胃癌患者血清VEGF浓度及外周血树突状细胞活性测定

Detection of serum VEGF level and dendritic cells activities in the peripheral blood of gastric cancer patients

应用酶联免疫吸附试验测定血清血管内皮细胞生长因子(VEGF)的浓度;分离胃癌患者和健康个体外周血单个核细胞,利用GM-CSF和IL-4体外诱导成树突状细胞(DCs),流式细胞仪检测DCs表面HLA-DR和CD86的表达;分别用LPS、重组VEGF蛋白体外刺激DCs,观察LPS、重组VEGF对DCs表达CD86的影响,探讨在胃癌中VEGF与DCs之间的关系。结果表明:胃癌患者血清VEGF浓度较健康者显著增高;胃癌患者外周血单核细胞诱导DCs表达HLA-DR和CD86降低;LPS可促进DCs表面CD86的表达,健康者较胃癌患者更加明显;rhVEGF可降低胃癌DCs表面CD86的表达。说明胃癌患者血清VEGF浓度高,可作为胃癌的一项诊断指标,胃癌患者体内DCs处于低活性,胃癌可通过分泌VEGF抑制DCs活性而介导免疫逃逸。

At first the concentration of serum VEGF was measured by an ELISA assay. Then peripheral blood mono- nuclear cells （PBMCs） were isolated from both gastric cancer patients and healthy controls, and stimulated with GM-CSF and IL-4 to induce DCs. HLA-DR and CD86 expression was detected by flow cytometry. Finally LPS and recombinant VEGF protein were added into DCs cultures to see how they affected CD86 expression, and to investigate their correlation in gastric cancer. Results： Serum VEGF level in gastric cancer patients was higher than that in the healthy controls; the expression of HLA-DR and CD86 on peripheral blood monocyte-derived DCs in gastric cancer patients decreased compared with healthy controls; LPS up-regulated CD86 expression on DCs in both groups, especially in the healthy controls; Recombinant VEGF inhibited CD86 expression on DCs directly. Serum VEGF level expressed highly in gastric cancer patients, and it can serve as diagnosis factors in gastric carcinoma. Activities of DCs was lower in gastric cancer patients, and VEGF secretion from gastric cancer cells would down-regulate activities of DCs and thus mediate immune evasion.