Effect of heat shock protein 90 (Hsp90) on migration and invasion of human cancer cells in vitro.

We studied the effect of purified native heat shock protein 90 (Hsp90) from bovine and mouse brain on migration and invasion of human glioblastoma (A-172) and fibrosarcoma (HT1080) cells. Hsp90 in concentrations of 0.01-0.10 mg/ml stimulated migration and invasion of tumor cells in vitro by 20-32% (p<0.05). Polyclonal antibodies to Hsp90 blocked the Hsp90-dependent stimulation of cell invasion, which indicates specificity of the stimulating effect of extracellular Hsp90 on tumor cell invasion. Hence, extracellular Hsp90 can be considered as a promising molecular target, because its inhibition can suppress invasion and metastasizing of tumor cells.