HEAT-SHOCK (HSP70) AND RESISTANCE PROTEINS IN NON-SMALL-CELL LUNG CARCINOMAS

The aim of the study was to prove whether or not an association exists between the heat shock protein 70 (hsp70) and drug resistance. Tumor samples of 90 patients with previously untreated non-small lung carcin omas were investigated immunohistochemically for expression of resista nce related proteins. Additionally, resistance to doxorubicin was dete rmined using a short term test. No association between resistance to d oxorubicin and hsp70 was found. Of 63 resistant tumors, 33 showed low and 30 high hsp70 expression. Of the 26 sensitive tumors, 11 had low a nd 16 had high hsp70 expression. No relationship could be found betwee n P-glycoprotein which is related to multidrug resistance and hsp70 ex pression or between hsp70 expression and expression of topoisomerase I I, thymidylate synthase and metallothionein. On the other hand, a tren d was noted for tumors with high glutathione S-transferase-pi expressi on to show high hsp70 expression. In addition, there was a significant relationship between hsp70 and catalase positivity. These data indica te that heat shock and stress promote intracellular oxidative damage a nd catalase is necessary for protection.