Project description:The objectives were to determine the molecular mechanisms involved in the development and progression of familial BMAH tumours, and the mechanisms of their inefficient steroidogenesis.
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:Our study showed that the steroidogenic capacity firstly decreased without tissue change (the first hit) and secondarily declined with tissue change (the second hit) in the adrenal cortex of lipoid congenital adrenal hyperplasia. The key feature of the secondary decline of steroidogenic capacity might be the decreased gene expression related to steroid biosynthesis following the lipid accumulation exacerbated by ACTH hypersecretion.
Project description:Familial pheochromocytoma (PCC) has been associated with germline mutations in 14 genes. Here we investigated three siblings, who presented with (metastatic) bilateral pheochromocytomas, renal oncocytoma, and erythrocytosis. By SNP-array on one patient’s germline DNA a large complex genomic alteration was identified encompassing the intragenic and promoter regions of Myc-Associated Factor X (MAX) and alpha-(1,6)-fucosyltransferase (FUT8). The alteration was confirmed in all patients, as well as loss of the wild type MAX and FUT8 alleles and corresponding loss of protein expression. Uniparental disomy of chromosome 14q, previously demonstrated as a hallmark for MAX-related PCC, was also shown in the index patient by SNP-array. Our results indicate that large genomic deletions of MAX should be considered in familial and bilateral PCC with prior negative testing for gene mutations. In addition, MAX appears to be a new tumor suppressor gene for renal oncocytomas. SNP array was performed for 2 samples: 1 tumor DNA sample and 1 corresponding germline DNA sample
Project description:Familial pheochromocytoma (PCC) has been associated with germline mutations in 14 genes. Here we investigated three siblings, who presented with (metastatic) bilateral pheochromocytomas, renal oncocytoma, and erythrocytosis. By SNP-array on one patient’s germline DNA a large complex genomic alteration was identified encompassing the intragenic and promoter regions of Myc-Associated Factor X (MAX) and alpha-(1,6)-fucosyltransferase (FUT8). The alteration was confirmed in all patients, as well as loss of the wild type MAX and FUT8 alleles and corresponding loss of protein expression. Uniparental disomy of chromosome 14q, previously demonstrated as a hallmark for MAX-related PCC, was also shown in the index patient by SNP-array. Our results indicate that large genomic deletions of MAX should be considered in familial and bilateral PCC with prior negative testing for gene mutations. In addition, MAX appears to be a new tumor suppressor gene for renal oncocytomas.
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: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.