title: hTERT, MYC and TP53 deregulation in gastric preneoplastic lesions.
abstract: BACKGROUND
  Gastric cancer is a serious public health problem in Northern Brazil and in the world due to its high incidence and mortality. Despite the severity of the disease, more research is needed to better understand the molecular events involved in this intestinal-type gastric carcinogenesis process. Since precancerous lesions precede intestinal-type gastric cancer, here, we evaluated the hTERT, MYC, and TP53 mRNA and protein expression, as well as TP33 copy number, in gastric preneoplastic lesions.
  
  
  METHODS
  We evaluated 19 superficial gastritis, 18 atrophic gastritis, and 18 intestinal metaplasia from cancer-free individuals of Northern Brazil. Quantitative reverse transcription PCR was used to analyze the mRNA expression and immunohistochemical methods were used to assess protein immunoreactivity in tissue samples. The number of TP53 gene copies was investigated in gastric diseases by quantitative PCR.
  
  
  RESULTS
  We observed hTERT, MYC, and p53 immunoreactivity only in intestinal metaplasia samples. The immunoreactivity of these proteins was strongly associated with each other. A significantly higher MYC mRNA expression was observed in intestinal metaplasia compared to gastritis samples. Loss of TP53 was also only detected in intestinal metaplasia specimens.
  
  
  CONCLUSIONS
  We demonstrated that hTERT, MYC, and TP53 are deregulated in intestinal metaplasia of individuals from Northern Brazil and these alterations may facilitate tumor initiation.
authors: Laboratório de Citogenética Humana, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
authors: Tanielly Cristina Raiol
authors: TC
authors: Silva
authors: Mariana Ferreira
authors: MF
authors: Leal
authors: Danielle Queiroz
authors: DQ
authors: Calcagno
authors: Carolina Rosal Teixeira
authors: CR
authors: de Souza
authors: André Salim
authors: AS
authors: Khayat
authors: Ney Pereira Carneiro
authors: NP
authors: dos Santos
authors: Raquel Carvalho
authors: RC
authors: Montenegro
authors: Silvia Helena Barem
authors: SH
authors: Rabenhorst
authors: Mayara Quaresma
authors: MQ
authors: Nascimento
authors: Paulo Pimentel
authors: PP
authors: Assumpção
authors: Marília
authors: M
authors: de Arruda Cardoso Smith
authors: Rommel Rodríguez
authors: RR
authors: Burbano
mesh_terms: D001938:Brazil; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D005260:Female; D005756:Gastritis / Q000235:genetics / Q000378:metabolism; D018628:Gene Dosage; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008679:Metaplasia / Q000235:genetics / Q000378:metabolism; D011230:Precancerous Conditions / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D016271:Proto-Oncogene Proteins c-myc / Q000032:analysis / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019098:Telomerase / Q000032:analysis / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000235:genetics / Q000378:metabolism*
chemical_list: C489427:MYC protein, human; D016271:Proto-Oncogene Proteins c-myc; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C509186:TERT protein, human; D019098:Telomerase