Wasabi Component 6-(Methylsulfinyl)hexly Isothiocyanate and Derivatives Improve the Survival of Skin Allografts.

We tested the effect of 6-(Methylsulfinyl)hexyl Isothiocyanate (6-MITC) and derivatives (I7447 and I7557) on the differentiation and maturation of human myeloid dendritic cells (DCs) in vitro, and skin transplantation in vivo. Triggering of CD14+ myeloid monocyte development toward myeloid DCs with and without 6-MITC and derivatives to examine the morphology, viability, surface marker expression, and cytokine production. Stimulatory activity on allogeneic naive T cells was measured by proliferation and interferon-γ production. The skin allograft survival area model was used to translate the 6-MITC and derivatives' antirejection effect. All of the compounds had no significant effects on DC viability and reduced the formation of dendrites at concentrations higher than 10 µM. At this concentration, 6-MITC and I7557, but not I7447, inhibited the expression of CD1a and CD83. Both 6-MITC and I7557 exhibited T-cells and interferon-γ augmentation at lower concentrations and suppression at higher concentration. The 6-MITC and I7557 prolonged skin graft survival. Both the 6-MITC and I7557 treatment resulted in the accumulation of regulatory T cells in recipient rat spleens. No toxicity was evident in 6-MITC and I7557 treatment. The 6-MITC and I7557 induced human DC differentiation toward a tolerogenic phenotype and prolonged rat skin allograft survival. These compounds may be effective as immunosuppressants against transplant rejection.

Moscatilin Inhibits Growth of Human Esophageal Cancer Xenograft and Sensitizes Cancer Cells to Radiotherapy.

Esophageal cancer prognosis remains poor in current clinical practice. We previously reported that moscatilin can induce apoptosis and mitotic catastrophe in esophageal cancer cells, accompanied by upregulation of polo-like kinase 1 (Plk1) expression. We aimed to validate in vitro activity and Plk1 expression in vivo following moscatilin treatment and to examine the treatment's radiosensitizing effect. Human esophageal cancer cells were implanted in nude mice. Moscatilin was intraperitoneally (i.p.) injected into the mice. Tumor size, body weight, white blood cell counts, and liver and renal function were measured. Aberrant mitosis and Plk1 expression were assessed. Colony formation was used to measure survival fraction after radiation. Moscatilin significantly suppressed tumor growth in mice bearing human esophageal xenografts without affecting body weight, white blood cell counts, or liver and renal function. Moscatilin also induced aberrant mitosis and apoptosis. Plk1 expression was markedly upregulated in vivo. Moreover, moscatilin pretreatment enhanced CE81T/VGH and BE3 cell radioresponse in vitro. Moscatilin may inhibit growth of human esophageal tumors and sensitize esophageal cancer cells to radiation therapy.

Traditional Chinese medicine Danggui Buxue Tang inhibits colorectal cancer growth through induction of autophagic cell death.

PURPOSE: The induction of autophagic cell death is an important process in the development of anticancer therapeutics. We aimed to evaluate the activity of the ancient Chinese decoction Danggui Buxue Tang (DBT) against colorectal cancer (CRC) and the associated autophagy-related mechanism. MATERIALS AND METHODS: CT26 CRC cells were implanted into syngeneic BALB/c mice for the tumor growth assay. DBT extracts and DBT-PD (polysaccharide-depleted) fractions were orally administered. The toxicity profiles of the extracts were analyzed using measurements of body weight, hemogram, and biochemical parameters. The morphology of tissue sections was observed using light and transmission electron microscopy. Western blotting and small interference RNA assays were used to determine the mechanism. RESULTS: DBT-PD and DBT, which contained an equal amount of DBT-PD, inhibited CT26 syngeneic tumor growth. In the tumor specimen, the expression of microtubule-associated proteins 1A/1B light chain 3B (LC3B) was upregulated by DBT-PD and DBT. The development of autophagosomes was observed via transmission electron microscopy in tumors treated with DBT-PD and DBT. In vitro experiments for mechanism clarification demonstrated that DBT-PD could induce autophagic death in CT26 cells accompanied by LC3B lipidation, downregulation of phospho-p70s6k, and upregulation of Atg7. RNA interference of Atg7, but not Atg5, partially reversed the effect of DBT-PD on LC3B lipidation and expression of phospho-p70s6k and Atg7. The changes in ultrastructural morphology and LC3B expression induced by DBT-PD were also partially blocked by the knockdown of Atg7 mRNA. CONCLUSION: DBT induced autophagic death of colorectal cancer cells through the upregulation of Atg7 and modulation of the mTOR/p70s6k signaling pathway.

Daphnoretin modulates differentiation and maturation of human dendritic cells through down-regulation of c-Jun N-terminal kinase.

Daphnoretin, an active constituent of Wikstroemia indica C.A. Meys, has been shown possessing anti-cancer activity. In this study, we examined the effect of daphnoretin on differentiation and maturation of human myeloid dendritic cells (DCs). After treatment with daphnoretin (0, 1.1, 3.3, 10 and 30µM) to initiate monocytes, the recovery rate of DCs was reduced in a dose-dependent manner. The mature DCs differentiated in the presence of daphnoretin had fewer and shorter dendrites. Daphnoretin modulated DCs differentiation and maturation in terms of lower expression of CD1a, CD40, CD83, DC-SIGN, and HLA-DR. Daphnoretin inhibited the allostimulatory activity of DCs on proliferation of naive CD4+CD45+RA+ T cell. On the mitogen-activated protein kinase, daphnoretin down-regulated the lipopolysaccharide-augmented expression of phosphorylated c-Jun N-terminal kinase (pJNK), but not p38 and extracellular signal-regulated kinase 1/2 (ERK1/2). Activation of JNK by anisomycin reversed the effect of daphnoretin on daphnoretin-inhibited pJNK expression and dendrite formation of DCs. In disease model related to maturation of DCs, daphnoretin suppressed the acute rejection of skin allografts in mice. Our results suggest that daphnoretin modulated differentiation and maturation of DCs toward a state of atypical maturation with impaired allostimulatory function and this effect may go through down-regulation of phosphorylated JNK.

The Traditional Chinese Medicine DangguiBuxue Tang Sensitizes Colorectal Cancer Cells to Chemoradiotherapy.

Chemotherapy is an important treatment modality for colon cancer, and concurrent chemoradiation therapy (CCRT) is the preferred treatment route for patients with stage II and III rectal cancer. We examined whether DangguiBuxue Tang (DBT), a traditional Chinese herbal extract, sensitizes colorectal cancer cells to anticancer treatments. The polysaccharide-depleted fraction of DBT (DBT-PD) contains greater amounts of astragaloside IV (312.626 µg/g) and ferulic acid (1.404 µg/g) than does the original formula. Treatment of the murine colon carcinoma cell line (CT26) with DBT-PD inhibits growth, whereas treatment with comparable amounts of purified astragaloside IV and ferulic acid showed no significant effect. Concurrent treatment with DBT-PD increases the growth inhibitory effect of 5-fluorouracil up to 4.39-fold. DBT-PD enhances the effect of radiation therapy (RT) with a sensitizer enhancement ratio (SER) of up to 1.3. It also increases the therapeutic effect of CCRT on CT26 cells. Cells treated with DBP-PD showed ultrastructural changes characteristic of autophagy, including multiple cytoplasmic vacuoles with double-layered membranes, vacuoles containing remnants of degraded organelles, marked swelling and vacuolization of mitochondria, and autolysosome-like vacuoles. We conclude that DBT-PD induces autophagy-associated cell death in CT26 cells, and may have potential as a chemotherapy or radiotherapy sensitizer in colorectal cancer treatment.

Modulation of Endothelial Injury Biomarkers by Traditional Chinese Medicine LC in Systemic Lupus Erythematosus Patients Receiving Standard Treatments.

LC is an herbal remedy effectively reduced therapeutic dosage of glucocorticoid for systemic lupus erythematosus (SLE) patients in clinical trial (ISRCTN81818883). This translational research examined the impact of LC on biomarkers of endothelial injury in the enrolled subjects. Fifty seven patients with SLE were randomized to receive standard treatment without or with LC supplements. Blood samples were taken serially for quantification of endothelial progenitor cells (EPCs), circulating endothelial cells (CECs) and serological factors. The proportion of EPCs in the placebo group continued to increase during trial and was further elevated after withdrawal of standard treatment. The EPC ratio of LC group remained stationary during the entire observation period. The CEC ratio in placebo group exhibited an increasing trend whereas that in LC group declined. The ratio of apoptotic CECs had an increasing trend in both groups, to a lesser extent in LC group. After treatment, the levels of VEGF and IL-18 have a trend declined to a level lower in the LC group than the placebo group. No significant alteration was noted in serum levels of IFN-α, IL-1ß and IL-6. The reduction of the steroid dosage by adding LC might be correlated with less extensive endothelial injury in SLE patients.

CCL-34, a synthetic toll-like receptor 4 activator, modulates differentiation and maturation of myeloid dendritic cells.

CCL-34, a synthetic α-galactosylceramide analog, has been reported as an activator of toll-like receptor 4 (TLR4) in macrophages. TLR4 is highly expressed in dendritic cell (DC) and several TLR4 agonists are known to trigger DC maturation. We herein evaluated the effect of CCL-34 on DC maturation. Human CD14+ monocyte-derived immature DC were treated with CCL-34, its inactive structural analog CCL-44, or LPS to assess the DC maturation. CCL-34 induced DC maturation according to their characteristically dendrite-forming morphology, CD83 expression and IL-12p70 production. The allostimulatory activity of DC on proliferation of naive CD4+CD45+RA+ T cells and their secretion of interferon-γ was increased by CCL-34. Phagocytosis, an important function of immature DC, was reduced after CCL-34 treatment. All these effects related to DC maturation were evidently induced by positive control LPS but not by CCL-44 treatment. TLR4 neutralization impaired human DC maturation triggered by CCL-34. The induction of IL-12, a hallmark of DC maturation, by CCL-34 and LPS was only evident in TLR4-competent C3H/HeN, but not in TLR4-defective C3H/HeJ mice. CCL-34 could further elicit the antigen presentation capability in mice inoculated with doxorubicin-treated colorectal cancer cells. In summary, CCL-34 triggers DC maturation via a TLR4-dependent manner, which supports its potential application as an immunostimulator.

Low-dose ionizing radiation induces mitochondrial fusion and increases expression of mitochondrial complexes I and III in hippocampal neurons.

High energy ionizing radiation can cause DNA damage and cell death. During clinical radiation therapy, the radiation dose could range from 15 to 60 Gy depending on targets. While 2 Gy radiation has been shown to cause cancer cell death, studies also suggest a protective potential by low dose radiation. In this study, we examined the effect of 0.2-2 Gy radiation on hippocampal neurons. Low dose 0.2 Gy radiation treatment increased the levels of MTT. Since hippocampal neurons are post-mitotic, this result reveals a possibility that 0.2 Gy irradiation may increase mitochondrial activity to cope with stimuli. Maintaining neural plasticity is an energy-demanding process that requires high efficient mitochondrial function. We thus hypothesized that low dose radiation may regulate mitochondrial dynamics and function to ensure survival of neurons. Our results showed that five days after 0.2 Gy irradiation, no obvious changes on neuronal survival, neuronal synapses, membrane potential of mitochondria, reactive oxygen species levels, and mitochondrial DNA copy numbers. Interestingly, 0.2 Gy irradiation promoted the mitochondria fusion, resulting in part from the increased level of a mitochondrial fusion protein, Mfn2, and inhibition of Drp1 fission protein trafficking to the mitochondria. Accompanying with the increased mitochondrial fusion, the expressions of complexes I and III of the electron transport chain were also increased. These findings suggest that, hippocampal neurons undergo increased mitochondrial fusion to modulate cellular activity as an adaptive mechanism in response to low dose radiation.

Modulation of Sonic hedgehog signaling and WW domain containing oxidoreductase WOX1 expression enhances radiosensitivity of human glioblastoma cells.

WW domain containing oxidoreductase, designated WWOX, FOR or WOX1, is a known pro-apoptotic factor when ectopically expressed in various types of cancer cells, including glioblastoma multiforme (GBM). The activation of sonic hedgehog (Shh) signaling, especially paracrine Shh secretion in response to radiation, is associated with impairing the effective irradiation of cancer cells. Here, we examined the role of Shh signaling and WOX1 overexpression in the radiosensitivity of human GBM cells. Our results showed that ionizing irradiation (IR) increased the cytoplasmic Shh and nuclear Gli-1 content in GBM U373MG and U87MG cells. GBM cells with exogenous Shh treatment exhibited similar results. Pretreatment with Shh peptides protected U373MG and U87MG cells against IR in a dose-dependent manner. Cyclopamine, a Hedgehog/Smoothened (SMO) inhibitor, reversed the protective effect of Shh in U87MG cells. Cyclopamine increased Shh plus IR-induced H2AX, a marker of DNA double-strand breaks, in these cells. To verify the role of Shh signaling in the radiosensitivity of GBM cells, we tested the effect of the Gli family zinc finger 1 (Gli-1) inhibitor zerumbone and found that it could sensitize GBM cells to IR. We next examined the role of WOX1 in radiosensitivity. Overexpression of WOX1 enhanced the radiosensitivity of U87MG (possessing wild type p53 or WTp53) but not U373MG (harboring mutant p53 or MTp53) cells. Pretreatment with Shh peptides protected both WOX1-overexpressed U373MG and U87MG cells against IR and increased the cytoplasmic Shh and nuclear Gli-1 content. Zerumbone enhanced the radiosensitivity of WOX1-overexpressed U373MG and U87MG cells. In conclusion, overexpression of WOX1 preferentially sensitized human GBM cells possessing wild type p53 to radiation therapy. Blocking of Shh signaling may enhance radiosensitivity independently of the expression of p53 and WOX1. The crosstalk between Shh signaling and WOX1 expression in human glioblastoma warrants further investigation.

Sorafenib induces autophagy in human myeloid dendritic cells and prolongs survival of skin allografts.

BACKGROUND: Sorafenib, a multikinase inhibitor approved for the treatment of advanced renal cell carcinoma and hepatocellular carcinoma, has been reported inhibitory on the function of dendritic cells. This study was aimed to determine the effects of sorafenib on inducing autophagy and immunomodulatory activity and its implication on graft rejection. METHODS: Cell viability and surface antigens were examined by 7-amino-actinomycin D and flow cytometric analysis. Autophagy was characterized using light microscopy and transmission electron microscopy for morphology, Western blotting for LC3B-I lipidation and mammalian target of rapamycin signaling molecules, and immunofluorescence staining for endogenous LC3B, GFP-LC3 transfection, and acidic component vacuoles. Skin allograft in mice was used as an experimental transplantation rejection model. Soluble factors contained in culture medium and serum were measured by enzyme-linked immunosorbent assay. RESULTS: We found that sorafenib inhibited the viability of dendritic cells accompanied by morphologic changes characteristic of autophagy and immature differentiation. This autophagic effect induced by sorafenib was validated by LC3B-I lipidation and autophagosome accumulation. Sorafenib treatment was associated with the down-regulation of phosphorylated mammalian target of rapamycin and its downstream substrate p70S6K. We next performed skin graft model to testify the role of sorafenib-induced immature and autophagic dendritic cells. Intriguingly, sorafenib prolonged the survival of skin allograft without major toxicity. Blockade of autophagic flux by chloroquine partially diminished the protective effect of sorafenib, indicating an autophagy-related mechanism in vivo. CONCLUSION: This study suggests that sorafenib, in addition to being an anticancer agent, may have potential to be developed as a new category of immunosuppressant drugs acting via autophagy induction of dendritic cells.

Costunolide causes mitotic arrest and enhances radiosensitivity in human hepatocellular carcinoma cells.

PURPOSE: This work aimed to investigate the effect of costunolide, a sesquiterpene lactone isolated from Michelia compressa, on cell cycle distribution and radiosensitivity of human hepatocellular carcinoma (HCC) cells. METHODS: The assessment used in this study included: cell viability assay, cell cycle analysis by DNA histogram, expression of phosphorylated histone H3 (Ser 10) by flow cytometer, mitotic index by Liu's stain and morphological observation, mitotic spindle alignment by immunofluorescence of alpha-tubulin, expression of cell cycle-related proteins by Western blotting, and radiation survival by clonogenic assay. RESULTS: Our results show that costunolide reduced the viability of HA22T/VGH cells. It caused a rapid G2/M arrest at 4 hours shown by DNA histogram. The increase in phosphorylated histone H3 (Ser 10)-positive cells and mitotic index indicates costunolide-treated cells are arrested at mitosis, not G2, phase. Immunofluorescence of alpha-tubulin for spindle formation further demonstrated these cells are halted at metaphase. Costunolide up-regulated the expression of phosphorylated Chk2 (Thr 68), phosphorylated Cdc25c (Ser 216), phosphorylated Cdk1 (Tyr 15) and cyclin B1 in HA22T/VGH cells. At optimal condition causing mitotic arrest, costunolide sensitized HA22T/VGH HCC cells to ionizing radiation with sensitizer enhancement ratio up to 1.9. CONCLUSIONS: Costunolide could reduce the viability and arrest cell cycling at mitosis in hepatoma cells. Logical exploration of this mitosis-arresting activity for cancer therapeutics shows costunolide enhanced the killing effect of radiotherapy against human HCC cells.

Sonic hedgehog signaling protects human hepatocellular carcinoma cells against ionizing radiation in an autocrine manner.

PURPOSE: Sonic hedgehog (Shh) signaling is critical to embryogenesis and resistance to chemotherapy. We aimed to examine the role of Shh signaling in the response to radiation of human hepatocellular carcinoma (HCC) cells. METHODS AND MATERIALS: Response to ionizing radiation therapy (RT) was evaluated by clonogenic assay. Quantitative RT-polymerase chain reaction for patched-1 (PTCH-1) expression was performed. Cytosolic accumulation of Shh and nuclear translocation of Gli-1 were assessed by immunofluorescence. Gli-1 knockdown was done by RNA interference (RNAi). Immunoprecipitation was performed to detect Shh ligand in conditioned medium. Immunofluorescent stain for γ-H2AX was used as an index of DNA double strand breaks (DSB). Expression of proteins related to DNA damage repair was assessed by Western blotting. RESULTS: We found that Shh ligand could protect human HCC HA22T and Sk-Hep1 cells against RT. In HA22T cells, Shh ligand activated the Shh signaling with upregulation of Shh, PTCH-1, and Gli-1 expression. The nuclear translocation of Gli-1 further supports the activation of Gli-1. The radioprotection by Shh ligand was partly blocked by Shh antibody neutralization and was abolished by Gli-1 RNAi, suggesting a critical role of Shh signaling in radiation resistance. Furthermore, we noted that soluble factors secreted into conditioned medium, either constitutively or responding to radiation, by HA22T or Sk-Hep1 cells protected subsequent culturing cells against RT. Immunoprecipitation shows the presence of Shh peptide in conditioned medium. Intriguingly, antibody neutralization of Shh ligand or knockdown of Gli-1 reversed the radioprotective effect of conditioned medium. Furthermore, Shh ligand reduced the RT-induced phosphorylation of checkpoint kinase 1 and impaired the repair of DNA DSB. CONCLUSIONS: Activation of Shh signaling protects HCC cells against ionizing radiation in an autocrine manner. Impairment of DNA damage repair might involve mechanism of Shh-induced radioresistance. Targeting Shh signaling pathway may be a novel strategy to enhance the radioresponse of human HCC cells.

Tai Chi Chuan increases circulating myeloid dendritic cells.

Dendritic cells, the most potent antigen-presenting cells linking innate and adoptive immunity, are thought to be important targets of immune modulators such as exercise. We examined the effect of Tai Chi Chuan (TCC) on dendritic cells. TCC practitioners were further divided to high-level practitioners (TCC-H) and low-level practitioners (TCC-L). The quantities of myeloid and plasmacytoid dendritic cells were estimated by flow cytometry. We examined parameters including age, body weight, body length, body fat, and serum albumin level, in the controls, TCC-H and TCC-L, which did not differ significantly. The mean peak VO(2) (volume of O(2) utilization) of the TCC-H group was greater than that of the sedentary control group. White blood cell (WBC) count in the entire TCC group was greater than that of the controls. The quantity of myeloid dendritic cells was significantly greater in the TCC group, whereas the quantity of plasmacytoid dendritic cells was similar for both groups. Among the TCC subgroups, the quantity of myeloid dendritic cells, but not plasmacytoid dendritic cells, in the TCC-H group was greater than that of TCC-L practitioners. TCC could increase the number of circulating myeloid dendritic cells, but not plasmacytoid dendritic cells, in a performance level-dependent manner.

Zoledronic acid, an aminobisphosphonate, modulates differentiation and maturation of human dendritic cells.

Zoledronic acid (ZOL), an effective nitrogen-containing bisphosphonate against excessive bone loss, has been shown affecting the function of cells of both innate and acquired immunity. In this study, we tested the effect of ZOL on differentiation and maturation of human myeloid dendritic cells (DC). When ZOL (1.1 to 10 microM) was added to the culture of starting monocytes, but not to immature DC, the recovery rate of DC was markedly reduced in a concentration-dependent manner. The mature DC differentiated in the presence of ZOL had fewer and shorter cell projections. ZOL treatment affected DC differentiation and maturation in terms of lower expression of CD1a, CD11c, CD83, CD86, DC-SIGN, HLA-DR, and, in contrast, higher expression of CD80. IL-10 production by DC was inhibited by ZOL treatment whereas IL-12p70 secretion remained unchanged. Interestingly, ZOL augmented the allostimulatory activity of DC on naive CD4(++)CD45(+)RA(++) T cells in terms of their proliferation and interferon-gamma production. Addition of geranylgeraniol abrogated the effect of ZOL on DC differentiation and prenylation of Rap1A. It suggests that ZOL redirects DC differentiation toward a state of atypical maturation with allostimulatory function and this effect may go through prevention of Rap1A prenylation.

Platonin induces autophagy-associated cell death in human leukemia cells.

Platonin is a photosensitizer used for photodynamic therapy. In this study, we tested the effect of platonin on human leukemic cells. Treatment with platonin in the dark markedly reduced cell membrane integrity, and induced significant G(0)/G(1) arrest of a panel of human leukemic cell lines, including U937, HL-60, K562, NB4 and THP-1. Development of hypodiploid cells was not evident in these cell lines within 24 h, but was noted in U937, HL-60 and NB4 cells after 24 h. No myeloid differentiation of these cells was noted after five-day treatment. Intriguingly, exposure of monoblastic U937 cells to platonin caused changes characteristic of autophagy, including appearance of cytoplasmic membranous vacuoles and formation of acidic vesicular organelles (AVO) in more than 95% of cells. The platonin-induced autophagy was accompanied by localization of microtubule-associated protein 1 light chain 3 to autophagosomes. Pretreatment with pancaspase inhibitor Z-VAD-fmk abrogated the platonin-induced hypodiploidity, but had no effect on growth inhibition and formation of AVO, indicating a caspase-independent autophagy-associated cell death. Pretreatment of cells with 3-methyladenine attenuated platonin-mediated growth inhibition and formation of AVO. Platonin augmented the expression of BNIP3 in both U937 and K562 cells, whereas had an opposite effect on phosphorylation of mTOR downstream molecule p70S6K. Platonin, at the condition inducing autophagy, induced the mitochondrial membrane permeation. These results suggest that the platonin is capable of inhibiting growth as well as inducing cell death, mainly autophagy-associated, in leukemic cells via a mitochondria-mediated and caspase-independent pathway. A markedly less viability inhibition was noted to human monocytes, the normal counterpart of these myeloid leukemic cells. Platonin, other than a photodynamic agent, may offer significant promise as a therapeutic agent against leukemia.

Antitumor effects of the partially purified polysaccharides from Antrodia camphorata and the mechanism of its action.

Antrodia camphorata is a popular folk medicine that has attracted great attention due to its fame for antitumor activity against cancer. However, there is little information available about its action. In the present study, we purified a unique polysaccharide component from A. camphorata mycelia (AC-PS) and found that it has pronounced anti-tumor effects on both in vitro and in vivo model. Our results showed that AC-PS alone did not show any direct cytotoxic effect to human leukemic U937 cells, even at high concentration (200 microg/ml). However, it could inhibit the proliferation of U937 cells via activation of mononuclear cells (MNCs). Treatment of U937 cells with AC-PS-stimulated-MNC-CM could significantly inhibit its proliferation with 55.3% growth inhibition rate. The in vitro antitumor activity was substantiated by the in vivo therapeutical study of AC-PS in sarcoma 180-bearing mice. Intraperitoneal and oral administration of AC-PS, 100 and 200 mg/kg significantly suppressed the tumor growth with the inhibition rate of 69.1% and 58.8%, respectively. In vivo studies also showed that several immunoparameters, such as the spontaneous proliferation of spleen cells, after AC-PS administration, were two-fold higher than in control mice. Furthermore, the cytolytic activity of spleen cells also increased from 9.8 +/- 1.1% in control mice to 34.2 +/- 5.5% and 48.2 +/- 2.5%, after oral and intraperitoneal treatment, respectively. Besides, the mice serum interleukin-12 levels increased significantly by AC-PS treatment. Considering all these results, it is suggested that AC-PS elicit its anti-tumor effect by promoting a Th1-dominant state and killer activities.

Inhibitory effect of caffeic acid phenethyl ester on angiogenesis, tumor invasion, and metastasis.

Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine and has several proven biological activities. The present study investigated the effect of CAPE on angiogenesis, tumor invasion, and metastasis. A cytotoxicity assay of CAPE in CT26 colon adenocarcinoma cells showed a dose-dependent decrease in cell viability but no significant influence on the growth of human umbilical vein epithelial cells (HUVEC). A low concentration of CAPE (1.5 microg/mL) inhibited 52.7% of capillary-like tube formation in HUVEC culture on Matrigel. CAPE (6 microg/mL)-treated CT26 cells showed not only inhibited cell invasion by 47.8% but also decreased expression of matrix metalloproteinase (MMP)-2 and -9. Vascular endothelial growth factor (VEGF) production from CT26 cells was also inhibited by treatment with CAPE (6 microg/mL). Intraperitoneal injection of CAPE (10 mg/kg/day) in BALB/c mice reduced the pulmonary metastatic capacity of CT26 cells accompanied with a decreased plasma VEGF level. CAPE treatment also prolonged the survival of mice implanted with CT26 cells. These results indicate that CAPE has potential as an antimetastatic agent.