The Study Of Associations Between Methylation Modified Gene MAPT And Prognosis Of The Patients With Colorectal Cancer

Background and objective: Abnormal expression of microtubule associated protein tau(MAPT)gene is associated with many human diseases,including Alzheimer's disease,Parkinson's disease,breast cancer and prostate cancer.However,few data are available on the expression and regulation of this gene in colorectal cancer(CRC).The purpose of this study was to evaluate the methylation status of Cp G islands in the MAPT gene promoter region and the expression of its encoded protein tau in CRC,and to determine the prognostic value of MAPT gene methylation in CRC patients.Methods: 1.Real-time quantitative methylation specific PCR was used to detect the methylation level of MAPT gene and Cp G island methylator phenotype(CIMP)status in the in-situ tumor samples of colorectal cancer patients.2.The expression level of tau in human colorectal cancer cells was detected by Western blot(WB).3.The expression level of tau in colorectal cancer samples was detected by immunohistochemistry(IHC).4.To validate the interactions between MAPT and HDAC6 by using the coimmunoprecipitation(Co-IP).Results: 1.MAPT Cp G island of promoter is hypermethylated in 23.4% of patients with stage II CRC.2.The prognosis of CRC patients with MAPT hypermethylation was poor.3.MAPT is differentially expressed in human colon cancer cells lines and primary tumor tissues in patients with CRC,and down-regulated in some primary tumor tissues.4.Interactions between MAPT and HDAC6 were validated.