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The thorns of Gleditsia sinensis are a traditional Oriental medicine used for the treatment of swelling, suppuration, carbuncle and skin diseases. In the present study, we identified a novel molecular mechanism by which an ethanol extract of Gleditsia sinensis thorns (EEGS) inhibits the growth of the SNU-5 human gastric cancer cell line. EEGS treatment inhibited cell growth and was associated with G1 phase cell cycle arrest at a concentration of 400 µg/ml (IC50) in SNU-5 cells. Treatment with EEGS also stimulated p21WAF1 expression, which significantly decreased the expression of cyclins and cyclin-dependent kinases (CDKs). Further study suggested that p38 MAP kinase pathways may be involved in the inhibition of cell proliferation through p21WAF1‑dependent G1 phase cell cycle arrest in EEGS-treated cells. In addition, NF-κB and AP-1 transcription factor binding sites were identified as the cis-elements for tumor necrosis factor-α (TNF-α)-induced matrix metalloproteinase-9 (MMP-9) expression in SNU-5 cells, as determined by gel-shift assay. Treatment of cells with EEGS suppressed MMP-9 expression induced by TNF-α via a decrease in the binding activity of both NF-κB and AP-1 motifs. These data demonstrate that EEGS-mediated inhibition of cell growth appears to involve the activation of p38 MAP kinase, subsequently leading to the induction of p21WAF1 and the downregulation of cyclin D1/CDK4 and cyclin E/CDK2 complexes. Moreover, EEGS strongly inhibited TNF-α-induced MMP-9 expression by impeding the DNA binding activity of NF-κB and AP-1. Overall, these results provide a potential mechanism for EEGS in the treatment of gastric cancer.

Although interleukin-28A (IL-28A) is believed to have an antiviral effect, its role in tumor migration requires further examination. The present study was intended to verify the effect of IL-28A on the migration of UMUC-3 bladder cancer cells. IL-28A and its receptor IL-28AR1 mRNA were detected in UMUC-3 cells. Although exogenous IL-28A showed no effect on cell proliferation, a wound-healing migration assay showed that the migration of UMUC-3 cells was induced by IL-28A. Furthermore, treatment of the cells with IL-28A significantly promoted MMP-9 expression via binding activities of NF-κB and AP-1. IL-28A also induced the activation of p38 MAPK and Jak2-Stat2 signaling. Using the p38 MAPK inhibitor SB203580 and the dominant-negative plasmid DN-p38, we found evidence that the inhibition of p38 MAPK signaling suppressed the effects of IL-28A including wound-healing migration and MMP-9 expression by activation of NF-κB and AP-1 binding in UMUC-3 cells. However, Jak-2 inhibition by AG490 did not affect IL-28A-induced migration of UMUC-3 cells. Collectively, we suggest for the first time that the p38 MAPK pathway mediates IL-28A-induced cell migration through MMP-9 expression by activating NF-κB and AP-1 binding motifs.

The thorns of Gleditsia sinensis are used as a medicinal herb in China and Korea. However, the mechanisms responsible for the antitumor effects of the water extract of Gleditsia sinensis thorns (WEGS) remain unknown. HCT116 cells treated with the WEGS at a dose of 800 μg/mL (IC50) showed a significant decrease in cell growth and an increase in cell cycle arrest during the G2/M-phase. G2/M-phase arrest was correlated with increased p53 levels and down-regulation of the check-point proteins, cyclinB1, Cdc2 and Cdc25c. In addition, treatment with WEGS induced phosphorylation of extracellular signal-regulated kinase (ERK), p38 MAP kinase and JNK (c-Jun N-terminal kinases). Moreover, inhibition of ERK by treatment of cells with the ERK-specific inhibitor PD98059 blocked WEGS-mediated p53 expression. Similarly, blockage of ERK function in the WEGS-treated cells reversed cell-growth inhibition and decreased cell cycle proteins. Finally, in vivo WEGS treatment significantly inhibited the growth of HCT116 tumor cell xenografts in nude mice with no negative side effects, including loss of body weight. These results describe the molecular mechanisms whereby the WEGS might inhibit proliferation of colon cancer both in vitro and in vivo, suggesting that WEGS has potential as an anticancer agent for the treatment of malignancies. Copyright © 2010 John Wiley & Sons, Ltd.

Magnolol has been reported to play a role in antitumor activity. However, the relevant pathway integrating cell cycle regulation and signaling pathways involved in growth inhibition in cancer cells remains to be identified. In the present study, magnolol treatment of these cells resulted in significant dose-dependent growth inhibition together with apoptosis, G1- and G2/M-phase cell cycle arrest at a 60 microM (IC50) dose in 5637 bladder cancer cells. In addition, magnolol treatment strongly induced p27KIP1 expression, and down-regulated expression of cyclin-dependent kinases (CDKs) and cyclins. Moreover, treatment with magnolol-induced phosphorylation of ERK, p38 MAP kinase, and JNK. Among the pathway inhibitors examined, only PD98059, an ERK-specific inhibitor, blocked magnolol-dependent p27KIP1 expression. Blockade of ERK function consistently reversed magnolol-mediated inhibition of cell proliferation and decreased G2/M cell cycle proteins, but not G1 cell cycle proteins. Furthermore, magnolol treatment increased both Ras and Raf activation. Transfection of cells with dominant negative Ras (RasN17) and Raf (RafS621A) mutant genes suppressed magnolol-induced ERK activity and p27KIP1 expression. Finally, the magnolol-induced reduction in cell proliferation and G2/M cell cycle proteins was also abolished in the presence of RasN17 and RafS621A mutant genes. These data demonstrate that the Ras/Raf/ERK pathway participates in p27KIP1 induction, leading to a decrease in the levels of cyclin B1/Cdc2 complexes and magnolol-dependent inhibition of cell growth. Overall, these novel findings concerning the molecular mechanisms of magnolol in 5637 bladder cancer cells provide a theoretical basis for therapeutic treatment of malignancies.

The present study identified a novel mechanism for the effects of sanguinarine in vascular smooth muscle cells (VSMC). Sanguinarine treatment of VSMC resulted in significant growth inhibition as a result of G1-phase cell-cycle arrest mediated by induction of p27KIP1 expression, and resulted in a down-regulation of the expression of cyclins and CDKs in VSMC. Moreover, sanguinarine-induced inhibition of cell growth appeared to be linked to activation of Ras/ERK through p27KIP1-mediated G1-phase cell-cycle arrest. Overall, the unexpected effects of sanguinarine treatment in VSMC provide a theoretical basis for clinical use of therapeutic agents in the treatment of atherosclerosis.

The thorns of Gleditsia sinensis, which are extensively used as a medicinal herb in Asian countries, have been reported to exert various pharmacological effects. However, the anti-atherogenic effect of Gleditsia sinensis thorns has never been investigated. In the present study, we investigated the role and effect of the ethanol extract of Gleditsia sinensis thorns (EEGS) on cultured vascular smooth muscle cells (VSMC). Treatment of VSMC with EEGS led to a significant decrease in cell growth by arresting cells in the G2/M-phase of the cell cycle, which was associated with up-regulated p21WAF1 levels and suppression of G2/M cell cycle regulators, cyclinB1, Cdc2 and Cdc25c. In addition, EEGS treatment led to the induction of extracellular signal-regulated kinase1/2 (ERK1/2), p38 MAPK, and JNK (c-Jun N-terminal kinases) activation. EEGS-induced p21WAF1 expression was blocked by treatment with the p38 MAPK-specific inhibitor SB203580. SB203580 also markedly recovered the inhibition of cell growth and decrease in cell cycle proteins in EEGS-treated VSMC. Moreover, EEGS inhibited matrix metalloproteinase-9 (MMP-9) expression induced by tumor necrosis factor-α (TNF-α) in VSMC. Finally, an electrophoresis mobility shift assay demonstrated that EEGS suppressed expression of transcription factor, nuclear factor kappaB (NF-κB) and activator protein-1 (AP-1), which are essential cis-elements for the MMP-9 promoter in TNF-α-treated VSMC. These results demonstrate that EEGS exerts a potent inhibitory effect on cell proliferation and MMP-9 expression in VSMC. These unexpected novel findings represent theoretical data for the preventive and therapeutic use of EEGS for the treatment of atherosclerosis disease.

Interleukin (IL)-28A, also called IFN-λ2, is a member of the classIIcytokine family and has demonstrated anti-proliferative and anti-viral signals. The present study demonstrated migration inducement of IL-28A-treated bladder cancer cells - a novel function. RNA microarray analysis showed an enhanced expression of IL-28A and its receptor IL-28AR1 in muscle invasive urothelial carcinoma in a human bladder. Strong expression of IL-28A and IL-28AR1 was detected in bladder cancer tissues and cell lines (5637, T-24, and HT1376 cells), as determined by real-time PCR and immunoblot analysis. IL-28A treatment induced migration of bladder cancer cells, independent of the cell growth. IL-28AR1-specific small interfering RNA (si-IL-28AR1) inhibited the induction of migration in IL-28A-treated cells. IL-28A treatment stimulated the expression of matrix metalloproteinases-9 (MMP-9) via activation of transcription factor NF-κB. Gene knockdown for MMP-9 and the p65 subunit of NF-κB, using siRNA transfection, suppressed wound healing migration in IL-28A-treated bladder cancer cells. Also, treatment with IL-28A induced activation of mitogen-activated protein kinase (MAPK) in bladder cancer cells. MAPK function blockage by a MAPK-specific inhibitor showed that MAPK phosphorylation is required for IL-28A-induced MMP-9 expression through activation of NF-κB. The transient transfection of bladder cancer cells with ERK1/2 knock down (si-ERK1/2) and dominant negative p38 (DNp38) suppressed IL-28A-induced migration. IL-28A-induced induction of MMP-9 expression, MAPK activation, and DNA binding activity of NF-κB was abolished in the presence of IL-28A neutralizing antibody or by transfection of si-IL-28AR1. These results show that IL-28A/IL-28AR1 dyad-induced wound healing migration requires NF-κB-mediated MMP-9 expression by MAPK activation.

Decursin, a pyranocoumarin isolated from the Korean Angelica gigas root, has demonstrated anti-cancer properties. In the present study, we found that decursin inhibited cell viability in cultured human urinary bladder cancer 235J cells and colon cancer HCT116 cells. The inhibited proliferation was due to apoptotic induction, because both cells treated with decursin dose-dependently showed a sub-G1 phase accumulation and an increased cytoplasmic DNA-histone complex. Cell death caused by decursin was also associated with the down-regulation of anti-apoptotic factor Bcl-2 and the up-regulation of pro-apoptotic molecules cytochrome c, caspase 3 and Bax. Treatment of both types of cancer cells with decursin resulted in G1-phase cell cycle arrest, as revealed by FACS analyses. In addition, decursin increased protein levels of p21WAF1 with a decrease in cyclins and cyclin dependent kinases (CDKs). Furthermore, decursin induced the activation of extracellular signal-regulated kinases (ERK) in both cancer cell lines, with the notable exceptions of c-Jun N-terminal kinase (JNK) and p38 mitogen activated protein (MAP) kinase. Finally, pretreatment with ERK-specific inhibitor PD98059 reversed decursin-induced p21WAF1 expression and decursin-inhibited cell growth. Thus, these findings suggest that decursin has potential therapeutic efficacy for the treatment of bladder and colon cancer.

The thorns of Gleditsia sinensis have traditionally been used in the treatment of several diseases, which includes their use as anti-tumor agents, but there has been no scientific evidence of this anti-tumor effect. However, the present study has identified a novel mechanism for the anti-tumor effect of Gleditsia sinensis thorns in the treatment of colon cancer. Treatment with the ethanol extract of Gleditsia sinensis thorns (EEGS) resulted in significant growth inhibition together with G2/M-phase cell cycle arrest at a dose of 600 microg/ml (IC50) in HCT116 cells. In addition, treatment with EEGS induced p27 expression and down-regulated expression of cyclins and cyclin-dependent kinases. Moreover, EEGS treatment induced phosphorylation of extracellular signal-regulated kinases (ERK), p38 MAP kinase and JNK (c-Jun N-terminal kinases). Among the pathways examined, only PD98059 (ERK-specific inhibitor) abolished EEGS-dependent p27 expression. Similarly, suppression of ERK function reversed EEGS-mediated cell proliferation inhibition and decreased cell cycle proteins. In addition, tumor necrosis factor-alpha (TNF-alpha)-induced matrix metalloproteinase-9 (MMP-9) expression was inhibited by EEGS treatment via decreased transcriptional activity of both activator protein-1 (AP-1) and nuclear factor-kappaB. Finally, EEGS treatment significantly reduced tumor sizes in HCT116 cell-xenografted tumor tissues, which was associated with the changed levels of ERK phosphorylation, p27 and MMP-9 expression. Overall, these results have identified a novel molecular mechanism for EEGS in the treatment of colon cancer and might provide a theoretical basis for the potential therapeutic use of EEGS in the treatment of malignancies.

Cordycepin (3'-deoxyadenosine) has many anti-cancer properties. However, neither its molecular mechanism nor its molecular targets are well understood. In the present study, we investigated novel molecular mechanisms for the anti-tumor effects of cordycepin in human colon cancer HCT116 cells. After treatment of cells with cordycepin, dose-dependent cell growth inhibition was observed at an IC(50) value of 200muM. Cordycepin treatment resulted in G2/M-phase cell-cycle arrest, which was associated with increased p21WAF1 levels and reduced amounts of cyclin B1, Cdc2, and Cdc25c in a p53-independent pathway. Moreover, cordycepin treatment induced activation of JNK (c-Jun N-terminal kinases). Pretreatment with SP600125, a JNK-specific inhibitor, abrogated cordycepin-mediated p21WAF1 expression, cell growth inhibition, and reduced cell-cycle proteins. Furthermore, JNK1 inhibition by small interfering RNA (siRNA) produced similar results: suppression of cordycepin-induced p21WAF1 expression, decreased cell growth, and reduced cell-cycle proteins. Together, these results suggest a critical role for JNK1 activation in cordycepin-induced inhibition of cell growth and G2/M-phase arrest in human colon cancer cells.

Cordycepin (3'-deoxyadenosine), a bioactive compound of Cordyceps militaris, has many pharmacological activities. The present study reveals novel molecular mechanisms for the anti-tumor effects of cordycepin in two different bladder cancer cell lines, 5637 and T-24 cells. Cordycepin treatment, at a dose of 200 microM (IC(50)) during cell-cycle progression resulted in significant and dose-dependent growth inhibition, which was largely due to G2/M-phase arrest, and resulted in an up-regulation of p21WAF1 expression, independent of the p53 pathway. Moreover, treatment with cordycepin-induced phosphorylation of JNK (c-Jun N-terminal kinases). Blockade of JNK function using SP6001259 (JNK-specific inhibitor) and small interfering RNA (si-JNK1) rescued cordycepin-dependent p21WAF1 expression, inhibited cell growth, and decreased cell cycle proteins. These results suggest that cordycepin could be an effective treatment for bladder cancer.

Cellular and molecular events in vascular smooth muscle cells (VSMC) from Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were investigated. SHR-derived VSMC showed increased proliferative capacity and MAP kinase levels in comparison with WKY-derived VSMC. Flow cytometry analysis revealed that progression from G1 to S phase was faster in SHR-derived VSMC in response to tumor necrosis factor-alpha (TNF-alpha) as compared with cells from WKY. The G1 cell cycle-associated proteins such as cyclin D1, cyclin E, CDK2 and CDK4, and kinase activities associated with CDK2 and CDK4, were increased in SHR-derived VSMC. In addition, CDK inhibitor p21 was elevated in SHR-derived cells. Matrix metalloproteinase-9 (MMP-9) expression and migration were also increased in response to TNF-alpha in SHR-derived cells. This increase was characterized by the up-regulation of MMP-9, which was transcriptionally regulated at the AP-1 and NF-kappaB sites in the MMP-9 promoter. These results suggest that the hypertensive-associated increase in VSMC proliferative capacity, G1 to S-phase cell-cycle progress and MMP-9 expression may play a role in vascular remodeling in hypertension.

Magnolia officinalis is a commonly used herb in East Asian countries and has multiple pharmacological effects. Although Magnolia officinalis has a variety of pharmacological effects on certain cancer cell types, the molecular mechanisms on urinary bladder cancer are unclear. An aqueous extract of M. officinalis inhibited cell proliferation in cultured human urinary bladder cancer 5637 cells. Inhibition of proliferation was associated with G1 cell cycle arrest. Treatment with M. officinalis extract blocked the cell cycle in the G1 phase, down-regulated the expression of cyclins and CDKs and up-regulated the expressions of p21WAF1 and p27 Kip1, which are CDK inhibitors. In addition, M. officinalis extract induced a marked activation of p38 MAP kinase and JNK. SB203580, a p38 MAP kinase specific inhibitor, blocked the expression of M. officinalis extract-dependent p38 MAP kinase and p21WAF1. Blockage of the p38 MAPK kinase function reversed M. officinalis extract-induced cell proliferation. These data demonstrate that M. officinalis extract-induced cell growth inhibition appears to be linked to the activation of p38 MAP kinase through p21WAF1 expression. Moreover, treatment of 5637 cells with M. officinalis extract suppressed constitutive and TNF-alpha-induced-nuclear factor-kappa B (NF-kappaB) activation. Furthermore, the transactivation of TNF-alpha-stimulated NF-kappaB was inhibited by SB203580 treatment. Collectively, these results suggest that the p38 MAP kinase pathway contributes, at least partially, to the anti-cancer activity of M. officinalis extract in human urinary bladder tumor 5637 cells.