Overexpression of RAB34 correlates with poor prognosis and tumor progression in hepatocellular carcinoma

RAB34, a protein belonging to the RAB family, is involved in protein transport, repositioning of lysosomes and activation of micropinocytosis. However, few studies have reported its function in human epithelial cancers. Immunohistochemistry (IHC) and western blotting were used to detect expression of RAB34 at the tissue and cell levels. Cell Counting Kit-8 (CCK-8), EDU assay and flow cytometry were used for analyzing cell proliferation. Transwell and scratch wound healing assays were used for assessing cell migration ability. Western blotting was used for detecting expression of E-cadherin and N-cadherin. In the present study, we found that both DNA copy and protein level of RAB34 were upregulating in human hepatocellular carcinoma (HCC) tissues when compared with that in adjacent tissues. Analysis of the correlation between RAB34 expression and clinicopathological features showed that patients with overexpression of RAB34 consistently had large tumor size, vessel invasion and poor tumor grade. Furthermore, overall survival analysis showed that patients with upregulated expression of RAB34 were associated with poor prognosis. Moreover, cell function experiments showed that suppression of RAB34 led to a lower proliferation rate and migration ability. In addition, this phenomenon may be attributed to cell cycle phase G1 arrest and mesenchymal-epithelial transition under condition of RAB34 suppression. The present study demonstrated that RAB34 plays an important role in the initiation and progression of HCC. Our results suggest a new therapeutic target for the clinical treatment of HCC.