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Genome-Wide Analysis of DNA Methylation in Gastrointestinal Cancer
07:50

Genome-Wide Analysis of DNA Methylation in Gastrointestinal Cancer

Published on: September 18, 2020

Promoter methylation and silencing of PTEN in gastric carcinoma

Young-Hwa Kang1, Hye Seung Lee, Woo Ho Kim

  • 1Cancer Research Institute, Seoul National University College of Medicine and BK21 Project for Medicine, Dentistry and Pharmacy, Seoul, Korea.

Laboratory Investigation; a Journal of Technical Methods and Pathology
|March 16, 2002
PubMed

Insights

Silencing of the PTEN gene, a tumor suppressor, is frequent in gastric cancer. Aberrant promoter methylation is a key mechanism, correlating with tumor progression and reduced patient survival.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • The PTEN gene (phosphatase and tensin homolog deleted on chromosome 10) is a crucial tumor suppressor involved in regulating Akt signaling pathways.
  • Aberrant promoter methylation is a known mechanism for silencing tumor suppressor genes in various cancers.

Purpose of the Study:

  • To investigate the methylation status and expression of the PTEN gene in gastric carcinomas.
  • To determine the correlation between PTEN alterations, clinicopathological features, and patient survival.

Main Methods:

  • Methylation-specific PCR was used to analyze the 5' CpG islands of the PTEN gene.
  • Immunohistochemical staining on tissue arrays assessed PTEN expression in 310 gastric carcinomas.
  • Clinicopathological data and patient survival were analyzed in relation to PTEN expression.

Main Results:

  • Loss of PTEN expression was observed in 20% (62/310) of gastric carcinomas.
  • PTEN promoter methylation was detected in 39% (26/66) of cases, with 73% (19/26) of methylated cases showing PTEN expression loss.
  • Altered PTEN expression significantly correlated with tumor depth, size, lymphatic invasion, advanced stage, and poorer patient survival (p < 0.001).

Conclusions:

  • PTEN gene silencing is a frequent event in gastric carcinoma.
  • Aberrant promoter methylation is a major mechanism driving PTEN silencing in gastric cancer.
  • PTEN gene abnormalities are associated with tumor progression, metastasis, and reduced survival, highlighting its role as a tumor suppressor in gastric carcinogenesis.

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