title: Up-regulation of a BCL9-related beta-catenin-binding protein, B9L, in different stages of sporadic colorectal adenoma.
abstract: Aberrant activation of Wnt signaling is a critical event in the development of human colorectal tumors. The aim of this study was to elucidate the role of B9L and its association with beta-catenin in each stage of the adenoma-carcinoma sequence of human colorectal tumorigenesis. We investigated the expression levels of B9L in sporadic colorectal adenomas and carcinomas, categorized according to the Vienna classification, using real-time quantitative polymerase chain reaction (RTQ-PCR) and immunohistochemical analysis. B9L was expressed in the nuclei of non-neoplastic colonic mucosa cells and was overexpressed in the nuclei of neoplasias and invasive carcinoma cells. Immunoreactivity to B9L protein was correlated with the progressive grades of colorectal neoplasias, as was the expression of B9L mRNA. A high level of immunoreactivity to nuclear B9L was present in 27% of low-grade neoplasias and in more than 50% of high-grade neoplasias and invasive carcinomas, whereas a high level of nuclear B9L immunoreactivity was not observed in any of the non-neoplastic mucosa samples. The expression of B9L was dramatically increased in low-grade neoplasias compared with that in non-neoplastic mucosa. B9L may play an important role in tumorigenesis induced by aberrant activation of Wnt signaling and may act as a key protein in the progressive dysplasia of adenoma.
authors.affiliation: Department of Surgery, Gunma University, Graduate School of Medicine, Gunma University Hospital 3-39-22 Showa-Machi, Maebashi, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sakamoto
authors.forename: Susumu
authors.initials: S
authors.lastname: Ohwada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Toya
authors.forename: Nozomi
authors.initials: N
authors.lastname: Togo
authors.forename: Kenji
authors.initials: K
authors.lastname: Kashiwabara
authors.forename: Tetsunari
authors.initials: T
authors.lastname: Oyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ito
authors.forename: Shungo
authors.initials: S
authors.lastname: Adachi
authors.forename: Takafumi
authors.initials: T
authors.lastname: Jigami
authors.forename: Tetsu
authors.initials: T
authors.lastname: Akiyama
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000236:Adenoma / Q000378:metabolism* / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D009367:Neoplasm Staging; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000096:biosynthesis*; D015854:Up-Regulation; D051176:beta Catenin / Q000378:metabolism
chemical_list: C495498:BCL9L protein, human; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D051176:beta Catenin