Anticancer Effect of Polyphyllin I in Suppressing Stem Cell-Like Properties of Hepatocellular Carcinoma via the AKT/GSK-3β/β-Catenin Signaling Pathway

Abstract

Polyphyllin I (PPI), also called Chong Lou saponin I, is a steroidal saponin isolated from the rhizome of Paris polyphylla. PPI has been demonstrated to have strong anticancer activity. However, its effect on the stemness of liver cancer stem cells (LCSCs) is not completely understood. Herein, we aimed to investigate the effect of PPI on the stem cell-like features of LCSCs and hepatocellular carcinoma (HCC). LCSCs were enriched in a serum-free medium and treated with PPI, sorafenib (Sora), or PPI and Sora. Several endpoints, including spheroid formation and differentiation, cell proliferation, surface markers of LCSCs, PPI binding targets, and stemness-associated protein expression, were evaluated. Immunofluorescence staining, quantitative real-time polymerase chain reaction, siRNA transfection, and coimmunoprecipitation ubiquitination assays were conducted for in-depth mechanistic studies. Evaluation of in vivo antitumor efficacy demonstrated that PPI effectively inhibited the proliferation of liver cancer cells and the self-renewal and differentiation of LCSCs. Flow cytometry indicated that PPI suppressed the expression of the stem cell surface markers EpCAM and CD13. Molecular docking showed a high affinity between PPI and proteins of the Wnt/β-catenin signaling pathway, including AKT, GSK-3β, and β-catenin, with the binding energies of -5.51, -5.32, and -5.40 kcal/mol, respectively, which suggested that PPI might regulate the Wnt/β-catenin signaling pathway to affect the stem cell-like properties of HCC. Further ex vivo experiments implied that PPI activated the AKT/GSK-3β-mediated ubiquitin proteasomal degradation of β-catenin and subsequently attenuated the prooncogenic effect of LCSCs. Finally, the anticancer property of PPI was confirmed in vivo. It was found that PPI inhibited the tumor growth in an HCC cell line xenograft model. Taken together, molecular docking analysis and experimental data highlighted the novel function of PPI in suppressing the stem cell-like characteristics of LCSCs via the AKT/GSK-3β/β-catenin signaling pathway.

Research progress of Paris polyphylla in the treatment of digestive tract cancers

“…It was shown that PPI was able to promote hepatocellular carcinoma cell death by activating the mitochondrial pathway [ 30 ]. Liao et al found that PPI was able to inhibit the proliferation of the hepatocellular carcinoma cell lines HepG2 and Huh-7 in a xenograft model [ 31 ]. In human hepatocellular carcinoma cells SMCC-7721, PPI was able to inhibit cell proliferation by regulating the PI3K/mTOR signaling pathway [ 16 ]; moreover, Pang et al found that PPII was able to inhibit the proliferation of hepatocellular carcinoma SMCC-7721 cells and exert antitumor effects by inhibiting the AKT/NF-κB signaling pathway [ 15 ].…”

“…Cancer stem cells (CSCs) have stem cell properties, such as self-replication and multicellular differentiation, which can give rise to tumors through self-renewal and differentiation into multiple stem cell types. These cells are hypothesized to persist in tumors as distinct populations and to generate new tumors, leading to tumor recurrence and metastasis [ 31 ]. Therefore, the development of specific therapies targeting CSCs is expected to improve the survival and quality of life of cancer patients, especially those with metastatic diseases.…”

Efficient production of 22(R)‐hydroxycholesterol via combination optimization of Saccharomyces cerevisiae

“…Steroids represent a significant class of metabolites present in almost all organisms, exhibiting various biological activities, including antitumor, [1] anticancer, [2] antifungal, [3] antidiabetic, [4] and antiinflammatory, [5] and are considered the second largest class of pharmaceuticals, following with antibiotics. [6] 22(R)-hydroxycholesterol (22(R)-HCHO) is an oxidized derivative of cholesterol (CHO) that exists in plants and animals.…”

A Water-Soluble Hydrogen Sulfide Donor Suppresses the Growth of Hepatocellular Carcinoma via Inhibiting the AKT/GSK-3β/β-Catenin and TGF-β/Smad2/3 Signaling Pathways

“…A number of studies have shown that the protein kinase B (PKB/AKT)/glycogen synthase kinase-3β (GSK-3β)/β-catenin pathway plays an important role in the progression of liver cancer [44][45][46]. Furthermore, the transforming growth factorβ (TGF-β)/Smad2/3 pathway is involved in the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of liver cancer [47][48][49].…”