hTERT promotes the invasion of telomerase-negative tumor cells in vitro and in vivo

Objective To investigate the biological behavior changes and the possible mechanisms of human osteosarcoma cell line U-2 OS after hTERT gene modifications. Methods Transform hTERT gene to U-2 OS cells (hTERT negative) by liposome method. Then test the expression of hTERT by immunochemistry and Western blot. Detect the changes of telomere length, telomerase activity, cell cycle of U-2 OS, biological and vito-dynamic changes and transwell matrigel ability after hTERT gene modification. Results Immunohistochemical staining and Western blot showed that the expression of hTERT was positive in U-2 OS cells after hTERT gene modification. The telomerase activity was upregulated, and the telomere was extended. The vacuum micropipette aspiration assay found that hTERT transfection increased the cellular adhesion capacity to the extracellular matrix(ECM). Transwell matrigel assay confirmed an increased invasion ability in hTERT/U2OS cells. Conclusion These results strongly suggest that hTERT transfection promotes the invasion of telomerase-negative cells. Telomerase-mediated telomere maintenance enables these cells to achieve a fully malignant endpoint, including invasion and metastasis.