Heat shock protein expression in human gliomas

Background: Heat shock proteins (HSP) are cytoprotective, antiapoptotic pro teins which may predict clinical prognosis in various types of cancer. Here , we asked whether the differential response to radiochemotherapy and diffe rent overall prognosis for astrocytic and oligodendroglial tumours can be a ccounted for by differences in HSP expression. Material and Methods: We exa mined aB-crystallin, HSP27, HSP70, HSC70 (HSP73) and HSP90 expression in 44 human gliomas (5 anaplastic and 5 low-grade astrocytomas, 5 anaplastic and 5 low-grade oligodendrogliomas and 24 glioblastomas) by immunohistochemist ry. Results: HSP were expressed in the tumour parenchyma of all high-grade and most low-grade gliomas, including oligodendrogliomas. Endothelial cells were more often positive for HSC70 and HSP90 but more often negative for H SP27 in glioblastomas than in the other tumours. HSP were also observed in macrophages/microglial cells, but not in a tumour-specific pattern. Conclus ion: Different patterns of HSP expression seem not to account for the diffe rential response of these tumours to adjuvant cytotoxic therapy.