Project description:Purpose: DROSHA plays an important role in breast cancer progression. Exploring the gene expression profiles regulated by DROSHA will facilitate to understand the mechanism which is responsible for DROSHA-induced breast cancer development. Results: We found that 105 genes were significantly up-regulated during DROSHA silencing in MDA-MB-231 cells, 200 genes were significantly down-regulated during DROSHA silencing in MDA-MB-231 cells. Conclusions: Our study indicated that DROSHA-mediated 305 differentially expressed genes might be invovled in breast cancer development.
Project description:Neural stem cell regulation is essential for the formation of the central nervous system and homeostatic neurogenesis in the adult mammalian brain. The RNAseIII Drosha, a key component of the miRNA microprocessor, plays a central role in regulating NSC maintenance partially through a miRNA-independent mechanism. Drosha controls mRNA expression levels by targeting and cleaving evolutionary conserved stem-loop hairpins located in the mRNAs of stem cell-related transcription factors. However, it is unknown how the Drosha-mediated endonucleolytic cleavage of mRNA is regulated. Here, we identify novel Drosha and NFIB interactors in hippocampal NSCs by in vitro pull-down assays followed by Mass Spectrometry. We unravel the RNA binding proteins implicated in Drosha-mediated regulation of neurogenesis and we find Scaffold Attachment Factor B1 to play a novel and essential role in NFIB mRNA regulation during neural stem cell differentiation.
Project description:Drosha is a type III RNAse, which plays a critical role in miRNA biogenesis. Drosha and its double-stranded RNA-binding partner protein Pasha/DGCR8 likely recognize and cleave miRNA precursor RNAs or pri-miRNA hairpins co-transcriptionally. To identify RNAs processed by Drosha, we used tiling microarrays to examine transcripts after depletion of drosha mRNA with dsRNA in Drosophila Schneider S2 cells. This strategy identified 137 Drosha-regulated RNAs, including 11 putative pri-miRNAs comprising 15 annotated miRNAs. Most of the identified pri-miRNAs seem extremely large, >10 kilobases as revealed by both the Drosha knock down strategy and by RNA PolII chromatin IP followed by Drosophila tiling microarrays. Surprisingly, more than a hundred additional RNAs not annotated as miRNAs are under Drosha control and are likely to be direct targets of Drosha action. This is because many of them encode annotated genes, and unlike bona fide pri-miRNAs, they are not affected by depletion of the miRNA processing factor, dicer-1. Moreover, application of the evofold analysis software indicates that at least 25 of the Drosha-regulated RNAs contain evolutionarily conserved hairpins similar to those recognized by the Drosha-Pasha/DGCR8 complex in pri-miRNAs. One of these hairpins is located in the 5′ UTR of both pasha and mammalian DGCR8. These observations suggest that a negative feedback loop acting on pasha mRNA may regulate the miRNA-biogenesis pathway: i.e., excess Drosha cleaves pasha/DGCR8 primary transcripts and leads to a reduction in pasha/DGCR8 mRNA levels and Pasha/DGCR8 synthesis. Keywords: time course, ChIP-chip
Project description:Anaysis of mRNA changes in HeLa cells following knockdown of Drosha or DGCR8. Drosha is a nuclear RNase III that carries out microRNA (miRNA) processing by cleaving primary microRNA transcript (pri-miRNA). DGCR8 is an essential co-factor of Drosha. Keywords: gene expression array-based (RNA / in situ oligonucleotide)
Project description:To determine genes regulated independently of microRNAs in early haematopoietic progenitors (LSKs) we compared the expression profiles of Drosha or Dicer deficient LSKs and control. Those genes differentially expressed between Drosha or Dicer deficient LSKs are likely regulated indepedently of microRNAs as either Drosha or Dicer deletion will lead to a complete and equivalent loss of microRNAs. LSKs were sorted from control, Drosha fl/fl of Dicer fl/fl mice.These cells were activated in vitro for 72 hours to induce total and equivalent deletion of Drosha or Dicer. RNA was extracted after 72 hours.3 repeats of the three groups were analyzed.
Project description:To determine genes regulated independently of microRNAs in early haematopoietic progenitors (LSKs) we compared the expression profiles of Drosha or Dicer deficient LSKs and control. Those genes differentially expressed between Drosha or Dicer deficient LSKs are likely regulated indepedently of microRNAs as either Drosha or Dicer deletion will lead to a complete and equivalent loss of microRNAs.
Project description:We report the ability of the Drosha null/conditional-null mouse model to enable the identification of pri-miRNA transcripts. The conditional-null allele of Drosha phenocopies the null allele both in mESC and in mice, upon conversion to the null state with Cre. Examination of the effects of Drosha deficiency in mouse embryonic stem cells.
Project description:We report the ability of the Drosha null/conditional-null mouse model to enable the identification of pri-miRNA transcripts. The conditional-null allele of Drosha phenocopies the null allele both in mESC and in mice, upon conversion to the null state with Cre.