目的: 探究白术多糖(polysaccharide of atractylodes macrocephala, PAM)对小鼠结肠癌细胞移植瘤生长的抑制作用及其机制。方法：将荧光酶标记的1×107个结肠癌细胞（HT-29）注射到小鼠结肠浆膜层，建立结肠癌细胞原位移植瘤模型小鼠。待瘤体积达到约230 mm3时，小鼠采用连续10 d 灌胃给药30 mg/kg PAM（PAM组）或生理盐水（对照组）；通过肿瘤活体成像技术检测PAM对小鼠体内结肠癌细胞生长的影响，通过流式细胞术检测PAM对瘤体组织中粒细胞、树突状细胞以及巨噬细胞的MHCII以及IL-12 的表达、淋巴细胞的激活以及CD4+和CD8+细胞分泌IFN-γ 功能的影响。结果：PAM可显著抑制结肠癌原位移植瘤模型小鼠体内结肠癌细胞生长（P<0.01）。PAM可通过增加MHCII 和IL-12 在树突状细胞和巨噬细胞中的表达水平（均P<0.01），PAM可显著增加瘤体组织中CD8+细胞、NK细胞、CD44+/NK细胞和CD44+/CD4+细胞比例以及提升单位组织体积中CD8+细胞和NK细胞细胞数量（均P<0.01），PAM可显著增加CD4+及CD8+细胞分泌IFN-γ 的能力（均P<0.01）。结论：PAM可通过激活结肠癌模型小鼠原位移植瘤组织中免疫细胞来抑制肿瘤生长。

Objective: To investigate the effect and mechanism of polysaccharide of atractylodes macrocephala (PAM) on the growth of colon cancer cells in mice bearing in-situ colon cancer transplantation tumor. Methods: 1×107 colon cancer HT-29 cells labeled with luciferase were injected into colon serosa of the mice to establish the in-situ colon cancer transplantation tumor model. When the tumor volume reached 230 mm3, the mice were given 30 mg/kg PAM (PAM group) or equal volume of normal saline (Control group) by gavage for 10 consecutive days. The effect of PAM on the growth of colon cancer cells in mice was tested by in vivo tumor imaging technology.The expressions of MHCII and IL-12 in granulocytes, dendritic cells and macrophages, the activation of lymphocytes, and IFN-γ expression in CD4+ and CD8+ cells of tumor tissues were detected by Flow cytometry. Results: PAM significantly inhibited the growth of colon cancer cells in mice bearing in-situ colon cancer transplantation tumor (P<0.01). PAM activated immune cells though increasing the expression levels of MHCII and IL-12 in dendritic cells and macrophages (both P<0.01). PAM significantly increased the frequency of CD8+ cells, NK cells, CD44+/NK cells and CD44+/CD4+ cells in tumor tissues and the number of CD8+ cells and NK cells per unit volume (all P<0.01). PAM significantly increased the IFN-γ secretion of CD4+ and CD8+ cells (both P<0.01), too. Conclusion:PAM inhibits the growth of colon cancer by activating immune cells in tumor tissues of mice bearing in-situ colon cancer transplantation tumor.

贵州省自然科学基金资助项目([2017]1193)