MicroRNA‑663b targets GAB2 to restrict cell proliferation and invasion in hepatocellular carcinoma

: Previous studies have demonstrated that numerous tumor‑specific microRNAs (miRNAs) are upregulated or downregulated in hepatocellular carcinoma (HCC), and that their dysregulation is implicated in HCC occurrence and development. Therefore, investigation of crucial miRNAs involved in HCC oncogenesis and progression may provide novel insights into the therapy of patients with this malignant tumor. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) assays were performed to detect tissue and cellular expression levels of miRNA‑663b (miR‑663b) in HCC. The effects of miR‑663b overexpression on the proliferation and invasion of HCC cells were examined using Cell Counting Kit‑8 and Transwell invasion assays, respectively. The direct target of miR‑663b in HCC cells was determined by bioinformatics analysis, luciferase reporter assay, RT‑qPCR and western blot analysis. It was observed that miR‑663b was expressed at low levels in HCC tissues and cell lines. miR‑663b upregulation suppressed the proliferative and invasive abilities of HCC cells. Additionally, Grb2‑associated binding 2 (GAB2) was regarded as a direct target gene of miR‑663b in HCC cells. Furthermore, GAB2 was overexpressed in HCC tissues, and overexpression of GAB2 was inversely correlated with levels of miR‑663b. GAB2 overexpression was able to rescue the suppressive effects of miR‑663b on HCC cells. These results demonstrated that this newly‑identified miR‑663b/GAB2 axis may be implicated in HCC occurrence and development.