ARHGAP9 suppresses the migration and invasion of hepatocellular carcinoma cells through up-regulating FOXJ2/E-cadherin

Hong Zhang,Zhi-Yi Shao,Li-Jun Zhang,Chun-Yan Zhang,Jian-Yong Zhu,Qing-Feng Tang,Yu-Li Shen,Bin Zhao,Meng-Yao Sun

doi:10.1038/s41419-018-0976-0

Hong Zhang, Zhi-Yi Shao + Show 7 more

Open Access

https://doi.org/10.1038/s41419-018-0976-0

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Abstract

Rho GTPase activating protein 9 (ARHGAP9), a member of RhoGAP family, has been identified as a RhoGAP for Cdc42 and Rac1. Here, we aimed to clarify the expression and functional role of ARHGAP9 in hepatocellular carcinoma (HCC). By analyzing TCGA (The Cancer Genome Atlas) LIHC (liver hepatocellular carcinoma) database, we found that ARHGAP9 expression was lower in HCC tissues than in normal liver tissues, and that patients with ARHGAP9 lower expression had a significant shorter overall survival time than those with ARHGAP9 higher expression. Cell counting kit-8 (CCK-8), transwell assays and in vivo experimental lung metastasis assay revealed that ARHGAP9 overexpression could inhibit HCC cell proliferation, migration and invasion, as well as HCC lung metastases. By next-generation RNA-sequencing, we identified that a transcription factor, Forkhead Box J2 (FOXJ2), was significantly induced by ARHGAP9 overexpression in HepG2 cells. Ectopic expression of FOXJ2 in HCC cell lines also exerted inhibitory effects on cell migration and invasion. Moreover, the inhibitory effects of ARHGAP9 on HCC cell migration and invasion was significantly attenuated by FOXJ2 knockdown. Luciferase reporter assay demonstrated that ARHGAP9 enhanced the transcription of E-cadherin (CDH1) via FOXJ2. Chromatin immunoprecipitation (ChIP) assay demonstrated that FOXJ2 modulated the transcription of E-cadherin (CDH1) by directly binding to its promoter. Furthermore, Pearson’s correlation analysis indicated that the mRNA levels of ARHGAP9 in HCC tissues were positively correlated with the mRNA levels of FOXJ2 and CDH1. These data clearly show that ARHGAP9/FOXJ2 inhibit cell migration and invasion during HCC development via inducing the transcription of CDH1.

Highlights

Hepatocellular carcinoma (HCC), as one of the most frequent malignancies, is the third leading cause of cancer-related deaths in the world[1,2]
To define ARHGAP9 expression patterns in hepatocellular carcinoma (HCC), we analyzed ARHGAP9 mRNA levels in TCGA LIHC dataset and found that ARHGAP9 mRNA was significantly lower in HCC tissues than in normal liver tissues (Fig. 1a)
To examine whether ARHGAP9 affected the proliferation of HCC cells, Cell counting kit-8 (CCK-8) assay was performed in WT, vector and ARHGAP9OE cells

Summary

Introduction

Hepatocellular carcinoma (HCC), as one of the most frequent malignancies, is the third leading cause of cancer-related deaths in the world[1,2]. More than 700,000 new cases are diagnosed each year, and more than 80% of HCCs occur in East/South-East Asia and Africa[3]. It is generally believed that hepatitis B or C viral infections, alcohol-related cirrhosis and non-alcoholic steatohepatitis are main risk factors for HCC4–6. Despite great progress in surgical techniques, the 5-year overall survival of HCC patients remains extremely low[7] because of late diagnosis, and high recurrence rate after surgical resection[8]. There is an urgent need for a deeper understanding of the molecular mechanisms of HCC progression, which is helpful for the early diagnosis and novel therapeutic strategies. Official journal of the Cell Death Differentiation Association

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