Project description:Background: Adrenocortical carcinoma (ACC) is a rare, often-aggressive neoplasm of the adrenal cortex, with a 14.5-month median overall survival. We asked whether tumors from patients with advanced or metastatic ACC would offer clues as to putative genes that might have critical roles in disease progression or in more aggressive disease biology. Methods: We conducted comprehensive genomic and expression analyses, including microRNA profiling, of 33 ACCs and 6 normal adrenals. Results: Copy number gains and losses matched that previously reported. We identified a median mutation rate of 3.38 per megabase (Mb), somewhat higher than in a previous study possibly related to the more advanced disease. The mutational signature was characterized by a predominance of C>T, C>A and T>C transitions. As in previously reports, only cancer genes TP53 (26%) and beta-catenin (CTNNB1, 14%) were mutated in more than 10% of samples. The TCGA-identified putative cancer genes MEN1 and PRKAR1A were found in low frequency – 4.7% and 2.3%, respectively. Most of the mutations were in genes not implicated in the etiology or maintenance of cancer. Specifically, amongst the 38 genes that were mutated in more than 9% of samples, only four were represented in Tier 1 of the 576 COSMIC Cancer Gene Census (CCGC). Thus, 82% of genes found to have mutations likely have no role in the etiology or biology of ACC; while the role of the other 18%, if any, remains to be proven. Finally, the transcript length for the 38 most frequently mutated genes in ACC is statistically longer than the average of all coding genes, raising the question of whether transcript length in part determined mutation probability. Conclusions: We conclude that the mutational and expression profiles of advanced and metastatic tumors is very similar to those from newly diagnosed patients –with very little in the way of genomic aberration to explain it. Our data and that in the previous analyses finds the rate of mutations in ACCs lower than that in other cancers and suggests an epigenetic basis for the disease should be the focus of future studies. The Exiqon miRCURY LNA microRNA array v.11.0 platform was used for the microRNA profiling.

Project description:Background: Adrenocortical carcinoma (ACC) is a rare, often-aggressive neoplasm of the adrenal cortex, with a 14.5-month median overall survival. We asked whether tumors from patients with advanced or metastatic ACC would offer clues as to putative genes that might have critical roles in disease progression or in more aggressive disease biology. Methods: We conducted comprehensive genomic and expression analyses of 43 ACCs. Results: Copy number gains and losses matched that previously reported. We identified a median mutation rate of 3.38 per megabase (Mb), somewhat higher than in a previous study possibly related to the more advanced disease. The mutational signature was characterized by a predominance of C>T, C>A and T>C transitions. As in previously reports, only cancer genes TP53 (26%) and beta-catenin (CTNNB1, 14%) were mutated in more than 10% of samples. The TCGA-identified putative cancer genes MEN1 and PRKAR1A were found in low frequency – 4.7% and 2.3%, respectively. Most of the mutations were in genes not implicated in the etiology or maintenance of cancer. Specifically, amongst the 38 genes that were mutated in more than 9% of samples, only four were represented in Tier 1 of the 576 COSMIC Cancer Gene Census (CCGC). Thus, 82% of genes found to have mutations likely have no role in the etiology or biology of ACC; while the role of the other 18%, if any, remains to be proven. Finally, the transcript length for the 38 most frequently mutated genes in ACC is statistically longer than the average of all coding genes, raising the question of whether transcript length in part determined mutation probability. Conclusions: We conclude that the mutational and expression profiles of advanced and metastatic tumors is very similar to those from newly diagnosed patients –with very little in the way of genomic aberration to explain it. Our data and that in the previous analyses finds the rate of mutations in ACCs lower than that in other cancers and suggests an epigenetic basis for the disease should be the focus of future studies. The Affymetrix PrimeView platform was used for the gene expression profiling.

Project description:Background: Adrenal myelolipoma (AML) is a relatively common and invariably benign tumor composed of adipose tissue and hematopoietic elements. Due to the variable proportion of fat and hematopoietic elements, it is sometimes challenging to differentiate AML from adrenocortical carcinoma (ACC). MicroRNAs have been identified as promising biomarkers in many tumors, including adrenocortical neoplasms, but the microRNA expression of adrenal myelolipoma has not been investigated, yet. Aims: To perform a large scale microRNA expression profiling in adrenal myelolipoma, benign and malignant adrenocortical tumors to identify potential microRNA biomarkers. Methods: Next-generation sequencing (NGS) on 30 formalin-fixed paraffin-embedded archived tissue samples (discovery cohort: 10 adrenocortical adenoma (ACA), 10 ACC and 10 myelolipoma) was performed by Illumina MiSeq. Significantly differentially expressed microRNAs were validated by real-time RT-qPCR in an independent validation cohort comprised of 10 ACA, 10 myelolipoma and 9 ACC samples. Results: We have found relative overexpression of miR- 451a, miR-486-5p, miR-363-3p and miR-150-5p in myelolipoma compared to the other two tumor groups by NGS. For ACC, we have found up-regulation of miR-184, miR-483-5p, miR-431-5p and miR-183-5p compared to myelolipoma and ACA. Validation by RT-qPCR, confirmed significant overexpression of miR-451a, miR-486-5p and miR-150-5p in myelolipomas relative to ACA and ACC, whereas significant overexpression of miR-184 and miR-183-5p was confirmed in ACC relative to the other 2 groups. The overexpression of miR-483-5p has not turned out to be significant in ACC relative to myelolipomas in the validation cohort. Conclusions: Overexpressed miR-451a, miR-486-5p and miR-150-5p might be potential tissue markers of adrenal myelolipoma. The lack of significance in the expression of miR-483-5p between ACC and myelolipoma is remarkable, as miR-483-5p has been considered to be the best marker of adrenal malignancy to date.

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MicroRNA expression analysis of metastatic adrenocortical tumors

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