells after chronic ACTH treatment.
Project description:Analysis of ACTH-regulation on adrenocortical cells at gene expression level. The hypothesis tested in the present study was that ACTH increases chronic cell growth and steroidogenesis in adrenal glands by changing the gene expression profile. Results provide important information of the response of adrenocortical cells gene expression to chronic ACTH treatment.