Clinical significance of PHPT1 protein expression in lung cancer

摘要

＜正＞ Background In our previous studies,we found the expression of 14-kD phosphohistidine phosphatase （PHPT1） wasassociated with lung cancer cells migration and invasion,and PHPT1 mRNA expression level in lung cancer tissuesclinically correlated with lymph node metastasis.In the present study,we aimed to further investigate the expression ofPHPT1 protein in lung cancer.Methods Expression of PHPT1 protein in tissue samples from 146 lung cancers and 30 normal tissues adjacent to lungcancers was assessed using immunohistochemical method.Fisher’s exact test was used to analyze expression patternsof PHPT1 protein in these tissue types.Meanwhile,we studied the correlation between expression of PHPT1 protein andclinicopathological features in lung cancer.Results Significantly higher expression levels of PHPT1 protein were found in lung cancer samples （53.42%） than innormal tissues adjacent to lung cancer （23.33%） （P=0.003）.Fisher’s exact test showed that lung cancer stage positivelycorrelated with expression of PHPT1 protein （P=0.02）,and lung cancer samples with lymph node metastasis showedhigher PHPT1 protein expression （P=0.016） than the samples without lymph node metastasis.Conclusions The results of this study agree with findings from our previous study of PHPT1 mRNA expression in lungcancer tissues,and strongly suggest that PHPT1 protein is closely associated with the carcinogenesis and metastasis oflung cancer.Thus,therapy targeting PHPT1 （inhibition or silencing） could be potentially benefited for lung cancerpatients.