Expression and Function of TNF α cDNA mutant in human bladder cancer EJ cell lines

Objective To study the function of a gene mutant of tumor necrosis factor α (TNF α) in bladder cancer. Methods A TNF α cDNA mutant was selected as the target gene.The novel mutant was transduced into human bladder cancer EJ cell lines with the plasmid pcDNA 3.1(+) as the vector by the method of calcium phosphate DNA coprecipitation. Results Polymerase chain reaction (PCR) analysis confirmed the exogenic gene was stably integrated into EJ cell lines.The level of TNF α in the supernatant collected from EJ cells transfected with TNF α cDNA mutant was (0.664±0.225)ng/ml by radioimmunoassay (RIA) and L929 bioassay showed its cytotoxicity was 4～8U/ml.The formation ability of clony in soft agar was decreased significantly and the inhibition rate was 36.5%. Conclusions The TNF α cDNA mutant can be used in gene therapy for bladder cancer.