Increased expression of high but not low molecular weight heat shock proteins in resectable lung carcinoma.
Strong expression of high-molecular-weight (HMW) heat-shock proteins (HSP) by lung carcinoma has been documented using immunohistochemistry. Far less is known about the expression of low-molecular-weight (LMW) HSP in lung cancer. We compared the quantitative expression of HMW (HSP-60, HSP-70) and LMW (HSP-27, ubiquitin) HSP in tumor and non-tumor lung tissue obtained from 47 patients undergoing surgical resection of lung carcinoma. HSP levels were determined in cell lysates from tissue samples by ELISA using streptavidin-biotin technology. Results were normalized to total protein content measured by spectrophotometry. Compared to disease-free lung tissue, tumor tissue samples showed higher levels of both HSP-60 (median value: 227 pg versus 96 pg per mg protein (P<0.001 by Wilcoxon Rank test for paired data) and HSP-70 (median value: 525 ng versus 401 ng per mg protein (P=0.01 by Wilcoxon Rank test for paired data). Tumor and tumor-free tissues show similar levels of ubiquitin and HSP-27. Neither the survival rate nor the histologic type and extent of cancer are correlated with the observed differences in HSP-60 and HSP-70 expression (P>0.1 by one way analysis of variance for repeated measures with one between subject factor). Our data confirm, on a quantitative basis, the increased expression of HSP-60 and HSP-70 in non-small-cell lung carcinoma. However, no prognostic value was found to be associated with this over-expression. In contrast, LMW stress proteins such as ubiquitin and HSP-27, although implicated in cellular processes potentially related to malignant transformation, show no increased expression in lung carcinoma.
Michils
A
A
Chest Department, CUB Erasme, 808 Route de Lennik, 1070 Brussels, Belgium. amichils@ulb.ac.be
Redivo
M
M
Zegers de Beyl
V
V
de Maertelaer
V
V
Jacobovitz
D
D
Rocmans
P
P
Duchateau
J
J
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000503:physiopathology* / Q000601:surgery; D002471:Cell Transformation, Neoplastic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006801:Humans; D008175:Lung Neoplasms / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight
D006360:Heat-Shock Proteins