Apigenin, a dietary flavonoid, inhibits proliferation of human bladder cancer T-24 cells via blocking cell cycle progression and inducing apoptosis.

BACKGROUND: Apigenin is a nontoxic dietary flavonoid, and it may have chemopreventive and therapeutic potential as an anti-inflammatory, antioxidant, and anti-cancer agent. However, its role in bladder cancer remains poorly understood. The aim of this study was to investigate the anti-proliferative activity of apigenin in human bladder cancer T-24 cells. METHODS AND RESULTS: Apigenin inhibited T-24 cell proliferation in a dose-dependent manner. We demonstrated that apigenin-induced early and mid-apoptotic cell could be identified by Annexnin V-Alexa Fluor 488/PI apoptosis detection and TUNEL assay. Moreover, using a JC-1 staining assay, we found that apigenin may induce the loss of the mitochondrial membrane potential. By performing flow cytometry and Western blotting, apigenin-mediated subG1 phase acculmulation was also associated with an increase in the phospho-p53, p53, p21, and p27 levels, and with a decrease in the Cyclin A, Cyclin B1, Cyclin E, CDK2, Cdc2, and Cdc25C levels, thereby blocking cell cycle progression. ELISA showed that the subG1 phase acculmulation was due to the increase in the p53, p21, and p27 levels. In addition, apigenin increased the Bax, Bad, and Bak levels, but reduced the Bcl-xL, Bcl-2, and Mcl-1 levels, and subsequently triggered the mitochondrial apoptotic pathway (release of cytochrome c and activation of caspase-9, caspase-3, caspase-7, and PARP). Further analysis demonstrated that apigenin increased the ROS levels and depleted GSH in T-24 cells at 12 h. CONCLUSIONS: The results suggested that apigenin inhibits T-24 cells proliferation via blocking cell cycle progression and inducing apoptosis. In addition, we discovered a potential anticancer activity of apigenin against T-24 cells.

Galangin, a novel dietary flavonoid, attenuates metastatic feature via PKC/ERK signaling pathway in TPA-treated liver cancer HepG2 cells.

BACKGROUND: Galangin (3,5,7-trihydroxyflavone) is a flavonoid compound found in high concentration in lesser galangal. The objective of this study was to investigate the ability of galangin to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced the invasion and metastasis of HepG2 liver cancer cells. RESULTS: First, using a cell-matrix adhesion assay, immunofluorescence assay, transwell-chamber invasion/migration assay, and wound healing assay, we observed that galangin exerted an inhibitory effect on TPA-induced cell adhesion, morphology/actin cytoskeleton arrangement, invasion and migration. Furthermore, the results of gelatin zymography and reverse transcriptase polymerase chain reaction (RT-PCR) assays showed that galangin reduced the TPA-induced enzyme activity of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in HepG2 cells; moreover, the messenger RNA level was downregulated. We also observed through a Western blotting assay that galangin strongly inhibited the TPA-induced protein expressions of protein kinase Cα (PKCα), protein kinase Cδ (PKCδ), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), the phospho-inhibitor of kappaBα (phospho-IκBα), c-Fos, c-Jun, and nuclear factor kappa B (NF-κB). Next, galangin dose-dependently inhibited the binding ability of NF-κB and activator protein 1 (AP-1) to MMP-2/MMP-9 promoters, respectively, resulting in the suppression of MMP-2/MMP-9 enzyme activity. CONCLUSIONS: The results revealed that galangin effectively inhibited the TPA-induced invasion and migration of HepG2 cells through a protein kinase C/extracellular signal-regulated kinase (PKC/ERK) pathway. Thus, galangin may have widespread applications in clinical therapy as an anti-metastatic medicament.

Antitumor effects of the flavone chalcone: inhibition of invasion and migration through the FAK/JNK signaling pathway in human gastric adenocarcinoma AGS cells.

Chalcones (benzylideneacetophenone) are cancer-preventive food components found in a human diet rich in fruits and vegetables. In this study, we first report the chemopreventive effect of chalcone in human gastric adenocarcinoma cell lines: AGS. The results showed that chalcone could inhibit the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay, Boyden chamber invasion/migration assay, and wound-healing assay. Molecular data showed that the effect of chalcone in AGS cells might be mediated via sustained inactivation of the phosphorylation of focal adhesion kinase (FAK) and c-Jun N-terminal kinase 1 and 2 (JNK1/2) signal involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Next, chalcone-treated AGS cells showed tremendous decrease in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), the nuclear level of NF-κB, and the binding ability of NF-κB to NF-κB response element. Furthermore, treating FAK small interfering RNA (FAK siRNA) and specific inhibitor for JNK (SP600125) to AGS cells could reduce the phosphorylation of JNK1/2 and the activity of MMP-2 and MMP-9. Our results revealed that chalcone significantly inhibited the metastatic ability of AGS cells by reducing MMP-2 and MMP-9 expressions concomitantly with a marked reduction on cell invasion and migration through suppressing and JNK signaling pathways. We suggest that chalcone may offer the application in clinical medicine.

Pinocembrin suppresses TGF-ß1-induced epithelial-mesenchymal transition and metastasis of human Y-79 retinoblastoma cells through inactivating αvß3 integrin/FAK/p38α signaling pathway.

BACKGROUND: Pinocembrin is the most abundant flavonoid in propolis. In this study, we investigated the antimetastatic effect of pinocembrin on TGF-ß1-induced epithelial-mesenchymal transition (EMT) and metastasis of human Y-79 retinoblastoma cells. RESULTS: Firstly, the results showed that pinocembrin significantly suppresses the TGF-ß1-induced abilities of the invasion and migration of Y-79 cells under non-cytotoxic concentration. Pinocembrin decreased TGF-ß1-induced expression of vimentin, N-cadherin, αv and ß3 integrin in Y-79 cells. Molecular data also showed pinocembrin inhibits the activation of focal adhesion kinase (FAK) and p38α signal involved in the downregulation of enzyme activities, protein and messenger RNA levels of matrix metalloproteinase-2/9 (MMP-2/-9) induced by TGF-ß1. Next, pinocembrin also strongly inhibited the degradation of inhibitor of kappaBα (IκBα) and the nuclear levels of nuclear factor kappa B (NF-κB). Also, a dose-dependent inhibition on the binding ability of NF-κB was further observed under pinocembrin treatment. CONCLUSIONS: Presented results indicated that pinocembrin inhibits TGF-ß1-induced epithelial-mesenchymal transition (EMT) and metastasis of Y-79 cells by inactivating the αvß3 integrin/FAK/p38α signaling pathway. Thus, our findings point to the anticancer potential of pinocembrin against retinoblastoma cells.

Nobiletin attenuates metastasis via both ERK and PI3K/Akt pathways in HGF-treated liver cancer HepG2 cells.

Hepatocyte growth factor (HGF), and its receptor, c-Met activation has recently been shown to play important roles in cancer invasion and metastasis in a wide variety of tumor cells. We use HGF as an invasive inducer of human HepG2 cells to investigate the effect of four flavones including apigenin, tricetin, tangeretin, and nobiletin on HGF/c-Met-mediated tumor invasion and metastasis. Among them, nobiletin markedly inhibited HGF-induced the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay and transwell-chamber invasion/migration assay under non-cytotoxic concentrations. Data also showed nobiletin inhibited HGF-induced cell scattering and cytoskeleton changed such as filopodia and lamellipodia. Furthermore, nobiletin could inhibit HGF-induced the membrane localization of phosphorylated c-Met, ERK2, and Akt, but not phosphorylated JNK1/2 and p38. Next, nobiletin significantly decreased the levels of phospho-ERK2 and phospho-Akt in ERK2 or Akt siRNA-transfected cells concomitantly with a marked reduction on cell invasion and migration. In conclusion, nobiletin attenuates HGF-induced HepG2 cells metastasis involving both ERK and PI3K/Akt pathways and are potentially useful as anti-metastatic agents for the treatment of hepatoma.

Suppression of 12-O-tetradecanoylphorbol-13-acetate-induced MCF-7 breast adenocarcinoma cells invasion/migration by α-tomatine through activating PKCα/ERK/NF-κB-dependent MMP-2/MMP-9 expressions.

α-Tomatine, isolated from Lycopersicon esculentum Linn., is a naturally occurring glycoalkaloids in immature green tomatoes. Some reports demonstrated that α-tomatine had various anti-carcinogenic properties. First, the result demonstrated α-tomatine could inhibit TPA-induced the abilities of the adhesion, morphology/actin cytoskeleton arrangement, invasion, and migration by cell-matrix adhesion assay, immunofluorescence stain assay, Boyden chamber invasion assay, and wound-healing assay. Data also showed α-tomatine could inhibit the activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and protein kinase C-α (PKCα) involved in the downregulation of the enzyme activities and messenger RNA levels of matrix metalloproteinase-2/9 (MMP-2/MMP-9) induced by TPA. Next, α-tomatine also strongly inhibited TPA-induced the activation of nuclear factor kappa B (NF-κB) and phospho-inhibitor of kappa Bα (phospho-IκBα). In addition, TPA-induced translocation of PKC-α from cytosol to membranes, and suppression of TPA elicited the expression of PKC-α by adding the PKC-α inhibitors, GF-109203X and Gö-6983. The treatment of specific inhibitor for ERK (U0126) to MCF-7 cells could inhibit TPA-induced MMP-2/MMP-9 and phospho-ERK along with an inhibition on cell invasion and migration. Application of α-tomatine to prevent the invasion/migration of MCF-7 cells through blocking PKCα/ERK/NF-κB activation is first demonstrated herein.

Diosgenin, a steroidal saponin, inhibits migration and invasion of human prostate cancer PC-3 cells by reducing matrix metalloproteinases expression.

BACKGROUND: Diosgenin, a steroidal saponin obtained from fenugreek (Trigonella foenum graecum), was found to exert anti-carcinogenic properties, such as inhibiting proliferation and inducing apoptosis in a variety of tumor cells. However, the effect of diosgenin on cancer metastasis remains unclear. The aim of the study is to examine the effect of diosgenin on migration and invasion in human prostate cancer PC-3 cells. METHODS AND PRINCIPAL FINDINGS: Diosgenin inhibited proliferation of PC-3 cells in a dose-dependent manner. When treated with non-toxic doses of diosgenin, cell migration and invasion were markedly suppressed by in vitro wound healing assay and Boyden chamber invasion assay, respectively. Furthermore, diosgenin reduced the activities of matrix metalloproteinase-2 (MMP-2) and MMP-9 by gelatin zymography assay. The mRNA level of MMP-2, -9, -7 and extracellular inducer of matrix metalloproteinase (EMMPRIN) were also suppressed while tissue inhibitor of metalloproteinase-2 (TIMP-2) was increased by diosgenin. In addition, diosgenin abolished the expression of vascular endothelial growth factor (VEGF) in PC-3 cells and tube formation of endothelial cells. Our immunoblotting assays indicated that diosgenin potently suppressed the phosphorylation of phosphatidylinositide-3 kinase (PI3K), Akt, extracellular signal regulating kinase (ERK) and c-Jun N-terminal kinase (JNK). In addition, diosgenin significantly decreased the nuclear level of nuclear factor kappa B (NF-κB), suggesting that diosgenin inhibited NF-κB activity. CONCLUSION/SIGNIFICANCE: The results suggested that diosgenin inhibited migration and invasion of PC-3 cells by reducing MMPs expression. It also inhibited ERK, JNK and PI3K/Akt signaling pathways as well as NF-κB activity. These findings reveal new therapeutic potential for diosgenin in anti-metastatic therapy.

BMP-2 suppresses renal interstitial fibrosis by regulating epithelial-mesenchymal transition.

Dysregulation of epithelial-to-mesenchymal transition (EMT) may contribute to renal fibrogenesis. Our previous study indicated that bone morphogenetic protein-2 (BMP-2) significantly reversed transforming growth factor (TGF)-ß1-induced renal interstitial fibrosis. In this study, we examined the underlying mechanism and elucidate the regulation of EMT process under BMP-2 treatment. Cultured renal interstitial fibroblast (NRK-49F) was treated with TGF-ß1 (10 ng/ml) with or without BMP-2 (10-250 ng/ml) for 24 h. The expression of α-smooth muscle actin (α-SMA), E-cadherin, fibronectin, or Snail transcriptional factors was analyzed by immunofluorescence staining or Western blotting. Cell migration was analyzed by wound-healing assay. NRK-49F treated with TGF-ß1 induced significant EMT including upregulatioin of α-SMA, fibronectin, and snail proteins and down-regulation of E-cadherin. Interestingly, co-treatment with BMP-2 dose-dependently reversed TGF-ß1-induced cellular fibrosis, cell migration, and above EMT change. The above effect was closely correlated with Snail since BMP-2 dose- and time-course dependently induced a significant decrease in the level of Snail. Moreover, Snail siRNA significantly reversed TGF-ß1-induced increases in the level of α-SMA and fibronectin (intracellular and extracellular). We suppose that BMP-2 have the potential to attenuate TGF-ß1-induced renal interstitial fibrosis by attenuating Snail expression and reversing EMT process.

Acacetin inhibits the invasion and migration of human non-small cell lung cancer A549 cells by suppressing the p38α MAPK signaling pathway.

Lung cancer is one of the most common malignancies in the world and its metastasis is the major cause of death in cancer patients. Acacetin (5,7-dihydroxy-4'-methoxyflavone), a flavonoid compound, has anti-peroxidative and anti-inflammatory effects. The effect of acacetin on invasion and migration in human NSCLC A549 cells was investigated. First, the result demonstrated acacetin could exhibit an inhibitory effect on the abilities of the adhesion, morphology/actin cytoskeleton arrangement, invasion, and migration by cell-matrix adhesion assay, immunofluorescence assay, Boyden chamber assay, and wound-healing assay. Molecular data showed that the effect of acacetin in A549 cells might be mediated via sustained inactivation of the phosphorylation of mixed-lineage protein kinase 3 (MLK3), mitogen-activated protein kinase kinases 3/6 (MKK3/6), and p38α MAPK signal involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), and urokinase-type plasminogen activator (u-PA). Next, acacetin significantly decreased in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), and the nuclear levels of nuclear factor kappa B (NF-κB), c-Fos, and c-Jun. Also, the treatment with acacetin to A549 cells also leads to a concentration-dependent inhibition on the binding abilities of NF-κB and activator protein-1 (AP-1). Furthermore, the treatment of specific inhibitor for p38 MAPK (SB203580) to A549 cells could cause reduced activities of MMP-2/9 and u-PA. In addition, acacetin significantly decreased the levels of phospho-p38α MAPK, MMP-2/9, and u-PA in p38α-cDNA-transfected cells concomitantly with a marked reduction on cell invasion and migration. Our results revealed the anti-migration and anti-invasion effects of acacetin, which may act as a promising therapeutic agent for the treatment of lung cancer.

α-Tomatine suppresses invasion and migration of human non-small cell lung cancer NCI-H460 cells through inactivating FAK/PI3K/Akt signaling pathway and reducing binding activity of NF-κB.

α-Tomatine, isolated from Lycopersicon esculentum Linn., is a naturally occurring steroidal glycoalkaloid in immature green tomatoes. Some reports demonstrated that α-tomatine had various anticarcinogenic properties. The purpose of this study is to investigate the anti-metastatic effect of α-tomatine in NCI-H460 human non-small cell lung cancer cells. First, the results showed that α-tomatine significantly suppressed the abilities of the adhesion, invasion, and migration of NCI-H460 cells under non-cytotoxic concentrations. Molecular data also showed α-tomatine could inhibit the activation of focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K)/Akt signal involve in the downregulation the enzyme activities, protein and messenger RNA levels of matrix metalloproteinase-7 (MMP-7). Next, α-tomatine also strongly inhibited the degradation of inhibitor of kappaBα (IκBα) and the nuclear levels of nuclear factor kappa B (NF-κB). Also, a dose-dependent inhibition on the binding ability of NF-κB by α-tomatine treatment was further observed. Furthermore, α-tomatine significantly decreased the levels of phospho-Akt and MMP-7 in Akt1-cDNA-transfected cells concomitantly with a marked reduction on cell invasion and migration. Presented results indicated α-tomatine might be further application for treating cancer metastasis.

Nobiletin, a citrus flavonoid, suppresses invasion and migration involving FAK/PI3K/Akt and small GTPase signals in human gastric adenocarcinoma AGS cells.

Nobiletin, a compound isolated from citrus fruits, is a polymethoxylated flavone derivative shown to have anti-inflammatory, antitumor, and neuroprotective properties. This study has investigated that nobiletin exerted inhibitory effects on the cell adhesion, invasion, and migration abilities of a highly metastatic AGS cells under non-cytotoxic concentrations. Data also showed nobiletin could inhibit the activation of focal adhesion kinase (FAK) and phosphoinositide-3-kinase/Akt (PI3K/Akt) involved in the downregulation of the enzyme activities, protein expressions, messenger RNA levels of matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-2 (MMP-9). Also, our data revealed that nobiletin inhibited FAK/PI3K/Akt with concurrent reduction in the protein expressions of Ras, c-Raf, Rac-1, Cdc42, and RhoA by western blotting, whereas the protein level of RhoB increased progressively. Otherwise, nobiletin-treated AGS cells showed tremendously decreased in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), the nuclear level of NF-κB, and the binding ability of NF-κB to NF-κB response element. Furthermore, nobiletin significantly decreased the levels of phospho-Akt and MMP-2/9 in Akt1-cDNA-transfected cells concomitantly with a marked reduction in cell invasion and migration. These results suggest that nobiletin can reduce invasion and migration of AGS cells, and such a characteristic may be of great value in the development of a potential cancer therapy.

α-Solanine inhibits human melanoma cell migration and invasion by reducing matrix metalloproteinase-2/9 activities.

α-Solanine, a naturally occurring steroidal glycoalkaloid in potato sprouts, was found to possess anti-carcinogenic properties, such as inhibiting proliferation and inducing apoptosis of tumor cells. However, the effect of α-solanine on cancer metastasis remains unclear. In the present study, we examined the effect of α-solanine on metastasis in vitro. Data demonstrated that α-solanine inhibited proliferation of human melanoma cell line A2058 in a dose-dependent manner. When treated with non-toxic doses of α-solanine, cell migration and invasion were markedly suppressed. Furthermore, α-solanine reduced the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9, which are involved in the migration and invasion of cancer cells. Our biochemical assays indicated that α-solanine potently suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositide-3 kinase (PI3K) and Akt, while it did not affect phosphorylation of extracellular signal regulating kinase (ERK). In addition, α-solanine significantly decreased the nuclear level of nuclear factor kappa B (NF-κB), suggesting that α-solanine inhibited NF-κB activity. Taken together, the results suggested that α-solanine inhibited migration and invasion of A2058 cells by reducing MMP-2/9 activities. It also inhibited JNK and PI3K/Akt signaling pathways as well as NF-κB activity. These findings reveal new therapeutic potential for α-solanine in anti-metastatic therapy.

Alpha-mangostin suppresses phorbol 12-myristate 13-acetate-induced MMP-2/MMP-9 expressions via alphavbeta3 integrin/FAK/ERK and NF-kappaB signaling pathway in human lung adenocarcinoma A549 cells.

The purpose of this study is to investigate the anti-metastatic effect of alpha-mangostin on phorbol 12-myristate 13-acetate (PMA)-induced matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) expressions in A549 human lung adenocarcinoma cells. Firstly, alpha-mangostin could inhibit PMA-induced abilities of the adhesion, invasion, and migration. Data also showed alpha-mangostin could inhibit the activation of alphavbeta3 integrin, focal adhesion kinase (FAK), and extracellular signal-regulated kinase1/2 (ERK1/2) involved in the downregulation the enzyme activities, protein and messenger RNA levels of MMP-2 and MMP-9 induced by PMA. Next, alpha-mangostin also strongly inhibited PMA-induced degradation of inhibitor of kappaBalpha (IkappaBalpha) and the nuclear levels of nuclear factor kappa B (NF-kappaB). Also, a dose-dependent inhibition on the binding abilities of NF-kappaB by alpha-mangostin treatment was further observed. Furthermore, reduction of FAK or ERK1/2 phosphorylation by FAK small interfering RNA (FAK siRNA) potentiated the effect of alpha-mangostin. Finally, the transient transfection of ERK siRNA significantly down-regulated the expressions of MMP-2 and MMP-9 concomitantly with a marked inhibition on cell invasion and migration. Presented results indicated alpha-mangostin is a novel, effect, anti-metastatic agent that functions by downregulating MMP-2 and MMP-9 gene expressions.

EP4 upregulation of Ras signaling and feedback regulation of Ras in human colon tissues and cancer cells.

Previous studies indicate that COX-2 and prostaglandin E(2) (PGE(2)) receptor subtypes are involved in intestinal carcinogenesis and activation of downstream pathways. In this report, we try to understand the association of PGE(2) receptor and K-ras cellular mechanism during the development of colorectal cancer. We collected 21 colorectal cancer patients and compared the protein expression of tumor tissues and normal mucosa tissues by using immunoblot. Furthermore, we transferred empty vector and pcDNA-K-ras into Ras-HT29 colon cancer cells. Result showed that phosphorylation of Akt and EP(1)/EP(4) were over-expressed in the colorectal tumor tissue. K-ras induces HT29 cells proliferation through the expressions of COX-2, EP1/EP4, pAkt, GSK3beta and increases Tcf transcriptional factor activation. Additionally, Ras protein was suppressed when treated with EP(4) inhibitor in Ras-HT29 cell. In cell cycle assay, K-ras mutation causing cell cycle S phase was prolonged with an increase in the G2/M phase ratio. In conclusion, we suggested that Ras overexpression leads to cell proliferation through activating Ras/PI3K/GSK3beta/EP(4) PGE(2) receptor signals and caused a feedback regulation of Ras by EP4 in colorectal tumor progression.

alpha-Mangostin, a novel dietary xanthone, suppresses TPA-mediated MMP-2 and MMP-9 expressions through the ERK signaling pathway in MCF-7 human breast adenocarcinoma cells.

This study first investigates the anti-metastatic effect of alpha-mangostin on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) expressions in human breast adenocarcinoma cells, MCF-7. First, the result demonstrated alpha-mangostin could inhibit TPA-induced abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay and Boyden chamber assay. Data also showed alpha-mangostin could inhibit the activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) involved in the downregulation the enzyme activities, protein, and messenger RNA levels of MMP-2 and MMP-9 induced by TPA. Next, alpha-mangostin also strongly inhibited TPA-induced degradation of inhibitor of kappaBalpha (IkappaBalpha) and the nuclear levels of nuclear factor kappa B (NF-kappaB), c-Fos, and c-Jun. Also, a dose-dependent inhibition on the binding abilities of NF-kappaB and activator protein-1 (AP-1) by alpha-mangostin treatment was further observed. Further, the treatment of specific inhibitor for ERK (U0126) to MCF-7 cells could inhibit TPA-induced MMP-2 and MMP-9 expressions along with an inhibition on cell invasion and migration. Presented data reveal that alpha-mangostin is a novel, effective, antimetastatic agent that functions by downregulating MMP-2 and MMP-9 gene expressions.

Acacetin inhibits TPA-induced MMP-2 and u-PA expressions of human lung cancer cells through inactivating JNK signaling pathway and reducing binding activities of NF-kappaB and AP-1.

Acacetin (5,7-dihydroxy-4'-methoxyflavone), a flavonoid compound, has antiperoxidative and antiinflammatory effects. The effect of acacetin on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMPs and u-PA expressions in human lung cancer A549 cells was investigated. First, the result demonstrated acacetin could inhibit TPA-induced the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay and Boyden chamber assay. Data also showed acacetin could inhibit phosphorylation of c-Jun N-terminal kinase 1 and 2 (JNK1/2) involved in the down-regulating protein expressions and transcriptions of matrix metalloproteinase-2 (MMP-2) and urokinase-type plasminogen activator (u-PA) induced by TPA. Next, acacetin also strongly inhibited TPA-stimulated the nuclear levels of nuclear factor kappa B (NF-kappaB), c-Fos, and c-Jun. Also, a dose-dependent inhibition on the binding abilities of NF-kappaB and activator protein-1 (AP-1) by acacetin treatment was further observed. Further, the treatment of specific inhibitor for JNK (SP600125) to A549 cells could inhibit TPA-induced MMP-2 and u-PA expressions along with an inhibition on cell invasion and migration. Taken together, these results suggest the antimetastatic effects of acacetin on the TPA-induced A549 cells might be by reducing MMP-2 and u-PA expressions through inhibiting phosphorylation of JNK and reducing NF-kappaB and AP-1 binding activities.

alpha-Chaconine inhibits angiogenesis in vitro by reducing matrix metalloproteinase-2.

alpha-Chaconine, a naturally occurring steroidal glycoalkaloid in potato sprouts, was found to possess anti-carcinogenic properties, such as inhibiting proliferation, migration, invasion, and inducing apoptosis of tumor cells. However, the effect of alpha-chaconine on tumor angiogenesis remains unclear. In the present study, we examined the effect of alpha-chaconine on angiogenesis in vitro. Data demonstrated that alpha-chaconine inhibited proliferation of bovine aortic endothelial cells (BAECs) in a dose-dependent manner. When treated with non-toxic doses of alpha-chaconine, cell migration, invasion and tube formation were markedly suppressed. Furthermore, alpha-chaconine reduced the expression and activity of matrix metalloproteinase-2 (MMP-2), which is involved in angiogenesis. Our biochemical assays indicated that alpha-chaconine potently suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositide-3 kinase (PI3K) and Akt, while it did not affect phosphorylation of extracellular signal regulating kinase (ERK) and p38. In addition, alpha-chaconine significantly increased the cytoplasmic level of inhibitors of kappaBalpha (IkappaBalpha) and decreased the nuclear level of nuclear factor kappa B (NF-kappaB), suggesting that alpha-chaconine could inhibit NF-kappaB activity. Furthermore, the treatment of inhibitors specific for JNK (SP600125), PI3K (LY294002) or NF-kappaB (pyrrolidine dithiocarbamate) to BAECs reduced tube formation. Taken together, the results suggested that alpha-chaconine inhibited migration, invasion and tube formation of BAECs by reducing MMP-2 activities, as well as JNK and PI3K/Akt signaling pathways and inhibition of NF-kappaB activity. These findings reveal a new therapeutic potential for alpha-chaconine on anti-angiogenic therapy.

Cinnamaldehyde impairs high glucose-induced hypertrophy in renal interstitial fibroblasts.

Cinnamaldehyde is a major and a bioactive compound isolated from the leaves of Cinnamomum osmophloeum kaneh. To explore whether cinnamaldehyde was linked to altered high glucose (HG)-mediated renal tubulointerstitial fibrosis in diabetic nephropathy (DN), the molecular mechanisms of cinnamaldehyde responsible for inhibition of HG-induced hypertrophy in renal interstitial fibroblasts were examined. We found that cinnamaldehyde caused inhibition of HG-induced cellular mitogenesis rather than cell death by either necrosis or apoptosis. There were no changes in caspase 3 activity, cleaved poly(ADP-ribose) polymerase (PARP) protein expression, and mitochondrial cytochrome c release in HG or cinnamaldehyde treatments in these cells. HG-induced extracellular signal-regulated kinase (ERK)/c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (MAPK) (but not the Janus kinase 2/signal transducers and activators of transcription) activation was markedly blocked by cinnamaldehyde. The ability of cinnamaldehyde to inhibit HG-induced hypertrophy was verified by the observation that it significantly decreased cell size, cellular hypertrophy index, and protein levels of collagen IV, fibronectin, and alpha-smooth muscle actin (alpha-SMA). The results obtained in this study suggest that cinnamaldehyde treatment of renal interstitial fibroblasts that have been stimulated by HG reduces their ability to proliferate and hypertrophy through mechanisms that may be dependent on inactivation of the ERK/JNK/p38 MAPK pathway.

Plumbagin inhibits TPA-induced MMP-2 and u-PA expressions by reducing binding activities of NF-kappaB and AP-1 via ERK signaling pathway in A549 human lung cancer cells.

This study first investigates the anti-metastatic effect of plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMPs and u-PA expressions in human lung cancer cells, A549. First, the result demonstrated plumbagin could inhibit TPA induced the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay and Boyden chamber assay. Data also showed plumbagin could inhibit the activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) involved in the down-regulating enzyme activities, protein and messenger RNA levels of matrix metalloproteinase-2 (MMP-2), and urokinase-type plasminogen activator (u-PA) induced by TPA. Next, plumbagin also strongly inhibited TPA-induced phosphorylation and degradation of inhibitor of kappaBalpha (IkappaBalpha), and the nuclear levels of nuclear factor kappa B (NF-kappaB), c-Fos, and c-Jun. Also, a dose-dependent inhibition on the binding abilities of NF-kappaB and activator protein-1 (AP-1) by plumbagin treatment was further observed. Further, the treatment of specific inhibitor for ERK (U0126) to A549 cells could inhibit TPA-induced MMP-2 and u-PA expressions along with an inhibition on cell invasion and migration. Presented data reveals that plumbagin is a novel, effective, anti-metastatic agent that functions by down-regulating MMP-2 and u-PA gene expressions.

Acacetin, a flavonoid, inhibits the invasion and migration of human prostate cancer DU145 cells via inactivation of the p38 MAPK signaling pathway.

Acacetin (5,7-dihydroxy-4'-methoxyflavone), a flavonoid compound, has anti-peroxidative and anti-inflammatory effects. The effect of acacetin on antimetastasis in human prostate cancer DU-145 cells was investigated. First, the result demonstrated acacetin could exhibit an inhibitory effect on the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay, wound-healing assay, and Boyden chamber assay. Data also showed acacetin could inhibit the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), and urokinase-type plasminogen activator (u-PA) at both the protein and mRNA levels. Next, acacetin significantly decreased the nuclear levels of nuclear factor kappa B (NF-kappaB), c-Fos, and c-Jun. Also, the treatment with acacetin to DU145 cells also leads to a dose-dependent inhibition on the binding ability of NF-kappaB and activator protein-1 (AP-1). Furthermore, the treatment of inhibitors specific for p38 MAPK (SB203580) to DU145 cells could cause reduced expressions of MMP-2, MMP-9, and u-PA. These results showed acacetin could inhibit the invasion and migration abilities of DU145 cells by reducing MMP-2, MMP-9, and u-PA expressions through suppressing p38 MAPK signaling pathway and inhibiting NF-kappaB- or AP-1-binding activity. These findings proved acacetin might be offered further application as an antimetastatic agent.