Figure 10. Expression of heat shock protein 27 (HSP27) varies in human osteosarcoma primary tumors and lung metastases.

Representative images of HSP27 expression in patient samples are shown. Using an institutional review board-approved established osteosarcoma tissue microarray, we performed immunohistochemistry staining for HSP27 using an HSP27-specific antibody. HSP27 expression varied between 0% and 100% in both primary resection specimens (obtained following treatment with neoadjuvant chemotherapy in most cases) and resected pulmonary metastasis specimens. HSP27 was expressed (defined as >10% staining in tumor tissue) in 81 of 132 primary resection specimens (61%) and 50 of 64 osteosarcoma pulmonary metastasis specimens (78%).