A novel method to assay molecular chaperone activity of HSP70: Evaluation of drug resistance in cancer treatment

In this work, we have proposed a novel method to specifically assay the molecular chaperone activity of HSP70 based on the HSP70-substrate peptide interaction. By selectively labeling the substrate peptide of HSP70 via host–guest interaction with two different cucurbituril species, the HSP70-substrate peptide interaction can be transduced into detectable signal readout. By using the signal readout, assay of the molecular chaperone activity of HSP70 can be achieved. Moreover, by using our method, chaperone activity of HSP70 can serve as a reliable indicator of drug resistance in cancer treatment. The experimental results reveal that enhanced chaperone activity of HSP70 is observed in both drug-resistant cancer cell line and the serum of cancer victim subject to anti-cancer therapy. Therefore, the proposed method to assay the molecular chaperone activity of HSP70 can be a tool of efficiency in evaluating therapeutic response in HSP70-targeted cancer treatment.

► A new assay method for the molecular chaperone activity of HSP70 is developed.
► The method is based on selective labeling of substrate peptide by cucurbiturils.
► Patient serum is assayed to evaluate drug resistance in cancer treatment.