The Clinical Significance Of HIF-1α, CA IX And GLUT-1 Expression In Nasopharyngeal Carcinoma

OBJECTIVE To investigate the correlation between the expression of HIF-la, CA IX and GLUT-1 protein in nasopharyngeal carcinoma(NPC) tissue and clinic biological behavior and prognosis, to explore the role of HIF-1α, CA IX and GLUT-1 in diagnosing, staging, treatment and prognosis evaluating of NPC.METHODS Expression of HIF-1α, CA IX and GLUT-1 protein were examined by immunochemistry in 134 samples of NPC and 20 samples of chronic nasopharyngitis which recruited between 2007 and 2011. Correlations between the expression of HIF-1α, CA IX and GLUT-1 protein in NPC tissue and clinical characteristics and clinical outcome were evaluated.RESULTS The positive expression rate of HIF-1αprotein was 51.5% in NPC,0% in chronic nasopharyngitis, respectively, and there was significant difference in the expression of HIF-1αprotein between NPC and chronic nasopharyngitis tissue (P<0.05). The expression of HIF-1αwere correlated significantly with patient's age (>50y vs.<50y), clinical staging (StageⅢandⅣvs. StageⅠandⅡ) and lymph node metastasis (positive vs. negative) (P<0.05), but no significant correlation were not observed between HIF-1αexpression and patient's gender and T-stage (P>0.05). HIF-1αexpression in NPC tissue was correlated significantly with poor progression free survival (P=0.014), however, No significant correlation was found between HIF-1αexpression and overall survival (P=0.055). The positive expression rate of CAⅨprotein was 54.5% in NPC,15% in chronic nasopharyngitis, respectively, and there was significant difference in the expression of CAⅨprotein between NPC and chronic nasopharyngitis tissue (P<0.05). No statistic significance were observed between the expression of CAⅨprotein and patient's gender, age, T-stage, clinical staging and lymph node metastasis (P>0.05). CAⅨexpression was correlated significantly with poor progression free survival (P=0.008), however, No significant correlation was found between CAⅨexpression and overall survival (P=0.150). The positive expression rate of GLUT-1 protein was 50% in NPC,10% in chronic nasopharyngitis, respectively, and there was significant difference in the expression of GLUT-1 protein between NPC and chronic nasopharyngitis tissue (P<0.05). The expression of GLUT-1 was correlated significantly with patient's age (P<0.05), but no significant correlation were observed between GLUT-1 expression and patient's gender, T-stage, clinical staging, and lymph node metastasis (P>0.05). GLUT-1 expression was correlated significantly with poor progression free survival (P=0.024). however, No significant correlation was found between GLUT-1 expression and overall survival (P=0.078). GLUT-1 protein expression were independent of HIF-la protein and CAⅨprotein expression in NPC. However, A positive correlation was observed between the HIF-la protein and CA IX protein in NPC(r=0.282, P=0.01).CONCLUSIONS Over-expression of HIF-1α, CA IX and GLUT-1 protein is common in NPC, and It may play an important role in carcinogenesis and the development of NPC. HIF-1α,CAⅨand GLUT-1 protein expression in NPC tissue was correlated with poor prognosis. Targeting the hypoxia pathway may be useful in the treatment of NPC.