Project description:To confirm the lack of expression of most miRNAs in DICER1 knock-out cell lines, we performed miRNA microarray analysis. The purpose of this study is to classify DICER1-dependent Small RNA and independent Small RNA using DICER1 cells using deficient cell lines, and to identify novel small RNA and small RNA processing mechanisms.
Project description:Goal: elucidate transcriptomic changes upon knock-out of components of the FERRY complex Methods: RNA extraction from HeLa wildtype and fy-1, fy-2, fy-4 and fy-5 knock-out celllines and subsequent RNASeq Results: We observed differences in the transcriptome of all four knock-out cell lines Conclusions: In the Analysis we focused on genes that were differentially expressed in all four KO cell lines or upon KO of fy-1 and fy-2.
Project description:Recurrent somatic hotspot mutations of DICER1 appear to be clustered around each of four critical metal binding residues in the RNase IIIB domain of DICER1. This domain is responsible for cleavage of the 3’ end of the 5p-miRNA strand of a pre-mRNA hairpin. To investigate the effects of these cancer-associated “hotspot” mutations we engineered mouse Dicer1-deficient ES cells to express wild-type and an allelic series of the mutant human DICER1 variants. Global miRNA and mRNA profiles from cells carrying the metal binding site mutations were compared to each other and wild-type human DICER1. The miRNA and mRNA profiles generated through the expression of the hotspot mutations were virtually identical, and the DICER1 hotspot mutation carrying cells were distinct from both wild-type and Dicer1-deficient cells. Further, miRNA profiles showed mutant DICER1 results in a dramatic loss in processing of mature 5p-miRNA strands but were still able to create 3p-strand miRNAs. Messenger-RNA profile changes were consistent with the loss of 5p-strand miRNAs and showed enriched expression for predicted targets of the lost 5p derived miRNAs. We therefore conclude that cancer-associated somatic hotspot mutations of DICER1, affecting any one of four metal binding residues in the RNase IIIB domain, are functionally equivalent with respect to miRNA-processing and are hypomorphic alleles, yielding a global loss in processing of mature 5p-strand miRNA. We further propose that this resulting 3p-strand bias in mature miRNA expression likely underpins the oncogenic potential of these hotspot mutations. A total of 28 Affymetrix Mouse Gene ST arrays were done for mRNA expression profiling of various DICER1 mutants (n=14), wildtype controls (n=6), vector only (n=3) and parental cell lines (n=5).
Project description:To further characterize differential expression of miRNA and mRNA levels in livers of 12 weeks old male Tax1BP1 wildtype and knock-out mice, the untreated mice were sacrificed and miRNA and mRNA levels were determined miRNA was labeled with the Affymetrix FlashTag Biotin HSR RNA Labeling Kit
Project description:Recurrent somatic hotspot mutations of DICER1 appear to be clustered around each of four critical metal binding residues in the RNase IIIB domain of DICER1. This domain is responsible for cleavage of the 3’ end of the 5p-miRNA strand of a pre-mRNA hairpin. To investigate the effects of these cancer-associated “hotspot” mutations we engineered mouse Dicer1-deficient ES cells to express wild-type and an allelic series of the mutant human DICER1 variants. Global miRNA and mRNA profiles from cells carrying the metal binding site mutations were compared to each other and wild-type human DICER1. The miRNA and mRNA profiles generated through the expression of the hotspot mutations were virtually identical, and the DICER1 hotspot mutation carrying cells were distinct from both wild-type and Dicer1-deficient cells. Further, miRNA profiles showed mutant DICER1 results in a dramatic loss in processing of mature 5p-miRNA strands but were still able to create 3p-strand miRNAs. Messenger-RNA profile changes were consistent with the loss of 5p-strand miRNAs and showed enriched expression for predicted targets of the lost 5p derived miRNAs. We therefore conclude that cancer-associated somatic hotspot mutations of DICER1, affecting any one of four metal binding residues in the RNase IIIB domain, are functionally equivalent with respect to miRNA-processing and are hypomorphic alleles, yielding a global loss in processing of mature 5p-strand miRNA. We further propose that this resulting 3p-strand bias in mature miRNA expression likely underpins the oncogenic potential of these hotspot mutations.
Project description:MicroRNAs (miRNAs) are a class of endogenous, non-coding RNAs that mediate post-transcriptional gene silencing by inhibiting mRNA translation and promoting mRNA decay. DICER1, an RNAse III endonuclease encoded by Dicer1, is required for processing short 21-22 nucleotide miRNAs from longer double-stranded RNA precursors. Here, we investigate the loss of Dicer1 in mouse postnatal male germ cells to determine how disruptions in the miRNA biogenesis pathway may contribute to infertility. Reduced levels of Dicer1 transcripts and DICER1 were confirmed in germ cell knock-out (GCKO) testes by postnatal day 18 (P18). Compared to wild-type (WT) at 8 weeks, GCKO males had no change in body weight, yet showed significant reductions in testis mass and sperm number. Histology and fertility tests confirmed spermatogenic failure in GCKO males. Array analyses at P18 showed 96% of miRNA genes were down-regulated and 37% of protein-coding genes were differentially expressed in GCKO testes. Interestingly, we observed preferential overexpression of genes on the sex chromosomes in GCKO testes, with more than 80% of the genes overlapping those proposed to undergo meiotic sex chromosome inactivation (MSCI) in the germ cells. Compared to WT, GCKO mice showed higher percentages of cells at early meiotic stages (leptotene and zygotene) but lower percentages at later stages (pachytene, diplotene and metaphase I), providing evidence that deletion of Dicer1 leads to disruptions in meiotic progression. Furthermore, we observed fewer elongating spermatids with proper translational activation of transition protein 2 (Tnp2), protamine 1 and 2 (Prm1 and Prm2) in GCKO testes after step 12-14. Therefore, deleting Dicer1 in early postnatal germ cells causes misregulation of transcripts encoded by genes on the sex chromosomes, impairs meiotic progression and post-meiotic translational control and results in spermatogenic failure and infertility. Total RNA, including miRNAs, were purified from a total of six individual mouse samples. The tissue collected was obtained from wild-type (control; n=3) and Dicer1 germ cell knockout (mutant; n=3) testes on P18. One miRNA GCKO sample, M36, was determined to be of poor quality and was excluded from the study; thus, a total of five miRNA samples were analyzed.
Project description:MicroRNAs (miRNAs) are a class of endogenous, non-coding RNAs that mediate post-transcriptional gene silencing by inhibiting mRNA translation and promoting mRNA decay. DICER1, an RNAse III endonuclease encoded by Dicer1, is required for processing short 21-22 nucleotide miRNAs from longer double-stranded RNA precursors. Here, we investigate the loss of Dicer1 in mouse postnatal male germ cells to determine how disruptions in the miRNA biogenesis pathway may contribute to infertility. Reduced levels of Dicer1 transcripts and DICER1 were confirmed in germ cell knock-out (GCKO) testes by postnatal day 18 (P18). Compared to wild-type (WT) at 8 weeks, GCKO males had no change in body weight, yet showed significant reductions in testis mass and sperm number. Histology and fertility tests confirmed spermatogenic failure in GCKO males. Array analyses at P18 showed 96% of miRNA genes were down-regulated and 37% of protein-coding genes were differentially expressed in GCKO testes. Interestingly, we observed preferential overexpression of genes on the sex chromosomes in GCKO testes, with more than 80% of the genes overlapping those proposed to undergo meiotic sex chromosome inactivation (MSCI) in the germ cells. Compared to WT, GCKO mice showed higher percentages of cells at early meiotic stages (leptotene and zygotene) but lower percentages at later stages (pachytene, diplotene and metaphase I), providing evidence that deletion of Dicer1 leads to disruptions in meiotic progression. Furthermore, we observed fewer elongating spermatids with proper translational activation of transition protein 2 (Tnp2), protamine 1 and 2 (Prm1 and Prm2) in GCKO testes after step 12-14. Therefore, deleting Dicer1 in early postnatal germ cells causes misregulation of transcripts encoded by genes on the sex chromosomes, impairs meiotic progression and post-meiotic translational control and results in spermatogenic failure and infertility.