Effect of Adenomatous Polyposis Coli(APC) Promoter Methylation on Gene Transcription in Lung Cancer Cell Lines
ZHANG Li-Xia1, PAN Shi-Yang1, CHEN Dan1, XIE Er-Fu1, GAO Li1, SHU Yong-Qian2, LU Zu-Hong3, CHENG Lu3, YANG Di4, ZHANG Ji-Nan4 1. Center of Clinical Laboratory, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210029, P. R. China 2. Department of Oncology, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210029, P. R. China 3. Department of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, 210096, P. R. China 4. Department of Cardiovascular Disease, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210029, P. R. China
BACKGROUND OBJECTIVE: Hypermethylation of CpG islands in adenomatous polyposis coli (APC) gene has been detected in a variety of human tumors, which is involved in the pathogenesis of these tumors. In previous research, we detected APC promoter methylation in 47% lung tumor tissues. This study was to analyze the effect of APC promoter methylation on the gene transcription in 3 lung cancer cell lines. METHODS: The methylation status of APC promoter 1A in lung adenocarcinoma cell line SPCA1, small cell lung cancer cell line NCI-H446, and big cell lung cancer cell line NCI-H460 was detected by methylation-specific polymerase chain reaction (MSP) and microarray; methylated cord blood DNA served as positive control, and unmethylated cord blood DNA served as negative control. The expression of APC was examined by real-time quantitative polymerase chain reaction (PCR) with Sybr-Green Ⅰ staining. After treatment of 1, 5, 10, 15 μmol/L DNA methyltransferase inhibitor 5-aza-2-deoxycytidine (5-aza-dC), the expression of APC in NCI-H460 cells was detected by real-time PCR. RESULTS: APC promoter 1A was methylated in NCI-H460 cells, and unmethylated in NCI-H446 and SPC-A1 cells. Hypermethylation was detected in all 5 CpG islands (687, 707, 714, 719, 726) of APC promoter 1A in NCI-H460 cells. The expression of APC in NCI-H460 cells was decreased by 26.04% of that in NCI-H446 cells and by 32.36% of that in SPCA1 cells. After treatment of 1, 5, 10, 15 μmol/L 5-aza-dC, the expression of APC promoter 1A in NCI-H460 cells was enhanced by 4.59, 5.78, 9.58, 5.98 folds, respectively. CONCLUSION: APC gene is hypermethylated in HCI-H460 cells, and its transcription coud be activated by 5-aza-dC.
【Fund】： 江苏省“135”重点实验室项目(No.SK200205);; 江苏省卫生厅面上项目(No.Z200601)~~
【CateGory Index】： R734.2
【CateGory Index】： R734.2