hMex-3A is associated with poor prognosis and contributes to the progression of hepatocellular carcinoma

BACKGROUND

HMex-3A, an RNA-binding protein, was found to be associated with tumorigenesis. However, the roles of hMex-3A in hepatocellular carcinoma (HCC) progression remained unclear.

METHODS

The different expression of hMex-3A between HCC tissues and non-tumor tissues was evaluated using The Cancer Genome Atlas database. Thereafter, the hMex-3A expression was evaluated in HCC tissues using Western blotting and qRT-PCR. Immunohistochemistry was performed to investigate the association between hMex-3A level and clinicopathological features including prognosis in HCC patients. In addition, we used si-hMex-3A to knockdown hMex-3A in HCC cells to test Cell Counting Kit-8, colony formation, cell migration and invasion.

RESULTS

The hMex-3A expression was significantly elevated in HCC tissues. Analysis of the clinicopathological parameters suggested that hMex-3A expression was significantly associated with pathological grade (P = 0.019) and TNM stage (P = 0.001) in HCC. Moreover, univariate and multivariate Cox-regression analyses revealed that high hMex-3A expression (HR = 1.491, 95% CI: 1.107-2.007; P = 0.009) was an independent risk factor for overall survival in HCC patients. Finally, we confirmed that si-hMex-3A could significantly inhibit HCC cell proliferation, migration, and invasion in vitro.

CONCLUSIONS

HMex-3A may contribute to the progression of HCC and might be used as a novel therapeutic target and prognostic marker in HCC.

Identification of hMex-3A and its effect on human bladder cancer cell proliferation

In this study, hMex-3A was selected from TCGA database as a research object to observe the effects of small interfering RNA (siRNA) targeting hMex-3A on the biological activities of human bladder cancer and explore its mechanism for the first time. In this study, there were 2 groups including negative control group and hMex-3A-siRNA-transfected cells group for 5637 and T24 cell lines, respectively. After bladder cancer cells were transfected with the interference RNA sequence, proliferation of transfected cells were assessed by Celigo Cell Counting, and apoptosis were detected by flow cytometry. The knockdown rate of hMex-3A was 74% in 5637 cells and 68% in T24 cells after RNA interference. In addition, Celigo Cell Counting indicated that cell viability was significantly lower in hMex-3A-siRNA-transfected cells group (2196/well) than in negative control group (6777/well) (P < 0.05), but T24 cells did not show statistical significance between hMex-3A-siRNA-transfected cells group (5799/well) and negative control group (7899/well) (P >0.05). Flow cytometer showed that apoptosis was the highest and cells were significantly blocked after cells were transfected in hMex-3A-siRNA-transfected cells group in 5 days later (P < 0.05). Mex-3A protein was detected in bladder carcinoma sections with a mean staining intensity of 7.06±2.60. Mex-3A protein expression was significantly higher in cancerous tissue than in para-cancerous tissue (P <0.05). Our study suggested that siRNA targeting hMex-3A could markedly inhibit cell proliferation and promote apoptosis in 5637 cells. These might have significant implications to bladder carcinogenesis and serve as a potential target for the treatment of bladder cancer.