Conclusion
ARHGAP20 was identified for the first time as a tumor suppressor gene that could inhibit HCC progression by regulating the PI3K-AKT signaling pathway and the immune microenvironment in HCC.
Methods
The expression and clinical role of ARHGAP20 were investigated using online databases and HCC samples from Meizhou People's Hospital. Wound healing assays, transwell migration/invasion assays, and lung metastasis models were performed using nude mice. Gene set enrichment analyses were used to further explore the potential mechanisms.
Results
Inspired by expression analyses of three different public databases (ie, TIMER, Oncomine, and HCCDB database), we confirmed that ARHGAP20 was downregulated in clinical HCC tumors compared with normal controls. ARHGAP20 expression inhibited HCC migration and invasion in vitro and in vivo. Based on GSEA results, we tested markers of the PI3K-AKT signaling pathway. Interestingly, while ARHGAP20 upregulation suppressed HCC migration/invasion and phosphorylation of AKT/PI3K molecules, exposure to the PI3K-AKT pathway agonist rhIGF-1 partially rescued these phenomena. ARHGAP20 also showed a close correlation with certain components in the HCC immune microenvironment. Furthermore, we revealed that downregulated ARHGAP20 was significantly correlated with larger tumor size and vascular invasion, and could be used as an adverse independent prognostic factor for HCC OS but not RFS.