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

Expression of retinoic acid receptor beta (RAR beta) 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 RAR beta, 69% expressed hTERT, whereas only 54% of the 94 RAR beta 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 RAR beta and hTERT expression suggests that RAR beta expression may be an indicator of increased risk of lung cancer in heavy smokers.