Heat shock protein 72 expression in chondrosarcoma correlates with differentiation

Purpose: Heat shock proteins (hsp) are involved in tumor immunity, and a co rrelation with survival, occurence of metastases, and drug resistance has b een reported. It was the aim of this study to investigate the expression of heat shock proteins in chondrosarcomas and chondromas. Methods: Hsp expres sion was investigated immunohistochemically on paraffin-embedded sections o f 37 consecutive patients (24 male and 13 female, mean age 48 years) with c hondrosarcoma and of ten patients (six male, four female, mean age 36 years ) with chondroma. Results: Chondromas showed a positive staining for hsp27 in 100%, for hsp60 in 30%, for hsp72 in 80%, for hsp73 in 80%, and Tor hsp9 0 in 90%. In chondrosarcoma a decreased expression was found for hsp27 (62% positive, P < 0.05) and hsp72 (43% positive, P < 0.05), whereas no signifi cant difference to chondromas was detected in the expression of hsp60 (49% positive), hsp73 and hsp90 (73% and 81% positive, respectively). In additio n, hsp72 expression showed a correlation with differentiation of the tumors (P < 0.05); the lowest hsp72 expression was found in G3 chondrosarcomas (on ly 13% positive). No correlation with respect to differentiation was found for the expression of the other hsps. Conclusions: This study shows a diffe rent expression of hsps in chondrosarcomas and chondromas. Together with th e correlation of hsp72 expression with low differentiation, this finding co uld lead to new experimental and diagnostic strategies.