[Role of telomerase in chrysotile induced malignant transformation of normal human embryonic lung fibroblasts].

Objective: To explore the role of telomerase in asbestos dust induced malignant transformation of human embryonic lung fibroblasts in vitro.

Methods: Human telomerase catalytic subunit (hTERT) was transferred into human embryonic lung fibroblasts (HELF). Chrysotile dust at concentration of 2.5 microg/cm(2) was added to HELF transduced with and without hTERT (HELF-T+), respectively, and their transduced foci were separated. Biological characteristics of the cells, telomerase activity, length of telomere and cell growth curve were observed. Colony forming test was performed on soft agar to evaluate the nature of transformation.

Results: The hTERT gene was transferred into HELF steadily, and HELF-T+ was established. Malignant transformation occurred in both HELF and HELF-T+ by asbestos stimulation. Asbestos dusts could induce higher rate of transformations in HELF-T+ [(2.08 +/- 1.08)/utensil] than in HELF [(1.08 +/- 0.10)/utensil], P < 0.05. Telomerase activity in both transformed malignant cells and HELF-T+ was higher, as well as the longer length of telomere in them.

Conclusion: Rate of malignant transformation in cells with more activity of telomerase and longer length of the telomere was higher after stimulation with asbestos, indicating telomerase could play an important role in asbestos induced human cells malignant transformation.