Citation

  • Authors: Sohn, E. J.. et al.
  • Year: 2018
  • Journal: Cancer Cell Int 18 2
  • Applications: in vitro / siRNA, miRNA / INTERFERin
  • Cell type: PC-3
    Description: Human prostate carcinoma cells
    Known as: PC3, PC 3

Abstract

Background: Autophagy is a response to cellular and environmental conditions and facilitates cell survival. Here, we investigated the role of ectopic expression of microRNA (miRNA) 200c-3p in autophagy. Methods: miRNA mimics were used to overexpress miRNAs. Quantitative real-time polymerase chain reaction (RT-qPCR) was performed to analyze miRNA expression. RT-qPCR and western blotting were performed to determine the expression levels of inositol requiring protein-1 (IRE1alpha), activating transcription factor-6 (ATF6), C/EBP homologous protein (CHOP), and light chain-3 (LC3). Results: Western blotting and RT-qPCR analysis revealed that ectopic expression of miR-200c-3p increased the expression of IRE1alpha, ATF6, and CHOP in PC-3 prostate cancer cells. Furthermore, the level of miR-200c-3p was enhanced by treatment with the endoplasmic reticulum (ER) stress inducer thapsigargin. In addition, ectopic expression of miR-200c-3p led to an increase in LC3-II expression, and formed puncta of green fluorescent protein-fused LC3-II in PC-3 cells. Interestingly, starvation stress induced by Hank's balanced salt solution buffer increased the level of miR-200c-3p and conversely miR-200c-3p inhibitor blocked the increased expression of LC3-II induced by starvation in PC-3 cells. In addition, silencing of IRE1alpha by transfection of short interfering RNA attenuated the expression of LC3-II induced by upregulation of miR-200c-3p in PC-3 cells. Conclusions: Overall, our findings suggest that miR-200c-3p regulates autophagy via upregulation of ER stress signaling.

Pubmed