The Aberrant Mathylation Of Fragile Histidine Triad Gene And The Expression Of Its Protein And The Regulation Between The Latter And Multidrug Resistance 1 In Lung Cancer

To explore the possible function of FHIT gene promoter methylation in lung cancer development, the expression of FHIT protein and its multi-drug resistance as a tumor suppressor genes applied in gene therapy for lung cancers, this study detected the abnormal methylation of FHIT gene and the expression of its protein in lung cancerous tissues and adjacent tissues by using MSPCR and immunohistochemistrical staining medthods. It also detected the expression of MDR1 protein in lung cancerous tissues by immunohistochemistrical staining. Results showed that the abnormal methylation in cancerous tissues was significantly higher than in adjacent tissues. The protein expression was identical to the results of gene detection. In adjacent tissues the positive expression rates of FHIT protein with bronchial epithelial hyperplasias were significantly lower than those without bronchial epithelial hyperplasias. What's more, the rates of abnormal methylation of FHIT gene for cancer patients with positive expression of FHIT protein were significantly lower than negative ones. The expression of FHIT protein indeed influenced the disease-free survival time of patients'directly and it was the crucial index to decide the live time of patients. However, abnormal methylation of FHIT gene and expression of its protein were irrelevant to clinical pathological factors. Moreover, in cancerous tissues it was related with the expression of MDR1 protein to some extend. That is to say, FHIT protein was not able to suppress the mechanism of MDR1 in lung cancer. On the contrary, its expression perhaps might induce or enhance the MDR of tumor.To sum up, the following conclusions could be drawn out from this study: (1) Abnormal methylation of FHIT gene in lung cancer occured frequently and the expression of FHIT protein was down regulation significantly. FHIT may play an important role in the development of lung cancer. (2) FHIT protein can be used as a major index to judge the disease-free survival time of patients. (3) To some extend, the expression of FHIT protein was related with the expression of MDR1 in cancerous tissues.