Effect of methylation of hMLH1 gene promotor on stage tumorigenesis and progression of human gastric cancer.
- Author:
Yue TENG
1
;
Dongqiu DAI
;
Wenjing SHEN
;
Hongbo LIU
Author Information
- Publication Type:Journal Article
- MeSH: Adaptor Proteins, Signal Transducing; Cell Transformation, Neoplastic; China; DNA Methylation; Disease Progression; Humans; MutL Protein Homolog 1; Nuclear Proteins; Polymerase Chain Reaction; Promoter Regions, Genetic; Stomach Neoplasms
- From: Chinese Journal of Gastrointestinal Surgery 2015;18(2):166-170
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo illustrate the role of methylation level of hMLH1 gene promoter in different stages of gastric carcinogenesis by methylation-specific PCR (MSP) detection of samples from paracancerous tissue and gastric cancer tissue.
METHODSMethylation status of hMLH1 gene promoter of 40 patients undergoing radical stomach cancer operation in the Tumor Research Institute of China Medical University between January 2006 and August 2006 was detected by MSP. For each patient, 2 samples were chosen from the cancer site, paracancerous tissues of 1 cm, 3 cm, 5 cm away from the cancer site, separately. One sample was used in pathology examination, and the other in methylation detection.
RESULTSPositive rates of hMLH1 gene promoter methylation in the paracancerous tissues of 1 cm, 3 cm, 5 cm away from the cancer site were 10%(4/40), 12.5%(5/40) and 2.5%(1/40) respectively, which were significantly lower than 32.5%(13/40) in cancer site(all P<0.05). Pathological examination showed precancerous lesions in 23 samples of paracancerous 1 cm and 3 cm tissues and normal tissues in 24 samples of paracancerous 5 cm tissues. Positive rates of hMLH1 gene promoter methylation in the cancer site, paracancerous tissue and normal gastric tissue were 32.5%(13/40), 8.7%(2/23) and 0(0/24) (P<0.01). For cancer tissue penetrated the gastric serosa, 8 out of 14 tissue samples were positive methylation (57.1%), which was significantly higher compared with 5 out of 26 tissue samples without penetration of gastric serosa(19.2%). Positive rate of hMLH1 gene promoter methylation in tissue samples with 7 or more of metastatic lymphatic node number was 61.5%(8/13), which was higher compared to that with less than 7(5/27, 18.5%) (P<0.05). No significant differences of positive rate of hMLH1 gene promoter methylation were found between different tumor gross types, tumor grow pattern, tumor differentiation degree, patient age and sex(all P>0.05).
CONCLUSIONHypermethylation of hMLH1 gene promoter may be associated with the carcinogenesis stages and progression of human gastric cancer.
