Combined Metabolomics and Transcriptomics Analysis Reveals the Mechanism of Celastrol in Inhibiting Pancreatic Cancer

This study aimed to investigate the anti-pancreatic cancer effect and mechanism of celastrol by means of multi-omics integration analysis. Pan02-luc-tdT and AsPC-1 pancreatic cancer cells were treated with different concentrations of celastrol. Cell viability was measured by the MTT assay; colony formation ability was assessed using plate colony formation assay; and cell apoptosis was detected by flow cytometry. A pancreatic cancer xenograft mouse model was established using Pan02-luc-tdT cells, and the mice were randomly divided into three groups: the vehicel group, the low-dose celastrol group (1 mg/kg), and the high-dose celastrol group (3 mg/kg). Mouse body weight, tumor size, and tumor weight were monitored. Immunohistochemistry was performed to detect Ki67, CD8, and CD4 expression in tumor tissues. Transcriptomic and untargeted metabolomic analyses were conducted to evaluate the effects of celastrol on gene expression and metabolite profiles. Investigation of the effects of triptolide on the oxidative phosphorylation pathway and linoleic acid metabolism pathway using qPCR and Western Blot experiments. The results showed that celastrol (1.25-5 μM) significantly suppressed the growth of pancreatic cancer cells, reduced their colony formation ability, and promoted apoptosis. In the pancreatic cancer mouse model, compared with the control group, tumor weight and volume were significantly decreased in the celastrol-treated groups without significant changes in body weight. Immunohistochemistry data showed that celastrol downregulated Ki67 expression while upregulated CD8 and CD4 expression in tumor tissues. Untargeted metabolomics revealed that celastrol treatment induced significant changes in 79 metabolites which were involving multiple pathways such as autophagy, choline metabolism, linoleic acid metabolism, and β-alanine metabolism. Transcriptomic sequencing showed that celastrol led to differential expression of 853 genes, which were mainly enriched in the oxidative phosphorylation pathway. Integrated omics analysis indicated that choline metabolism, glycerophospholipid metabolism, and linoleic acid metabolism were the common significantly altered pathways. qPCR and Western Blot experimental results show that treatment with celastrol activates the oxidative phosphorylation pathway and inhibits the linoleic acid metabolism pathway. In summary, celastrol possesses good in vitro and in vivo anti-pancreatic cancer activity, and its mechanism may be related to the regulation of oxidative phosphorylation pathway, linoleic acid metabolism, choline metabolism, and glycerophospholipid metabolism pathways, making it a promising potential anti-pancreatic cancer candidate drug.