Inducible HSP70 antagonized IL-1β-induced cytotoxic effect on HeLa cells and improved the cell survival.

<p>(A) HeLa cells were stimulated with IL-1β (10 ng/ml) for indicated times, HSP70, HSP27, HSP90, and β-actin levels were determined by Western blotting. (B) HeLa cells were transfected with pcDNA3.0 (−) or pcDNA3.0-Flag-HSP70 (+). After 48 h, cells with either baseline level of or overexpression of HSP70 were exposed to IL-1β(10 ng/ml) or CHX (1 µg/ml) or both for 24 h. Cell viability was subsequently detected by CCK8 assay as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050059#s2" target="_blank">Material and Methods</a>. Cell viability is shown relative to the untreated control. The experiment was independently repeated for three times and data were shown as mean ± SD; bars: SD. Significant difference was determined by student’s <i>t</i>-test comparing HSP70 transfected cells with vector transfected control exposed to both IL-1β and CHX, * <i>P</i><0.05.