title: Adipo-R1 and adipo-R2 expression in colorectal adenomas and carcinomas.
abstract: BACKGROUND
  Human adiponectin (ApN), a 30 kDa glycoprotein of 244-amino acids which is predominantly produced by adipocytes, exerts its effects via two receptors, namely adiponectin receptor-1 (adipo-R1) and adiponectin receptor-2 (adipo-R2) with differential binding affinity to globular adiponectin. Adiponectin receptor expression has been studied in several cancer tissues. However, there are no studies of colorectal adenomas which are considered to be precursors for colorectal carcinoma (CRC).
  
  
  OBJECTIVE
  In the present study, the expression of adipo-R1 and adipo-R2 was investigated immunohistochemically in colorectal adenomas and colorectal carcinoma tissues in an attempt to determine associations with these tumors.
  
  
  METHODS
  The study enrolled 50 CRC patients with tumor resection and 82 patients who were diagnosed with adenomatous polyps, classified as negative for neoplasia, low-grade dysplasia (L-GD) or high- grade dysplasia (H-GD).
  
  
  RESULTS
  Expression of both adipo-R1 and adipo-R2 was found to be significantly lower in the CRCs than in colorectal adenomas (tubular and tubulovillous, p=0.009 and p<0.001, respectively). Adipo-R1 and adipo-R2 expression was also significantly lower in the CRC group when compared with the groups of patients with low grade dysplasia, high-grade dysplasia or no neoplasia (p=0.012 and p<0.001, respectively). In addition, it was observed that adipo-R2 expression was generally positive in the non-neoplastic group irrespective of the adipo-R2 expression. In the L-GD, H-GD and CRC groups, the adipo-R2 result was positive whenever adipo-R1 result was positive but some patients with negative adipo-R1 had positive adipo-R2 (p<0.001, p=0.004, p<0.001, respectively).
  
  
  CONCLUSIONS
  This study indicated that ApN may play a role in the progression of colorectal adenomatous polyps to carcinoma through actions on adipo-R1 and adipo-R2 receptors.
authors: Department of Gastroenterology, Medical Faculty, Ondokuz Mayis University, Samsun, Turkey E-mail : talatayy@gmail.com.
authors: Talat
authors: T
authors: Ayyildiz
authors: Enver
authors: E
authors: Dolar
authors: Nesrin
authors: N
authors: Ugras
authors: Ahmet Tarik
authors: AT
authors: Eminler
authors: Banu
authors: B
authors: Erturk
authors: Saduman Balaban
authors: SB
authors: Adim
authors: Omer
authors: O
authors: Yerci
mesh_terms: D000236:Adenoma / Q000473:pathology*; D018256:Adenomatous Polyps / Q000473:pathology; D017667:Adipocytes / Q000378:metabolism; D052242:Adiponectin / Q000378:metabolism; D002277:Carcinoma / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D054419:Receptors, Adiponectin / Q000096:biosynthesis*; D012189:Retrospective Studies
chemical_list: C475418:ADIPOR1 protein, human; C475420:ADIPOR2 protein, human; D052242:Adiponectin; D054419:Receptors, Adiponectin