title: Expression of gastrin-releasing peptide receptor in epidermoid carcinoma of the anal canal.
abstract: Gastrin-releasing peptide is a neuroendocrine homolog of bombesin that demonstrated important growth-stimulatory effects in various types of cancer. High levels of expression of gastrin-releasing peptide receptors (GRPR) has been found in different malignancies, and the studies exploring the therapeutic use of GRPR antagonists have shown promising results. Our aim was to determine the GRPR expression in epidermoid carcinoma of the anal canal and discuss its potential clinical applications. We performed immunohistochemical analysis for GRPR on formalin-fixed and paraffin-embedded tumor samples obtained from 35 patients with anal cancer. As a control group, we analyzed 24 samples of nonmalignant anal tissues (hemorrhoidectomy specimens). GRPR expression was evaluated using a semiquantitative approach according to the intensity and distribution of staining. All analyzed tissues, except 1 control sample, showed positive GRPR immunoexpression. GRPR was strongly expressed in 54% of cancer specimens as compared with only 12% of the control specimens (P<0.003). In tumors, the receptor showed a diffuse and homogenous pattern of distribution within the specimens. In contrast, control specimens showed a focal pattern of staining restricted to the basal half of the epithelium. In conclusion, we demonstrated that GRPR is highly expressed in epidermoid carcinoma of the anal canal, suggesting this receptor might have a role in anal carcinogenesis. Our results provide a basis for exploiting GRPR as a target for diagnostic and therapeutic purposes in the anal cancer.
authors: *Division of Coloproctology, Hospital de Clinicas de Porto Alegre §Department of Internal Medicine, Division of Oncology Departments of †Surgery ‡Pathology, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors: Fabíola F
authors: FF
authors: Martins
authors: Paulo C
authors: PC
authors: Contu
authors: Luise
authors: L
authors: Meurer
authors: Gilberto
authors: G
authors: Schwartsmann
authors: Daniel C
authors: DC
authors: Damin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001005:Anus Neoplasms / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D018004:Receptors, Bombesin / Q000096:biosynthesis*
chemical_list: D009363:Neoplasm Proteins; D018004:Receptors, Bombesin