Detection Of CpG Island Hypermethylation Of TSLC1 Gene In Cervical Carcinoma And Pre-malignant Lesion And Its Clinical Significance

Objective: To observe the methylation status of tslc1 gene and its relationship with cervical carcinoma and pre-malignant lesion and its clinical significance .Methods: (1)DNA Preparation:Genomic DNA was extracted from chronical cervicitis tissues, cervical intraepithelial neoplasia(CIN) and cervical carcinoma by TE9 extracted liquid and the phenol-chloroform extraction procedure. (2)Bisulfite modification: A total of genomic DNA,obtained from tissues,was modified by EZ-DNA Methylation-Gold Kit^TM sodium bisulfite to convert unmethylated cytosines to uracils. (3)Methylation-Specific PCR(MSP):MSP distinguishes unmethylated from methylated alleles based on sequence changes produced after the bisulfite treatment of DNA,which converts only unmethylated cytosine to uracil,and subsequent PCR using primers designed for either methylated or unmethylated DNA. (4)Statistical analysis:The SPSS Statistical Package program 10.0 was used for all analyses.Associations between the variables weretested by x² test.Value of less than 0.05(P<0.05)was deemed significant.Result: The positive expression rate 66.2% (45/68) of MSP in uterine cervical carcinoma was significantly higher than 43.3% (29/67)in cervical intraepithelial neoplasia(CIN)and 6.7%(2/29)in chronical cervicitis tissues . compared with the three relationship differentiation had statistical significance(P<0.05);The frequency of promoter hypermethylation of tslc1 gene was significantly lower in cancers of stage I than that in stage II and III (P <0.05); There was no significant diference was foundbetween squamous cell carcinoma and adenocarcinoma ( P >0.05) . but a highly significant diference was observed between patients with and without lymphnode metastasis(N0 and N1)(P<0.05).Conclusion: Hypermethylation of TSLC1 promoter is associated with loss of its transcription in cervical carcinoma.The high frequency hypermethylation of TSLC1 promoter illustrates its potential clinical application as tumor marker for diagnosis and prognosis.