<正> Objective: To induce changes in biological character of human liver cancer cell line SMMC-7721 by bloc-king the expression of telomerase genes hTRT and to explore its value in cancer gene therapy. Methods: The vehiclefor eukaryotic expression of antisense hTRT was constructed and then transfected into SMMC-7721 cells. The effects ofantisense hTRT gene on telomerase activity

cancer cell growth and malignant phenotypes were analyzed. Results: Theobtained transfectants that could express antisense hTRT gene stably showed marked decrease in telomerase activity;the shortening of telomere was obvious; cells presented contact growth inhibition; in nude mice transplantation

the rateof tumor induction dramatically decreased. Conclusion: Antisense hTRT gene expression can significantly inhibit te-lomerase activity of cancer cells and decrease malignant phenotypes in vitro and in vivo. Therefore

as a telomerase in-hibitor

antisense hTRT gene may be a new pathway for cancer therapy.