Wang Ya-Nan, Gui Ming-Bin, Qu Lian-Ping, Zou Min, Gao Feng
Department of Colorectal & Anal Surgery, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army Lanzhou 730050, China.
Zhongguo Zhong Yao Za Zhi. 2023 Sep;48(17):4722-4730. doi: 10.19540/j.cnki.cjcmm.20230510.705.
This study aims to investigate the regulatory effects of Astragalus polysaccharide(APS) and APS combined with 5-fluorouracil(5-FU) on indoleamine-2,3-dioxygenase(IDO1) in the colon tumor microenvironment. Sixty Balb/c mice were randomized into a blank group, a model group, an APS group, an APS + 5-FU group, an APS + low-dose 5-FU group, and a 5-FU group. A tumor model was established by subcutaneous transplantation with CT-26 mouse colon cancer cells in other groups except the blank group. After successful modeling, each group was treated with corresponding drugs for 7 days. The general condition, body weight, and tumor volume of the mice were observed and measured daily during the treatment period. The mice were sacrificed at the end of treatment, and the tumor suppression rate and spleen index of the mice were calculated. Western blot and fluorescence quantitative PCR were employed to determine the protein and mRNA levels, respectively, of IDO1 in the tumor tissue of mice. High performance liquid chromatography was employed to measure the levels of tryptophan(Trp) and kynurenine(Kyn) in the tumor tissue of mice. Hematoxylin-eosin(HE) staining was performed to observe the histological changes of the tumor tissue, and immunohistochemistry to detect the changes of CD4 and CD8 expression in the tumor tissue. Compared with that in the model group, the tumor volume of mice in each treatment group significantly reduced. The body weights of mice in APS + 5-FU group and 5-FU group significantly reduced from day 4 to day 7 of treatment. In addition, the APS + 5-FU group and 5-FU group showed significantly decreased spleen index. The protein and mRNA levels of IDO1 were significantly down-regulated in the APS, APS + 5-FU, and APS + low-dose 5-FU groups. The drug interventions significantly increased the Trp content and decreased the Kyn content. The APS + 5-FU group showed significantly reduced infiltration of CD4+ T lymphocytes and increased infiltration of CD8+ T lymphocytes. APS inhibited the expression of IDO1 in the colon tumor microenvironment to increase CD8~+ T lymphocyte infiltration, and the combination of APS with 5-FU demonstrated better effect.
本研究旨在探讨黄芪多糖（APS）以及APS联合5-氟尿嘧啶（5-FU）对结肠肿瘤微环境中吲哚胺-2,3-双加氧酶（IDO1）的调控作用。将60只Balb/c小鼠随机分为空白组、模型组、APS组、APS + 5-FU组、APS +低剂量5-FU组和5-FU组。除空白组外，其他组通过皮下移植CT-26小鼠结肠癌细胞建立肿瘤模型。建模成功后，各组用相应药物治疗7天。在治疗期间，每天观察并测量小鼠的一般状况、体重和肿瘤体积。治疗结束时处死小鼠，计算小鼠的肿瘤抑制率和脾脏指数。采用蛋白质免疫印迹法和荧光定量PCR分别测定小鼠肿瘤组织中IDO1的蛋白质和mRNA水平。采用高效液相色谱法测定小鼠肿瘤组织中色氨酸（Trp）和犬尿氨酸（Kyn）的水平。进行苏木精-伊红（HE）染色以观察肿瘤组织的组织学变化，采用免疫组织化学法检测肿瘤组织中CD4和CD8表达的变化。与模型组相比，各治疗组小鼠的肿瘤体积均显著减小。APS + 5-FU组和5-FU组小鼠的体重在治疗第4天至第7天显著下降。此外，APS + 5-FU组和5-FU组的脾脏指数显著降低。APS组、APS + 5-FU组和APS +低剂量5-FU组中IDO1的蛋白质和mRNA水平均显著下调。药物干预显著增加了Trp含量，降低了Kyn含量。APS + 5-FU组CD4+T淋巴细胞浸润显著减少，CD8+T淋巴细胞浸润增加。APS抑制结肠肿瘤微环境中IDO1的表达以增加CD8+T淋巴细胞浸润，且APS与5-FU联合使用效果更佳。
