Yanlin Ming

Antiproliferation and apoptosis induced by curcumin in human ovarian cancer cells

Curcumin, an active ingredient from the rhizome of the plant, Curcuma longa, has antioxidant, anti‐inflammatory and anti‐cancer activities. It has recently been demonstrated that the chemopreventive activities of curcumin might be due to its ability to inhibit cell growth and induce apoptosis. In the present study, we have investigated the effects of curcumin on growth and apoptosis in the human ovarian cancer cell line Ho‐8910 by MTT assay, fluorescence microscopy, flow cytometry and Western blotting. Our data revealed that curcumin could significantly inhibit the growth and induce apoptosis in Ho‐8910 cells. A decrease in expression of Bcl‐2, Bcl‐XL and pro‐caspase‐3 was observed after exposure to 40 μM curcumin, while the levels of p53 and Bax were increased in the curcumin‐treated cells. These activities may contribute to the anticarcinogenic action of curcumin.

Osteopontin promotes gastric cancer metastasis by augmenting cell survival and invasion through Akt‐mediated HIF‐1α up‐regulation and MMP9 activation

Osteopontin (OPN) is a secreted, integrin‐binding matrix phosphorylated glycoprotein. OPN has been shown to facilitate the progression and metastasis of malignancies and has prognostic value in several types of cancer, including gastric cancer. However, the functional mechanism of OPN mediated metastatic growth in gastric cancer remains unclear. Here, using multiple in vitro and in vivo models, we report that OPN strongly promoted the progression and metastasis of gastric cancer. Immunohistochemical staining revealed that OPN, matrix metalloproteinase (MMP)9 and hypoxia‐inducible factor (HIF)‐1α have statistically significant different expression patterns between well‐ and poorly differentiated tissue samples (P < 0.05). Correlations existed between OPN and MMP9, and between OPN and HIF‐1α (r1= 0.872, p1 < 0.01 and r2= 0.878, p2 < 0.01). Furthermore, OPN dramatically increased colony formation and invasion of gastric cancer cells in vitro and promoted tumour growth and metastasis in vivo. In addition, OPN potently protected gastric cancer cells from serum depletion‐induced apoptosis. Further study shows that OPN activated phosphoinositide 3‐kinase/Akt survival pathway and up‐regulated HIF‐1αvia binding to αvβ3 integrins in gastric cancer cells. Moreover, we found that OPN could activate MMP9 and up‐regulate MMP2. Taken together, our results suggest that the survival‐promoting function is crucial for OPN to promote the development of gastric cancer, and HIF‐1α and MMP9 may play key roles during this process. Thus, targeting OPN and its related signalling network may develop an effective therapeutic approach for the management of gastric cancer.

Anti-proliferation and apoptosis induced by a novel intestinal metabolite of ginseng saponin in human hepatocellular carcinoma cells

20‐O‐(β‐d‐glucopyranosyl)‐20(S)‐protopanaxadiol (IH‐901), a novel intestinal bacterial metabolite of ginseng protopanaxadiol saponins, is reported to induce apoptosis in a variety of cancer cells. We purified the compound and measured its in vitro anti‐tumor activity. IH‐901 inhibited cell growth of human hepatocellular carcinoma SMMC7721 cells in a dose‐ and time‐dependent manner. We also found that IH‐901 induced apoptotic cell death concurrent with cell cycle arrest in G0–G1 phase in SMMC7721 cells. At the molecular level, we show that IH‐901 upregulates cytochrome c, p53, and Bax expression, and downregulates pro‐caspase‐3 and pro‐caspase‐9 expressions in a dose‐dependent manner, while the levels of Bcl‐2 and Bcl‐XL were unchanged in IH‐901‐treated SMMC7721 cells. These results provide significant insight into the anticarcinogenic action of IH‐901.

Ginsenoside Compound K Attenuates Metastatic Growth of Hepatocellular Carcinoma, which Is Associated with the Translocation of Nuclear Factor-κB p65 and Reduction of Matrix Metalloproteinase-2/9

The intestinal metabolite of ginseng saponin, compound K (CK), has various chemopreventive and chemotherapeutic activities, including anti-tumor activity. However, the functional mechanisms through which CK attenuates metastatic growth in hepatocellular carcinoma (HCC) remain unclear. Here, using multiple IN VITRO and IN VIVO models, we reported that CK strongly attenuated colony formation, adhesion, and invasion of HCC cells IN VITRO and dramatically inhibited spontaneous HCC metastatic growth IN VIVO. At the molecular level, immunofluorescence and Western blotting analysis confirmed that inhibition of metastatic growth of HCC induced by CK treatment caused a time-dependent decrease in nuclear NF- κB p65 and a concomitant increase in cytosolic NF- κB p65, indicating that CK suppressed the activation of the NF- κB pathway. Meanwhile, our study showed that the inhibition of matrix metalloproteinase2/9 (MMP2/9) expression caused by CK treatment was associated with NF- κB p65 nuclear export. Taken together, our results not only revealed that NF- κB p65 nuclear export and the reduction of MMP2/9 expression were associated with the metastatic inhibition induced by CK, but also suggested that CK may become a potential cytotoxic drug in the prevention and treatment of HCC.

Osteopontin Prevents Curcumin-Induced Apoptosis and Promotes Survival Through Akt Activation via alpha(v)beta(3) Integrins in Human Gastric Cancer Cells

Osteopontin (OPN) is a secreted, integrin-binding matrix phosphorylated glycoprotein that is overexpressed in many advanced cancers. However, the functional mechanisms by which OPN contributes to gastric cancer development are poorly understood. Here, we report that curcumin inhibited the growth of SGC7901 cell and induced apoptosis in a concentration- and time-dependent manner, while the acquired expression of OPN in SGC7901 cells dramatically promoted cell survival under serum depletion and prevented curcumin-induced apoptosis. Furthermore, PI3-K inhibitor LY294002 attenuated OPN-mediated Akt activation. Moreover, inhibiting the binding of OPN to αvβ3 integrins reduced activation of Akt. Taken together, these results demonstrate that the pro-survival and anti-apoptosis activities of OPN in gastric cancer cells are mediated in part through PI3-K/Akt pathway via αvβ3 integrins.

Compound K-induced apoptosis of human hepatocellular carcinoma MHCC97-H cells in vitro

An intestinal bacterial metabolite of ginseng protopanaxadiol saponin, 20-O-(β-D-glucopyranosyl)-20(S)-protopanaxadiol (compound K), has been reported to induce apoptosis in a variety of cancer cells. However, the precise mechanisms induced by compound K in human hepatocellular carcinoma (HCC) cells remain unclear. In order to examine possible apoptotic mechanisms, we investigated the anticancer effect of compound K in MHCC97-H. MTT assay showed that compound K inhibited the proliferation of MHCC97-H cells with a relatively low toxicity in normal hepatoma cells. Cell cycle progression and cell staining showed an increase in apoptotic sub-G1 fraction. Treatment of MHCC97-H with compound K also induced a reduction in mitochondrial membrane potential (Δψm) and DNA damage. Further study showed that compound K upregulated Fas, FasL, Bax/Bcl-2 ratio and downregulated pro-caspase-9, pro-caspase-3 in a dose-dependent manner, and it also inhibited Akt phosphorylation. These results suggest that compound K significantly inhibits cell proliferation and induces apoptosis in MHCC97-H cells through Fas- and mitochondria-mediated caspase-dependent pathways in human HCC cells.

Corilagin inhibits hepatocellular carcinoma cell proliferation by inducing G2/M phase arrest

Hepatocellular carcinoma (HCC) is one of most common types of malignant tumours. Therefore, it is very important to identify powerful drugs and their antitumour mechanisms. Corilagin has a significant antitumour potential and lower toxicity in normal cells in vitro. The IC50 values of corilagin for normal Chang‐liver cells and the HCC cell lines Bel7402 and SMMC7721 were 131.4, 24.5 and 23.4 µM, respectively, in the methyl thiazolyl tetrazolium (MTT) assay. MHCC97‐H xenografts in Balb/c mice intraperitoneally injected with 30 mg/kg corilagin for 5 weeks showed a 47.3% inhibition of tumour growth in vivo. Furthermore, data from flow cytometry and Western blot analyses of cell cycle and cell cycle‐related proteins suggest that corilagin arrests SMMC7721 cells at the G2/M phase by downregulating p‐Akt and cyclin B1/cdc2 and upregulating p‐p53 and p21Cip1. In conclusion, corilagin is a potential antitumour drug that is effective in retarding the growth of HCC, which is correlated with the activation of p‐p53‐p21Cip1‐cdc2/cyclin B1.

A new flavonoside from the invasive plant Macfadyena unguis-cati.

A new flavonoside, namely cirsimarin B (1), along with two known compounds cirsimarin (2) and acteoside (3), were isolated from the aerial parts of the invasive plant Macfadyena unguis-cati. Their structures were elucidated by extensive spectroscopic analyses (IR, FT-ICR-MS, 1D and 2D NMR) and by comparison with those reported. Compounds 1 and 2 were evaluated for their cytotoxic activity by the MTT method.

Corilagin induces the apoptosis of hepatocellular carcinoma cells through the mitochondrial apoptotic and death receptor pathways

Corilagin, a gallotannin, is one of the major active components of many ethnopharmacological plants and exhibits antitumor, anti-inflammatory and antioxidative properties. In recent years, corilagin has provoked much attention due to its antitumor activity, yet the mechanisms attributed to its anticancer actions are largely unknown. In our previous research, our group reported that corilagin could inhibit the proliferation of hepatocellular carcinoma (HCC) cells by inducing G2/M phase arrest. In the present study, observation of the morphological changes showed that corilagin induced the apoptosis of HCC cells as determined by AO/EB and Hoechst 33258 staining assays. Furthermore, flow cytometric analysis was carried out to calculate the apoptotic rate which was 24.1% following treatment with corilagin (37.5 µM). At the molecular level, mitochondrial membrane potential assay and western blot analysis showed that the mitochondrial transmembrane potential was reduced and the rate of release of cytochrome c was increased, which led to the activation of caspase-9, caspase-3 and cleavage of PARP in the cytoplasm indicating activation of the mitochondrial apoptotic pathway. Moreover, following treatment with corilagin, we noted upregulation of Fas and FasL and activation of caspase-8 which represented activation of the death receptor pathway, and we also observed downregulation of Bcl-2 and survivin which was also attributed to the antitumor effect of corilagin. These results suggest that corilagin significantly induced the apoptosis of HCC cells through both the mitochondrial apoptotic pathway and the death receptor pathway, and corilagin is a potential complementary anticancer herbal drug for HCC therapy.