N6-methyladenosine-modified oncofetal lncRNA MIR4435-2HG contributed to stemness features of hepatocellular carcinoma cells by regulating rRNA 2'-O methylation

Yiqing Zhu; Bang Xiao; Meng Liu; Meiting Chen; Ningqi Xia; Haiyan Guo; Jinfeng Huang; Zhiyong Liu; Fang Wang

doi:10.1186/s11658-023-00493-2

N6-methyladenosine-modified oncofetal lncRNA MIR4435-2HG contributed to stemness features of hepatocellular carcinoma cells by regulating rRNA 2'-O methylation

Cell Mol Biol Lett. 2023 Oct 27;28(1):89. doi: 10.1186/s11658-023-00493-2.

Authors

Yiqing Zhu^#¹, Bang Xiao^#¹, Meng Liu^#¹, Meiting Chen^#¹, Ningqi Xia¹, Haiyan Guo², Jinfeng Huang³, Zhiyong Liu⁴, Fang Wang⁵

Affiliations

¹ Department of Medical Genetics, Naval Medical University, Shanghai, 200433, China.
² Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai, 200011, China.
³ Department of Medical Genetics, Naval Medical University, Shanghai, 200433, China. jfhuang@smmu.edu.cn.
⁴ Department of Urology, Shanghai Changhai Hospital, Naval Medical University, Shanghai, 200433, China. chyang@sibs.ac.cn.
⁵ Department of Medical Genetics, Naval Medical University, Shanghai, 200433, China. wfsjz@smmu.edu.cn.

^# Contributed equally.

Abstract

Background: The unique expression pattern endows oncofetal genes with great value in cancer diagnosis and treatment. However, only a few oncofetal genes are available for clinical use and the underlying mechanisms that drives the fetal-like reprogramming of cancer cells remain largely unknown.

Methods: Microarray assays and bioinformatic analyses were employed to screen for potential oncofetal long non-coding RNAs (lncRNAs) in hepatocellular carcinoma (HCC). The expression levels of MIR4435-2HG, NOP58 ribonucleoprotein (NOP58), insulin like growth factor 2 mRNA binding protein 1 (IGF2BP1) and stem markers were detected by quantitative polymerase chain reaction. The 2'-O-methylation (2'-O-Me) status of rRNA were detected through reverse transcription at low dNTP concentrations followed by PCR. The regulation of MIR4435-2HG by IGF2BP1 was explored by RNA immunoprecipitation (RIP), methylated RIP (MeRIP) and dual-luciferase assays. The interaction between MIR4435-2HG and NOP58 was investigated by RNA Pulldown, RIP and protein stability assays. In vitro and in vivo function assays were performed to detect the roles of MIR4435-2HG/NOP58 in HCC.

Results: MIR4435-2HG was an oncofetal lncRNA associated with poor prognosis in HCC. Functional experiments showed that overexpression of MIR4435-2HG remarkably enhanced the stem-cell properties of HCC cells, promoting tumorigenesis in vitro and in vivo. Mechanically, MIR4435-2HG directly bound NOP58 and IGF2BP1. IGF2BP1 upregulated MIR4435-2HG expression in HCC through N6-methyladenosine (m6A) modification. Moreover, MIR4435-2HG protected NOP58 from degradation, which raised rRNA 2'-O-Me levels and promoted internal ribosome entry site (IRES)-dependent translation of oncogenes.

Conclusions: This study identified an oncofetal lncRNA MIR4435-2HG, characterized the role of MIR4435-2HG/NOP58 in stemness maintenance and proliferation of HCC cells, and confirmed m6A as a 'driver' that reactivated MR4435-2HG expression in HCC.

Keywords: Hepatocellular carcinoma; N6-methyladenosine; Oncofetal lncRNA; Stemness maintenance; rRNA 2′-O-methylation.

MeSH terms

Carcinoma, Hepatocellular* / genetics
Carcinoma, Hepatocellular* / pathology
Cell Proliferation / genetics
Gene Expression Regulation, Neoplastic
Humans
Liver Neoplasms* / genetics
Liver Neoplasms* / pathology
Methylation
RNA, Long Noncoding* / genetics

Substances

RNA, Long Noncoding

Abstract

MeSH terms

Substances

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