A promising biomarker to diagnosis gastric and colorectal cancer

RASSF1A inactivation by promoter hypermethylation in gastric and colorectal cancer has been reported. However, serum promoter methylation of RASSF1A in gastric and colorectal cancer has not been well studied. Comparative studies using both primary tumor tissue and serum samples can evaluate the diagnostic role of serum RASSF1A promoter hypermethylation in gastric and colorectal cancer.

A research article published on May 21, 2008 in the World Journal of Gastroenterology addresses this question. The research team led by Professor Chen from Jinling Hospital studied RASSF1A promoter methylation status in serum DNA and paired tumor genomic DNA of patients with gastric and colorectal adenocarcinomas using methylation specific PCR, and further evaluated the diagnostic role of serum RASSF1A promoter hypermethylation in gastric and colorectal cancer.

The detectable frequencies of serum RASSF1A promoter hypermethylation in gastric (34.0%) and colorectal (28.9%) adenocarcinoma patients were significantly higher than those in patients with benign gastric (3.3%) or colorectal (6.7%) disease or in healthy donors (0%), suggesting that aberrant CpG island methylation within the promoter region of RASSF1A is a promising biomarker for gastric and colorectal cancer. In terms of its clinical application, the authors hold that combinational study of promoter hypermethylation of relevant tumor suppressor genes using serum samples would be promising in the early diagnosis of gastric and colorectal cancer.

Dr. Chen, the corresponding author of this work, is interested in nucleotide acid research, especially in the diagnostic and prognostic role of serum tumor suppressor gene hypermethylation in gastric and colorectal cancer. His group has recently shown that aberrant promoter methylation of several tumor suppressors including p16, DAPK, RASSF1A, etc, in patient sera, may become promising biomarkers of cancer diagnosis. Dr. Chen hopes that future researches from his group would help improve the early diagnosis of cancer.