Neoplasma Vol.67, No.4, p.724–734, 2020
|
Title: miR-375 targeting autophagy-related 2B (ATG2B) suppresses autophagy and tumorigenesis in cisplatin-resistant osteosarcoma cells |
Author: S. Gao, K. Wang, X. Wang |
|
Abstract: Acquisition of drug resistance is an enormous obstacle for osteosarcoma (OS) treatment. Copious microRNAs (miRNAs) have been reported to participate in chemoresistance. However, the role and molecular basis of miR-375 in cisplatin (Cis/DDP) sensitivity in OS remain unclear. Expression of miR-375 and autophagy-related 2B (ATG2B) in OS was examined by reverse-transcription qPCR (RT-qPCR) and western blot assay. The value of 50% growth inhibitory concentration (IC50) for DDP was determined by Cell Counting Kit (CCK)-8 assay. Cell autophagy was measured with cell proliferation, apoptotic rate, acridine orange-positive cells, and LC3-II/LC3-I ratio determined by MTT assay, flow cytometry, and western blot assay. The candidate target of miR-375 was predicted using TargetScan and was further validated by luciferase reporter and western blot analyses. Mice xenograft model was established to further investigate the tumorigenesis of U2OS/DDP in vivo. In the study, miR-375 was downregulated in DDP-resistant OS tissues and cell lines U2OS and MG63. Elevated miR-375 or reduced ATG2B decreased cell proliferation, acridine orange-positive cells and LC3-II/LC3-I ratio, and increased apoptosis rate in U2OS/DDP and MG63/DDP cells, as accompanied with lower IC50 value for DDP. ATG2B was identified to be a target of miR-375. Re-expression of ATG2B abolished miR-375-mediated effects on cell autophagy. Moreover, the reintroduction of miR-375 slowed down tumor growth of U2OD/DDP cells in vivo. In conclusion, miR-375 suppressed cells autophagy and tumor growth in DDP-resistant U2OS/DDP and MG63/DDP cells by targeting ATG2B, providing a potential target for the treatment of DDP-resistant OS.
|
|
Keywords: miR-375, DDP-resistant osteosarcoma, ATG2B, autophagy |
|
Published online: 28-Jul-2020
|
Year: 2020, Volume: 67, Issue: 4 |
Page From: 724, Page To: 734 |
doi:10.4149/neo_2020_190423N366
|
|
download file |
|
|
|
|