Project description:RNAi-mediated knockdown of DICER1 and DROSHA, enzymes critically involved in miRNA biogenesis, has been postulated to affect the homeostasis and the angiogenic capacity of human endothelial cells. To re-evaluate this issue, we reduced the expression of DICER1 or DROSHA by RNAi-mediated knockdown and subsequently investigated the effect of these interventions on the angiogenic capacity of human umbilical vein endothelial cells (HUVEC) in vitro (proliferation, migration, tube formation, endothelial cell spheroid sprouting) and in a HUVEC xenograft assay in immune incompetent NSGTM mice in vivo. In contrast to previous reports, neither knockdown of DICER1 nor knockdown of DROSHA profoundly affected migration or tube formation of HUVEC or the angiogenic capacity of HUVEC in vivo. Furthermore, knockdown of DICER1 and the combined knockdown of DICER1 and DROSHA tended to increase VEGF-induced BrdU incorporation and induced angiogenic sprouting from HUVEC spheroids. Consistent with these observations, global proteomic analyses showed that knockdown of DICER1 or DROSHA only moderately altered HUVEC protein expression profiles but additively reduced, for example, expression of the angiogenesis inhibitor thrombospondin-1. In conclusion, global reduction of miRNA biogenesis by knockdown of DICER1 or DROSHA does not inhibit the angiogenic capacity of HUVEC. Further studies are therefore needed to elucidate the influence of these enzymes in the context of human endothelial cell-related angiogenesis.
Project description:miRNAs regulate mRNA stability and translation through the action of the RNAi-induced silencing complex. In this study, we systematically identified endogenous miRNA target genes by using AGO2 immunoprecipitation (AGO2-IP) and microarray analyses in two breast cancer cell lines, MCF7 and MDA-MB-231, representing luminal and basal-like breast cancer, respectively. The expression levels of ~70% of the AGO2-IP mRNAs were increased by DROSHA or DICER1 knockdown. In addition, integrated analysis of miRNA expression profiles, mRNA-AGO2 interaction, and the 3'-UTR of mRNAs revealed that >60% of the AGO2-IP mRNAs were putative targets of the fifty most abundantly expressed miRNAs. To identify mRNAs responsive to miRNA synthesis inhibition, total RNA was prepared from control cells and cells that stably express small hairpin RNA against DICER1 or DROSHA. Expression array analysis was performed with duplicates for each cell type.
Project description:miRNAs regulate mRNA stability and translation through the action of the RNAi-induced silencing complex. In this study, we systematically identified endogenous miRNA target genes by using AGO2 immunoprecipitation (AGO2-IP) and microarray analyses in two breast cancer cell lines, MCF7 and MDA-MB-231, representing luminal and basal-like breast cancer, respectively. The expression levels of ~70% of the AGO2-IP mRNAs were increased by DROSHA or DICER1 knockdown. In addition, integrated analysis of miRNA expression profiles, mRNA-AGO2 interaction, and the 3'-UTR of mRNAs revealed that >60% of the AGO2-IP mRNAs were putative targets of the fifty most abundantly expressed miRNAs.
Project description:miRNAs regulate mRNA stability and translation through the action of the RNAi-induced silencing complex. In this study, we systematically identified endogenous miRNA target genes by using AGO2 immunoprecipitation (AGO2-IP) and microarray analyses in two breast cancer cell lines, MCF7 and MDA-MB-231, representing luminal and basal-like breast cancer, respectively. The expression levels of ~70% of the AGO2-IP mRNAs were increased by DROSHA or DICER1 knockdown. In addition, integrated analysis of miRNA expression profiles, mRNA-AGO2 interaction, and the 3'-UTR of mRNAs revealed that >60% of the AGO2-IP mRNAs were putative targets of the fifty most abundantly expressed miRNAs.
Project description:miRNAs regulate mRNA stability and translation through the action of the RNAi-induced silencing complex. In this study, we systematically identified endogenous miRNA target genes by using AGO2 immunoprecipitation (AGO2-IP) and microarray analyses in two breast cancer cell lines, MCF7 and MDA-MB-231, representing luminal and basal-like breast cancer, respectively. The expression levels of ~70% of the AGO2-IP mRNAs were increased by DROSHA or DICER1 knockdown. In addition, integrated analysis of miRNA expression profiles, mRNA-AGO2 interaction, and the 3'-UTR of mRNAs revealed that >60% of the AGO2-IP mRNAs were putative targets of the fifty most abundantly expressed miRNAs. To identify mRNAs associated with AGO2, cell lysate was precleaned with control IgG and immunoprecipitated with anti-human Ago2 (Clone 2E12-1C9, Abnova). Total RNA from cell lysate or coimmunoprecipitated with AGO2 was extracted with Trizol and subjected to microarray analysis, with three biological repeats for each experimental condition.
Project description:Through whole-exome sequencing we identified somatic missense mutations in DICER1 and DROSHA in Wilms tumor, a childhood kidney cancer. DICER1 and DROSHA are key enzymes in the microRNA biogenesis pathway. To determine the effect of these mutations on microRNA expression, we prepared small RNAs from Wilms tumors and used next-generation sequencing to determine the expression levels of microRNAs in the tumors. Comparison of miRNA expression in tumors with and without mutations in DICER1 or DROSHA.
Project description:Through whole-exome sequencing we identified somatic missense mutations in DICER1 and DROSHA in Wilms tumor, a childhood kidney cancer. DICER1 and DROSHA are key enzymes in the microRNA biogenesis pathway. To determine the effect of these mutations on microRNA expression, we prepared small RNAs from Wilms tumors and used next-generation sequencing to determine the expression levels of microRNAs in the tumors.