The role HOXA5 in extrahepatic cholangiocarcinoma (Methylation)

Homeobox A5 (HOXA5) is a transcription factor in mammalian and can regulate cell differentiation, proliferation and apoptosis as well as tumorigenesis. However, little is known on whether and how HOXA5 can regulate the malignant behaviors of cholangiocarcinoma. The methylation levels of HOXA5 were evaluated by methylation microarray and bisulfite sequencing PCR. We found that hypermethylation in the HOXA5 promoter down-regulated HOXA5 expression in extrahepatic cholangiocarcinoma (ECCA) tissues, which was correlated with worse overall survival. HOXA5 over-expression significantly inhibited the proliferation and tumor growth. A fresh extrahepatic cholangiocarcinoma cell sample (TFK-1) and a normal bile duct sample were used for methylation analysis and we found HOXA5 was hypermethylated in extrahepatic cholangiocarcinoma sample compared with normal control sample.