D Alwyn Dart1,2, Sarah Koushyar3,4, Ben E Lanning3, Wenguo Jiang3. 1. Cardiff China Medical Research Collaborative, Cardiff University School of Medicine, Cardiff, U.K. a.dart@imperial.ac.uk. 2. Imperial College London, London, U.K. 3. Cardiff China Medical Research Collaborative, Cardiff University School of Medicine, Cardiff, U.K. 4. European Cancer Stem Cell Research Institute, Cardiff University, Cardiff, U.K.
Abstract
BACKGROUND/AIM: MiR-221, often described both as an oncogenic microRNA and as a tumour suppressor, targets mRNAs involved in carcinogenesis. While other oncogenic microRNAs showed correlations with prostate cancer cell lines' aggressiveness, miR-221 showed an unusual overexpression in PC3. MATERIALS AND METHODS: CRISPR was used to delete miR-221 from PC3 cells. Analysing the characteristics of PC3miR-221del cells, a reduced growth rate and expression of cell-cycle genes was observed. In global gene expression/ontology analysis of PC3miR-221del cells, cell-cell and cell-substrate adhesion pathways were found to be greatly affected. In addition, reduced levels of adhesion, invasion and motility for PC3miR-221del cells, a change in F-actin localisation and a reduction of EMT markers were observed. RESULTS: The tumour suppressor gene, DIRAS3, was a predicted target of miR-221. In PC3miR-221del cells DIRAS3 was up-regulated at the gene and protein level. Ectopic expression of DIRAS3 in PC3wt cells recapitulated the cellular morphology changes seen in PC3miR-221del cells. DIRAS3 3'UTR was more stable in PC3miR-221del cells, as measured by semi-quantitative PCR and luciferase fusion reporter assays. CONCLUSION: MiR-221 promotes aggressiveness of PC3 cells by down-regulating DIRAS3, and promoting epithelial-to-mesenchymal transition. Copyright
BACKGROUND/AIM: MiR-221, often described both as an oncogenic microRNA and as a tumour suppressor, targets mRNAs involved in carcinogenesis. While other oncogenic microRNAs showed correlations with prostate cancer cell lines' aggressiveness, miR-221 showed an unusual overexpression in PC3. MATERIALS AND METHODS: CRISPR was used to delete miR-221 from PC3 cells. Analysing the characteristics of PC3miR-221del cells, a reduced growth rate and expression of cell-cycle genes was observed. In global gene expression/ontology analysis of PC3miR-221del cells, cell-cell and cell-substrate adhesion pathways were found to be greatly affected. In addition, reduced levels of adhesion, invasion and motility for PC3miR-221del cells, a change in F-actin localisation and a reduction of EMT markers were observed. RESULTS: The tumour suppressor gene, DIRAS3, was a predicted target of miR-221. In PC3miR-221del cells DIRAS3 was up-regulated at the gene and protein level. Ectopic expression of DIRAS3 in PC3wt cells recapitulated the cellular morphology changes seen in PC3miR-221del cells. DIRAS3 3'UTR was more stable in PC3miR-221del cells, as measured by semi-quantitative PCR and luciferase fusion reporter assays. CONCLUSION:MiR-221 promotes aggressiveness of PC3 cells by down-regulating DIRAS3, and promoting epithelial-to-mesenchymal transition. Copyright