23-hydroxybetulinic acid reduces tumorigenesis, metastasis and immunosuppression in a mouse model of hepatocellular carcinoma via disruption of the MAPK signaling pathway

Abstract

Hepatocellular carcinoma (HCC) shows recurrence and lung metastasis even after treatment. 23-hydroxybetulinic acid (23-HBA), a major active constituent of Pulsatilla chinensis, exhibits potent antitumor activities. We herein investigate the biological effect of 23-HBA on metastasis and immunosuppression in a mouse model of HCC. Microarray-based gene expression profiling was employed to identify the target genes of 23-HBA in the treatment of HCC. The effect of 23-HBA on the progression of HCC was evaluated by in-vitro cell function measurements along with in-vivo xenograft implantation, lung metastasis and CD11b+Gr1+ staining experiments. The potential mechanism involving target signaling pathway was investigated by western blot analysis. Bioinformatics analysis revealed that matrix metalloproteinase 2 (MMP2) was a key target gene mediated by 23-HBA in HCC, whereas Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis demonstrated that MMP2 mainly affects the development and metastasis of HCC. 23-HBA significantly reduced cell malignant functions in vitro while delaying the HCC growth and metastasis in vivo. In addition, the number of myeloid-derived suppressor cells was shown to be reduced following administration of 23-HBA in mice. Mechanistic analysis indicated that these effects of 23-HBA during HCC were involved with the mitogen-activated protein kinase (MAPK) signaling pathway inactivation and resulted in decreased phosphorylation of both mitogen-activated protein kinases 1/2 and extracellular signal-regulated kinase 1/2. Our study reveals that 23-HBA acts as a tumor suppressor agent and suppresses HCC tumorigenesis, metastasis and immunosuppression via blockade of the MAPK signaling pathway, suggesting that 23-HBA may serve as a promising drug target to treat HCC.

Effect of 23‑hydroxybetulinic acid on lung adenocarcinoma and its mechanism of action

“…KEGG analysis was conducted on the selected intersecting genes to delve further into the mechanism of 23-HBA in lung adenocarcinoma ( 20 ). The pathway exhibiting the highest degree of enrichment was the ‘PPAR signaling pathway’, which plays a pivotal regulatory role in immunity ( 53 ), inflammation, vascular function ( 54 ), cell proliferation, differentiation, development, apoptosis and cancer.…”

“…23-HBA exhibits a synergistic effect with antitumor drugs such as 5-fluorouracil ( 18 ). It can also inhibit the activity of the ATP binding cassette subfamily B member 1 ATPase ( 19 ), leading to the accumulation of drugs ( 20 ) within cells and effectively reversing P-glycoprotein-mediated multidrug resistance. In addition, 23-HBA can induce beclin-1-dependent autophagy and apoptosis ( 21 ) in HL-60 cells.…”

“…23-HBA can inhibit the activation of NF-κB p65 and the MAPK pathway, and reduce the secretion of inflammatory factors in mice with DSS-induced acute ulcerative colitis ( 23 ). Furthermore, 23-HBA has been shown to reduce tumorigenesis, metastasis and immunosuppression in mouse models of hepatocellular carcinoma by disrupting MAPK signaling pathways ( 20 ).…”

“…The Pulsatilla compounds were combined with lung adenocarcinoma, and databases, such as SwissTargetPrediction, were utilized to demonstrate a robust association between the target genes of 23-HBA and the pathogenesis of lung adenocarcinoma ( 24 ). MTT and flow cytometry assays were conducted to validate the effect of 23-HBA on lung adenocarcinoma cells ( 20 ). Target genes of 23-HBA in lung adenocarcinoma were identified by bioinformatics analysis and characterized to test their functions.…”