[Research on expression and control of p16 and p21 by wild-type p53 gene in two lung adenocarcinoma cell lines].

Objective: To evaluate the potential of p53 gene therapy for lung cancer in nude mice.

Methods: Two lung adenocarcinoma cell lines L-18 and 95D were infected with adenovirus encoding wild-type p53 gene pAdCMV -p53 (Ad-p53 ) in vitro and in vivo. The antitumor effect of wild type p53 gene was assessed by cell growth curve, reverse transcriptase polymerase chain reaction (RT-PCR) analysis and TUNEL staining methods.

Results: The p53-specific growth inhibition and apoptosis of tumor cells were observed in both cell lines in vitro. By RT-PCR analysis, the increasing expression of p21 gene but not of p16 gene after p53 gene infection suggested that p21 gene played an important role in p53 gene induced cell apoptosis. The in vivo study revealed that celiac injection of p53 gene significantly inhibited the tumorigenesis in 95D and L-18 cells in nude mice. However, no obvious inhibition of tumorigenesis was observed after subcutaneous injection of p53 gene in L-18 cell line, compared with the inhibition noted in 95D cell line.

Conclusion: The results showed the adenovirus-mediated antitumor therapy by means of p53 gene infection might be a potential way to inhibit cancer growth and induce tumor cell apoptosis.