Detection Of GDF15 Gene Promoter Methylation In Bladder Cancer And Its Reverse Status Effect On The Proliferation,Migration And Invasion Of 5637 Cell

Objective To detect the Growth Differentiation 15 Factor(GDF15)methylation status and explore the role of promoter region aberrant methylation in the development of bladder cancer.Methods We detected the methylation status of GDF15 promoter CpG island(CGI)in bladder cancer cell line 5637、HT1376、KU19-19,normal bladder tissue and 1 pairs of bladder tissues(cancer and para-cancerous tissue)by using bisulfite genomic sequencing PCR(BSP)combined with TA clone for sequencing.The methylation rate of GDF15 in 5637 was compared before and after treatment of the inhibitor of DNA methyltransferase(5-Aza-2-deoxycitydine,5-Aza-dc);Western blot was used to detect the protein expression of GDF15,MTT was used to detect cell proliferation,scratch assay was used to detect cell migration and transwell assay was used to detect cell invasion capability.Results The average methylation rate of GDF15 promoter CGI was 86.91% in 5637,10.71% in HT1376,8.33% in KU19-19,and 86.91% in cancer tissues,9.52% in paracancerous tissues,5.95% in normal tissues.The methylation rate of cancer tissue was higher than that of normal bladder and para-cancerous tissues(P<0.05).5-Aza-dc could reverse the methylation status of GDF15 promoter in 5637,and compared with before trement all of the index including of protein increasing,cell proliferation,migration and invasion ability decreasing had statistical significance(P<0.05).Conclusion This promoter hypemlethylation is correlated with GDF15 gene expression in bladder cancer cell line 5637 and bladder tissues,and plays a key role in GDF15 silencing.Reverse methylation status can result in protein increasing,cell proliferation,migration and invasion ability decreasing.Aberrant hypermethylation of GDF15 might become early diagnosis index and treatment target of bladder cancer.