BACKGROUND & AIMS: Apobec-1 is an RNA-specific cytidine deaminase whose forced overexpression in transgenic animals is associated with hepatic carcinogenesis. Apobec-1 messenger RNA (mRNA) undergoes alternative splicing, generating a catalytically inactive peptide, apobec-T. We have examined apobec-1 gene expression in human gastrointestinal tumors and in colon cancer-derived cell lines. METHODS: Levels of the full-length (apobec-1) and alternatively spliced (apobec-T) mRNAs were measured by RNase protection assay, and apobec-T distribution was determined by immunocytochemical localization. RESULTS: Apobec-1 mRNA was detectable in normal and colon cancer tissue, metastatic nodules, and certain colon cancer-derived cell lines. Apobec-T mRNA abundance was increased an average of 3.5-fold in colon cancers compared with paired control tissue (range, 0.5-14-fold). Immunocytochemical analysis showed apobec-T expression in normal fetal and adult colon and in gastric and small intestinal adenocarcinomas, colonic tubular adenomas, and both primary and metastatic colonic tumors. Overexpression of apobec-T in a tetracycline-responsive cell line decreased cellular proliferation. CONCLUSIONS: Apobec-T is expressed in normal, adenomatous, and cancerous gastrointestinal tissues, and levels of the mRNA encoding this peptide are significantly increased in colon cancer. Although its relationship to colon carcinogenesis has not been defined, the regulated overexpression of apobec-T is associated with an altered growth phenotype.
BACKGROUND & AIMS:Apobec-1 is an RNA-specific cytidine deaminase whose forced overexpression in transgenic animals is associated with hepatic carcinogenesis. Apobec-1 messenger RNA (mRNA) undergoes alternative splicing, generating a catalytically inactive peptide, apobec-T. We have examined apobec-1 gene expression in humangastrointestinal tumors and in colon cancer-derived cell lines. METHODS: Levels of the full-length (apobec-1) and alternatively spliced (apobec-T) mRNAs were measured by RNase protection assay, and apobec-T distribution was determined by immunocytochemical localization. RESULTS:Apobec-1 mRNA was detectable in normal and colon cancer tissue, metastatic nodules, and certain colon cancer-derived cell lines. Apobec-T mRNA abundance was increased an average of 3.5-fold in colon cancers compared with paired control tissue (range, 0.5-14-fold). Immunocytochemical analysis showed apobec-T expression in normal fetal and adult colon and in gastric and small intestinal adenocarcinomas, colonic tubular adenomas, and both primary and metastatic colonic tumors. Overexpression of apobec-T in a tetracycline-responsive cell line decreased cellular proliferation. CONCLUSIONS: Apobec-T is expressed in normal, adenomatous, and cancerous gastrointestinal tissues, and levels of the mRNA encoding this peptide are significantly increased in colon cancer. Although its relationship to colon carcinogenesis has not been defined, the regulated overexpression of apobec-T is associated with an altered growth phenotype.
Authors: Debnath Mukhopadhyay; Shrikant Anant; Robert M Lee; Susan Kennedy; David Viskochil; Nicholas O Davidson Journal: Am J Hum Genet Date: 2001-11-27 Impact factor: 11.025
Authors: Krisztina A Szigeti; Alexandra Kalmár; Orsolya Galamb; Gábor Valcz; Barbara K Barták; Zsófia B Nagy; Sára Zsigrai; Ildikó Felletár; Árpád V Patai; Tamás Micsik; Márton Papp; Eszter Márkus; Zsolt Tulassay; Peter Igaz; István Takács; Béla Molnár Journal: BMC Cancer Date: 2022-06-02 Impact factor: 4.638
Authors: K Klimek-Tomczak; M Mikula; A Dzwonek; A Paziewska; J Karczmarski; E Hennig; J M Bujnicki; P Bragoszewski; O Denisenko; K Bomsztyk; J Ostrowski Journal: Br J Cancer Date: 2006-02-27 Impact factor: 7.640