Salvia mitiorrhiza Bunge aqueous extract attenuates infiltration of tumor-associated macrophages and potentiates anti-PD-L1 immunotherapy in colorectal cancer through modulating Cox2/PGE2 cascade.
Salvia mitiorrhiza Bunge aqueous extract attenuates infiltration of tumor-associated macrophages and potentiates anti-PD-L1 immunotherapy in colorectal cancer through modulating Cox2/PGE2 cascade.
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DOI：
10.1016/j.jep.2023.116735
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发表时间：
2023-06
影响因子：
5.4
通讯作者：
Mengyao Song;Chengyao Qian;Teng Zhang;Yu Tang;Yueke Zhou;Zhonghong Wei;Aiyun Wang;Chongjin Zhong-Chongjin
中科院分区：
文献类型：
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作者：
Mengyao Song;Chengyao Qian;Teng Zhang;Yu Tang;Yueke Zhou;Zhonghong Wei;Aiyun Wang;Chongjin Zhong-Chongjin
民族药理学相关性基于中医学的观点，活血化瘀理论是临床上治疗癌症的重要方法。因此，丹参作为活血化瘀中药的代表，已被证明是治疗癌症的有效草药。研究目的阐明丹参水提物（SMAE）对结直肠癌（CRC）的抗癌作用，并探讨SMAE的治疗作用是否通过减少肿瘤相关巨噬细胞（TAMs）的浸润来介导。材料与方法采用高效液相色谱法（HPLC）测定SMAE的主要成分。皮下注射MC 38细胞建立小鼠结直肠癌模型。肿瘤体积测量法测定肿瘤生长曲线。模型组每日1次蒸馏水灌胃。SMAE治疗组每天给予SMAE 5 g/kg或10 g/kg。抗PD-L1治疗组每三天接受一次5 mg/kg抗PD-L1。Western blot检测Cox 2和PD-L1蛋白表达。ELISA法检测PGE 2、IL-1β、IL-6、MCP-1和GM-CSF的分泌水平。采用RT-qPCR检测CSF 1、CCL 2、CXCL 1、CXCL 2和CXCL 3的mRNA表达。Ki 67、TUNEL、Caspase 3染色观察细胞增殖和凋亡情况。免疫组织化学染色用于确定CD 8 +T细胞分布。H&E染色用于确认组织病理学变化。流式细胞术检测肿瘤和淋巴结中F4/80和CD 68的表达，以鉴定巨噬细胞。流式细胞仪检测CD 8 +T细胞数、PD-1、IFN-γ和颗粒酶B（GZMB）的表达。SMAE可显著抑制肿瘤组织中Cox 2的表达和PGE 2的分泌，通过Cox 2/PGE 2级联反应减少TAM的浸润。同时，SMAE通过提高IFN-γ+ CD 8 +T细胞和GZMB+ CD 8 +T细胞的比例，增强抗肿瘤免疫，从而降低肿瘤负荷。结论SMAE可抑制TAM向肿瘤的浸润，并通过调节Cox 2/PGE 2级联反应协同抗PD-L1治疗结直肠癌。
Ethnopharmacological relevanceBased on the notion of traditional Chinese medicine, the theory of invigorating the circulation of blood is a prominent treatment for cancer in clinic. Therefore,Salvia miltiorrhizaBunge, as a representative of Chinese medicine of invigorating the circulation of blood, has been proved to be an effective medicinal herb for treating cancer.Aim of the studyTo clarify the anti-cancer effect ofSalvia miltiorrhizaBunge aqueous extract (SMAE) on colorectal cancer (CRC) and investigate whether the therapeutic effect of SMAE was mediated by attenuating the infiltration of tumor-associated macrophages (TAMs) into the tumor microenvironment (TME).Materials and methodsHigh-performance liquid chromatography (HPLC) was used for determined the main compounds of SMAE. MC38 cells were subcutaneously injected into the mice to establish the mouse model of CRC. Tumor growth curve was detected by tumor volume measurement. The model group received distilled water irrigation once a day. SMAE-treated group received 5 g/kg or 10 g/kg SMAE once a day. Anti-PD-L1 treated group received 5 mg/kg anti-PD-L1 once every three days. Protein expression of Cox2 and PD-L1 was determined by Western blot assay. The secretion levels of PGE2, IL-1β, IL-6, MCP-1, and GM-CSF were evaluated through ELISA. The mRNA expression ofCSF1,CCL2,CXCL1,CXCL2, andCXCL3was measured by using RT-qPCR. Staining of Ki67, TUNEL and Caspase3 was used to investigate cell proliferation and apoptosis. Immunohistochemical staining was used to determine CD8+T cell distribution. H&E staining was used to confirm histopathological changes. The expressions of F4/80 and CD68 were measured by flow cytometry to identify macrophages in tumors and lymph nodes. The number of CD8+T cells and the expression of PD-1, IFN-γ, and Granzyme B (GZMB) were determined by flow cytometry.ResultsSMAE significantly retarded the growth of MC38 mouse colorectal cancer. SMAE strikingly inhibited the expression of Cox2 and impaired the secretion of PGE2 in tumors, contributing to the attenuated intra-tumoral infiltration of TAMs via Cox2/PGE2 cascade. Meanwhile, SMAE augmented anti-tumor immunity by the elevated proportion of IFN-γ+CD8+T cells and GZMB+CD8+T cells, which decreased the tumor load. Furthermore, the combination of SMAE and anti-PD-L1 showed a higher therapeutic efficacy than either monotherapy in controlling tumor growth in MC38 xenograft model.ConclusionsSMAE attenuated the infiltration of TAMs into tumors and synergized with anti-PD-L1 to treat CRC via modulating Cox2/PGE2 cascade.