Methylation Of The 5'CpG Island Of The FHIT Gene And Its Relationship To Gastrointestinal Cancer

ObjectiveTo study the methylation of the FHIT gene and the relationship to its inactivation in gastrointestinal cancer cell lines and colorectal cancer and the effect of demethylation agent 5-aza-2' -deoxycytine on the growth of HCT1116 cells.MethodsMethylation of the FHIT gene in seven gastrointestinal cancer cell lines and 30 primary tumors from colorectal cancer patients and its corresponding normal tissue was analyzed by methylation specific PCR (MSP) and the difference in the expression of FHIT by RT-PCR before and after treatment with 5-aza-2' -deoxycytine and the effect of 5-aza-2' -deoxycytine on the growth of HCT1116 cells by flow cytometry and hematoxylin and eosinstain and immuocytochemistry.ResultsSix of seven cell lines(85.70%) and 14 of 30(46.70%) primary tumors demonstrated methylation of the 5' CpG island of the FHIT gene . Methylated cell line exhibited reexpression of the FHIT gene and HCT1116 cells exhibited increased expression of the FHIT gene after treatment with 5-aza-2' -deoxycytine(P<0.05).The apoptotic rate increased remarkably in HCT1116 cells after treatment with 5-aza-2' -deoxycytine(P<0.05).HCT1116 cells exhibited increased expression of the FHIT protein(P<0.05) and HCT1116 cells were smaller and decreased after treatment with 5-aza-2' -deoxycytine.