The miR-30 family microRNAs confer epithelial phenotype to human pancreatic cells.

Epithelial-to-mesenchymal transition is a phenomenon necessary for embryonic development and also seen during certain pathological conditions.  We show here for the first time that reduction in miR-30 family microRNAs, is responsible for mesenchymal transition of primary cultures of human pancreatic epithelial cells.  We found that miR-30 family microRNAs target mesenchymal gene transcripts and maintain them in a translationally inactive state.  Forced depletion using miR-30 family specific anti-miRs leads to mesenchymal transition while ectopic overexpression maintains the epithelial phenotype.  We also show that miR-30 family microRNAs increase in abundance during differentiation of pancreatic islet-derived mesenchymal cells into hormone-producing islet-like cell aggregates.  Our studies in human adult diseased pancreas also demonstrate that miR-30 family microRNAs are expressed at lower abundance in fibrotic lesions during pancreatitis.  Together, our data confirm that miR-30 family microRNAs form a part of the regulatory signaling events involved in cellular response of pancreatic epithelial cells during mesenchymal transition.