RESUMO
<p><b>OBJECTIVE</b>To investigate the effect of PTEN tumor suppressor gene combined with doxycycline on telomerase activity in human mucoepidermoid carcinoma cell line.</p><p><b>METHODS</b>The wild-type PTEN tumor suppressor gene or empty vector was introduced into mucoepidermoid carcinoma cell line in vitro, then the cancer cells were treated with doxycycline. Cancer cell survival was determined by MTT assay. Telomerase activity was determined using telomerase repeat amplification protocol-enzyme-linked immunosorbent assay (TRAP-ELISA).</p><p><b>RESULTS</b>Compared to the control cells, cancer cells transfected with the wild-type PTEN gene showed growth inhibition and increased sensitivity to doxycycyline, and the ratio of augment of drug sensitivity was 1.65-4.75. The telomerase activity in cancer cells treared with PTEN gene transfection or doxycycline alone decreased, however, telomerase activity in combined group decreased more remarkably.</p><p><b>CONCLUSION</b>PTEN gene in combination with doxycycline has significant inhibitory effect on telomerase activity in cancer cells.</p>