[Detection and significance of APC gene promoter hypermethylation in serum of breast cancer patients].
OBJECTIVE
Detection of circulating tumor markers is one of current hot spots in tumor research. Free tumor DNA may exist in the peripheral blood of malignant tumor patients. Identical DNA mutations existing in both peripheral serum and primary tumor are found in many kinds of malignant tumors. This study used adenomatous polyposis coli (APC) gene promoter hypermethylation as a tumor marker to investigate the correlations of free tumor DNA to primary tumor and clinicopathologic features of breast cancer.


METHODS
The methylation status of APC gene in tumor tissue, paracancer normal tissue, and paired peripheral serum from 84 patients with breast cancer and 10 patients with benign breast diseases were detected by methylation-specific polymerase chain reaction (MSP).


RESULTS
The detection rate of APC gene promoter hypermethylation was 45.2% in tumor tissues and 31.0% in paired peripheral sera. APC gene hypermethylation in peripheral serum was significantly correlated to that in tumor tissue (r=0.977, P=0.002). The sensitivity of detecting APC gene hypermethylation in peripheral serum was 68.4%; the specificity was 97.8%. The aberrant methylation of APC gene in tumor tissue and peripheral serum had no correlation to patients' age, tumor stage, tumor size, histological type, and receptor status (P>0.05). No aberrant methylation of APC gene was found in the serum samples from healthy control and the patients without gene methylation in tumor tissue.


CONCLUSIONS
The aberrant tumor gene methylation in peripheral serum of breast cancer patients is significantly correlated to that in primary tumor.
Zhang
Jing-Jie
JJ
Department of Breast Surgery, The First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, 230022, P. R. China. zhangjingjie1996@yahoo.com
Ouyang
Tao
T
Wan
Wen-Hui
WH
Xu
Guang-Wei
GW
Deng
Guo-Ren
GR
D000328:Adult; D001943:Breast Neoplasms / Q000097:blood / Q000235:genetics*; D018270:Carcinoma, Ductal, Breast / Q000097:blood / Q000235:genetics; D018275:Carcinoma, Lobular / Q000097:blood / Q000235:genetics; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000097:blood* / Q000378:metabolism; D005260:Female; D017491:Genes, APC; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D011401:Promoter Regions, Genetic / Q000235:genetics*
D004273:DNA, Neoplasm