title: Downregulated inhibitor of growth 3 (ING3) expression during colorectal carcinogenesis.
abstract: OBJECTIVE
  ING3 (inhibitor of growth protein 3) overexpression decreased S-phase cell population and colony-forming efficiency, and induced apoptosis at a p53-mediated manner. The aim of this study was to investigate the clinicopathological and prognostic significance of ING3 expression in colorectal carcinogenesis and subsequent progression.
  
  
  METHODS
  ING3 expression was examined by immunohistochemistry on tissue microarray containing colorectal non-neoplastic mucosa (NNM), adenoma and adenocarcinoma. Colorectal carcinoma tissue and cell lines were studied for ING3 expression by Western blot or RT-PCR.
  
  
  RESULTS
  ING3 mRNA was differentially expressed in Colo201, Colo205, DLD-1, HCT-15, HCT-116, HT-29, KM-12, SW480, SW620 and WiDr cells. Carcinomas showed significantly lower ING3 expression than matched NNM at mRNA level (P< 0.05), but not at protein level. Immunohistochemically, ING3 expression was significantly decreased from NNM, adenoma to adenocarcinoma (P< 0.05). ING3 expression was not correlated with age, sex, tumour size, depth of invasion, lymphatic or venous invasion, lymph node metastasis, tumour- node- metastasis staging or differentiation. Kaplan-Meier analysis indicated that ING3 protein expression was not associated the prognosis of the patients with colorectal carcinoma (P< 0.05).
  
  
  CONCLUSIONS
  Our study showed that downregulated ING3 expression might play an important role in colorectal adenoma-adenocarcinoma sequence. Further studies are required to understand the mechanism.
authors.forename: Wen-feng
authors.initials: WF
authors.lastname: Gou
authors.forename: Hong-zhi
authors.initials: HZ
authors.lastname: Sun
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhao
authors.forename: Zhe-feng
authors.initials: ZF
authors.lastname: Niu
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Mao
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takano
authors.affiliation: Cancer Research Center, The First Affiliated Hospital of Liaoning Medical University, JinZhou, PR China, .
authors.forename: Hua-chuan
authors.initials: HC
authors.lastname: Zheng
mesh_terms: D015153:Blotting, Western; D063646:Carcinogenesis / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007564:Japan; D053208:Kaplan-Meier Estimate; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D018398:Homeodomain Proteins; C459806:ING3 protein, human; D025521:Tumor Suppressor Proteins