Heat shock protein 72 expression in chondrosarcoma correlates with differentiation

Purpose: Heat shock proteins (hsp) are involved in tumor immunity, and a correlation with survival, occurrence of metastases, and drug resistance has been reported. It was the aim of this study to investigate the expression of heat shock proteins in chondrosarcomas and chondromas. Methods: Hsp expression was investigated immunohistochemically on paraffin-embedded sections of 37 consecutive patients (24 male and 13 female, mean age 48 years) with chondrosarcoma 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 for hsp90 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 significant difference to chondromas was detected in the expression of hsp60 (49% positive), hsp73 and hsp90 (73% and 81% positive, respectively). In addition, hsp72 expression showed a correlation with differentiation of the tumors (P < 0.05); the lowest hsp72 expression was found in G3 chondrosarcomas (only 13% positive). No correlation with respect to differentiation was found for the expression of the other hsps. Conclusions: This study shows a different expression of hsps in chondrosarcomas and chondromas. Together with the correlation of hsp72 expression with low differentiation, this finding could lead to new experimental and diagnostic strategies.