Retinoic acid receptor β and telomerase catalytic subunit expression in bronchial epithelium of heavy smokers

Expression of retinoic acid receptor β (RARβ) and telomerase catalytic subunit (human telomerase reverse transcriptase [hTERT]) was analyzed in 285 bronchial biopsy specimens from 53 heavy cigarette smokers and four former smokers by using in situ hybridization. Of the 191 biopsy specimens that were positive for RARβ, 69% expressed hTERT, whereas only 54% of the 94 RARβ negative biopsy specimens expressed hTERT (P = .014). Because hTERT expression in bronchial tissue has been previously associated with increased risk of lung cancer, the association between RARβ and hTERT expression suggests that RARβ expression may be an indicator of increased risk of lung cancer in heavy smokers.