HBXIP suppression reduces cell proliferation and migration and its overexpression predicts poor prognosis in non-small-cell lung cancer.

Emerging evidence has demonstrated that the high expression of HBXIP has been correlated with many cancers. With evaluation of the functional role of HBXIP in non-small-cell lung cancer, the primary aim of this study is to investigate the correlation between HBXIP expression and the prognosis of non-small-cell lung cancer patients. The protein levels of HBXIP were detected using western blotting in non-small-cell lung cancer cells. Cell proliferation and migration assays were measured to evaluate the function of HBXIP in non-small-cell lung cancer cells. A total of 120 non-small-cell lung cancer patients with strict follow-up and 60 adjacent non-tumor lung tissues were selected for immunohistochemical staining of the HBXIP protein. The localization of the HBXIP protein was detected in A549 non-small-cell lung cancer cells using immunofluorescence staining. The correlation between HBXIP expression and the clinicopathological features of non-small-cell lung cancer patients was analyzed by a chi-squared and Fisher's exact test. The overall survival rates of all of the non-small-cell lung cancer patients were calculated using the Kaplan-Meier method, and univariate and multivariate analyses were performed using the Cox proportional hazards regression model. In function, we showed that suppression of HBXIP decreased A549 cell proliferation and migration. HBXIP protein showed a mainly cytoplasmic staining pattern in non-small-cell lung cancer using immunohistochemical staining in paraffin-embedded non-small-cell lung cancer tissues and immunofluorescence staining in A549 cells. The HBXIP protein had strong positive staining in the non-small-cell lung cancer tissues, which was significantly higher than the percentage of adjacent non-tumor tissues. The overexpression of HBXIP was closely correlated with histological grade, clinical stage, lymph node metastasis, and lower overall survival rates of patients with non-small-cell lung cancer. Moreover, multivariate analysis suggested that HBXIP emerged as a significant independent prognostic factor along with clinical stage in patients with non-small-cell lung cancer. In conclusion, a high level of expression of HBXIP is associated with the progression of non-small-cell lung cancer and may be a useful biomarker for poor prognostic evaluation and a potential molecular therapy target for patients with non-small-cell lung cancer.