Mealworm larvae (Tenebrio molitor L.) exuviae as a novel prebiotic material for BALB/c mouse gut microbiota.

The objective of this study was to evaluate the effect of yellow mealworm (Tenebrio molitor L.) exuviae (ME) given as a prebiotic in 20% of the diet fed to BALB/c mice. Analysis of the ME revealed that it was mostly composed of crude protein (52.94%), crude fiber (10.70%), and moisture (10.54%). When ME was fed to mice for 8 weeks, the number of intestinal lactic acid bacteria increased, reaching similar numbers (4.50 ± 0.80 CFU/mL) to those (4.70 ± 0.80 CFU/mL) of the control group not fed ME. Microbiome analysis showed that 8 weeks feeding of ME promoted the growth of Bifidobacteriaceae and Lactobacillaceae compared to the POS group, indicating the positive effects of feeding 20% ME on the intestinal microbiota of mice. These results suggest that ME can be considered as a dietary prebiotics to improve human gut microbial population, but further application study to human is necessary.

Effects of mealworm (Tenebrio molitor) larvae hydrolysate on nutrient ileal digestibility in growing pigs compared to those of defatted mealworm larvae meal, fermented poultry by-product, and hydrolyzed fish soluble.

OBJECTIVE: To investigate effect of mealworm (Tenebrio molitor) larvae hydrolysate on nutrient ileal digestibility compared to those of dried mealworm larvae meal, fermented poultry by-product, and hydrolyzed fish soluble in growing pigs. METHODS: A total of 12 crossbred ([Landrace×Yorkshire]×Duroc) growing pigs with average body weight of 28.70±0.32 kg were surgically equipped with simple T-cannulas. A total of 12 pigs were assigned to individual metabolic crates and allotted to one of four treatments with 3 replicates in a fully randomized design. RESULTS: Apparent ileal digestibility (AID) of dry matter (DM) was the highest in pigs fed HML diet. AIDs of crude protein (CP) were higher in pigs fed HML and DMLM diets than those in pigs fed the other two diets. AID of total amino acid was higher (p = 0.06) in pigs fed HML diet. AIDs of lysine (Lys), methionine (Met), and threonine (Thr) were similar in pigs fed DMLM and HML diets, but were higher (p = 0.05, p<0.05, and p = 0.05, respectively) than those in pigs fed FPBM or HFS diet. Pigs fed HML diet had higher standardized ileal digestibilities (SIDs) of DM and CP (p<0.05 and p<0.05, respectively) compared to pigs fed the other FPBM and HFS diets. SIDs of total amino acid were not different (p = 0.06) between treatments. For SIDs of Lys, Met, and Thr, pigs fed HML and DMLM diets showed higher SIDs (p = 0.05, p<0.05, and p<0.05, respectively) than pigs fed FPBM and HFS diets. SIDs of non-essential amino acids (aspartic acid, glycine, and alanine) were higher (p<0.05, p< 0.05, and p<0.05, respectively) in pigs fed HML, FPBM, and DMLM diets than those in pigs fed the HFS diet. AID and SID of glutamic acid were higher in pigs fed HML and FPBM diets. CONCLUSION: In conclusion, dietary supplementation of mealworm larvae hydrolysate had higher digestibility in DM, CP, Lys, Met, and Thr compared to dietary supplementation with fermented poultry by-product and hydrolyzed fish soluble.

PLOD3 suppression exerts an anti-tumor effect on human lung cancer cells by modulating the PKC-delta signaling pathway.

Current lung cancer treatments are far from satisfactory; thus, finding novel treatment targets is crucial. We recently identified procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3), which is involved in fibrosis and tissue remodeling as a radioresistance-related protein in lung cancer cells; however, its mechanism is unclear. In this study, we designed human PLOD3-specific short interfering (si)RNAs and tested their effects on tumor growth inhibition in vitro and in vivo. PLOD3 knockdown overcame chemoresistance and decreased radioresistance by inducing caspase-3-dependent apoptosis in lung cancer cells. Furthermore, PLOD3 interacted with PKCδ to activate caspase-2,4-dependent apoptosis through ER-stress-induced IRE1α activation and the downstream unfolded-protein response pathway. In a mouse xenograft model, PLOD3 knockdown promoted radiation-induced tumor growth inhibition, without side effects. Moreover, lung cancer patients with high PLOD3 expression showed poorer prognosis than those with low PLOD3 expression upon radiotherapy, suggesting that PLOD3 promotes tumor growth. Therefore, PLOD3 siRNA suppresses radioresistance and chemoresistance by inducing apoptosis and renders PLOD3 as a candidate lung cancer biomarker. PLOD3 gene therapy might enhance the efficacy of radiotherapy or chemotherapy in lung cancer patients.

PLOD3 promotes lung metastasis via regulation of STAT3.

Procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD3), a membrane-bound homodimeric enzyme, hydroxylates lysyl residues in collagen-like peptides; however, its role in lung cancer is unknown. This study aimed to investigate the role of PLOD3 as a pro-metastatic factor and to elucidate the underlying mechanism. First, we experimentally confirmed the release of PLOD3 in circulation in animal models, rendering it a potential serum biomarker for lung cancer in humans. Thereafter, we investigated the effects of PLOD3 overexpression and downregulation on cancer cell invasion and migration in vitro and in vivo, using human lung cancer cell lines and a mouse tumor xenograft model, respectively. Further, PLOD3 levels were determined in lung tissue samples from lung cancer patients. Functional analyses revealed that PLOD3 interacts with STAT3, thereby expressing matrix metalloproteinases (MMP-2 and MMP-9) and with urokinase plasminogen activator (uPA) to enhance tumor metastasis. PLOD3 and the STAT3 pathway were significantly correlated in the metastatic foci of lung cancer patients; PLOD3-STAT3 levels were highly correlated with a poor prognosis. These results indicate that PLOD3 promotes lung cancer metastasis in a RAS-MAP kinase pathway-independent manner. Therefore, secreted PLOD3 serves as a potent inducer of lung cancer metastasis and a potential therapeutic target to enhance survival in lung cancer.

Gingerenone A, a polyphenol present in ginger, suppresses obesity and adipose tissue inflammation in high-fat diet-fed mice.

SCOPE: Ginger exerts protective effects on obesity and its complications. Our objectives here are to identify bioactive compounds that inhibit adipogenesis and lipid accumulation in vitro, elucidate the anti-obesity effect of gingerenone A (GA) in diet-induced obesity (DIO), and investigate whether GA affects adipose tissue inflammation (ATI). METHODS AND RESULTS: Oil red O staining showed that GA had the most potent inhibitory effect on adipogenesis and lipid accumulation in 3T3-L1 cells among ginger components tested at a single concentration (40 µM). Consistent with in vitro data, GA attenuates DIO by reducing fat mass in mice. This was accompanied by a modulation of fatty acid metabolism via activation of AMP-activated protein kinase (AMPK) in vitro and in vivo. Additionally, GA suppressed ATI by inhibiting macrophage recruitment and downregulating pro-inflammatory cytokines. CONCLUSION: These results suggest that GA may be used as a potential therapeutic candidate for the treatment of obesity and its complications by suppressing adipose expansion and inflammation.

Dietary oleuropein inhibits tumor angiogenesis and lymphangiogenesis in the B16F10 melanoma allograft model: a mechanism for the suppression of high-fat diet-induced solid tumor growth and lymph node metastasis.

Previously, we reported that high-fat-diet (HFD)-induced obesity stimulates melanoma progression in the B16F10 allograft model. In this study, we examined whether oleuropein (OL), the most abundant phenolic compound in olives, inhibits HFD-induced melanoma progression. Four-week-old male C57BL/6N mice were fed a HFD-diet with or without OL. After 16 weeks of feeding, B16F10-luc cells were subcutaneously injected and the primary tumor was resected 3 weeks later. OL suppressed HFD-induced solid tumor growth. In the tumor tissues, OL reduced HFD-induced expression of angiogenesis (CD31, VE-cadherin, VEGF-A, and VEGFR2), lymphangiogenesis (LYVE-1, VEGF-C, VEGF-D, and VEGFR3), and hypoxia (HIF-1α and GLUT-1) markers as well as HFD-induced increases in lipid vacuoles and M2 macrophages (MΦs). All animals were euthanized 2.5 weeks after tumor resection. OL suppressed HFD-induced increases in lymph node (LN) metastasis; expression of VEGF-A, VEGF-C, and VEGF-D in the LN; and M2-MΦs and the size of adipocytes in adipose tissues surrounding LNs. Co-culture results revealed that the crosstalk between B16F10s, M2-MΦs, and differentiated 3T3-L1 cells under hypoxic conditions increased the secretion of VEGF-A and -D, which stimulated tube formation and migration of endothelial cells (HUVECs) and lymphatic endothelial cells (LEC), respectively. Additionally, OL directly inhibited the differentiation of 3T3-L1 preadipocytes and tube formation by HUVECs and LECs. The overall results indicated that dietary OL inhibits lipid and M2-MΦ accumulation in HFD-fed mice, which contributes to decreases in VEGF secretion, thereby leading to inhibition of angiogenesis and lymphangiogenesis.

Benzyl Isothiocyanate Inhibits Prostate Cancer Development in the Transgenic Adenocarcinoma Mouse Prostate (TRAMP) Model, Which Is Associated with the Induction of Cell Cycle G1 Arrest.

Benzyl isothiocyanate (BITC) is a hydrolysis product of glucotropaeolin, a compound found in cruciferous vegetables, and has been shown to have anti-tumor properties. In the present study, we investigated whether BITC inhibits the development of prostate cancer in the transgenic adenocarcinoma mouse prostate (TRAMP) mice. Five-week old, male TRAMP mice and their nontransgenic littermates were gavage-fed with 0, 5, or 10 mg/kg of BITC every day for 19 weeks. The weight of the genitourinary tract increased markedly in TRAMP mice and this increase was suppressed significantly by BITC feeding. H and E staining of the dorsolateral lobes of the prostate demonstrated that well-differentiated carcinoma (WDC) was a predominant feature in the TRAMP mice. The number of lobes with WDC was reduced by BITC feeding while that of lobes with prostatic intraepithelial neoplasia was increased. BITC feeding reduced the number of cells expressing Ki67 (a proliferation marker), cyclin A, cyclin D1, and cyclin-dependent kinase (CDK)2 in the prostatic tissue. In vitro cell culture results revealed that BITC decreased DNA synthesis, as well as CDK2 and CDK4 activity in TRAMP-C2 mouse prostate cancer cells. These results indicate that inhibition of cell cycle progression contributes to the inhibition of prostate cancer development in TRAMP mice treated with BITC.

ß-Caryophyllene potently inhibits solid tumor growth and lymph node metastasis of B16F10 melanoma cells in high-fat diet-induced obese C57BL/6N mice.

We reported previously that high-fat diet (HFD) feeding stimulated solid tumor growth and lymph node (LN) metastasis in C57BL/6N mice injected with B16F10 melanoma cells. ß-caryophyllene (BCP) is a natural bicyclic sesquiterpene found in many essential oils and has been shown to exert anti-inflammatory activities. To examine whether BCP inhibits HFD-induced melanoma progression, 4-weeks old, male C57BL/6N mice were fed a control diet (CD, 10 kcal% fat) or HFD (60 kcal% fat + 0, 0.15 or 0.3% BCP) for the entire experimental period. After 16 weeks of feeding, B16F10s were subcutaneously injected into mice. Three weeks later, tumors were resected, and mice were killed 2 weeks post-resection. Although HFD feeding increased body weight gain, fasting blood glucose levels, solid tumor growth, LN metastasis, tumor cell proliferation, angiogenesis and lymphangiogenesis, it decreased apoptotic cells, all of which were suppressed by dietary BCP. HFD feeding increased the number of lipid vacuoles and F4/80+ macrophage (MΦ) and macrophage mannose receptor (MMR)+ M2-MΦs in tumor tissues and adipose tissues surrounding the LN, which was suppressed by BCP. HFD feeding increased the levels of CCL19 and CCL21 in the LN and the expression of CCR7 in the tumor; these changes were blocked by dietary BCP. In vitro culture results revealed that BCP inhibited lipid accumulation in 3T3-L1 preadipocytes; monocyte migration and monocyte chemoattractant protein-1 secretion by B16F10s, adipocytes and M2-MΦs; angiogenesis and lymphangiogenesis. The suppression of adipocyte and M2-cell accumulation and the inhibition of CCL19/21-CCR7 axis may be a part of mechanisms for the BCP suppression of HFD-stimulated melanoma progression.

A high-fat diet containing lard accelerates prostate cancer progression and reduces survival rate in mice: possible contribution of adipose tissue-derived cytokines.

To examine the effects of high-fat diet (HFD) containing lard on prostate cancer development and progression and its underlying mechanisms, transgenic adenocarcinoma mouse prostate (TRAMP) and TRAMP-C2 allograft models, as well as in vitro culture models, were employed. In TRAMP mice, HFD feeding increased the incidence of poorly differentiated carcinoma and decreased that of prostatic intraepithelial neoplasia in the dorsolateral lobes of the prostate, which was accompanied by increased expression of proteins associated with proliferation and angiogenesis. HFD feeding also led to increased metastasis and decreased survival rate in TRAMP mice. In the allograft model, HFD increased solid tumor growth, the expression of proteins related to proliferation/angiogenesis, the number of lipid vacuoles in tumor tissues, and levels of several cytokines in serum and adipose tissue. In vitro results revealed that adipose tissue-conditioned media from HFD-fed mice stimulated the proliferation and migration of prostate cancer cells and angiogenesis compared to those from control-diet-fed mice. These results indicate that the increase of adipose tissue-derived soluble factors by HFD feeding plays a role in the growth and metastasis of prostate cancer via endocrine and paracrine mechanisms. These results provide evidence that a HFD containing lard increases prostate cancer development and progression, thereby reducing the survival rate.

Benzyl isothiocyanate suppresses high-fat diet-stimulated mammary tumor progression via the alteration of tumor microenvironments in obesity-resistant BALB/c mice.

We previously reported that a high-fat diet (HFD) and M2-macrophages induce changes in tumor microenvironments and stimulate tumor growth and metastasis of 4T1 mammary cancer cells in BALB/c mice. In this study, we attempted to determine whether benzyl isothiocyanate (BITC) inhibits HFD-induced changes in tumor progression and in tumor microenvironments. Four groups of female BALB/c mice (4-week-old) were fed on a control diet (CD, 10 kcal% fat) and HFD (60 kcal% fat) containing BITC (0, 25, or 100 mg/kg diet) for 20 weeks. Following 16 weeks of feeding, 4T1 cells (5×10(4) cells) were injected into the mammary fat pads, and animals were killed 30 d after the injection. HFD feeding increased solid tumor growth and the number of tumor nodules in the lung and liver, as compared to the CD group, and these increases were inhibited by BITC supplementation. The number of lipid vacuoles, CD45+ leukocytes and CD206+ M2-macrophages, expression of Ki67, levels of cytokines/chemokines, including macrophage-colony stimulating factor (M-CSF) and monocyte chemoattractant protein-1, and mRNA levels of F4/80, CD86, Ym1, CD163, CCR2, and M-CSF receptor were increased in the tumor tissues of HFD-fed mice, and these increases were inhibited by BITC supplementation. In vitro culture results demonstrated that BITC inhibited macrophage migration as well as lipid droplet accumulation in 3T3-L1 cells. These results suggest that suppression of lipid accumulation and macrophage infiltration in tumor tissues may be one of the mechanisms by which BITC suppresses tumor progression in HFD-fed mice.

Kaempferol Downregulates Insulin-like Growth Factor-I Receptor and ErbB3 Signaling in HT-29 Human Colon Cancer Cells.

BACKGROUND: Novel dietary agents for colon cancer prevention and therapy are desired. Kaempferol, a flavonol, has been reported to possess anticancer activity. However, little is known about the molecular mechanisms of the anticancer effects of kaempferol. The aim of this study was to determine the inhibitory effect of kaempferol on growth factor-induced proliferation and to elucidate its underlying mechanisms in the HT-29 human colon cancer cell line. METHODS: To assess the effects of kaempferol and/or growth factors [insulin-like growth factor (IGF)-I and heregulin (HRG)-ß], cells were cultured with or without 60 µmol/L kaempferol and/or 10 nmol/L IGF-I or 20 µg/L HRG-ß. Cell proliferation, DNA synthesis, and apoptosis were determined by a cell viability assay, a [(3)H]thymidine incorporation assay, and Annexin-V staining, respectively. Western blotting, immunoprecipitation, and an in vitro kinase assay were conducted to evaluate expression and activation of various signaling molecules involved in the IGF-I receptor (IGF-IR) and ErbB3 signaling pathways. RESULTS: IGF-I and HRG-ß stimulated HT-29 cell growth but did not abrogate kaempferol-induced growth inhibition and apoptosis. Kaempferol reduced IGF-II secretion, HRG expression and phosphorylation of Akt and extracellular signal-regulated kinase (ERK)-1/2. Kaempferol reduced IGF-I- and HRG-ß-induced phosphorylation of the IGF-IR and ErbB3, their association with p85, and phosphatidylinositol 3-kinase (PI3K) activity. Additionally, kaempferol inhibited IGF-I- and HRG-ß-induced phosphorylation of Akt and ERK-1/2. CONCLUSIONS: The results demonstrate that kaempferol downregulates activation of PI3K/Akt and ERK-1/2 pathways by inhibiting IGF-IR and ErbB3 signaling in HT-29 cells. We suggest that kaempferol could be a useful chemopreventive agent against colon cancer.

Licochalcone E present in licorice suppresses lung metastasis in the 4T1 mammary orthotopic cancer model.

We investigated whether licochalcone E (LicE), a phenolic constituent of licorice, inhibits mammary tumor growth and metastasis using animal and cell culture models. 4T1 mammary carcinoma cells were injected into the mammary fat pads of syngeneic BALB/c mice. Starting 7 days after the injection, the mice received LicE (7 or 14 mg/kg body weight/day) via oral gavage for 25 days. LicE suppressed solid tumor growth and lung metastasis, but did not exhibit kidney or liver toxicity. In tumor tissues, LicE treatment induced a reduction in the expression of Ki67, cyclins, and cyclin-dependent kinases and stimulated apoptosis with increased expression of Bax and cleaved caspase-3 but decreased expression of Bcl-2. In addition, LicE decreased expression of CD31, vascular endothelial growth factor (VEGF)-A and C, VEGF-receptor 2, lymphatic vessel endothelial receptor-1, CD45, cyclooxygenase-2, inducible nitric oxide synthase, and hypoxia inducible factor-1α in tumor tissues. In lung tissues, LicE reduced the levels of proinflammatory cytokines and angiogenesis/metastasis-related proteins. In mammary cancer cell cultures, LicE (5-20 µmol/L) dose dependently inhibited cell migration and invasion. LicE inhibited secretion of matrix metalloproteinase-9, urokinase-type plasminogen activator and VEGF-A, and stimulated secretion of tissue inhibitor of metalloproteinase-2 in MDA-MB-231 cells. In addition, LicE inhibited tube formation of vascular endothelial cells. We show that LicE administration suppressed tumor growth and lung metastasis in the mouse model in conjunction with LicE inhibition of cell migration, invasion, and tube formation in vitro. Reduced tumor growth and metastasis in LicE-treated mice may be, at least in part, attributed to reduced inflammation and tumor angiogenesis.

Bone marrow-derived, alternatively activated macrophages enhance solid tumor growth and lung metastasis of mammary carcinoma cells in a Balb/C mouse orthotopic model.

INTRODUCTION: Tumor-associated macrophages, which are derived from the infiltration of circulating bone marrow-derived monocytes, consist primarily of a polarized M2 macrophage (M2-Mϕ) population and are associated with poor prognosis in various cancers. In the present study, we attempted to assess whether M2-Mϕs derived from bone marrow stimulate the promotion and progression of mammary tumors. METHODS: 4T1 murine mammary carcinoma cells were injected either alone or coupled with M2-Mϕs into the mammary fat pads of syngeneic female Balb/C mice. M2-Mϕs were prepared by treating monocytes isolated from female Balb/C mouse bone marrow with IL-4. Tumor cell growth was determined using an in vivo imaging system and the expression of cell proliferation-related, angiogenesis-related, and lymphangiogenesis-related proteins in tumor tissues was immunohistochemically analyzed. To evaluate the effects of the crosstalk between 4T1 cells and M2-Mϕs on the secretion and mRNA expression of cytokines and the migration of monocytes, 4T1 cells and M2-Mϕs were co-cultured and cytokine antibody array, real-time RT-PCR, and trans-well migration assays were conducted. RESULTS: The co-injection of M2-Mϕs into the mammary fat pads of mice increased solid tumor growth and lung metastasis of 4T1 cells as well as the infiltration of CD45+ leukocytes into tumor tissues. The proportions of Ki-67+ proliferating cells and the expression of hypoxia inducible factor-1α, vascular endothelial cell growth factor A, CD31, vascular endothelial cell growth factor C, and lymphatic vessel endothelial receptor-1 were increased significantly in the tumor tissues of mice co-injected with 4T1 cells and M2-Mϕs. The in vitro results revealed that the proliferation of 4T1 cells, the migration of monocytes, and the secretion of granulocyte colony-stimulating factor, IFNγ, IL-1α, IL-2, IL-16, IFNγ-induced protein-10, keratinocyte-derived chemokine, macrophage colony-stimulating factor, monocyte chemotactic protein-1, macrophage inflammatory protein-1α, and RANTES were increased when 4T1 cells were co-cultured with M2-Mϕs, as compared with when the 4T1 cells were cultured alone. CONCLUSION: The crosstalk between 4T1 cells and M2-Mϕs increased the production of cytokines, which may have induced immune cell infiltration into tumor tissues, tumor cell proliferation, angiogenesis, and lymph angiogenesis, thereby increasing solid tumor growth and lung metastasis.

A high-fat diet increases angiogenesis, solid tumor growth, and lung metastasis of CT26 colon cancer cells in obesity-resistant BALB/c mice.

We evaluated whether high-fat diet (HFD), in the absence of increased calorie intake, increases colon cancer growth and metastasis. Four-week-old male BALB/c mice were fed on an HFD (60 kcal% fat) or control diet (10 kcal% fat) for 16 wk, after which CT26 colon cancer cells were subcutaneously injected into the right flank. Solid tumor growth and the number and volume of tumor nodules in the lung were increased markedly in the HFD group with only a slight increase in body weight (5.9%). HFD feeding increased tumor tissue levels of Ki67, cyclin A, cyclin D1, CDK2, Bcl-xL, and Bcl-2; reduced p53 levels and TUNEL-positive apoptotic cells; increased the levels of CD45, CD68, CD31, VEGF, P-VEGF receptor-2, iNOS, and COX-2 as well as hemoglobin content; and increased the levels of HIF-1α, P-STAT3-Y705, P-STAT3-S727, P-IκB-α, P-p65, p65, P-c-Jun, P-Akt, P-ERK1/2, P-p38, and P-SAPK/JNK. HFD feeding increased the serum levels of EGF, insulin, IGF-I, IFN-γ, leptin, RANTES, MCP-1, IL-1ra, and SDF-1α and media conditioned by epididymal fat tissue explants from HFD-fed mice caused an increase in microvessel outgrowth from the mouse aorta and tube formation of human umbilical vein endothelial cells. These results indicate that the chronic consumption of an HFD increases colon cancer cell proliferation, tumor angiogenesis, and lung metastasis in mice in the absence of discernible weight gain. HFD feeding increases the levels of growth factors which activate transcription factors, thereby inducing the expression of many genes involved in the stimulation of inflammation, angiogenesis, and cellular proliferation.

The hexane extract of Saussurea lappa and its active principle, dehydrocostus lactone, inhibit prostate cancer cell migration.

Saussurea lappa has been used in Chinese traditional medicine for the treatment of abdominal pain, tenesmus, nausea, and cancer; previous studies have shown that S. lappa also induces G(2) growth arrest and apoptosis in gastric cancer cells. In this study, we investigated the effects of hexane extracts of S. lappa (HESLs) on the migration of DU145 and TRAMP-C2 prostate cancer cells. DU145 and TRAMP-C2 cells were cultured in the presence of 0-4 µg/mL HESL with or without 10 ng/mL epidermal growth factor (EGF). HESL inhibited the basal and EGF-induced migration of prostate cancer cells in a dose-dependent manner, whereas HESL did not influence the viability of these cancer cells under the conditions used in this study. Active fractions of HESL were separated via column chromatography, and the structure of the active principle was determined using (1)H and (13)C nuclear magnetic resonance spectroscopy. The active compound, dehydrocostus lactone (DHCL), in fraction 7 dose-dependently inhibited the basal and EGF-induced migration of prostate cancer cells. HESL and DHCL reduced matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 secretion but increased TIMP-2 levels in both the absence and presence of EGF. Our results demonstrate that the inhibition of MMP-9 secretion and the stimulation of TIMP-2 secretion contribute to reduced migration of DU145 cells treated with HESL and DHCL. These results indicate that HESL containing its active principle, DHCL, has potential as an antimetastatic agent for the treatment of prostate cancer.

Piceatannol inhibits migration and invasion of prostate cancer cells: possible mediation by decreased interleukin-6 signaling.

Piceatannol (trans-3,4,3',5'-tetrahydroxystilbene) is a polyphenol detected in grapes, red wine and Rheum undulatum; it has also been demonstrated to exert anticarcinogenic effects. In this study, in order to determine whether piceatannol inhibits the lung metastasis of prostate cancer cells, MAT-Ly-Lu (MLL) rat prostate cancer cells expressing luciferase were injected into the tail veins of male nude mice. The oral administration of piceatannol (20 mg/kg) significantly inhibited the accumulation of MLL cells in the lungs of these mice. In the cell culture studies, piceatannol was demonstrated to inhibit the basal and epidermal growth factor (EGF)-induced migration and invasion of DU145 cells, in addition to the migration of MLL, PC3 and TRAMP-C2 prostate cancer cells. In DU145 cells, piceatannol attenuated the secretion and messenger RNA levels of matrix metalloproteinase-9, urokinase-type plasminogen activator (uPA) and vascular endothelial growth factor (VEGF). Piceatannol increased the protein levels of tissue inhibitor of metalloproteinase-2 in a concentration-dependent fashion. Additionally, piceatannol inhibited the phosphorylation of signal transducer and activator of transcription (STAT) 3. Furthermore, piceatannol effected reductions in both basal and EGF-induced interleukin (IL)-6 secretion. An IL-6 neutralizing antibody inhibited EGF-induced STAT3 phosphorylation and EGF-stimulated migration of DU145 cells. Interleukin-6 treatment was also shown to enhance the secretion of uPA and VEGF, STAT3 phosphorylation and the migration of DU145 cells; these increases were suppressed by piceatannol. These results demonstrate that the inhibition of IL-6/STAT3 signaling may constitute a mechanism by which piceatannol regulates the expression of proteins involved in regulating the migration and invasion of DU145 cells.

Sensitive fern (Onoclea sensibilis) extract suppresses proliferation and migration of vascular smooth muscle cells inflamed by neighboring macrophages.

Vascular smooth muscle cell (SMC) migration and proliferation contribute to arterial wound repair and thickening of the intimal layer in atherosclerosis. SMC can physically interact with monocytes and macrophages within the intima. This study evaluated whether macrophages modulated proliferation and migration of SMC in close proximity, which was suppressed by 1-25 µg/ml sensitive fern (Onoclea sensibilis) extract (SFE) inhibiting protein-tyrosine phosphatase-1B activity. The addition of conditioned media of THP-1-derived macrophages substantially promoted human aortic smooth muscle cell (HAoSMC) proliferation by ≈30%. HAoSMC proliferation was significantly attenuated by ≥10 µg/ml SFE most likely due to its diminution of platelet derived growth factor (PDGF)-BB secreted by neighbor macrophages. HAoSMC migration was also enhanced by culturing in THP-1 macrophage conditioned media, as evidenced by a scratch wound assay. However, the presence of ≥10 µg/ml SFE did not allow such migaration. When SFE was treated to THP-1 macrophages, the secretion of the adipokines, visfatin and resistin, was abrogated. SFE at 1-25 µg/ml dose-dependently diminished resistin-stimulated secretion of collagen IV and connective tissue growth factor (CTGF) in HAoSMC, indicating that macrophage resistin plays a role in the extracellular matrix (ECM) production of vascular SMC. These results demonstrate that SFE disturbed proliferation and migration of SMC instigated by inflammatory macrophages in close proximity. Therefore, this study provides novel information that SFE has the potential capability to prevent atherosclerosis involving SMC proliferation, migration and fibrogenic activation within the vessels.

trans-10,cis-12 Conjugated linoleic acid induces depolarization of mitochondrial membranes in HT-29 human colon cancer cells: a possible mechanism for induction of apoptosis.

Conjugated linoleic acid (CLA), which is naturally present in a variety of foods such as milk fat and the meat of ruminant animals, has been demonstrated to exert chemoprotective effects in several tissues in experimental animals. CLA is a collective term, which denotes one or more positional and geometric isomers of octadecadienoic acid, with cis-9,trans-11 (c9t11) and trans-10,cis-12 CLA (t10c12) being the principal isomers in commercial preparations. We observed previously that physiological levels of CLA inhibited HT-29 cell growth, and the growth inhibitory effects of CLA were attributed to the effect of t10c12, but not c9t11. In the present study, we assessed the mechanisms by which physiological levels of CLA and t10c12 induce apoptosis in HT-29 cells. HT-29 cells were cultured for 3 days in serum-free medium in the presence of various concentrations of CLA (0-20 micromol/L) or t10c12 (0-4 micromol/L). Addition of CLA or t10c12 to culture medium resulted in a dose-dependent increase in the numbers of apoptotic cells. The results of western blot analysis of total cell lysates showed that CLA and t10c12 increased the levels of cleaved caspase-9, caspase-3, and poly(ADP-ribose) polymerase but did not alter the levels of Bcl-2 family member proteins. However, these fatty acids were shown to increase the translocation of Bad and Bax to the mitochondria, increase mitochondrial membrane permeability, and induce the release of cytochrome c and Smac/Diablo from the mitochondria. In addition, CLA and t10c12 diminished Akt content and Akt phosphorylation. These findings indicate that physiological levels of t10c12 induce apoptosis in HT-29 colon cancer cells, which is mediated via mitochondrion-mediated events associated with a decline in Akt activity, an increase in the translocation of the pro-apototic Bad and Bax to the mitochondria, and the subsequent disruption of normal mitochondrial membrane potential.

Isoliquiritigenin inhibits migration and invasion of prostate cancer cells: possible mediation by decreased JNK/AP-1 signaling.

Isoliquiritigenin (ISL, 4,2',4'-trihydroxychalcone), which is found in licorice, shallot and bean sprouts, is a potent antioxidant with anti-inflammatory and anti-carcinogenic effects. The purpose of this study was to investigate the effects of ISL treatment on the migration, invasion and adhesion characteristics of DU145 human prostate cancer cells. DU145 cells were cultured in the presence of 0-20 micromol/L ISL with or without 10 microg/L epidermal growth factor (EGF). ISL inhibited basal and EGF-induced cell migration, invasion and adhesion dose dependently. ISL decreased EGF-induced secretion of urokinase-type plasminogen activator (uPA), matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and vascular endothelial growth factor (VEGF), but increased TIMP-2 secretion in a concentration-dependent manner. In addition, ISL decreased the protein levels of integrin-alpha2, intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM), and mRNA levels of uPA, MMP-9, VEGF, ICAM and integrin-alpha2. Furthermore, basal and EGF-induced activator protein (AP)-1 binding activity and phosphorylation of Jun N-terminal kinase (JNK), c-Jun and Akt were decreased after ISL treatment. However, phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase was not altered. The JNK inhibitor SP600125 inhibited basal and EGF-induced secretion of uPA, VEGF, MMP-9 and TIMP-1, as well as AP-1 DNA binding activity and cell migration. These results provide evidence for the role of ISL as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of prostate cancer cells. The inhibition of JNK/AP-1 signaling may be one of the mechanisms by which ISL inhibits cancer cell invasion and migration.