title: Retinoic acid receptor-beta expression in stage I non-small cell lung cancer and adjacent normal appearing bronchial epithelium.
abstract: Retinoic acid receptor-beta (RAR-beta) is induced by and mediates the growth-inhibitory and apoptotic effects of retinoic acid (RA), suggesting that loss of RAR-beta expression may be one of the critical events involved in the carcinogenesis/ progression of non-small cell lung cancer (NSCLC) and in the responsiveness to retinoid chemotherapy. However, recent contradictory reports that the expression of RAR-beta is associated with poor clinical outcome, and the fact that treatment of serum-deprived type 2 alveolar cells with RA leads to a stimulation of cell proliferation, require the verification of RAR-beta as a biomarker of chemoprevention or prognosis. The expression status of RAR-beta in cancer cells and adjacent normal appearing bronchial epithelium from 39 patients, diagnosed as stage I NSCLC and undergone a curative lung resection, was analyzed in paraffin-embedded tissue sections by IHC staining. The normal appearing bronchial epithelium of 14 out of 33 (42.4%) specimens expressed RAR-beta, whereas 22 out of the 39 (56.4%) stage I NSCLC specimens expressed RAR-beta. RAR-beta was more frequently expressed in the adenocarcinoma (72.7%) than in the squamous cell carcinoma (31.3%) (p=0.026). Neither the expression status in normal appearing adjacent tissue nor that in the tumor tissue had prognostic implications. The higher expression of RAR-beta in cancer tissue, the focal and uneven distribution in normal appearing adjacent bronchial epithelium, and inconsistency with the corresponding tumor tissue, suggest that the expression status of RAR-beta as a biomarker for chemoprevention/early diagnosis or the prognosis of NSCLC requires further consideration.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, 134 Shin chon-dong, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Yoon Soo
authors.initials: YS
authors.lastname: Chang
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Chung
authors.forename: Dong Hwan
authors.initials: DH
authors.lastname: Shin
authors.forename: Kyung Young
authors.initials: KY
authors.lastname: Chung
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Kim
authors.forename: Joon
authors.initials: J
authors.lastname: Chang
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Kim
authors.forename: Se Kyu
authors.initials: SK
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001980:Bronchi / Q000378:metabolism / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000473:pathology; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta