Metformin Suppresses Hepatocellular Carcinoma through Regulating Alternative Splicing of LGR4

Han Zhuo; Shuying Miao; Zhenquan Jin; Deming Zhu; Zhenggang Xu; Dongwei Sun; Jie Ji; Zhongming Tan

doi:10.1155/2022/1774095

Metformin Suppresses Hepatocellular Carcinoma through Regulating Alternative Splicing of LGR4

J Oncol. 2022 Nov 4:2022:1774095. doi: 10.1155/2022/1774095. eCollection 2022.

Authors

Han Zhuo¹, Shuying Miao², Zhenquan Jin³, Deming Zhu¹, Zhenggang Xu¹, Dongwei Sun¹, Jie Ji⁴, Zhongming Tan¹

Affiliations

¹ Hepatobiliary Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
² Department of Pathology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
³ The First Clinical Medical College of Nanjing Medical University, Nanjing, Jiangsu, China.
⁴ Jiangsu Breast Disease Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.

Abstract

Methods: First, the expression of LGR4 in HCC tumor tissues and cell lines was detected by western blotting and immunofluorescence. The ability of cell proliferation, migration, and invasion was detected with CCK8, wound-healing, and transwell assays when overexpressing LGR4 or treating with metformin. The β-catenin expression was detected by immunofluorescence. In order to investigate novel AS-associated LGR4, we discarded LGR4 isoforms from GSO databases. We used siRNA to knock down the specific isoform to check the cell proliferation, migration, and invasion when treated with metformin.

Results: The level of LGR4 expression was higher in HCC cell lines and tumor tissues. The HCC cell proliferation, migration, and invasion were increased when overexpressing LGR4, which could be reduced by metformin treatment. The GEO database (GSE190076) showed that LGR4 had switching properties in HCC cell lines treated with metformin. We used siRNA to knock down the specific isoform, and the result showed that the specific isoform siRNA could promote the inhibition of cell invasion caused by metformin treatment.

Conclusions: LGR4 could promote the ability of cell proliferation, migration, and invasion in HCC, which could be reduced by metformin through alternative splicing.