Low expression of γ-glutamyl hydrolase mRNA in primary colorectal cancer with the CpG island methylator phenotype
2008

Low GGH Expression in Colorectal Cancer with CIMP+

Sample size: 114 publication 10 minutes Evidence: moderate

Author Information

Author(s): Kawakami K, Ooyama A, Ruszkiewicz A, Jin M, Watanabe G, Moore J, Oka T, Iacopetta B, Minamoto T

Primary Institution: Kanazawa University

Hypothesis

Is there a specific mRNA expression pattern for folate- and nucleotide-metabolising enzymes in CIMP+ colorectal cancer?

Conclusion

Low expression of γ-glutamyl hydrolase (GGH) is associated with the CpG island methylator phenotype in colorectal cancer.

Supporting Evidence

  • Low GGH expression was consistently associated with CIMP+ features in both Australian and Japanese colorectal cancer cohorts.
  • Only 5.6% of CIMP+ tumors showed hypermethylation of the GGH promoter, indicating it does not account for low expression.
  • GGH expression was significantly lower in CIMP+ colorectal cancer compared to CIMP−.

Takeaway

This study found that colorectal cancer with a specific genetic change has lower levels of a protein called GGH, which might affect how the cancer grows.

Methodology

mRNA levels for 17 genes were measured by real-time RT-PCR in colorectal cancer samples, and CIMP+ status was determined by methylation-specific PCR.

Potential Biases

Potential biases may arise from the selection of samples and the methods used for gene expression analysis.

Limitations

The study's findings may not be generalizable due to the specific populations studied (Australian and Japanese cohorts).

Participant Demographics

Participants included colorectal cancer patients from Australia and Japan.

Statistical Information

P-Value

0.023

Confidence Interval

95% CI: 0.51–0.95

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1038/sj.bjc.6604346

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