Background & objective: Specific gene expression plays an important role in cancer gene therapy. Construction of specific expression vector is the basis of cancer gene therapy. This study was conducted to explore the expression specificity of osm (oncostatin M) gene driven by human telomerase reverse transcriptase (hTERT) gene promoter in tumor cells with telomerase activity and to investigate the growth inhibitory capability of expression of osm gene on telomerase-positive tumor cells.
Methods: The authors constructed the expression vector of osm gene afforded by the hTERT promoter and investigated its effect on tumors in vitro using reverse transcription polymerase chain reaction (RT-PCR), transient transfection, and MTT method.
Results: Expression of extrinsic osm gene driven by hTERT gene promoter was detected in HepG2 cell with telomerase activity, and not detected in human embryonic lung fibroblast (HEL) cell without telomerase activity. After transfection of phTERT-osm, the proliferation of HepG2, HeLa, Glc, and A549 cells showed significant inhibitory effect, and the inhibitory rate was 12.4-46%. No inhibitory effect appeared in HEL cell.
Conclusion: The expression of osm gene under the control of hTERT gene promoter can restrict toxic effect to telomerase-positive tumor cells, and alleviate the toxic effect on normal cells without telomerase activity.