Poster abstracts
Poster number 47 submitted by Shan-Qing Gu
The human PMR1 endonuclease stimulates cell motility by down regulating miR-200 family microRNAs
Shan-Qing Gu (Center for RNA Biology, Department of Biological Chemistry and Pharmacology), Daniel Gallego-Perez (Department of Surgery, Department of Biomedical Engineering, Center for Affordable Nanoengineering of Polymeric Biomedical Devices, Center for Regenerative Medicine and Cell-Based Therapies), Sean P. McClory (Center for RNA Biology, Department of Biological Chemistry and Pharmacology), Joonhee Han (Center for RNA Biology, Department of Biological Chemistry and Pharmacology), L. James Lee (Center for Affordable Nanoengineering of Polymeric Biomedical Devices), Daniel R. Schoenberg (nter for RNA Biology, Department of Biological Chemistry and Pharmacology)
Abstract:
The motility of MCF-7 cells increases following expression of a human PMR1 transgene and the current study sought to identify the molecular basis for this phenotypic change. Ensemble and single cell analyses show increased motility is dependent on the endonuclease activity of hPMR1, and cells expressing active but not inactive hPMR1 invade extracellular matrix. Nanostring profiling identified 14 microRNAs that are downregulated by hPMR1, including all 5 members of the miR-200 family and others that also regulate invasive growth. miR-200 levels increase following hPMR1 knockdown, and changes in miR-200 family microRNAs were matched by corresponding changes in miR-200 targets and reporter expression. PMR1 preferentially cleaves between UG dinucleotides within a consensus YUGR element when present in the unpaired loop of a stem-loop structure. This motif is present in the apical loop of precursors to most of the downregulated microRNAs, and hPMR1 targeting of pre-miRs was confirmed by their loss following induced expression and increase following hPMR1 knockdown. Introduction of miR-200c into hPMR1-expressing cells reduced motility and miR-200 target gene expression, confirming hPMR1 acts upstream of Dicer processing. These findings identify a new role for hPMR1 in the post-transcriptional regulation of microRNAs in breast cancer cells.
Keywords: Post-transcriptional control , miR-200, hPMR1 endonuclease