Robert K Nam1, Tania Benatar2, Yutaka Amemiya3, Christopher Sherman4, Arun Seth5,6,7,8. 1. Division of Urology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada. 2. Platform Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada. 3. Genomics Core Facility, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada. 4. Department of Laboratory Medicine and Pathobiology, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada. 5. Platform Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada; arun.seth@utoronto.ca. 6. Genomics Core Facility, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada arun.seth@utoronto.ca. 7. Department of Laboratory Medicine and Pathobiology, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada; arun.seth@utoronto.ca. 8. Faculty of Dentistry, University of Toronto, Toronto, ON, Canada arun.seth@utoronto.ca.
Abstract
BACKGROUND/AIM: We previously identified a panel of five miRNAs (including miR-139) associated with biochemical recurrence and metastasis in prostate cancer patients. MATERIALS AND METHODS: We examined miR-139 transfected PC3, DU145 and LNCaP cells by morphology as well as by cell-based assays, confocal microscopy and immunoblotting. RESULTS: We found that treatment of prostate cancer cells with miR-139 resulted in phenotypic changes characteristic of autophagic cells. MiR-139 increased the autophagy-related conversion of the microtubule-associated protein light chain 3 (LC3-I to LC3-II) that was specifically inhibited by the miR-139 antagomir. The upregulation of LC3 II was further confirmed by confocal microscopy. miR-139 regulated activation of both mTOR and Beclin1 the two important autophagy-related molecules. We found that upon miR-139 treatment, the cargo adaptor protein p62 which is degraded during autophagy, accumulates. CONCLUSION: These results suggest that miR-139 is inducing autophagic flux blockade leading to apoptosis in prostate cancer cells through the mTOR and Beclin-1 proteins.
BACKGROUND/AIM: We previously identified a panel of five miRNAs (including miR-139) associated with biochemical recurrence and metastasis in prostate cancerpatients. MATERIALS AND METHODS: We examined miR-139 transfected PC3, DU145 and LNCaP cells by morphology as well as by cell-based assays, confocal microscopy and immunoblotting. RESULTS: We found that treatment of prostate cancer cells with miR-139 resulted in phenotypic changes characteristic of autophagic cells. MiR-139 increased the autophagy-related conversion of the microtubule-associated protein light chain 3 (LC3-I to LC3-II) that was specifically inhibited by the miR-139 antagomir. The upregulation of LC3 II was further confirmed by confocal microscopy. miR-139 regulated activation of both mTOR and Beclin1 the two important autophagy-related molecules. We found that upon miR-139 treatment, the cargo adaptor protein p62 which is degraded during autophagy, accumulates. CONCLUSION: These results suggest that miR-139 is inducing autophagic flux blockade leading to apoptosis in prostate cancer cells through the mTOR and Beclin-1 proteins.
Authors: Milad Ashrafizadeh; Mahshid Deldar Abad Paskeh; Sepideh Mirzaei; Mohammad Hossein Gholami; Ali Zarrabi; Farid Hashemi; Kiavash Hushmandi; Mehrdad Hashemi; Noushin Nabavi; Francesco Crea; Jun Ren; Daniel J Klionsky; Alan Prem Kumar; Yuzhuo Wang Journal: J Exp Clin Cancer Res Date: 2022-03-22