DISTINCTIVE IMMUNOHISTOCHEMICAL PROFILES OF SMELL HEAT-SHOCK PROTEINS(HEAT-SHOCK-PROTEIN-27 AND ALPHA-B-CRYSTALLIN) IN HUMAN BRAIN-TUMORS

BACKGROUND, Recent studies have described alpha B-crystallin as a memb er of the small heat shock protein (HSP) family, and the expressions o f alpha-crystallin-related small heat shock proteins, namely HSP27 and alpha B-crystallin, in the brain appear to be regulated in a similar way by various stress conditions. METHODS, A comparative immunohistoch emical analysis was performed on 198 human brain tumors to examine the expressions of HSP27 and alpha B-crystallin. RESULTS, Positive staini ng with HSP27 was frequently observed in schwannomas, craniopharyngiom as, epidermoid cysts, and metastatic tumors to the brain. The immunopo sitivity of HSP27 was relatively low in tumors originating from neuroe pithelium as well as in meningiomas; however, a statistically signific antly higher percentage of HSP27-positive cells was noted in their ana plastic counterparts, such as glioblastomas, anaplastic oligodendrogli omas, anaplastic ependymomas, and anaplastic meningiomas (P < 0.005). Conversely, a positive immunoexpression of alpha B-crystallin was freq uently observed among astrocytic tumors, schwannomas, hemangioblastoma s, and chordomas. CONCLUSIONS, The immunohistochemical expression of H SP27 and alpha B-crystallin differed among histologic types of tumors. Furthermore, the immunopositivity of HSP27, which was considered to p lay a role not only in drug resistance but also in the regulation of c ell proliferation, increased in proportion to the anaplasia of the tum ors. (C) 1996 American Cancer Society.