Eupalinolide B Suppresses Pancreatic Cancer by Inducing Cuproptosis

Abstract

Background: Pancreatic cancer, known for its diagnostic challenges, limited treatment options, and low survival rates, is particularly difficult to manage. Eupalinolide B (EB), an active component from Eupatorium lindleyanum DC (EL), has shown significant antitumor effects across various cancer types. However, its role and mechanisms in pancreatic cancer remain unclear.

Methods: The cytotoxicity, biological functions, and effects on xenograft tumors in nude mice of EB in pancreatic cancer cell lines were evaluated. Molecular mechanisms of EB were explored through transcriptomic sequencing, differential gene expression analysis, pathway enrichment studies, and Western blotting. Additionally, EB-induced cell death pathways were identified using chemical inhibitors, and the synergistic effects of EB combined with Elesclomol (ES) were examined.

Results: In vitro studies revealed that EB selectively reduces the viability of pancreatic cancer cells, compared to normal pancreatic cells, and inhibits their proliferation, colony formation, and migratory and invasive capabilities. In vivo, EB treatment significantly restrained tumor growth in xenografted tumor-bearing nude mice. Molecular mechanism exploration indicated that EB affects the MAPK pathway, particularly enhancing JNK phosphorylation, although JNK activation was not solely responsible for EB-induced cell death. Further analysis revealed that EB induces cell death through a copper-dependent mechanism, increasing intracellular copper levels and ROS generation, with specific inhibitors highlighting the role of these elements in EB's cytotoxicity. Moreover, EB was found to enhance the effects of Elesclomol (ES)- induced cuproptosis.

Conclusion: This study found that EB suppresses the growth of pancreatic cancer cells by regulating intracellular copper concentrations and ROS production, suggesting its potential application in pancreatic cancer treatment. Additionally, EB was shown to enhance the effects of ES-induced cuproptosis, providing important preliminary information for new therapeutic strategies against pancreatic cancer. Future research should further explore EB's clinical potential and clarify the mechanisms of synergistic cuproptosis pathway activation by EB and ES.

Note:
Funding Information: This study was supported by Guangdong Basic and Applied Basic Research Foundation (2021A1515010716), Foundation of Traditional Medicine Bureau of Guangdong Province (20211458), Qingyuan Science and Technology Project (2021SJXM014), Qingyuan People’s Hospital doctoral start-up funding programs (15001019001140), Clinical Research Special Fund of Qingyuan People's Hospital in 2022 (QYRYCRC2023014).

Declaration of Interests: The authors declare that they have no conflicts of interest.

Ethics Approval Statement: All experiments involving animals were in accordance with institutional animal welfare guidelines and were approved by the Experimental Animal Ethics Committee of Qingyuan People's Hospital (Approval Number: LAEC-2021-028).

Keywords: Eupalinolide B; Cuproptosis; Pancreatic Cancer; ROS; Elesclomol