Heat shock protein inhibitors and vaccines as new agents in cancer treatment

Background: Heat shock proteins (HSP) play an essential role as molecular chaperones by assisting correct holding and folding in human cells. At the same time they present implications in tumor cell proliferation, differentiation, matrix invasion, angiogenesis, metastasis and cell death. They also possess the ability to present tumor molecules to the immune system and elicit an immune response. New agents targeting HSP, as anticancer treatment, are under clinical evaluation. Objective: The aim of this review is to explore the role of HSP90 inhibitors as anticancer agents as well as to evaluate the benefit from the use of autologous HSP vaccines in both the adjuvant setting and first-line treatment. Methods: The latest evidence regarding the use of geldanamycin analogues or newer water-soluble and synthetics molecules that inhibit the binding of HSP90 to client proteins was reviewed. Immunization using tumor-derived HSP in several cancer types was also evaluated. Conclusions: HSP90 inhibitors represent a promising therapeutic option although further evaluation in larger clinical trials is needed. On the other hand, HSP vaccination has already an established role in our armory against cancer.