MiR-451a promotes cell growth, migration and EMT in osteosarcoma by regulating YTHDC1-mediated m6A methylation to activate the AKT/mTOR signaling pathway

Dong Cao; Shanshan Ge; Mengchun Li

doi:10.1016/j.jbo.2022.100412

MiR-451a promotes cell growth, migration and EMT in osteosarcoma by regulating YTHDC1-mediated m6A methylation to activate the AKT/mTOR signaling pathway

J Bone Oncol. 2022 Jan 19:33:100412. doi: 10.1016/j.jbo.2022.100412. eCollection 2022 Apr.

Authors

Dong Cao¹, Shanshan Ge¹, Mengchun Li²

Affiliations

¹ The Physical Examination Center, First Hospital of Shanxi Medical University, Taiyuan 030001, Shanxi, China.
² Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Taiyuan 030001, Shanxi, China.

Abstract

Background: Osteosarcoma is the most prevalent primary malignant bone tumor containing mesenchymal cells with poor prognosis. Being a hot spot of anti-tumor therapy researches, AKT/mammalian target of rapamycin (mTOR) signaling pathway could affect various cellular processes including transcription, protein synthesis, apoptosis, autophagy and growth.

Materials and methods: The levels of RNA and protein were detected by quantitative real-time polymerase chain reaction (q-PCR) and western blot analyses respectively. Functional assays were carried out to analyze the malignant phenotypes of osteosarcoma cells. RNA-binding protein immunoprecipitation (RIP), Co-immunoprecipitation (Co-IP), RNA pulldown, luciferase reporter and in vitro kinase assays were conducted to uncover the specific mechanism of microRNA-451a (miR-451a) in osteosarcoma cells.

Results: Functionally, miR-451a represses the malignant progression of osteosarcoma. Mechanically, miR-451a could curb the AKT/mTOR pathway via 3-phosphoinositide dependent protein kinase 1 (PDPK1)-mediated phosphorylation modification. After the certification that YTH domain containing 1 (YTHDC1) regulates the m6A phosphorylation modification of PDPK1 mRNA, we further proved that miR-451a-mediated YTHDC1 stabilizes PDPK1 mRNA via m6A-dependent regulation.

Conclusion: This study demonstrated that miR-451a regulates YTHDC1-mediated m6A methylation to activate the AKT/mTOR pathway, stimulating the malignancy of osteosarcoma.

Keywords: AKT/mTOR signaling pathway; ANOVA, Analysis of variance; Cdna, Complementary DNA; GEO, Gene Expression Omnibus; Osteosarcoma; PDPK1, 3-phosphoinositide dependent protein kinase 1; RIP, Co-IP, Co-immunoprecipitation; SD, Standard deviation; YTHDC1, YTH domain containing 1; m6A methylation; mTOR, Mammalian target of rapamycin; miR-451a; miR-451a, MicroRNA-451a; q-PCR, Quantitative real-time polymerase chain reaction.