Role of traditional Chinese medicine and its chemical components in anti-tumor metastasis

Characterization of chikusetsusaponin IV and V induced apoptosis in HepG2 cancer cells

BACKGROUND

Chikusetsusaponin IV and V (CsIV and CsV), two typical oleanolic acid saponins, are mainly derived from the rhizome of Panax japonicus C.A. Mey. To reveal the anti-cancer effect of CsIV and CsV on liver cancer cells, human hepatic cancer cell lines (HepG2) were exposed to these saponins, and various physiological responses of HepG2 were investigated.

METHODS AND RESULTS

HepG2 cells were treated with CsIV, CsV and 5-fluorouracil (5-FU). Cell proliferation was measured by CCK-8 assay. The cell cycle arrest, cell apoptosis and intracellular Ca²⁺ levels were respectively identified by flow cytometry. The mitochondrial membrane potential was detected by fluorescence microscopy. And, the levels of apoptosis-related proteins were analyzed by western blotting. Both CsIV and CsV were demonstrated to inhibit cell viability, and induce cell cycle arrest and apoptosis of HepG2 in a dose-dependent manner. They also enhanced the intracellular Ca²⁺ level and decreased the mitochondrial membrane potential in HepG2 cells. Furthermore, p53 and p21 were found up-regulated in HepG2 cells treated by CsIV and CsV. The apoptotic proteins, bax, cytochrome c, cleaved caspase-3/-9, were all found activated in HepG2 cells after CsIV and CsV treatment. The anti-apoptotic protein, bcl-2, was significantly down-regulated in all treated HepG2 cells.

CONCLUSION

Our data demonstrated that CsIV and CsV exerted significant cytotoxic effects on HepG2 cells without affecting normal liver cells. And, these chikusetsusaponins, especially for CsIV, showed a potent effect on promoting cell apoptosis in HepG2 cells, which was associated with the activation of p53-mediated apoptosis pathway.

The Synergistic Antitumor Effect of Tanshinone IIA Plus Adriamycin on Human Hepatocellular Carcinoma Xenograft in BALB/C Nude Mice and Their Influences on Cytochrome P450 CYP3A4 In Vivo

OBJECTIVE

Hepatocellular carcinoma is one of the most common diseases that seriously threaten human life and health. In this study, we evaluated the inhibitory effect of tanshinone IIA (Tan IIA) combined with adriamycin (ADM) on human hepatocellular carcinoma and developed a platform to assess the function if Chinese herbal ingredients combined with chemotherapy drugs have synergistic antitumor effects in vivo.

METHODS

Established animal model of human hepatocarcinoma HepG2 cell in nude mice. Mice were divided into model control group, Tan IIA group, ADM group, and Tan IIA + ADM group. The changes from general condition, weight, tumor volume, and inhibition rate were observed. The data were gathered from serum AST level and histopathological changes. The content and activity of cytochrome P450 were determined by spectrophotometric analysis. CYP3A4 protein expression was analyzed by western blotting. The binding model crystal structure of Tan IIA and ADM with pregnane X receptor (PXR) was evaluated by Discovery Studio 2.1.

RESULTS

A combination of Tan IIA with ADM could improve life quality by relieving ADM toxicity, decreasing tumor volume, declining serum AST level, and improving liner pathological section in tumor-bearing mice. The inhibitory rates of Tan IIA, ADM, and cotreatment were 32.77%, 60.96%, and 73.18%, respectively. The Tan IIA group significantly enhanced the content of cytochrome b5, P450, and erythromycin-N-demethylase activity. CYP3A4 protein expression was enhanced obviously by the Tan IIA + ADM group. Virtual molecular docking showed that both Tan IIA and ADM could be stably docked with the same binding site of PXR but different interactions.

CONCLUSIONS

Tan IIA in combination with ADM could improve the life quality in tumor-bearing mice and enhance the antitumor effect. The Tan IIA group increased the concentration of cytochrome P450 enzymes and activity. Combined Tan IIA with ADM could upregulate the CYP3A4 protein expression and make relevant interaction with protein PXR by virtual docking.

Novel Antitumor Invasive Actions of p-Cymene by Decreasing MMP-9/TIMP-1 Expression Ratio in Human Fibrosarcoma HT-1080 Cells

p-Cymene (4-isopropyltoluene) has been reported to have beneficial actions such as anti-inflammatory and antinociceptive activities. To evaluate whether p-cymene exhibits antitumor invasive actions, we examined the effects of p-cymene on the production of matrix metalloproteinase 9 (MMP-9)/gelatinase B and tissue inhibitor of metalloproteinases-1 (TIMP-1) in human fibrosarcoma HT-1080 cells. p-Cymene was found to dose-dependently inhibit the 12-O-tetradecanoylphorbol 13-acetate (TPA)-augmented production and gene expression of MMP-9 in HT-1080 cells. In contrast, p-cymene enhanced the TPA-augmented production and gene expression of TIMP-1 in HT-1080 cells. However, there was no change in the constitutive level of MMP-9 and TIMP-1 mRNAs and TIMP-1 protein in p-cymene-treated cells. In addition, we found that the in-vitro TPA-augmented invasiveness of HT-1080 cells was inhibited by p-cymene in a dose-dependent manner. Furthermore, p-cymene was found to suppress the constitutive and/or TPA-augmented phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) in HT-1080 cells. Thus, these results provide novel evidence that p-cymene is an effective candidate for the prevention of tumor invasion and metastasis through mechanisms that include the inhibition of MMP-9 expression and the augmentation of TIMP-1 production along with the suppression of ERK1/2 and p38 MAPK signal pathways in tumor cells.

Emodin inhibits migration and invasion of MHCC-97H human hepatocellular carcinoma cells

Emodin, an anthraquinone derivative from the root and rhizome of Rheum palmatum L., was found to have antitumor effects in different types of cancer by regulating multi-molecular targets. The aim of the present study was to explore the effect of emodin on the migration and invasion of MHCC-97H human hepatocellular carcinoma cells and the underlying molecular mechanisms. Firstly, it was demonstrated that emodin can inhibit cell proliferation and induce apoptosis of cells in a time- and dose-dependent manner, using a MTT assay and flow cytometry, respectively. However, when emodin concentration was <50 µmol/l, it had little effect on the inhibition of proliferation or the induction of apoptosis. Then, it was observed that emodin can significantly suppress cell migration and invasion with a treatment dose <50 µmol/l compared with the control (P<0.05), which was not attributed to a decrease in cell number. Further study demonstrated that emodin significantly suppressed the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 compared with the control, which may be mediated by the activation of the p38 mitogen-activated protein kinases (MAPK) signaling pathway and suppression of extracellular signal regulated kinase (ERK)/MAPK and phosphatidylinositol 3-kinase/Akt signaling pathways. Therefore, the present study, for the first time, used MHCC-97H cells, which have the high potential of malignant invasion, to demonstrate that emodin may inhibit cell migration and invasion.