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P53 and Rb tumor suppressor gene alterations in gastric cancer

Rejane Mattar1, Suely Nonogaki, Cleonice Silva

  • 1Department of Gastroenterology, Hospital das Clínicas, Faculty of Medicine, University of São Paulo, São Paulo, SP, Brazil. rejanemattar@hotmail.com

Revista Do Hospital Das Clinicas
|September 14, 2004
PubMed
Abstract

Insights

Tumor suppressor gene inactivation, specifically Rb and p53, plays a role in gastric cancer development. Rb gene loss was noted in intestinal-type gastric cancer, while p53 alterations occurred in both types.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • Gastric carcinogenesis is frequently associated with tumor suppressor gene inactivation.
  • Understanding the roles of specific genes like p53, APC, DCC, and Rb is crucial for gastric cancer research.

Purpose of the Study:

  • To investigate the involvement of p53, APC, DCC, and Rb genes in gastric carcinoma.
  • To analyze gene alterations and their correlation with disease characteristics.

Main Methods:

  • Studied loss of heterozygosity for p53, APC, DCC, and Rb genes in 22 gastric cancer tissues using PCR.
  • Analyzed p53 gene mutations via single-strand conformation polymorphism and detected p53 protein expression using immunohistochemistry.

Main Results:

  • No loss of heterozygosity was found for the studied tumor suppressor genes.
  • Homozygous deletion of the Rb gene occurred in 23% of intestinal-type gastric carcinomas.
  • p53 gene alterations (band mobility shifts) were observed in 81.8% of cases, and p53 protein was detected in 63.6% of gastric cancer cells, suggesting mutant forms.

Conclusions:

  • Inactivation of Rb and p53 genes is implicated in gastric carcinogenesis.
  • Rb gene loss in intestinal-type gastric cancer warrants further investigation, potentially linked to Helicobacter pylori.
  • p53 gene alterations affect both intestinal and diffuse types of gastric cancer.

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