目的研究胃癌患者手术前、后调节性T细胞(Treg)及FoxP3表达的变化。方法采用流式细胞术检测20例胃癌患者术前及其中15例接受了手术者术后1周(简称术后)以及15例因胃部不适接受胃镜检查的自愿者(正常对照组)外周血中Treg数量的变化,用RT-PCR法检测Treg的特异性分子标志物FoxP3的转录水平,同时用免疫组织化学法检测胃癌组织中FoxP3蛋白的表达情况。结果胃癌患者术前外周血中CD4+T细胞中的CD4+CD25+比例明显高于正常对照组〔(19.39±5.58)%比(9.91±3.23)%,P<0.01〕,而术后CD4+CD25+比例较术前明显下降〔(13.50±5.93)%比(19.39±5.58)%,P<0.05〕。胃癌患者术前外周血中FoxP3转录水平明显高于正常对照组(0.86±0.03比0.64±0.02,P<0.01),而术后较术前明显下降(0.73±0.04比0.86±0.03,P<0.05),提示FoxP3转录水平与Treg变化一致。胃癌患者外周血中CD4+T细胞在单个核细胞中的比例与正常对照组相比明显下降(P<0.01),而手术前、后变化不明显。20例胃癌患者中13例胃癌癌细胞的细胞浆中有不同程度的FoxP3蛋白表达(强阳性2例,中阳性6例,弱阳性5例),7例胃癌患者的胃癌细胞中不表达。结论 Treg可能通过免疫抑制作用在胃癌的发生、发展中发挥作用,肿瘤组织本身可能是引起Treg变化的重要始动因素。 Objective To study the changes of Treg and FoxP3 in gastric cancer patients before and after operation. Methods Flow cytometry was used to detect the peripheral blood of 20 patients with gastric cancer before operation and 15 patients underwent surgery one week after operation (shortly after operation) and 15 volunteers (normal control group) who suffered gastroscopy due to stomach discomfort Treg, the number of Foxp3 was detected by RT-PCR, and the expression of FoxP3 in gastric cancer was detected by immunohistochemistry. Results The proportion of CD4 + CD25 + in preoperative CD4 + T cells in gastric cancer patients was significantly higher than that in the control group (19.39 ± 5.58% vs 9.91 ± 3.23%, P <0.01) The proportion decreased significantly compared with that before operation 〔(13.50 ± 5.93)% vs (19.39 ± 5.58)%, P <0.05〕. The level of FoxP3 in peripheral blood of patients with gastric cancer was significantly higher than that of the normal control group (0.86 ± 0.03 vs 0.64 ± 0.02, P <0.01), but significantly lower than that before the operation (0.73 ± 0.04 vs 0.86 ± 0.03, P <0.05 ), Suggesting that FoxP3 transcription level is consistent with the change of Treg. The proportion of CD4 + T cells in mononuclear cells in gastric cancer patients was significantly lower than that in the normal control group (P <0.01), but not before and after operation. In 20 gastric cancer patients, 13 cases of gastric cancer cells had different degrees of FoxP3 protein expression in the cytoplasm (2 in strong positive, 6 in positive, and 5 in weakly positive), but not in gastric cancer in 7 patients with gastric cancer. Conclusion Treg may play an important role in the occurrence and development of gastric cancer through immunosuppression. Tumor tissue itself may be an important factor to initiate Treg changes.