Long Noncoding RNA DICER1-AS1 Functions in Methylation Regulation on the Multi-Drugresistance of Osteosarcoma Cells via miR-34a-5p and GADD45A

Feng Wang; Lingsuo Kong; Youguang Pu; Fengmei Chao; Chunbao Zang; Wei Qin; Fangfang Zhao; Shanbao Cai

doi:10.3389/fonc.2021.685881

Long Noncoding RNA DICER1-AS1 Functions in Methylation Regulation on the Multi-Drugresistance of Osteosarcoma Cells via miR-34a-5p and GADD45A

Front Oncol. 2021 Jul 9:11:685881. doi: 10.3389/fonc.2021.685881. eCollection 2021.

Authors

Feng Wang¹, Lingsuo Kong², Youguang Pu³, Fengmei Chao³, Chunbao Zang⁴, Wei Qin⁵, Fangfang Zhao³, Shanbao Cai⁶

Affiliations

¹ Department of Oncology, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
² Department of Anesthesiology, West district of The First Affiliated Hospital of USTC, Division of life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
³ Department of Cancer Epigenetics Program, Anhui Provincial Cancer Hospital, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
⁴ Department of Radiation Oncology, Anhui Provincial Cancer Hospital, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
⁵ Department of Science and Education Section, Anhui Provincial Cancer Hospital, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
⁶ Department of Orthopedic Surgery, Anhui Provincial Cancer Hospital, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.

Abstract

Osteosarcoma (OS) is a common malignant bone tumor that commonly occurs in children and adolescents. Long noncoding RNAs (lncRNAs) are recognized as a novel class of regulators of gene expression associated with tumorigenesis. However, the effect and mechanism of lncRNAs in OS tumorigenesis and drug resistance have not been characterized. The purpose of the study is to screen potential biomarker and therapeutic target against OS. We compared the lncRNA expression profiles between OS cell lines with different drug resistance levels using RNA-seq analysis and found that lncRNA DICER1-AS1 was significantly differentially expressed in multi-drugresistant OS cells SJSA-1 versus multi-drugsensitive OS cells G-292. Bisulfite Sequencing PCR (BSP) assay was performed to analyze the differential methylation status of the promoter region of DICER1-AS1 in four OS cells. Subsequently, in vitro gain- and loss-of-function experiments demonstrated the roles of DICER1-AS1 and miR-34a-5p in the multi-drugresistance of OS cells. The main findings is that DICER1-AS1 directly binds to miR-34a-5p, and their expression has a negative correlation with each other. The hypermethylation of the promoter region of DICER1-AS1 silenced its expression in the drugresistant cells SJSA-1 and MNNG/HOS. Moreover, we found that growth arrest and DNA damage-inducible alpha (GADD45A) participates in the DICER1-AS1/miR-34a-5p-regulated drug resistance of OS cells, probably via the cell cycle/pRb-E2F pathway. Our results revealed DICER1-AS1/miR-34a-5p-regulated drug resistance of OS cells, a new lncRNA-regulated network in OS tumorigenesis, suggested that DICER1-AS1 can be considered as a potential biomarker and therapeutic target against OS cells.

Keywords: DICER1-AS1; GADD45A; drug resistance; miR-34a-5p; osteosarcoma.