OBJECTIVETo observe the effects of Dujieqing Oral Liquid (DJQ) on the promoter methylation of the O6-methylguanine-DNA methyltransferase (MGMT) gene in the plasma DNA samples from middle-and-late stage tumor patients receiving chemotherapy.

METHODSRecruited 60 patients were randomly assigned to the treatment group (treated by conventional chemotherapy combined DJQ, 20 mL each time, three times daily) and the control group (treated by chemotherapy alone), 30 in each group. The therapeutic course was 8 weeks. The promoter methylation of the MGMT gene in the plasma DNA samples form middle-and-late stage tumor patients receiving chemotherapy was detected before and after treatment using nested methylation-specific polymerase chain reaction (MSP). Meanwhile, the peripheral hemogram was detected. The clinical efficacy and toxic/adverse reactions were assessed using Karnofsky performance scale (KPS).

RESULTSResults of the promoter methylation of MGMT genes showed that methylation rate was 20.00% in the treatment group and 46.67% in the control group (P<0.05). Compared with before treatment, the KPS was significantly improved in the treatment group after treatment, while it significantly decreased in the control group after treatment (both P<0.05). There was statistical difference in the KPS between the two groups after treatment (P<0.01). The toxic/adverse reactions were milder in the treatment group than in the control group (P<0.01).

CONCLUSIONSDJQ showed efficiency synergism and toxicity reducing effects, but with no effect on the hematopoietic function of the bone marrow. MGMT gene was indicated as DJQ's target point for efficiency synergism and toxicity reducing. The efficiency synergism and toxicity reducing effects were achieved by regulating the activities of MGMT gene.