Department of Medicine, Xizang Minzu University, Xianyang, Shaanxi, China.
Basic Medical College, Xinjiang Medical University, Urumqi, China.
BMC Cancer. 2023 Aug 1;23(1):717. doi: 10.1186/s12885-023-11036-5.
The treatment of non-small cell lung cancer (NSCLC) is challenging due to immune tolerance and evasion. Salidroside (SAL) is an extract in traditional Chinese medicine and has a potential antitumor effect. However, the mechanism of SAL in regulating the immunological microenvironment of NSCLC is yet to be clarified.
The mouse model with Lewis lung cancer cell line (3LL) in C57BL/6 mice was established. And then, the percentage of tumor-infiltrating T cell subsets including Treg was detected in tumor-bearing mice with or without SAL treatment. In vitro, the effect of SAL on the expression of IL-10, Foxp3 and Stub1 and the function of Treg were detected by flow cytometry. Network pharmacology prediction and molecular docking software were used to predict the target of SAL and intermolecular interaction. Furthermore, the effect of SAL on the expression of Hsp70 and the co-localization of Stub1-Foxp3 in Treg was confirmed by flow cytometry and confocal laser microscopy. Finally, Hsp70 inhibitor was used to verify the above molecular expression.
We discovered that SAL treatment inhibits the growth of tumor cells by decreasing the percentage of tumor-infiltrated CD4Foxp3T cells. SAL treatment downregulates the expression of Foxp3 in Tregs, but increases the expression of Stub1, an E3 ubiquitination ligase upstream of Foxp3, and the expression of Hsp70. Inhibiting the expression of Hsp70 reverses the inhibition of SAL on Foxp3 and disrupts the colocalization of Stub1 and Foxp3 in the nucleus of Tregs.
SAL inhibits tumor growth by regulating the Hsp70/stub1/Foxp3 pathway in Treg to suppress the function of Treg. It is a new mechanism of SAL for antitumor therapy.
非小细胞肺癌（NSCLC）的治疗具有挑战性，因为存在免疫耐受和逃逸。红景天苷（SAL）是一种中药提取物，具有潜在的抗肿瘤作用。然而，SAL 调节 NSCLC 免疫微环境的机制尚不清楚。
建立 C57BL/6 小鼠Lewis 肺癌细胞系（3LL）荷瘤小鼠模型。然后，检测荷瘤小鼠在 SAL 治疗前后肿瘤浸润性 T 细胞亚群（包括 Treg）的百分比。体外通过流式细胞术检测 SAL 对 IL-10、Foxp3 和 Stub1 表达以及 Treg 功能的影响。网络药理学预测和分子对接软件预测 SAL 的靶标和分子间相互作用。进一步通过流式细胞术和共聚焦激光显微镜确认 SAL 对 Treg 中 Hsp70 表达和 Stub1-Foxp3 共定位的影响。最后，用 Hsp70 抑制剂验证上述分子表达。
我们发现 SAL 治疗通过降低肿瘤浸润性 CD4Foxp3T 细胞的百分比来抑制肿瘤细胞的生长。SAL 治疗下调 Treg 中 Foxp3 的表达，但增加了 Foxp3 上游 E3 泛素连接酶 Stub1 和 Hsp70 的表达。抑制 Hsp70 的表达逆转了 SAL 对 Foxp3 的抑制作用，并破坏了 Treg 细胞核中 Stub1 和 Foxp3 的共定位。
SAL 通过调节 Treg 中的 Hsp70/stub1/Foxp3 通路抑制肿瘤生长，从而抑制 Treg 的功能。这是 SAL 抗肿瘤治疗的新机制。
