Icariin activates autophagy to trigger TGFß1 upregulation and promote angiogenesis in EA.hy926 human vascular endothelial cells.

Angiogenesis plays an important role in tissue development and repair, and how to regulate angiogenesis effectively is a widely studied problem in the biomedical field. In recent years, the role of autophagy in vascular endothelial cells has attracted extensive attention. Icariin (ICA) is a traditional Chinese medicine that has been proven to have outstanding protective effects on the vascular system and to regulate cellular autophagy effectively. However, at present, it has not been reported whether ICA can affect the angiogenic ability of endothelial cells by affecting autophagy. In this study, we aimed to investigate whether ICA affects the angiogenesis capacity of EA.hy926 human vascular endothelial cells through autophagy and explain the underlying potential mechanisms. First, we determined that ICA at appropriate concentrations has the ability to promote cell migration and angiogenesis using wound healing assays and tube formation assays. Then, at the molecular level, we observed the upregulation of VEGFA, VEGFR2, ANGI, ANGII, and Tie2 mRNA and detected the upregulation of TGFß1 protein by Western blotting. We also demonstrated that angiogenic concentrations of ICA can effectively activate autophagy. The autophagy inhibitor 3-MA significantly suppressed TGFß1 expression and tube formation in EA.hy926 cells. Overall, we hope that our studies might help to further understand the effect of ICA on vascular endothelial cells and provide a theoretical basis for future angiogenic applications of ICA.

Wound healing potential of licorice extract in rat model: Antioxidants, histopathological, immunohistochemical and gene expression evidences.

Wound healing is a public health concern. Licorice gained a great attention for its antioxidant and anti-inflammatory properties which expand its valuable effects as a herbal medicine. In this study, we pointed out to the wound healing potential and the mechanism by which licorice alcoholic extract can modulate cutaneous wound healing through immune, antioxidant, histopathological, immunohistochemical (IHC) and molecular studies. 24 Wister rats were assigned into 3 groups (n = 8 each); control group, topical and oral supplied groups. Licorice extract administration significantly increased total and differential leucocyte counts, phagocytic activity of neutrophils, antioxidant biomarkers as superoxide dismutase (SOD), glutathione peroxidase activities (GPx) and reduced glutathione (GSH) content with a notable reduction in oxidative stress marker malondialdehyde (MDA). Moreover, histopathological findings detected complete re-epithelialization with increasing collagen synthesis while IHC results revealed a significant enhancement in the expression of α-SMA, PDGFR-α, FGFR1 and Cytokeratin 14 in licorice treated groups compared with the control group. Licorice extract supplementation accelerated wound healing by increasing angiogenesis and collagen deposition through up-regulation of bFGF, VEGF and TGF-ß gene expression levels compared with the control group. UPLC-PDA-MS/MS aided to authenticate the studied Glycyrrihza species and recognized 101 potential constituents that may be responsible for licorice-exhibited potentials. Based on our observations we concluded that licorice enhanced cutaneous wound healing via its free radical-scavenging potential, potent antioxidant activities, and anti-inflammatory actions. Therefore, licorice could be used as a potential alternative therapy for wound injury which could overcome the associated limitations of modern therapeutic products.

Da-Huang-Xiao-Shi decoction protects against3, 5-diethoxycarbonyl-1,4-dihydroxychollidine-induced chronic cholestasis by upregulating bile acid metabolic enzymes and efflux transporters.

ETHNOPHARMACOLOGICAL RELEVANCE: Chronic cholestasis is a usual clinical pathological process in hepatopathy and has few treatment options; it is classified under the category of jaundice in Chinese medicine. Da-Huang-Xiao-Shi decoction (DHXSD) is a classic Chinese prescription which is used to treat jaundice. AIM OF THE STUDY: We aimed to examine the protective effect of DHXSD on liver and its potential mechanism of action against chronic cholestasis. MATERIALS AND METHODS: Chronic cholestasis was induced using 3, 5-diethoxycarbonyl-1,4-dihydroxychollidine (DDC) in mice. Mice were then administered DHXSD intragastrically at doses of 3.68, 7.35, and 14.70 g/kg for four weeks followed by further analyses. Serum biochemical indices and liver pathology were explored. Eighteen individual bile acids (BAs) in mice serum and liver were quantified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The expression of BA related metabolic enzymes, transporters, along with nuclear receptor farnesoid X receptor (FXR) was detected by real-time qPCR and Western blot. RESULTS: DHXSD treatment reduced the serum biochemical indices, ameliorated pathological injury, and improved the disordered BA homeostasis. Mice treated with DHXSD showed significantly upregulated expression of the metabolic enzymes, cytochrome P450 2b10 (Cyp2b10), Cyp3a11, and UDP-glucuronosyltransferase 1a1 (Ugt1a1); and the bile acid transporters, multidrug resistance protein 2 (Mdr2), bile salt export pump (Bsep), and multidrug resistance-associated protein 3 (Mrp3). DHXSD treatment also significantly upregulated FXR expression in mice with DDC-induced chronic cholestasis. CONCLUSIONS: DHXSD exerted protective effects on chronic cholestasis in DDC-treated mice by alleviating the disordered homeostasis of BAs through increased expression of BA related metabolic enzymes and efflux transporters.

Pulsed Electromagnetic Fields Increase Angiogenesis and Improve Cardiac Function After Myocardial Ischemia in Mice.

BACKGROUND: Previous studies have shown that pulsed electromagnetic fields (PEMF) stimulate angiogenesis and may be a potential treatment strategy to improve cardiac function after myocardial infarction (MI). This study explored the effects and its related mechanisms of PEMF in MI mice.Methods and Results:MI mice were used in PEMF treatment (15 Hz 1.5 mT PEMF or 30 Hz 3.0 mT PEMF) for 45 min per day for 2 weeks. Furthermore, an in vivo Matrigel plug assay was used to observe the effect of PEMF in promoting angiogenesis. Compared with the sham PEMF group, PEMF treatment with 30 Hz 3.0 mT significantly improved heart function. PEMF treatment with 15 Hz 1.5 mT and 30 Hz 3.0 mT both increased capillary density, decreased infarction area size, increased the protein expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), Ser473-phosphorylated Akt (pSer473-Akt) and S1177-phosphorylated endothelial nitric oxide synthase (pS1177-eNOS), and increased the mRNA level of VEGF and hypoxia inducible factor 1-alpha (HIF-1α) in the infarct border zone. Additionally, treatment with 30 Hz 3.0 mT also increased protein and mRNA level of fibroblast growth factor 2 (FGF2), and protein level of ß1 integrin, and shows a stronger therapeutic effect. CONCLUSIONS: PEMF treatment could promote angiogenesis of the infarct border zone and improve cardiac function in MI mice. A treatment parameter of 30 Hz 3.0 mT is remarkably effective in MI mice. The effect is associated with the proangiogenic signaling pathways of HIF-1α/VEGF/Akt/eNOS or HIF-1α/FGF2/Akt/eNOS.

Photobiomodulation Enhances the Angiogenic Effect of Mesenchymal Stem Cells to Mitigate Radiation-Induced Enteropathy.

Radiation-induced enteropathy remains a major complication after accidental or therapeutic exposure to ionizing radiation. Recent evidence suggests that intestinal microvascular damage significantly affects the development of radiation enteropathy. Mesenchymal stem cell (MSC) therapy is a promising tool to regenerate various tissues, including skin and intestine. Further, photobiomodulation (PBM), or low-level light therapy, can accelerate wound healing, especially by stimulating angiogenesis, and stem cells are particularly susceptible to PBM. Here, we explored the effect of PBM on the therapeutic potential of MSCs for the management of radiation enteropathy. In vitro, using human umbilical cord blood-derived MSCs, PBM increased proliferation and self-renewal. Intriguingly, the conditioned medium from MSCs treated with PBM attenuated irradiation-induced apoptosis and impaired tube formation in vascular endothelial cells, and these protective effects were associated with the upregulation of several angiogenic factors. In a mouse model of radiation-induced enteropathy, treatment with PBM-preconditioned MSCs alleviated mucosal destruction, improved crypt cell proliferation and epithelial barrier functions, and significantly attenuated the loss of microvascular endothelial cells in the irradiated intestinal mucosa. This treatment also significantly increased angiogenesis in the lamina propria. Together, we suggest that PBM enhances the angiogenic potential of MSCs, leading to improved therapeutic efficacy for the treatment of radiation-induced enteropathy.

Adipocytokine Regulation and Antiangiogenic Activity Underlie the Molecular Mechanisms of Therapeutic Effects of Phyllanthus niruri against Non-Alcoholic Fatty Liver Disease.

The growth of adipose tissues is considered angiogenesis-dependent during non-alcoholic fatty liver disease (NAFLD). We have recently reported that our standardized 50% methanolic extract (ME) of Phyllanthus niruri (50% ME of P. niruri) has alleviated NAFLD in Sprague⁻Dawley rats. This study aimed to assess the molecular mechanisms of action, and to further evaluate the antiangiogenic effect of this extract. NAFLD was induced by eight weeks of high-fat diet, and treatment was applied for four weeks. Antiangiogenic activity was assessed by aortic ring assay and by in vitro tests. Our findings demonstrated that the therapeutic effects of 50% ME among NAFLD rats, were associated with a significant increase in serum adiponectin, reduction in the serum levels of RBP4, vaspin, progranulin, TNF-α, IL-6, and significant downregulation of the hepatic gene expression of PPARγ, SLC10A2, and Collα1. Concomitantly, 50% ME of P. niruri has exhibited a potent antiangiogenic activity on ring assay, cell migration, vascular endothelial growth factor (VEGF), and tube formation, without any cytotoxic effect. Together, our findings revealed that the protective effects of P. niruri against NAFLD might be attributed to its antiangiogenic effect, as well as to the regulation of adipocytokines and reducing the expression of adipogenic genes.

Thrombus leukocytes exhibit more endothelial cell-specific angiogenic markers than peripheral blood leukocytes do in acute coronary syndrome patients, suggesting a possibility of trans-differentiation: a comprehensive database mining study.

BACKGROUND: Current angiogenic therapies for cancers and cardiovascular diseases have not yet achieved expected benefits, which reflects the need for improved understanding of angiogenesis. In this study, we focused on solving the problem of whether tissues have different angiogenic potentials (APs) in physiological conditions and how angiogenesis is regulated in various disease conditions. METHODS: In healthy and diseased human and mouse tissues, we profiled the expression of 163 angiogenic genes, including transcription regulators (TRs), growth factors and receptors (GF/Rs), cytokines and chemokines (C/Cs), and proteases and inhibitors (P/Is). TRs were categorized as inflammatory, homeostatic, and endothelial cell-specific TRs, and C/Cs were categorized as pro-angiogenic, anti-angiogenic, and bi-functional C/Cs. RESULTS: We made the following findings: (1) the human heart, muscle, eye, pancreas, and lymph node are among the tissues with the highest APs; (2) tissues with high APs have more active angiogenic pathways and angiogenic C/C responses; (3) inflammatory TRs dominate regulation of all angiogenic C/Cs; homeostatic TRs regulate all to a lower extent, while endothelial cell-specific TRs mainly regulate pro-angiogenic and bi-functional C/Cs; (4) tissue AP is positively correlated with the expression of oxygen sensors PHD2 and HIF1B, VEGF pathway gene VEGFB, and stem cell gene SOX2; (5) cancers of the digestive system tend to have increased angiogenesis dominated by endothelial cell-specific pro-angiogenic pathways, while lung cancer and prostate cancer have significantly decreased angiogenesis; and (6) endothelial cell-specific pro-angiogenic pathways are significantly increased in thrombus-derived leukocytes in patients with acute coronary artery disease. CONCLUSIONS: Our results demonstrate that thrombus-derived leukocytes express more endothelial cell-specific angiogenic markers to directly promote angiogenesis after myocardial infarction and that certain solid tumors may be more sensitive to anti-angiogenic therapies than others.

The combination effects of Shen-Ling-Bai-Zhu on promoting apoptosis of transplanted H22 hepatocellular carcinoma in mice receiving chemotherapy.

ETHNOPHARMACOLOGICAL RELEVANCE: Shen-Ling-Bai-Zhu Powder (SLBZP) is a classic traditional Chinese medical formula that has been used for several decades in the treatment of patients with gastrointestinal malignancies. Whether SLBZP is best employed as single agent or adjunctive therapy has yet to be determined as does the mechanism whereby SLBZP exerts its anti-tumor effects. AIM OF THE STUDY: To investigate the effects of SLBZP alone and in combination with Cytoxan (CTX) on tumor growth, malignant cell apoptosis and Akt/Nuclear Factor kappa B (NF-КB) signaling in a murine model of hepatocellular carcinoma (HCC) receiving chemotherapy. MATERIALS AND METHODS: Sixty-four adult mice developed HCC following subcutaneous inoculation with H22 hepatocellular carcinoma cells. Seven days later, all received chemotherapy with CTX (200mg/kg) once. Mice were then randomized into eight study groups (N=8/group). Three groups were treated with different concentrations of SLBZP alone (6.00, 3.00, 1.5g/kg), three with SLBZP (6.00, 3.00, 1.5g/kg) plus CTX (20mg/kg), one with CTX (20mg/kg) alone (positive control), and one with physiologic saline (untreated, negative control). All groups were treated for 14 days. Tumor size, histology and serum or tissue levels and/or mRNA expression of PDGF-BB, VEGF, Ang-1, Ang-2, NF-КB, B-cell lymphoma-2 (Bcl-2); B-cell lymphoma-extra large (Bcl-xL); X-linked inhibitor of apoptosis (XIAP), Survivin, Caspase-3, Caspase-9, Caspase-7, Akt and phosphorylated Akt expression were documented at the end of treatment. RESULTS: Compared to untreated negative controls, tumor sizes were decreased in the CTX alone, SLBZP (M)+CTX and SLBZP (H)+CTX groups (-52%,-53% and -58% respectively). Tumor cell density was decreased in all treated groups but most apparent in the SLBZP (H)+CTX group. Electron microscopic evidence of apoptosis was also most apparent in this group. Serum and/or tissue levels and expression of PDGF-BB, VEGF, Ang-1, Ang-2, their downstream signaling proteins and anti-apoptotic markers were lowest and pro-apoptotic markers highest in SLBZP (H)+CTX treated mice. CONCLUSIONS: In this chemotherapy-induced animal model of HCC, SLBZP was most efficacious as adjunctive therapy and appears to act by inhibiting tumor growth promoters and anti-apoptotic proteins while enhancing pro-apoptotic proteins.

MicroRNA-126 contributes to Niaspan treatment induced vascular restoration after diabetic retinopathy.

Diabetic retinopathy (DR) is a serious microvascular complication of diabetes and a major cause of blindness in the developing world. Early diabetic retinopathy is characterized by a loss of pericytes and vascular endothelial cells, a breakdown of the blood-retinal barrier, vascular dysfunction and vascular-neuroinflammation. However, optimal treatment options and related mechanisms are still unclear. MicroRNA-126 (miR-126) plays a potential role in the pathogenesis in DR, which may regulate VEGF, Ang-1 and VCAM-1 expressions. This study investigated the therapeutic effects and mechanisms of Niaspan treatment of DR in diabetes (DM) rats. DM rats exhibits significantly decreased miR-126 and tight junction Claudin-5/Occludin/ZO-1 genes expression, and increased Blood retinal-barrier (BRB) breakdown, retinal apoptosis and VEGF/VEGFR, as well as VCAM-1/CD45 expressions in the retina compared to normal control group. Niaspan treatment significantly improved clinical and histopathological outcomes; decreased the expressions of VEGF/VEGFR, VCAM-1/CD45, apoptosis and BRB breakdown, significantly increased tight junction proteins and Ang-1/Tie-2 expressions, as well as increased retinal miR-126 expression compared to non-treatment diabetic rats. These data are the first to show that Niaspan treatment ameliorates DR through its repair vascular and inhibits inflammatory effects, and also suggest that the miR-126 pathway may contribute to Niaspan treatment induced benefit effects.

Combination of Cilostazol and L-Carnitine Improves Walking Performance in Peripheral Arterial Disease Model Rats.

Cilostazol and L-carnitine have been used as a first-line drug and supplement, respectively, in patients with peripheral arterial disease with intermittent claudication. In this study, the effect of the combination of cilostazol and L-carnitine has been investigated in rats with unilateral hindlimb ischemia. For 28 days, cilostazol and L-carnitine were administrated separately or as a combination. The distance walked before gait disturbance developed was measured using a treadmill for 5 days a week. The capillary density of the ischemic hindlimb was evaluated by immunohistochemical staining at days 7, 14, 21, and 28. Angiogenic gene expression was measured by real-time RT-PCR at days 7 and 28. The greatest increase in the distance was observed in the combination therapy group when compared to the other groups. The capillary density in the adductor muscles of rats treated with cilostazol alone and combination therapy increased at day 28. Angiopoietin-2/Angiopoietin-1 expression ratios were higher, suggesting the promotion of angiogenesis, with cilostazol alone and combination therapy at day 7. This is the first study to show functional improvement of the hind limb following combination therapy with cilostazol and L-carnitine in experimental animals. This study also revealed that cilostazol promotes angiogenesis, and L-carnitine additively contributes to functional improvement via a non-angiogenic mechanism.

Essential role of interleukin-6 in post-stroke angiogenesis.

Ambivalent effects of interleukin-6 on the pathogenesis of ischaemic stroke have been reported. However, to date, the long-term actions of interleukin-6 after stroke have not been investigated. Here, we subjected interleukin-6 knockout (IL-6(-/-)) and wild-type control mice to mild brain ischaemia by 30-min filamentous middle cerebral artery occlusion/reperfusion. While ischaemic tissue damage was comparable at early time points, IL-6(-/-) mice showed significantly increased chronic lesion volumes as well as worse long-term functional outcome. In particular, IL-6(-/-) mice displayed an impaired angiogenic response to brain ischaemia with reduced numbers of newly generated endothelial cells and decreased density of perfused microvessels along with lower absolute regional cerebral blood flow and reduced vessel responsivity in ischaemic striatum at 4 weeks. Similarly, the early genomic activation of angiogenesis-related gene networks was strongly reduced and the ischaemia-induced signal transducer and activator of transcription 3 activation observed in wild-type mice was almost absent in IL-6(-/-) mice. In addition, systemic neoangiogenesis was impaired in IL-6(-/-) mice. Transplantation of interleukin-6 competent bone marrow into IL-6(-/-) mice (IL-6(chi)) did not rescue interleukin-6 messenger RNA expression or the early transcriptional activation of angiogenesis after stroke. Accordingly, chronic stroke outcome in IL-6(chi) mice recapitulated the major effects of interleukin-6 deficiency on post-stroke regeneration with significantly enhanced lesion volumes and reduced vessel densities. Additional in vitro experiments yielded complementary evidence, which showed that after stroke resident brain cells serve as the major source of interleukin-6 in a self-amplifying network. Treatment of primary cortical neurons, mixed glial cultures or immortalized brain endothelia with interleukin 6-induced robust interleukin-6 messenger RNA transcription in each case, whereas oxygen-glucose deprivation did not. However, oxygen-glucose deprivation of organotypic brain slices resulted in strong upregulation of interleukin-6 messenger RNA along with increased transcription of key angiogenesis-associated genes. In conclusion, interleukin-6 produced locally by resident brain cells promotes post-stroke angiogenesis and thereby affords long-term histological and functional protection.

Angiogenic efficacy of simplified 2-herb formula (NF3) in zebrafish embryos in vivo and rat aortic ring in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Diabetic foot ulceration results in high risk of lower extremity amputation, and represents a significant health care expenditure worldwide. Radix Astragali (RA) and Radix Rehmanniae (RR) are widely used Chinese medicinal herbs in treating diabetes, and have shown positive effects in enhancing wound healing in diabetic foot ulcer animal model. MATERIALS AND METHODS: The angiogenic efficacy of NF3, a simplified 2-herb formula consisting of RA and RR in 2:1 ratio, was investigated. Median lethal concentration (LC50) and median effective concentration (EC50) were determined by treating zebrafish embryos with different concentrations of NF3 from 20 hpf to 72 hpf. The angiogenic activity of NF3 was examined in zebrafish embryos in vivo and by rat aortic ring assay in vitro. Cell cycle analysis of endothelial cells induced by NF3 was analyzed by flow cytometry using transgenic zebrafish Tg(fli1:EGFP). Real-time PCR was used to analyze mRNA expression profiles of selected genes involved in VEGF, FGF and MAPK pathways. RESULTS: NF3 enhanced blood vessel formation as indicated by extra growth of intersegmental vessels in zebrafish embryos, and increased microvessels formation in rat aortic ring. NF3 also enhanced endothelial cells proliferation as shown by increased percentage of cells accumulating in S phase and G2/M phase of the cell cycle. NF3 exposure significantly induced up-regulation of VEGF-A, Flk-1, fgf1 and bRaf expression in zebrafish embryos. CONCLUSIONS: Our results demonstrated that NF3 was effective in promoting angiogenesis in zebrafish embryos and by rat aortic ring assay, which provided scientific basis to support the use of NF3 as potential therapeutics in treating diabetic foot ulceration.

Mutant hypoxia inducible factor-1α improves angiogenesis and tissue perfusion in ischemic rabbit skeletal muscle.

Hypoxia-inducible factor-1α (HIF-1α) is one of the most potent angiogenic growth factors. It regulates genes involved in angiogenesis, but is inactivated rapidly by normoxia. Ad-HIF-1α-Trip was constructed by transforming Pro402, Pro564, and Asn803 in HIF-1α to alanine in order to delay degradation and create a constitutive transcriptional activator. In this study, we investigated whether Ad-HIF-1α-Trip could induce functional mature angiogenesis and the possible mechanisms involved. We found that Ad-HIF-1α-Trip increased the expression of multiple angiogenic genes in cultured HMVEC-Ls, including VEGF, PLGF, PAI-1, and PDGF. In a rabbit model of acute hind limb ischemia, Ad-HIF-1α-Trip improved tissue perfusion and collateral vessels, as measured by contrast-enhanced ultrasound (CEU), CT angiography, and vascular casting. Ad-HIF-1α-Trip also produced more histologically identifiable capillaries, which were verified by immunostaining, compared with controls. Interestingly, inhibition of CBP/p300 by curcumin prevented HIF-1α from inducing the expression of several angiogenic genes. The present study suggests that Ad-HIF-1α-Trip can induce mature angiogenesis and improve tissue perfusion in ischemic rabbit skeletal muscle. CBP/p300, which interacts with the transactivation domains of HIF-1α, is important for HIF-1α-induced transcription of angiogenic genes.

Harmine inhibits tumour specific neo-vessel formation by regulating VEGF, MMP, TIMP and pro-inflammatory mediators both in vivo and in vitro.

Harmine is a beta-carboline alkaloid present in medicinal plants such as Peganum harmala that have been used as folk medicine in anticancer therapy. In this study, we demonstrated the anti-angiogenic activity of harmine using in vivo and in vitro assay systems. In vivo anti-angiogenic activity was studied using B16F-10 melanoma cells which induced capillary formation in C57BL/6 mice. Intraperitoneal administration of harmine at 10 mg/kg body weight significantly decreased tumour directed capillary formation. A drastic elevation in serum pro-angiogenic factors such as vascular endothelial growth factor (VEGF), nitric oxide (NO) and pro-inflammatory cytokines in angiogenesis induced animals was significantly decreased by harmine treatment. At the same time harmine increased anti-tumour factors like interleukin-2 (IL-2) and tissue inhibitor metalloprotease (TIMP). Moreover nuclear factor (NF)-κB and other transcription factors like CREB, ATF-2 involved in tumour development and angiogenesis were also inhibited by harmine. Various in vitro assays also supported the anti-angiogenic activity of harmine. It reduced proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVEC). Direct treatment of the harmine also inhibited microvessel outgrowth from the rat aortic ring. Production of other factors by tumour cells which are involved in angiogenesis like cyclooxygenase (COX-2), inducible nitric oxide synthase (iNOS) and matrix metalloproteases (MMPs) were also decrease by the treatment with harmine. Our data suggest that harmine may be a strong angiogenic inhibitor with the ability to decrease the proliferation of vascular endothelial cells and to reduce expression of various pro-angiogenic factors.

Black tea polyphenols target matrix metalloproteinases, RECK, proangiogenic molecules and histone deacetylase in a rat hepatocarcinogenesis model.

BACKGROUND: The aim of this study was to evaluate the chemopreventive effects of black tea polyphenols (Polyphenon-B) on markers of invasion and angiogenesis during dimethylaminoazobenzene (DAB)-induced hepatocarcinogenesis. MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into four groups. The rats in groups 1 and 2 were given 0.06% DAB in the diet for 3 months followed by the normal diet. The rats in group 2 received in addition 0.05% Polyphenon-B in the basal diet. The group 3 animals were given 0.05% Polyphenon-B alone in the basal diet. The group 4 animals served as the control. RESULTS: The dietary administration of DAB induced well-differentiated hepatocellular carcinomas (HCC) that showed increased expression of the markers of invasion, angiogenesis and epigenetic histone deacetylation compared with the controls. The administration of Polyphenon-B significantly reduced the incidence of DAB-induced hepatomas as evidenced by modulation of the markers of invasion (matrix metalloproteinase, MMP-2, MMP-9, tissue inhibitor of matrix metalloproteinase, TIMP-2, and reversion-inducing cysteine rich protein with Kazal motifs RECK) and angiogenesis (hypoxia inducible factor 1alpha, HIF1alpha, vascular endothelial growth factor, VEGF, and VEGF receptor, VEGFR1) as well as the expression of histone deacetylase HDAC-1. CONCLUSION: The results of the present study provide evidence that Polyphenon-B has potential as a chemopreventive agent.

Molecular basis of therapeutic approaches to gastric cancer.

Gastric cancer is the top lethal cancer in Asia. As the majority of cases present with advanced disease, conventional therapies (surgery, chemotherapy, and radiotherapy) have limited efficacy to reduce mortality. Emerging modalities provide promise to combat this malignancy. Target-protein-based cancer therapy has become available in clinical practice. Numerous molecules have been shown potential to target specific pathways for tumor cell growth. Cyclooxygenase-2 (COX-2) is overexpressed in and correlated with gastric cancer, and knockdown of COX-2 or administration of COX-2 inhibitors suppresses tumor formation in models of gastric cancer. Induction of apoptosis, reduction of angiogenesis, and blocking of potassium ion channels may present new mechanisms of COX-2 inhibition. Runt-related transcription factor 3 (RUNX3) is a candidate tumor suppressor gene whose deficiency is causally related to gastric cancer. RUNX3 is downregulated in metastatic gastric cancer. RUNX3 activation inhibits angiogenesis in xenograft tumors in nude mice. Tumor microenvironment modulation also provides a powerful tool to inhibit cancer development and progress; details of the potential roles of angiopoietins are discussed in this review. Osteopontin is a secreted protein involved in stress response, inflammation, wound healing, and immune response. Inhibition of osteopontin by RNA interfering technique suppressed tumorigenesis as well as angiogenesis in gastric cancer. Immunotherapy remains another important choice of adjuvant therapy for cancer. A tumor-specific antigen MG7-Ag has been identified with great potential for inducing immune response in gastric cancer. Using HLA-A-matched allogeneic gastric cancer cells to induce tumor-specific cytotoxic T lymphocytes appeared to be an alternative option of immunotherapy for gastric cancer.

Gene expression in cerebral ischemia: a new approach for neuroprotection.

Cerebral ischemia is one of the strongest stimuli for gene induction in the brain. Hundreds of genes have been found to be induced by brain ischemia. Many genes are involved in neurodestructive functions such as excitotoxicity, inflammatory response and neuronal apoptosis. However, cerebral ischemia is also a powerful reformatting and reprogramming stimulus for the brain through neuroprotective gene expression. Several genes may participate in both cellular responses. Thus, isolation of candidate genes for neuroprotection strategies and interpretation of expression changes have been proven difficult. Nevertheless, many studies are being carried out to improve the knowledge of the gene activation and protein expression following ischemic stroke, as well as in the development of new therapies that modify biochemical, molecular and genetic changes underlying cerebral ischemia. Owing to the complexity of the process involving numerous critical genes expressed differentially in time, space and concentration, ongoing therapeutic efforts should be based on multiple interventions at different levels. By modification of the acute gene expression induced by ischemia or the apoptotic gene program, gene therapy is a promising treatment but is still in a very experimental phase. Some hurdles will have to be overcome before these therapies can be introduced into human clinical stroke trials.