ORIGINAL PAPER
Ergotamine modulates CTSK-associated glutamine metabolism and M2 macrophage polarization in hepatocellular carcinoma
1
Zhejiang Chinese Medical University, Hangzhou, 310053, China
2
Department of Hepatobiliary Surgery, Jinhua Guangfu Cancer Hospital, Jinhua, 321000, China
3
Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Shulan International Medical College, Zhejiang Shuren University, Hangzhou, 310000, China
4
Key Laboratory of Artificial Organs and Computational Medicine in Zhejiang Province, Hangzhou, 310000, China
Submission date: 2025-05-26
Final revision date: 2026-04-02
Acceptance date: 2026-05-24
Online publication date: 2026-09-15
Corresponding author
Zhe Yang
Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Shulan International Medical College, Zhejiang Shuren University, Hangzhou, 310000, China
Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Shulan International Medical College, Zhejiang Shuren University, Hangzhou, 310000, China
KEYWORDS
ABSTRACT
Introduction:
Tumor-associated macrophages (TAMs) are a key component of the tumor microenvironment (TME) in hepatocellular carcinoma (HCC). Cathepsin K (CTSK) has been implicated in promoting TAM polarization toward an anti-inflammatory phenotype and tumor progression. However, its role and mechanism in HCC-associated TAMs remain unclear.
Material and Methods:
The expression of CTSK in HCC was assessed using bioinformatics, western blot, and qRT-PCR. HCC cells with CTSK knockdown were generated to investigate the effects of CTSK on the M2 polarization of TAMs, using assays including CCK-8, immunofluorescence, and enzyme-linked immunosorbent assay (ELISA). A glutamine metabolism assay kit was used to investigate the effect of CTSK on glutamine metabolism. Rescue experiments were conducted to elucidate the role of glutamine metabolism in macrophage M2 polarization. The interaction between the small molecule drug ergotamine and CTSK was evaluated using molecular docking and Cellular Thermal Shift Assay (CETSA). The influence of ergotamine on macrophage M2 polarization was further clarified through gene overexpression and pharmacological studies.
Results:
CTSK expression was substantially upregulated in HCC tissues and cells and was associated with increased M2 macrophage polarization. CTSK overexpression enhanced glutamine metabolism-related parameters, while inhibition of glutamine metabolism attenuated CTSK-mediated effects on macrophage polarization. Ergotamine interacted with CTSK and reduced M2 macrophage polarization in HCC.
Conclusions:
This study suggests that CTSK contributes to M2 macrophage polarization in HCC, potentially via modulation of glutamine metabolism. Ergotamine, a small-molecule compound, may modulate CTSK-associated effects and warrants further investigation as a potential regulator of the HCC tumor microenvironment. These findings provide insights into the role of CTSK in HCC-associated macrophage polarization.
Tumor-associated macrophages (TAMs) are a key component of the tumor microenvironment (TME) in hepatocellular carcinoma (HCC). Cathepsin K (CTSK) has been implicated in promoting TAM polarization toward an anti-inflammatory phenotype and tumor progression. However, its role and mechanism in HCC-associated TAMs remain unclear.
Material and Methods:
The expression of CTSK in HCC was assessed using bioinformatics, western blot, and qRT-PCR. HCC cells with CTSK knockdown were generated to investigate the effects of CTSK on the M2 polarization of TAMs, using assays including CCK-8, immunofluorescence, and enzyme-linked immunosorbent assay (ELISA). A glutamine metabolism assay kit was used to investigate the effect of CTSK on glutamine metabolism. Rescue experiments were conducted to elucidate the role of glutamine metabolism in macrophage M2 polarization. The interaction between the small molecule drug ergotamine and CTSK was evaluated using molecular docking and Cellular Thermal Shift Assay (CETSA). The influence of ergotamine on macrophage M2 polarization was further clarified through gene overexpression and pharmacological studies.
Results:
CTSK expression was substantially upregulated in HCC tissues and cells and was associated with increased M2 macrophage polarization. CTSK overexpression enhanced glutamine metabolism-related parameters, while inhibition of glutamine metabolism attenuated CTSK-mediated effects on macrophage polarization. Ergotamine interacted with CTSK and reduced M2 macrophage polarization in HCC.
Conclusions:
This study suggests that CTSK contributes to M2 macrophage polarization in HCC, potentially via modulation of glutamine metabolism. Ergotamine, a small-molecule compound, may modulate CTSK-associated effects and warrants further investigation as a potential regulator of the HCC tumor microenvironment. These findings provide insights into the role of CTSK in HCC-associated macrophage polarization.
REFERENCES (36)
1.
Vogel A, Meyer T, Sapisochin G, et al. (2022): Hepatocellular carcinoma. Lancet 400: 1345-1362.
2.
Devarbhavi H, Asrani SK, Arab JP, et al. (2023): Global burden of liver disease: 2023 update. J Hepatol 79: 516-537.
3.
Finn RS, Qin S, Ikeda M, et al. (2020): Atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma. N Engl J Med 382: 1894-1905.
4.
Llovet JM, Castet F, Heikenwalder M, et al. (2022): Immunotherapies for hepatocellular carcinoma. Nat Rev Clin Oncol 19: 151-172.
5.
Chen C, Wang Z, Ding Y, Qin Y (2023): Tumor microenvironment-mediated immune evasion in hepatocellular carcinoma. Front Immunol 14: 1133308.
6.
Sas Z, Cendrowicz E, Weinhäuser I, Rygiel TP (2022): Tumor microenvironment of hepatocellular carcinoma: challenges and opportunities for new treatment options. Int J Mol Sci 23: 3778.
7.
Huang J, Wu Q, Geller DA, Yan Y (2023): Macrophage metabolism, phenotype, function, and therapy in hepatocellular carcinoma (HCC). J Transl Med 21: 815.
8.
Wang Z, Wang Y, Gao P, Ding J (2023): Immune checkpoint inhibitor resistance in hepatocellular carcinoma. Cancer Lett 555: 216038.
9.
Yu Z, Li Y, Li Y, et al. (2022): Bufalin stimulates antitumor immune response by driving tumor-infiltrating macrophage toward M1 phenotype in hepatocellular carcinoma. J Immunother Cancer 10: e004297.
10.
Cheng K, Cai N, Zhu J, et al. (2022): Tumor-associated macrophages in liver cancer: From mechanisms to therapy. Cancer Commun (Lond) 42: 1112-1140.
11.
Xu W, Cheng Y, Guo Y, et al. (2022): Targeting tumor associated macrophages in hepatocellular carcinoma. Biochem Pharmacol 199: 114990.
12.
Ma G, Zhang Z, Li P, et al. (2022): Reprogramming of glutamine metabolism and its impact on immune response in the tumor microenvironment. Cell Commun Signal 20: 114.
13.
Jin J, Byun JK, Choi YK, Park KG (2023): Targeting glutamine metabolism as a therapeutic strategy for cancer. Exp Mol Med 55: 706-715.
14.
Li T, Copeland C, Le A (2021): Glutamine metabolism in cancer. Adv Exp Med Biol 1311: 17-38.
15.
Zhang F, Wang B, Zhang W, et al. (2025): NEIL3 upregulated by TFAP2A promotes M2 polarization of macrophages in liver cancer via the mediation of glutamine metabolism. Digestion 106: 30-44.
16.
Chen S, Jiang Y, Zheng J, et al. (2025): Folate-targeted nanoparticles for glutamine metabolism inhibition enhance anti-tumor immunity and suppress tumor growth in ovarian cancer. J Control Release 379: 89-104.
17.
Qian D, He L, Zhang Q, et al. (2022): Cathepsin K: A versatile potential biomarker and therapeutic target for various cancers. Curr Oncol 29: 5963-5987.
18.
Zhang C, Liu Z, Wang X, et al. (2023): Cathepsin K promotes the proliferation of hepatocellular carcinoma cells through induction of SIAH1 ubiquitination and degradation. iScience 26: 106852.
19.
Lin G, Tian F, Yu Q, et al. (2024): IL-17RA/CTSK axis mediates H. pylori-induced castration-resistant prostate cancer growth. Oncogene 43: 3598-616.
20.
Li R, Zhou R, Wang H, et al. (2019): Gut microbiota-stimulated cathepsin K secretion mediates TLR4-dependent M2 macrophage polarization and promotes tumor metastasis in colorectal cancer. Cell Death Differ 26: 2447-2463.
21.
Kong Y, Wu M, Wan X, et al. (2023): Lipophagy-mediated cholesterol synthesis inhibition is required for the survival of hepatocellular carcinoma under glutamine deprivation. Redox Biol 63: 102732.
22.
Chandrasekhar B, Gor R, Ramalingam S, et al. (2024): Repurposing FDA-approved compounds to target JAK2 for colon cancer treatment. Discov Oncol 15: 226.
23.
Wu N, Wang Y, Wang K, et al. (2022): Cathepsin K regulates the tumor growth and metastasis by IL-17/CTSK/EMT axis and mediates M2 macrophage polarization in castration-resistant prostate cancer. Cell Death Dis 13: 813.
24.
Zhou S, Wu H, Chen Y, et al. (2025): Lifting the veil on tumor metabolism: A GDH1-focused perspective. iScience 28: 112551.
25.
Zhang F, Liu W, Meng F, et al. (2024): Inhibiting PLA2G7 reverses the immunosuppressive function of intratumoral macrophages and augments immunotherapy response in hepatocellular carcinoma. J Immunother Cancer 12: e008094.
26.
Liu YT, Mao ZW, Ding Y, Wang WL (2024): Macrophages as targets in hepatocellular carcinoma therapy. Mol Cancer Ther 23: 780-790.
27.
Feng H, Xing W, Han Y, et al. (2020): Tendon-derived cathepsin K-expressing progenitor cells activate Hedgehog signaling to drive heterotopic ossification. J Clin Invest 130: 6354-6365.
28.
Pan W, Yin W, Yang L, et al. (2019): Inhibition of Ctsk alleviates periodontitis and comorbid rheumatoid arthritis via downregulation of the TLR9 signalling pathway. J Clin Periodontol 46: 286-296.
29.
Mou J, Zheng W, Wei D, et al. (2023): CD200-CD200R affects cisplatin and paclitaxel sensitivity by regulating cathepsin K-mediated p65 NF-B signaling in cervical cancer. Heliyon 9: e19220.
30.
Ding Y, Li Z, Wang H, et al. (2023): CTSK and PLAU as prognostic biomarker and related to immune infiltration in pancreatic cancer: evidence from bioinformatics analysis and qPCR. Int J Genomics 2023: 3914687.
31.
Chen M, Meng X, Zhu Y, et al. (2025): Cathepsin K aggravates pulmonary fibrosis through promoting fibroblast glutamine metabolism and collagen synthesis. Adv Sci (Weinh) 12: e13017.
32.
Ren W, Xia Y, Chen S, et al. (2019): Glutamine metabolism in macrophages: A novel target for obesity/type 2 diabetes. Adv Nutr 10: 321-330.
33.
Kieler M, Hofmann M, Schabbauer G (2021): More than just protein building blocks: how amino acids and related metabolic pathways fuel macrophage polarization. FEBS J 288: 3694-3714.
34.
Jacob H, Braekow P, Schwarz R, et al. (2023): Ergotamine stimulates human 5-HT(4)-serotonin receptors and human H(2)-histamine receptors in the heart. Int J Mol Sci 24: 4749.
35.
Prysor-Jones RA, Jenkins JS (1980): Effect of bromocriptine, ergotamine and other ergot alkaloids on the hormone secretion and growth of a rat pituitary tumour. J Endocrinol 86: 147-153.
36.
Bao B, Yu X, Zheng W, Sun J (2024): Ergotamine targets KIF5A to facilitate anoikis in lung adenocarcinoma. Clin Respir J 18: e70020.
| eISSN: | 1644-4124 |
| ISSN: | 1426-3912 |
We process personal data collected when visiting the website. The function of obtaining information about users and their behavior is carried out by voluntarily entered information in forms and saving cookies in end devices. Data, including cookies, are used to provide services, improve the user experience and to analyze the traffic in accordance with the Privacy policy. Data are also collected and processed by Google Analytics tool (more).
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
