Establishment of HSP90 overexpressing cell line and effects of HSP90 overexpressing on cell stress responses / 中国病理生理杂志

ABSTRACT

AIM: To establish a HSP90 highly expressing cell line and study the effect of high level of HSP90 on cell stress response. METHODS: The recombined plasimid pSmycHSP, which contains the full length DNA coding for human HSP90?, was introduced into mouse fibroblast cell line NIH-3T3 by electroporation after being subcloned, purified and identified by limited enzyme digestion. Screened by G418, the positive clones were selected and identified by immunofluorescence, immunocytochemistry and Western-blotting. NIH-3T3 cells transfected with empty plasmid served as control, hyperthermia(44 ℃, 20 min, 40 min)was used to simulate oxidative stress. The activity of lactate dehydrogenase (LDH) in supernatant and damage of DNA were detected by automatic biochemistry analyzer and flow cytometer separately to analyze the effect of high-level HSP90 on cell membrane and DNA injuries under stress condition. RESULTS: The rising level of HSP90 was shown by immunofluorescence, immunocytochemistry and Western-blotting in HSP90 overexpressing cell line. There was no difference in the leakage of LDH between HSP90 overexpressing cell line and control, but the damage of DNA was more severe at 44 ℃for 20 min in HSP90 overexpressing cell line than control. Compared with control, the above indices were relieved at 44 ℃ for 40 min in HSP90 overexpressing cell line. CONCLUSION: The NIH-3T3 derived cell line, which stably expressed high level of HSP90, was established. The effect of high-level HSP90 on cells is complex at different intensity of stress, and the protection may be shown at more severe stress circumstance.