BACKGROUND: The suppressors of cytokine signalling (SOCS) are inhibitors of cytokine signalling; methylation of SOCS-3 has been implicated in the tumorigenesis of liver as well as head and neck cancer. AIMS: This study was performed to elucidate the role of SOCS-1 and SOCS-3 in Barrett's adenocarcinoma and its precursor lesions. METHODS: DNA of specimens from 19 Barrett's adenocarcinomas, 56 Barrett's intraepithelial neoplasias (n = 29 low grade and n = 27 high grade), 30 Barrett's mucosa without neoplasia, 20 samples of normal squamous and gastric epithelium and four cell lines were studied using methylation specific PCR for the SOCS-1 and SOCS-3 promoter following microdissection. The presence of SOCS-3 mRNA transcripts was confirmed by semiquantitative real time PCR, and the SOCS-3 protein was analysed immunohistochemically. RESULTS: In normal squamous epithelium and normal gastric mucosa, neither SOCS-3 nor SOCS-1 methylation was observed. In Barrett's mucosa without intraepithelial neoplasia, SOCS-3 methylation occurred in 4/30 cases (13%) whereas SOCS-1 was unmethylated. A hypermethylated SOCS-3 promoter was found in 14/19 Barrett's adenocarcinomas (74%) and in 20/29 high and 6/27 low grade intraepithelial neoplasias (69% and 22%, respectively). SOCS-1 promoter hypermethylation occurred in 8/19 adenocarcinomas (42%) and in 6/29 high grade and 1/27 low grade intraepithelial neoplasias (21% and 4%, respectively). Methylation of the SOCS-3 promoter correlated with downregulation of SOCS-3 transcripts and protein expression in these tumours and various cell lines. In the cell lines tested, SOCS-3 and SOCS-1 transcripts increased after treatment with the demethylation compound 5-aza-2-deoxycytidine. CONCLUSIONS: These data indicate that promoter methylation and subsequent transcript downregulation of SOCS-3 transcripts and, to a much lesser extent, SOCS-1 are involved in the multistep carcinogenesis of Barrett's adenocarcinoma.
BACKGROUND: The suppressors of cytokine signalling (SOCS) are inhibitors of cytokine signalling; methylation of SOCS-3 has been implicated in the tumorigenesis of liver as well as head and neck cancer. AIMS: This study was performed to elucidate the role of SOCS-1 and SOCS-3 in Barrett's adenocarcinoma and its precursor lesions. METHODS: DNA of specimens from 19 Barrett's adenocarcinomas, 56 Barrett's intraepithelial neoplasias (n = 29 low grade and n = 27 high grade), 30 Barrett's mucosa without neoplasia, 20 samples of normal squamous and gastric epithelium and four cell lines were studied using methylation specific PCR for the SOCS-1 and SOCS-3 promoter following microdissection. The presence of SOCS-3 mRNA transcripts was confirmed by semiquantitative real time PCR, and the SOCS-3 protein was analysed immunohistochemically. RESULTS: In normal squamous epithelium and normal gastric mucosa, neither SOCS-3 nor SOCS-1 methylation was observed. In Barrett's mucosa without intraepithelial neoplasia, SOCS-3 methylation occurred in 4/30 cases (13%) whereas SOCS-1 was unmethylated. A hypermethylated SOCS-3 promoter was found in 14/19 Barrett's adenocarcinomas (74%) and in 20/29 high and 6/27 low grade intraepithelial neoplasias (69% and 22%, respectively). SOCS-1 promoter hypermethylation occurred in 8/19 adenocarcinomas (42%) and in 6/29 high grade and 1/27 low grade intraepithelial neoplasias (21% and 4%, respectively). Methylation of the SOCS-3 promoter correlated with downregulation of SOCS-3 transcripts and protein expression in these tumours and various cell lines. In the cell lines tested, SOCS-3 and SOCS-1 transcripts increased after treatment with the demethylation compound 5-aza-2-deoxycytidine. CONCLUSIONS: These data indicate that promoter methylation and subsequent transcript downregulation of SOCS-3 transcripts and, to a much lesser extent, SOCS-1 are involved in the multistep carcinogenesis of Barrett's adenocarcinoma.
Authors: Peter K K Wong; Paul J Egan; Ben A Croker; Kristy O'Donnell; Natalie A Sims; Sarah Drake; Hiu Kiu; Edward J McManus; Warren S Alexander; Andrew W Roberts; Ian P Wicks Journal: J Clin Invest Date: 2006-05-18 Impact factor: 14.808
Authors: Diego F Calvisi; Sara Ladu; Alexis Gorden; Miriam Farina; Elizabeth A Conner; Ju-Seog Lee; Valentina M Factor; Snorri S Thorgeirsson Journal: Gastroenterology Date: 2006-04 Impact factor: 22.682
Authors: R C Sobti; Neha Singh; Showket Hussain; Vanita Suri; Raje Nijhawan; A C Bharti; Mausumi Bharadwaj; B C Das Journal: Cell Oncol (Dordr) Date: 2011-09-21 Impact factor: 6.730
Authors: Victoria A Newton; Nicole M Ramocki; Brooks P Scull; James G Simmons; Kirk McNaughton; P Kay Lund Journal: Am J Pathol Date: 2010-03-26 Impact factor: 4.307