中文摘要：

目的：研究幽门螺杆菌中性粒细胞激活蛋白（HP-NAP）对肝癌H22荷瘤小鼠肿瘤的生长抑制作用及可能机制。方法：构建pET28a-NAP重组质粒,转入E.coli BL21（DE3）菌株,IPTG诱导HP-NAP的表达,Ni柱亲和层析法对其进行分离纯化。取BALB/c小鼠,皮下注射H22细胞（2×106个/只）构建荷瘤模型,随机分为PBS组和HP-NAP组,以皮下瘤旁注射的方式给予PBS或HP-NAP,监测肿瘤体积和小鼠体重变化。1周后牺牲小鼠,取瘤体及各脏器称重,以ELISA法检测脾细胞IFN-γ分泌水平,实时荧光定量PCR法检测肿瘤组织中IFN-γ mRNA的表达水平。结果：利用大肠杆菌原核表达系统成功制备了HP-NAP。HP-NAP可显著抑制荷瘤小鼠肿瘤的生长,对小鼠体重和脏器指数无明显影响。与PBS组相比,HP-NAP组小鼠脾细胞IFN-γ的分泌水平及肿瘤组织中IFN-γ mRNA的表达水平均升高（P＜0.05）。结论：HP-NAP可能通过上调IFN-γ的表达抑制肝癌H22荷瘤小鼠肿瘤的生长。

英文摘要：

Aim： To investigate the inhibitive effect of the Helicobacter pylori neutrophil-activating protein（HP-NAP）on mice bearing hepatoma H22 tumor and the potential mechanism.Methods： The recombined plasmid pET28a-NAP was constructed and transformed into E. coli BL21 to induce the expression of HP-NAP by IPTG, and then HP-NAP was purified using ProteinIsoTM Ni-NTA Resin. H22 hepatoma cells（2×106 per mouse）were injected subcutaneously into the flank of BALB/c mice and then the mice were allocated into 2 groups and treated with HP-NAP（HP-NAP group）and PBS（PBS group）, respectively. The body weight and tumor size were monitored every day. The mice were sacrificed after being treated with HP-NAP or PBS for one week.The weight of tumor and visceral organs was measured, the level of IFN-γ secreted from splenocytes was assayed by ELISA, and the mRNA expression level of IFN-γ in tumor tissue was evaluated by Real-time PCR.Results： HP-NAP was successful prepared using E.coli expression system. HP-NAP could significantly inhibit the tumor growth in mice bearing H22 tumor without influence of the body weight or organ indexes. HP-NAP could significantly improve the IFN-γ secretion from splenocytes and enhance the production of IFN-γ in tumor tissue（P〈0.05）.Conclusion： HP-NAP could inhibit the tumor growth in mice bearing H22 tumor by up-regulating the expression of IFN-γ.