Circulating Methylated MINT2 Promoter DNA Is a Potential Poor Prognostic Factor in Gastric Cancer

Aberrant DNA methylation has been shown to be associated with the growth, development, metastasis, and prognosis of tumors. Methylated DNAs may be suitable biomarkers for cancer patients. Here, we investigated whether circulating methylated MINT2 DNAs represent a potential poor prognostic factor in gastric cancer (GC). MINT2 methylation was detected by real-time methylation-specific PCR in tumor tissues, pairing preoperative peritoneal lavage fluid (PPLF) and blood from 92 GC patients. The theory meaning and clinical practicality value of MINT2 methylation in different specimens were analyzed. The methylation status of the MINT2 gene was found to be significantly higher in tumor tissues (44.6 %, 41/92) than in adjacent normal tissues (3.3 %, 3/92). No MINT2 methylation was found in healthy controls, and partial MINT2 methylation was observed in three (6.25 %, 3/48) patients with chronic atrophic gastritis. The frequency of MINT2 methylation in pairing PPLF and blood samples from 92 GC patients was 40.2 % (37/92) and 39.1 % (36/92), respectively. Methylated MINT2 in tumor tissues, pairing PPLF, and blood samples were very approximate. Aberrant MINT2 methylation in tumor tissues and pairing PPLF or blood samples were closely related to peritoneal dissemination, tumor progression, and poor prognosis (all P < 0.0001). Aberrant MINT2 methylation in PPLF/blood may predict peritoneal micrometastasis for GC patients, which is a potential poor prognostic factor in GC.