​ 肿瘤细胞源性乳酸诱导的肿瘤相关巨噬细胞中HMGB1的上调进一步促进结直肠癌的进展

2023年1月，中国科学院大学肿瘤医院(浙江省肿瘤医院)放射科;中国科学院基础医学与肿瘤研究所，中国科学院大学肿瘤医院(浙江省肿瘤医院)结直肠外科;浙江省上消化道肿瘤防治重点实验室 (Department of Radiology, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), 1 Banshan East Road, Hangzhou 310022, Zhejiang,People’s Republic of China；Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, 1 Banshan East Road, Hangzhou 310022, Zhejiang, People’sRepublic of China；Department of Colorectal Surgery, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), 1 Banshan East Road, Hangzhou 310022, Zhejiang, People’s Republic of China；Key Laboratory of Prevention, Diagnosis and Therapy of Upper Gastrointestinal Cancer of Zhejiang Province, Hangzhou 310022, China) Xinyi Gao老师研究团队在《Journal of Translational Medicine》上发表论文：

“Upregulation of HMGB1 in tumor-associated macrophages induced by tumor cell-derived lactate further promotes colorectal cancer progression”

“肿瘤细胞源性乳酸诱导的肿瘤相关巨噬细胞中HMGB1的上调进一步促进结直肠癌的进展”

Abstract：

Background: Lactate accumulation leads to an acidic tumor microenvironment (TME), in turn promoting colorectal cancer (CRC) progression. Tumor-associated macrophages (TAMs) are the predominant cells in TME. This study aimed to reveal the regulation mechanism of CRC cell-derived lactate on TAMs and explore the mechanism underlying lactate accumulation-induced aggravation in CRC.

Methods: Cell growth and metastasis were evaluated by colony formation, Transwell, and wound healing assays. Western blot and RT-qPCR were applied to determine the protein and mRNA expression. Flow cytometry was used to analyze the polarization state and apoptotic rate of macrophages induced in THP-1 cells. The lactate in the cell supernatant was quantified using an ELISA kit. Immunofluorescence was performed to visualize the location of High Mobility Group Box 1 (HMGB1). H&E and Ki67 staining assays were used to assess tumorigenesis in nude mice bearing ectopic tumors.

Results: Cell growth and metastasis were promoted in the hypoxic CRC cells. The hypoxic cell supernatant stimulated the M2-type polarization of macrophages. The lactate level increased in hypoxic cancer cells. However, the inhibition of lactate using 3-hydroxy-butyrate (3-OBA) reversed the effects of hypoxia. Also, macrophages showed no promoting effect on cancer cell growth and migration in the presence of 3-OBA. HMGB1 was secreted into the extracellular space of lactate-induced macrophages, further enhancing the malignant behaviors of cancer cells. ERK, EMT, and Wnt signaling pathways were activated in cancer cells due to HMGB1 upregulation.

Conclusions: The lactate metabolized by cancer cells stimulated M2 polarization and HMGB1 secretion by macrophages, aggravating the carcinogenic behaviors of cancer cells.

摘要：

背景

乳酸积累导致酸性肿瘤微环境(TME)，进而促进结直肠癌(CRC)的进展。肿瘤相关巨噬细胞(TAMs)是TME的主要细胞。本研究旨在揭示CRC细胞源性乳酸对TAMs的调控机制，探讨乳酸积累诱导CRC加重的机制。

方法

通过菌落形成、Transwell和伤口愈合试验来评估细胞生长和转移。Western blot和RT-qPCR检测蛋白和mRNA的表达。采用流式细胞术分析THP-1细胞诱导巨噬细胞极化状态及凋亡率。用ELISA试剂盒定量细胞上清液中的乳酸。采用免疫荧光法观察高迁移率组盒1 (HMGB1)的位置。采用H&E和Ki67染色法评价异位瘤裸鼠的肿瘤发生情况。

结果

低氧CRC细胞促进细胞生长和转移。低氧细胞上清刺激巨噬细胞的m2型极化。缺氧癌细胞中乳酸水平升高。然而，使用3-羟基丁酸(3-OBA)抑制乳酸逆转了缺氧的影响。此外，巨噬细胞在3-OBA存在下对癌细胞的生长和迁移没有促进作用。HMGB1分泌到乳酸诱导的巨噬细胞胞外间隙，进一步增强了癌细胞的恶性行为。由于HMGB1的上调，癌细胞中的ERK、EMT和Wnt信号通路被激活。

结论

癌细胞代谢的乳酸刺激巨噬细胞M2极化和HMGB1分泌，加重了癌细胞的致癌行为。

该论文中，SW480 (AW-CCH107)、HT29 (AW-CCH054)和THP-1 (AW-CCH098)及其经过体外刺激诱导的细胞的体外培养是使用Ausbian特级胎牛血清完成的。欲了解或购买Ausbian特级胎牛血清可以联系北京缔一生物400-166-8600.