Silencing of the human TERT gene by RNAi inhibits A549 lung adenocarcinoma cell growth in vitro and in vivo.

Human telomerase reverse transcriptase (hTERT) is the catalytic subunit and the activity determinant factor of the telomerase enzyme which maintains the length of human chromosomes. In recent years it has become an attractive molecular target for cancer gene therapy. In the present study, we show that hTERT siRNA effectively suppressed the expression of hTERT mRNA and hTERT protein levels, reduced telomerase activity, and induced apoptosis of A549 lung adenocarcinoma cells (P<0.05). In vivo, tumors treated with the hTERT siRNA were of reduced sizes, indicating that the hTERT siRNA also reduced the tumorigenic potential of lung adenocarcinoma cells (P<0.05). These results demonstrate that hTERT siRNA can cause effective suppression of telomerase and lead to apoptosis in A549 lung adenocarcinoma cells. hTERT siRNA may, therefore, be a strong candidate for highly selective therapy for chemoprevention and treatment of lung adenocarcinoma.