FBXW7 overexpression suppresses renal cancer cell proliferation and induces apoptosis.

FBXW7 gene (F-box and WD-40 domain protein 7) is also named HCDC4 and is a significant tumor suppressor gene, which can regulate human cell cycle, proliferation and differentiation. In this study, we tend to investigate protein expression and related biological functions of FBXW7 gene. FBXW7 expression level in renal cell carcinoma (RCC) tissues is highly related to its clinical pathologic grade (P = 0.0094) and TNM phase (P = 0.0080) and is highly lower than in paracancerous normal tissues through immunohistochemistry study. FBXW7 high-expression patients have overall better prognosis than low-expression patients (P < 0.001). After transfected with FBXW7 plasmid, the RCC cell lines ACHN and A704 showed a depressed proliferation activity and high proportion of apoptosis through CCK8, colony formation and flow cytometry assay studies. By Western blot analysis, expression of cell proliferation-activating protein c-Myc and c-Jun is downregulated in FBXW7 high-expression RCC compared with negative control. These data suggested that FBXW7 is a significant tumor suppressor gene in RCC.