title: Inactivation of 14-3-3sigma by hypermethylation is a rare event in colorectal cancers and its expression may correlate with cell cycle maintenance at the invasion front.
abstract: In many kinds of cancers, 14-3-3sigma, one of the cell cycle negative regulator, is inactivated by hypermethylation of the gene. In colorectal cancers, this study revealed that the hypermethylation of the 14-3-3sigma gene was an uncommon event and 14-3-3sigma expression was kept even in established colorectal cancer cell lines. Immunohistochemical study using surgical materials showed the expression of 14-3-3sigma was localized at the deep peripheral area of the tumor, so-called invasion front. According to the results of Ki-67 and cyclin B1 immunohistochemistry, 14-3-3sigma-positive cases maintained higher proliferative activity compared to 14-3-3sigma-negative cases at IF. However, a significant correlation between 14-3-3sigma expression and proliferative activity in CRC cells remains to be unsolved.
authors.affiliation: Department of Tumor Pathology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. muide@showa.gunma-u.ac.jp
authors.forename: Munenori
authors.initials: M
authors.lastname: Ide
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Takayuki
authors.initials: T
authors.lastname: Asao
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kuwano
mesh_terms: D048948:14-3-3 Proteins; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D002453:Cell Cycle; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000378:metabolism; D005092:Exonucleases / Q000235:genetics* / Q000378:metabolism; D005095:Exoribonucleases; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D019394:Ki-67 Antigen / Q000378:metabolism; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D015347:RNA Probes; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D048948:14-3-3 Proteins; D014408:Biomarkers, Tumor; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D004273:DNA, Neoplasm; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D015347:RNA Probes; D016159:Tumor Suppressor Protein p53; D005092:Exonucleases; D005095:Exoribonucleases; C413442:SFN protein, human