Project description:Despite the intensive search for an effective drug to treat steroid-producing adrenocortical carcinomas, there are few therapeutic options. We sought whether splicing modifying compounds are effective on this devastating disease. Here, we show that a chemical compound in clinical trial, CX-4945, suppressed the expression of NR5A1 through aberrant multiple exon skipping leading to suppressed steroidogenesis and induced dysfunctional autophagy and progression to ER-stress-related apoptosis. A circular RNA of NR5A1 exons with an IRE1α-cleavage site on the ligated ends (circAd4BP HAC1-type ex1-6 RNA) is expressed in normal adrenal cortex but not in H295R adrenocortical cancer cells, and CX-4945 induced a different circular RNA of NR5A1 exons (circAd4BP ex2-4 RNA). This potential pharmacological control of abnormal steroidogenesis through NR5A1 aberrant splicing and interplay with its circAd4BP makes CX-4945 a strong candidate novel drug for the treatment of adrenocortical carcinomas.
Project description:The adrenal cortex produces vital steroid hormones that maintain homeostasis. While steroid hormones produced from the fetal zone adrenal cortex are essential for both fetal development and maintenance of pregnancy, the molecular mechanisms leading to human adrenal cortex development and steroid synthesis remain poorly understood due to the paucity of model systems. Through progressive generation of fetal zone adrenal cortex-like cells (FZLCs) from human induced pluripotent stem cells through posterior intermediate mesoderm-like, adrenogenic coelomic epithelium and adrenal primordium-like states, we provide the first in vitro reconstitution of human adrenocortical fetal specification. Generation of FZLCs faithfully recapitulates human embryonic adrenal cortex specification as evidenced by histomorphological and ultrastructural analysis, transcriptional profiles and delta-5 steroid biosynthesis and occurs in an adrenocorticotropic hormone (ACTH)-independent manner, consistent with clinical observations. Furthermore, we demonstrate that FZLC generation is promoted by SHH and inhibited by NOTCH, ACTIVIN and WNT signaling and that steroid synthesis is amplified by ACTH/PKA signaling and blocked by pharmacologic inhibitors of delta 5 steroid synthesis enzymes. Finally, NR5A1 appear to self-stabilize its promoter activity and promote FZLC survival and steroidogenesis. Together, these findings provide a framework for understanding and reconstituting human adrenocortical development in vitro and pave the way for future cell-based therapies of adrenal insufficiency.
Project description:The adrenal cortex produces vital steroid hormones that maintain homeostasis. While steroid hormones produced from the fetal zone adrenal cortex are essential for both fetal development and maintenance of pregnancy, the molecular mechanisms leading to human adrenal cortex development and steroid synthesis remain poorly understood due to the paucity of model systems. Through progressive generation of fetal zone adrenal cortex-like cells (FZLCs) from human induced pluripotent stem cells through posterior intermediate mesoderm-like, adrenogenic coelomic epithelium and adrenal primordium-like states, we provide the first in vitro reconstitution of human adrenocortical fetal specification. Generation of FZLCs faithfully recapitulates human embryonic adrenal cortex specification as evidenced by histomorphological and ultrastructural analysis, transcriptional profiles and delta-5 steroid biosynthesis and occurs in an adrenocorticotropic hormone (ACTH)-independent manner, consistent with clinical observations. Furthermore, we demonstrate that FZLC generation is promoted by SHH and inhibited by NOTCH, ACTIVIN and WNT signaling and that steroid synthesis is amplified by ACTH/PKA signaling and blocked by pharmacologic inhibitors of delta 5 steroid synthesis enzymes. Finally, NR5A1 appear to self-stabilize its promoter activity and promote FZLC survival and steroidogenesis. Together, these findings provide a framework for understanding and reconstituting human adrenocortical development in vitro and pave the way for future cell-based therapies of adrenal insufficiency.
Project description:The adrenal cortex produces vital steroid hormones that maintain homeostasis. While steroid hormones produced from the fetal zone adrenal cortex are essential for both fetal development and maintenance of pregnancy, the molecular mechanisms leading to human adrenal cortex development and steroid synthesis remain poorly understood due to the paucity of model systems. Through progressive generation of fetal zone adrenal cortex-like cells (FZLCs) from human induced pluripotent stem cells through posterior intermediate mesoderm-like, adrenogenic coelomic epithelium and adrenal primordium-like states, we provide the first in vitro reconstitution of human adrenocortical fetal specification. Generation of FZLCs faithfully recapitulates human embryonic adrenal cortex specification as evidenced by histomorphological and ultrastructural analysis, transcriptional profiles and delta-5 steroid biosynthesis and occurs in an adrenocorticotropic hormone (ACTH)-independent manner, consistent with clinical observations. Furthermore, we demonstrate that FZLC generation is promoted by SHH and inhibited by NOTCH, ACTIVIN and WNT signaling and that steroid synthesis is amplified by ACTH/PKA signaling and blocked by pharmacologic inhibitors of delta 5 steroid synthesis enzymes. Finally, NR5A1 appear to self-stabilize its promoter activity and promote FZLC survival and steroidogenesis. Together, these findings provide a framework for understanding and reconstituting human adrenocortical development in vitro and pave the way for future cell-based therapies of adrenal insufficiency.
Project description:Despite the intensive search for an effective drug to ameliorate excess steroid production, there are few pharmacological options, especially for diseases as steroid-producing adrenocortical cancers. While splice-modifying-compounds have pleiotropic effects including anticancer properties, none have been tested on abnormal steroidogenesis. Using H295R adrenocortical carcinoma cells, CX-4945 induced multiple exon skipping of the NR5A1 gene, the master regulator of steroidogenesis. The resulting exon-skipped NR5A1 proteins were non-functional when added-back to NR5A1 knocked down H295R cells. This eventually suppressed steroidogenesis and induced dysfunctional autophagy with progression to ER-stress-related apoptosis. Intriguingly, a circular RNA of NR5A1 exons (circNR5A1 ex2-4 RNA) not originating from the skipped exons, was induced. Transient expression of this circNR5A1 ex2-4 RNA induced the same multiple exon-skipped isoforms of the NR5A1 gene. This potential pharmacological control of NR5A1 aberrant multiple exon-skipping and interplay with its circNR5A1 RNA gives us a novel target for treating abnormal steroidogenesis in adrenocortical carcinomas.
Project description:Transcription factor 21 (TCF21) directly binds and regulates SF1 in tumor and normal adrenocortical cells, and both are involved in the development and steroidogenesis of the adrenal cortex. TCF21 is a tumor suppressor gene and its expression is reduced in malignant tumors. In adrenocortical tumors, it is less expressed in adrenocortical carcinomas (ACC) than in adrenocortical adenomas (ACA) and normal tissue. However, a comprehensive analysis to identify TCF21 targets have not yet been conducted in any type of cancer. In this study, we performed Chromatin Immunoprecipitation and Sequencing (ChIP-Seq) in adrenocortical carcinoma cell line (NCI-H295R) overexpressing TCF21, with the aim of identifying TCF21 new targets. The five most frequently identified sequences corresponded to the PRDM7, CNTNAP2, CACNA1B, PTPRN2 and KCNE1B genes. Validation experiments showed that, in NCI-H295R cells, TCF21 regulates gene expression positively in PRDM7 and negatively in CACNA1B. Recently, it was observed that the N-type calcium channel v2.2 (Cav2.2) encoded by CACNA1B gene is important in Angiotensin II signal transduction for corticosteroid biosynthesis in NCI-H295R adrenocortical carcinoma cells. Indeed, TCF21 inhibits CACNA1B and Cav2.2 expression in NCI-H295R. In addition, in a cohort of 55 adult patients with adrenocortical tumor, CACNA1B expression was higher in ACC than ACA, and was related to poor disease-free survival in ACC patients. These results suggest a mechanism of steroidogenesis control by TCF21 in adrenocortical tumor cells, in addition to the control observed through SF1 inhibition. Importantly, steroid production could impair tumor immunogenicity, contributing to the immune resistance described in adrenal cancer.
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.
Project description:SF-1, a transcription factor belonging to the nuclear receptor superfamily, has a pivotal role for adrenogonadal development in humans and mice. A constant feature of childhood adrenocortical tumors (ACT) is SF-1 amplification and overexpression. Using an inducible cellular system, here we show that SF-1 overexpression increases human adrenocortical cell proliferation through opposing effects on cell cycle and apoptosis. SF-1 overexpression also selectively modulates steroidogenesis, reducing cortisol and aldosterone secretion. We identified a novel pro-apoptotic factor for adrenocortical cells, NOV/CCN3, whose levels are significantly reduced by SF-1 overexpression in human adrenocortical cells and are also reduced in primary adrenal tumors. Moreover, Sf-1 overexpression triggers adrenocortical hyperplasia and tumor formation in mice. These tumors express gonadal markers and activated Stat3. Our studies reveal the critical role of SF-1 gene dosage for adrenocortical tumorigenesis and constitute a rationale for the development of drugs targeting SF-1 transcriptional activity for ACT therapy. Keywords: differential expression, transcription factor