Heat shock protein 27 is over-expressed in tumor tissues and increased in sera of patients with gastric adenocarcinoma

Background: In a previous study, we found that heat shock protein 27 (HSP27) was over-expressed in gastric adenocarcinoma (GA) tissue. In this study, our goal was to further verify the expression profile of HSP27 in patients with GA. Methods: Western blot and immunohistochemistry were employed to determine HSP27 expression in 50 paired tumor and adjacent normal tissue. ELISA was used to quantify serum HSP27 concentrations in the same 50 GA patients and 50 healthy individuals. Results: Compared to adjacent normal tissues, HSP27 was over-expressed in 25 (50%, p = 0.000) and 24 (48%, p = 0.000) cases of GA tissue by Western blot and immunohistochemistry, respectively. ELISA revealed significantly higher serum concentrations of HSP27 in patients with GA patients (mean = 986 pg/mL) compared to healthy individuals (mean = 573 pg/mL) (p = 0.003). In addition, infection with Helicobacter pylori (HP) in healthy individuals was associated with increased expression of HSP27 in both gastric mucosa and serum. Conclusions: These data suggest that HSP27 is over-expressed in GA tissue and serum concentrations of HSP27 are increased in patients with GA. Over-expression of HSP27 may indicate a gastric malignant/infectious process. The detection of serum HSP27 concentrations by ELISA may be useful for screening for GA. Clin Chem Lab Med 2010;48: 263-9.