title: RARRES1 expression is significantly related to tumour differentiation and staging in colorectal adenocarcinoma.
abstract: Retinoic acid receptor responder 1 (RARRES1) is a retinoid regulated gene. Its expression is frequently down-regulated through DNA hypermethylation in several types of malignant tissues. This study investigated the clinical significance of RARRES1 protein and its association with RARRES3 protein expression in 161 (26 adenoma, 13 distal normal mucosa and 122 primary colorectal adenocarcinoma) paraffin-embedded colorectal tissues by immunohistochemistry. RARRES1 protein was detected at the highest levels in terminally differentiated cells of normal mucosal tissues and all 26 adenoma tissues. Among 122 colorectal adenocarcinomas, the poorly differentiated adenocarcinomas and Dukes' stage D tumours showed a significant decrease in RARRES1 expression (P < 0.001 and P < 0.01, respectively). RARRES1 expression was significantly (P < 0.001) correlated with RARRES3 expression, which was positively associated with tumour differentiation (P < 0.001). Difference in expression of RARRES1 among 119 patients had no apparent effect on patient survival. Our results suggest the role of RARRES1 in colorectal epithelial differentiation, and the down-regulation of RARRES1 is related to stage D progression.
authors.affiliation: Graduate Institutes of Medical Sciences, National Defense Medical Center, 161 Minchuan East Road, Sec. 6, Taipei 114, Taiwan, ROC.
authors.forename: Chang-Chieh
authors.initials: CC
authors.lastname: Wu
authors.forename: Rong-Yaun
authors.initials: RY
authors.lastname: Shyu
authors.forename: Jung-Mao
authors.initials: JM
authors.lastname: Chou
authors.forename: Shu-Wen
authors.initials: SW
authors.lastname: Jao
authors.forename: Pei-Chieh
authors.initials: PC
authors.lastname: Chao
authors.forename: Jung-Cheng
authors.initials: JC
authors.lastname: Kang
authors.forename: Sheng-Tang
authors.initials: ST
authors.lastname: Wu
authors.forename: Shiang-Long
authors.initials: SL
authors.lastname: Huang
authors.forename: Shun-Yuan
authors.initials: SY
authors.lastname: Jiang
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000378:metabolism* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D016019:Survival Analysis
chemical_list: D008565:Membrane Proteins; C437968:PLAAT4 protein, human; C452562:RARRES1 protein, human; D018168:Receptors, Retinoic Acid