Detection of RASSF1A promoter hypermethylation in serum from gastric and colorectal adenocarcinoma patients.
OBJECTIVE
To evaluate the diagnostic role of serum RASSF1A promoter hypermethylation in gastric and colorectal adenocarcinoma.


METHODS
Methylation-specific polymerase chain reaction (MSPCR) was used to examine the promoter methylation status of the serum RASSF1A gene in 47 gastric adenocarcinoma patients, 45 colorectal adenocarcinoma patients, 60 patients with benign gastrointestinal disease (30 with benign gastric disease and 30 with benign colorectal disease), and 30 healthy donor controls. A paired study of RASSF1A promoter methylation status in primary tumor, adjacent normal tissue, and postoperative serum were conducted in 25 gastric and colorectal adenocarcinoma patients who later were underwent surgical therapy.


RESULTS
The frequencies of detection 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%) (P < 0.01). The methylation status of RASSF1A promoter in serum samples was consistent with that in paired primary tumors, and the MSPCR results for RASSF1A promoter methylation status in paired preoperative samples were consistent with those in postoperative serum samples. The serum RASSF1A promoter hypermethylation did not correlate with patient sex, age, tumor differentiation grade, surgical therapy, or serum carcinoembryonic antigen level. Although the serum RASSF1A promoter hypermethylation frequency tended to be higher in patients with distant metastases, there was no correlation between methylation status and metastasis.


CONCLUSIONS
Aberrant CpG island methylation within the promoter region of RASSF1A is a promising biomarker for gastric and colorectal cancer.
Wang
Yu-Cai
YC
Department of Medical Oncology, Jinling Hospital, Nanjing 210002, Jiangsu Province, China.
Yu
Zheng-Hong
ZH
Liu
Chang
C
Xu
Li-Zhi
LZ
Yu
Wen
W
Lu
Jia
J
Zhu
Ren-Min
RM
Li
Guo-Li
GL
Xia
Xin-Yi
XY
Wei
Xiao-Wei
XW
Ji
Hong-Zan
HZ
Lu
Heng
H
Gao
Yong
Y
Gao
Wei-Min
WM
Chen
Long-Bang
LB
D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D018899:CpG Islands; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000097:blood*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology; D025521:Tumor Suppressor Proteins / Q000235:genetics*
D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins