Expression And Its Clinical Significance Of Caspase-3,HIF-2α And CAIX In Nasopharyngeal Carcinoma

OBJECTIVE To investigate the correlation between the expression of Caspase-3, HIF-2αand CA IX protein in nasopharyngeal carcinoma(NPC) tissue and clinic biological behavior,and to explore the role of Caspase-3,HIF-2αand CA IX in diagnosing,staging,treating and prognosis evaluating of NPC.METHODS Expression of Caspase-3,HIF-2αand CA IX protein were examined by immunochemistry in 46 samples of NPC and 20 samples of chronic nasopharynxitis. The dynamic variations in expression levels of Caspase-3,HIF-2αand CA IX protein in pre-radiotherapy(pre-RT),during-radiotherapy(during-RT)(36Gy) and post-radiotherapy (post-RT) were detected in 17 cases of NPC patients.RESULTS The positive expression rate of Caspase-3 protein was 60.9%in NPC, 90%in chronic nasopharynxitis,respectively,and there was significant difference in the expression of Caspase-3 protein between NPC and chronic nasopharynxitis tissue (P＜0.05).The expression of Caspase-3 was not significantly correlated with patients gender,age,tumor size,clinical staging,and lymph node metastasis(P＞0.05).The positive expression rate of HIF-2αprotein was 41.3%in NPC,5%in chronic nasopharynxitis,respectively,and there was significant difference in the expression of HIF-2αprotein between NPC and chronic nasopharynxitis tissue(P＜0.05).No statistic significance were observed between the expression of HIF-2αprotein and patients gender and age(P＞0.05).There were significant stastistical correlations between overexpression of HIF-2αprotein and tumor size(P=0.014),clinical staging (P=0.027) as well as lymph node metastasis(P=0.028).The positive expression rate of CA IX protein was 54.3%in NPC,15%in chronic nasopharynxitis,respectively,and there was significant difference in the expression of CA IX protein between NPC and chronic nasopharynxitis tissue(P＜0.05).The expression of CA IX was not significantly correlated with patients gender,age,tumor size,clinical staging,and lymph node metastasis(P＞0.05).Caspase-3 protein expression were independent of HIF-2αprotein expression and CA IX protein expression in NPC.However,a positive correlation was observed between the expression of HIF-2αprotein and CA IX protein expression in NPC(r=0.467,P＜0.05).Among 17 patients had been examined dynamically,the positive expression rate of Caspase-3 protein in during-RT patients significantly increased as compared to that of pre-RT patients(P＜0.05),however, HIF-2αand CA IX protein in during-RT patients significantly decreaced as compared to that of pre-RT patients(P＜0.05).CONCLUSIONS The expression of Caspase-3 protein was lower in NPC than it in chronic nasopharynxitis,and reduced Caspase-3 protein expression may be correlated with carcinogenesis and development of NPC.Overexpression of HIF-2αand CA IX protein is common in NPC,and it may be associated with the carcinogenesis and development of NPC.Detection of HIF-2αprotein expression level is of significance in diagnosing and staging of NPC.Combined detection of HIF-2αand CA IX protein expression level may be important for judging outcome and evaluating the prognosis of NPC.Targeting the hypoxia pathway may be useful in the treatment of NPC.