Evaluation of potential reference genes for qRT-PCR studies in human hepatoma cell lines treated with TNF-α

In this study, the expression of eight candidate reference genes, B2M, ACTB, GAPDH, HMBS, HPRT1, TBP, UBC, and YWHAZ, was examined to identify optimal reference genes by quantitative reverse transcripfion-polymerase chain reaction （qRT-PCR） analysis in two human hepatoma cell lines, BEL-7402 and SMMC-7721, treated with tumor necrosis factor-α （TNF-α） for different time periods. The ex- pression stability of these genes was analyzed by three inde- pendent algorithms： geNorm, NormFinder, and BestKeeper. Results showed that TBP was the most stably expressed gene in BEL-7402 and SMMC-7721 cell lines under current experi- mental conditions, and that the optimal set of reference genes required for accurate normalization was TBP and HMBS, based on the pairwise variation value determined with geNorm. UBC and ACTB were ranked as the least stable genes by same algorithms. Our findings provide evidence that using TBP alone or in combination with HMBS as endogen- ous controls could be a reliable method for normalizing qRT- PCR data in human hepatoma cell lines treated with TNF-α.