Heat shock proteins as novel therapeutic targets in cancer

Heat shock proteins (HSPs) are evolutionarily conserved molecules synthesised by cells exposed to sub-lethal stresses. Acting as molecular chaperones, HSPs protect cells from environmental stress damage by assisting in proper folding and stabilisation of proteins. In addition, they help to sequester severely damaged proteins for degradation. Owing to the nature of their function, HSPs are often found to be overexpressed in a wide range of cancers. Members of the HSP family have been implicated in cancer growth as promoting tumour cell proliferation as well as inhibiting cellular death pathways. In recent years, several HSP90 client proteins have been validated as clinically important therapeutic targets for treatment of cancer, and inhibitors of HSP90 have emerged as potentially beneficial anticancer agents. This review explores the involvement of HSPs in cancer and the development of several anticancer agents with promising therapeutic applications.