Background: The relation between smoking, chronic obstructive pulmonary disease (COPD), and lung cancer (LC) is an open field of investigation. A higher frequency of adenocarcinoma has been reported in patients with COPD. Heat shock proteins (Hsps) are implicated in tumoral cell growth and differentiation. The aim of the present study was to investigate the expression of Hsp60 and Hsp10 in bronchial biopsies from smokers with COPD and in 10 lung cancer patients and to evaluate the association between Hsps expression and carcinogenetic steps of LC.
Method: An immunohistochemical study was performed for Hsp60 and Hsp10 in bronchial biopsies from 35 COPD (postbronchodilator forced expiratory volume in 1 second [FEV(1)]: 53 +/- 19% [mean +/- SD]) patients with a history of smoking (53 +/- 34 pack/years) and in 10 patients with adenocarcinoma or adenosquamous carcinoma (ASC). Immunopositivity was quantified in the bronchial epithelium and in specimens with ASC. RESULTS.: In smokers with COPD, 10 out of 35 patients had a normal bronchial epithelium (NBE), 12 showed basal cell hyperplasia (BCH), 5 squamous metaplasia (SM), and 8 dysplasia (Dy). It was found that 58 +/- 23% and 54 +/- 23% of NBE and 48 +/- 29% and 52 +/- 26% of BCH expressed Hsp60 and Hsp10, respectively; in contrast, only 3 +/- 3% and 3.6 +/- 2% of SM, 1.9 +/- 4% and 1.1 +/- 2% of Dy expressed Hsp60 and Hsp10, respectively. ASC specimens were negative for Hsps proteins. Interestingly, NBE also present at the edges of ASC specimens was negative for Hsps proteins.
Conclusions: The loss of Hsp60 and Hsp10 immunopositivity is related to the development and progression of bronchial cancer in smokers with COPD.