Modification of STIM2 by m6A RNA methylation inhibits metastasis of cholangiocarcinoma

Feng-Qiu Chen; Hao Zheng; Ting Gu; Yu-Hua Hu; Le Yang; Zhi-Ping Huang; Guang-Lei Qiao; Hong-Jie Li

doi:10.21037/atm-21-6485

Modification of STIM2 by m⁶A RNA methylation inhibits metastasis of cholangiocarcinoma

Ann Transl Med. 2022 Jan;10(2):40. doi: 10.21037/atm-21-6485.

Authors

Feng-Qiu Chen^#¹, Hao Zheng^#², Ting Gu^#³, Yu-Hua Hu^#³, Le Yang⁴, Zhi-Ping Huang⁵, Guang-Lei Qiao⁶, Hong-Jie Li⁷

Affiliations

¹ The Department of Biobank, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
² The Third Department of Hepatic Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China.
³ Department of Oral Pathology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
⁴ National Liver Tissue Bank, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China.
⁵ Department of Hepatobiliary Surgery, General Hospital of Southern Theatre Command, Guangzhou, China.
⁶ Department of Oncology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
⁷ Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

^# Contributed equally.

Abstract

Background: N6-methyladenosine (m⁶A) is the most frequent internal methylation of eukaryotic RNA (ribonucleic acid) transcripts and plays an important function in RNA processing. The current research aimed to investigate the role of m⁶A-STIM2 axis in cholangiocarcinoma (CCA) progression.

Methods: The expression of STIM2 (Stromal Interaction Molecule 2) in CCA was measured using quantitative polymerase chain reaction (PCR) and immunohistochemistry (IHC). STIM2 was examined in vivo for its effects on the malignant phenotypes of CCA cells. The m⁶A modification of STIM2 was assessed through MeRIP (methylated RNA Immunoprecipitation)-PCR.

Results: Based on the GEPIA (Gene Expression Profiling Interactive Analysis) 2 database findings, a low STIM2 mRNA (messenger RNA) level was related to a poor prognosis in individuals with CCA. Quantitative PCR and IHC assays indicated decreased protein satin in CCA tissues and were associated with extrahepatic metastasis. Vianude mice tail vein injection model indicated that increased STIM2 levels suppressed CCA cell metastasis in vivo, while KRT8 (keratin 8) was detected as the direct downstream target of STIM2-mediated CCA cell metastasis in vivo. Meanwhile, based on SRAMP database and MeRIP assays indicated that m⁶A alteration resulted in abnormal STIM2 expression in CCA via METTL14 and YTHDC2.

Conclusions: Our findings revealed the epi-transcriptomic dysregulation in CCA and metastasis by proposing a complicated STIM2-KRT8 regulatory paradigm based on m⁶A alteration.

Keywords: Intrahepatic cholangiocarcinoma; KRT8; N6-methyladenosine (m6A); STIM2; metastasis.