Analysis of RUNX3 promoter hypermethylation in the serum DNA of gastric and colorectal adenocarcinoma patients

Objective Human runt-related transcription factor 3(RUNX3) is a new candidate tumor suppressor gene involved in the transforming growth factor beta(TGF-β) signaling pathway.The purpose of this study was to evaluate the diagnostic role of RUNX3 methylation in the serum DNA of gastric cancer(GC) and colorectal cancer(CRC) patients.Methods Serum DNA was extracted from the peripheral blood of 42 GC patients,45 CRC patients and 30 controls(20 cases of benign gastrointestinal disease and 10 healthy donors).The promoter methylation status of the RUNX3 gene was determined by methylation-specific polymerase chain reaction(MSP),and the correlation between methylation profiles and clinicopathological parameters was statistically analyzed.Results Aberrant methylation of RUNX3 was detected in 20(47.6%) of the 42 GC patients,18(40.0%) of the 45 CRC patients,the frequency was significantly higher than that in 1(5.0%) of the 20 benign gastrointestinal patients,and none of the 10 healthy controls,with statistically significant differences between the malignant cases and the controls(P 0.01).RUNX3 hypermethylation was not correlated with the clinicopathological parameters and elevated levels of CEA and CA19-9 in the GC and CRC patients.Conclution Frequent hypermethylation of the RUNX3 promoter exists in GC and CRC,suggesting that it may be a promising biomarker for their early diagnosis.