Methylation of PCDH8 in pancreatic carcinoma cell lines

Objective To investigate the methylation status of PCDH8 gene in pancreatic carcinoma.Methods Methylation of PCDH8 gene in 2 samples of normal pancreatic tissues and 6 pancreatic carcinoma cell lines (PANC1, ASPC1, BxPC3, CFPAC, PaTu8988 and SW1990) was detected by the methylationspecific PCR (MSP) method. The expression of PCDH8 mRNA was detected with 5-Aza-2-deoxycytidine (5-Aza-dC) treatment, a kind of DNA methyltransferase (DNMT) inhibitor in 6 pancreatic carcinoma cell lines by real-time-PCR. Results The methylation of PCDH8 gene was not detected in normal tissues, while it was partially methylated in PANC1, BxPC3, CFPAC and it was totally methylated in PaTu8988, ASPC1, SW1990.PCDH8 mRNA was expressed in PANC1, SW1990, PaTu8988 and the relative quantities of mRNA expression (RQ) were 1.576 ± 0.648, 0.013 ± 0.008, 0.002 ± 0.001; PCDH8 mRNA was not expressed in BxPC3,CFPAC, ASPC1. After 5-Aza-dC treatment, PCDH8 mRNA was expressed in PANC1, ASPC1, BxPC3,CFPAC, PaTu8988, SW1990 and the relative quantities of mRNA expression all significantly increased, and they were 7. 463 ± 2.628, 10. 696 ± 1.539, 7.852 ± 2.762,421.815 ± 1.493, 118.595 ± 4.089, 6.690 ±1.884. Conclusions The methylation of PCDH8 gene may be the major mechanism of down-regulated expression of PCDH8 gene in pancreatic carcinoma. Key words: Pancreatic neoplasms;  Methylation;  Polymerase chain reaction;  Protocadherin 8