Beijing Friendship Hospital, Capital Medical University, No. 95 Yong an Road, Xi Cheng District, Beijing, 100053, China.
Guang'an Men Hospital, China Academy of Chinese Medical Sciences, No. 5 Beixiange St., Xicheng District, Beijing, China.
J Ethnopharmacol. 2021 Dec 5;281:113305. doi: 10.1016/j.jep.2020.113305. Epub 2020 Sep 3.
Traditional Chinese medicine Shuangshen granules (SSG) have been used to treat lung cancer patients with Qi deficiency and blood stasis for decades. According to clinical experience, SSG indeed improve the quality of life and prolong the survival time of patients with lung cancer after surgery. Each of the components herbs was proved to be effective in anti-cancer therapy. Both the American ginseng and notoginseng belong to genus Panax of the family Araliaceae. Preclinical and clinical studies demonstrated that ginsenosides of them have anti- or preventive activities to various tumors, including cancers of gastric, breast, liver, lung, ovarian, colon, melanoma and leukemia. PDS, such as ginsenoside Rb1, and PTS, such as ginsenoside Rg1 are the main anticancer compositions. Cordyceps sinensis had also been found effective in inhibiting tumour growth and metastasis, especially on tumour associated immune cells, such as macrophages. However, limited information is available regarding potential mechanisms of SSG. Myeloid-derived suppressor cell (MDSC)-mediated immunosuppression, which is closely associated with poor clinical outcomes in cancer patients, may be the target of SSG, which regulate immune function.
The present study aimed to explore whether SSG attenuate the differentiation of bone marrow cells (BMCs) into MDSCs by blocking the mTOR signalling, leading to the suppression of lung metastasis.
First, we observed the differentiation of BMCs into MDSCs in vitro and in vivo. BMCs were cultured alone or co-cultured with Lewis lung carcinoma (LLC) cell supernatant in vitro. The effects of different concentrations of SSG, or LLC cell supernatant as a control, on BMC differentiation were detected by flow cytometry and western blotting. Male C57BL/6J mice were subcutaneously implanted with LLC cells, and SSG were administered by gavage twice daily before and after implantation for 7 or 14 days, respectively. The tumour weight, proportion of MDSCs, presence of CD11bLy6CLy6G and CD11bLy6CLy6G cells in the bone marrow, blood, and lungs, as well as the expression levels of differentiation-related proteins in the bone marrow and lungs were evaluated.
SSG attenuated the differentiation of BMCs into MDSCs, and reduced the fraction of CD11bLy6CLy6G cells by inhibiting the mTOR/S6K1/Myc signalling pathway. In vivo, SSG attenuated differentiation-associated protein markers and reduced the fractions of MDSCs and CD11bLy6CLy6G cells in the bone marrow, blood, and lungs. In addition, SSG administration reduced the tumour weight and inhibited lung metastasis.
SSG may reduce lung metastasis by attenuating BMC differentiation into CD11bLy6CLy6G cells by inhibiting mTOR signalling in vitro and in vivo.
传统中药双参颗粒（SSG）已被用于治疗数十年的肺癌气虚血瘀证患者。根据临床经验，SSG 确实可以提高肺癌患者手术后的生活质量并延长其生存时间。每个成分草药都被证明在抗癌治疗中有效。西洋参和三七均属于五加科人参属。临床前和临床研究表明，它们的人参皂苷具有抗或预防多种肿瘤的作用，包括胃癌、乳腺癌、肝癌、肺癌、卵巢癌、结肠癌、黑色素瘤和白血病。PDS，如人参皂苷 Rb1，和 PTS，如人参皂苷 Rg1 是主要的抗癌成分。蛹虫草也被发现可有效抑制肿瘤生长和转移，特别是对肿瘤相关免疫细胞，如巨噬细胞。然而，关于 SSG 的潜在机制的信息有限。髓系来源的抑制细胞（MDSC）介导的免疫抑制与癌症患者的不良临床结局密切相关，可能是 SSG 的作用靶点，它可以调节免疫功能。
本研究旨在探讨 SSG 是否通过阻断 mTOR 信号通路来抑制骨髓细胞（BMCs）分化为 MDSC，从而抑制肺转移。
首先，我们观察了 BMCs 在体外和体内向 MDSC 的分化。BMCs 在体外单独培养或与 Lewis 肺癌（LLC）细胞上清液共培养。通过流式细胞术和 Western blot 检测不同浓度的 SSG 或 LLC 细胞上清液（对照）对 BMC 分化的影响。雄性 C57BL/6J 小鼠皮下植入 LLC 细胞，在植入前和植入后每天两次通过灌胃给予 SSG，分别持续 7 天或 14 天。评估肿瘤重量、MDSC 比例、骨髓、血液和肺部中 CD11bLy6CLy6G 细胞的存在以及骨髓和肺部中分化相关蛋白的表达水平。
SSG 通过抑制 mTOR/S6K1/Myc 信号通路抑制骨髓细胞向 MDSC 的分化，减少 CD11bLy6CLy6G 细胞的比例。在体内，SSG 减弱了与分化相关的蛋白标志物，并减少了骨髓、血液和肺部中 MDSC 和 CD11bLy6CLy6G 细胞的比例。此外，SSG 给药减少了肿瘤重量并抑制了肺转移。
SSG 可能通过在体外和体内抑制 mTOR 信号抑制骨髓细胞向 CD11bLy6CLy6G 细胞分化来减少肺转移。
