Inducible heat shock protein 70 expression as a potential predictive marker of metastasis in breast tumors.

Heat shock protein (Hsp)-peptide complexes purified from tumors can prime the immune system against tumor antigens, but how they contribute to the generation of immune responses against naturally occurring tumors is unknown. Murine tumors expressing high amounts of Hsp70 are preferentially rejected by the immune system, suggesting that low Hsp70 expression is advantageous for tumor growth in the host. To determine whether Hsp70 was differentially expressed in human tumors, inducible Hsp70 expression was quantitatively (by Western blot) and qualitatively (by immunohistology) analyzed in 53 biopsies of tumor and normal breast tissue.