Natural Phenolic Acid, Product of the Honey Bee, for the Control of Oxidative Stress, Peritoneal Angiogenesis, and Tumor Growth in Mice.

Tumor-associated macrophages (TAM) are key regulators of the link between inflammation and cancer, and the interplay between TAM and tumor cells represents a promising target of future therapeutic approaches. We investigated the effect of gallic acid (GA) and caffeic acid (CA) as strong antioxidant and anti-inflammatory agents on tumor growth, angiogenesis, macrophage polarization, and oxidative stress on the angiogenic model caused by the intraperitoneal (ip) inoculation of Ehrlich ascites tumor (EAT) cells (2.5 × 106) in Swiss albino mouse. Treatment with GA or CA at a dose of 40 mg/kg and 80 mg/kg ip was started in exponential tumor growth phase on days 5, 7, 9, and 11. On day 13, the ascites volume and the total number and differential count of the cells present in the peritoneal cavity, the functional activity of macrophages, and the antioxidant and anti-angiogenic parameters were determined. The results show that phenolic acids inhibit the processes of angiogenesis and tumor growth, leading to the increased survival of EAT-bearing mice, through the protection of the tumoricidal efficacy of M1 macrophages and inhibition of proangiogenic factors, particularly VEGF, metalloproteinases -2 and -9, and cyclooxygenase-2 activity.

Salvianolic Acid B Slows the Progression of Breast Cancer Cell Growth via Enhancement of Apoptosis and Reduction of Oxidative Stress, Inflammation, and Angiogenesis.

Breast cancer is the current leading cause of cancer death in females worldwide. Although current chemotherapeutic drugs effectively reduce the progression of breast cancer, most of these drugs have many unwanted side effects. Salvianolic acid B (Sal-B) is a bioactive compound isolated from the root of Danshen Radix with potent antioxidant and anti-inflammatory properties. Since free radicals play a key role in the initiation and progression of tumor cells growth and enhance their metastatic potential, the current study was designed to investigate the antitumor activity of Sal-B and compare it with the antitumor activity of the traditional anticancer drug, cisplatin. In vitro, Sal-B decreased the human breast cancer adenocarcinoma (MCF-7) cells proliferation in a concentration and time dependent manner. In vivo and similar to cisplatin treatment, Sal-B significantly reduced tumor volume and increased the median survival when compared to tumor positive control mice group injected with Ehrlich solid carcinoma cell line (ESC). Sal-B decreased plasma level of malondialdehyde as a marker of oxidative stress and increased plasma level of reduced glutathione (GSH) as a marker of antioxidant defense when compared to control ESC injected mice. Either Sal-B or cisplatin treatment decreased tumor tissue levels of tumor necrosis factor (TNF-α), matrix metalloproteinase-8 (MMP-8), and Cyclin D1 in ESC treated mice. Contrary to cisplatin treatment, Sal-B did not decrease tumor tissue Ki-67 protein in ESC injected mice. Immunohistochemical analysis revealed that Sal-B or cisplatin treatment increased the expression of the apoptotic markers caspase-3 and P53. Although Sal-B or cisplatin significantly reduced the expression of the angiogenic factor vascular endothelial growth factor (VEGF) in ESC injected mice, only Sal-B reduced expression level of COX-2 in ESC injected mice. Our data suggest that Sal-B exhibits antitumor features against breast cancer cells possibly via enhancing apoptosis and reducing oxidative stress, inflammation, and angiogenesis.

Angio-Suppressive Effect of Partially Purified Lectin-like Protein from Musa acuminata pseudostem by Inhibition of VEGF-Mediated Neovascularization and Induces Apoptosis Both In Vitro and In Vivo.

Lifestyle and nutritional changes have contributed much to the somatic genetic changes which have concurrently led to an increase cancer in humans. Hence the plant-based and nutritional involvements block oncogenic transformation are in good demand. We evaluate Phloem exudates of the dietary plant, Musa acuminate pseudostem, the initial domesticated plant species with the effective lectin activity for its functional role against the tumor development and its mechanism of action. Our experimental data exhibit that Musa acuminata Lectin Protein (MALP) shows a promising cytotoxic effect against the various human cancer cell lines. Supporting this, we evaluate the in vivo anti-tumor and anti-angiogenic activity of MALP in Ehrlich Ascites Carcinoma mice model (EAC). MALP treatment resulted in tumor growth inhibition and increased the lifespan of the EAC-bearing mice without showing any side effects on normal mice, as revealed by histological parameters. Further, a significant decrease in the ascites vascular endothelial growth factor (VEGF) secretion and microvessel density supports the anti-angiogenic property of the MALP. Apoptosis-inducing activity of MALP was revealed by DNA fragmentation assay, Caspase-3 inhibitor assay and cellular morphology were studied by fluorescence staining methods. Our study delivers the real evidence that MALP with a promising an anticancer potential expressively degenerates the tumor development by affecting angiogenesis and apoptosis.

cis-[RuCl(BzCN)(bipy)(dppe)]PF6 induces anti-angiogenesis and apoptosis by a mechanism of caspase-dependent involving DNA damage, PARP activation, and Tp53 induction in Ehrlich tumor cells.

Antimetastatic activities, low toxicity to normal cells and high selectivity for tumor cells make of the ruthenium complexes promising candidates in the search for develop new chemotherapeutic agents for the treatment of cancer. This study aimed to determine the cytotoxic, genotoxic and to elucidate the signaling pathway involved in the death cell process induced by cis-[RuCl(BzCN)(bipy)(dppb)]PF6(1) and cis-[RuCl(BzCN)(bipy)(dppe)]PF6(2) in Ehrlich ascites carcinoma (EAC) in vitro. Moreover, we report for the first time the anti-angiogenic potential on chick embryo chorioallantoic membrane (CAM) model. Peripheral blood mononuclear cells (PBMC) were isolated from healthy controls with an age range of 20-30 years and used to calculate the selectivity index (SI). The complex 2 (IC50 = 8.5 ± 0.4/SI = 6.3) showed high cytotoxic and selectivity index against EAC cells than complex 1 (IC50 = 14.9 ± 0.2/SI = 0.2) using the MTT assay. Complex 2 induced DNA damage on Ehrlich tumor cells at concentrations and time periods evalueted. In consequence, it was observed an increase of Tp53 gene expression, G0/G1-arrest cells, and increased levels of cleaved PARP protein. Beside that, the treatment of EAC with complex 2 led to an increase in Annexin V-positive cells and apoptosis induction by Caspase-7. Additionally, the complex 2 inhibited the angiogenesis caused by Ehrlich tumor cells in CAM model. This complex is active and selective for Ehrlich tumor cells, inducing DNA damage, cell cycle arrest and cell death by caspase-dependent apoptosis involving PARP activation (PARP1), and Tp53 induction.

Oxidative stress, polarization of macrophages and tumour angiogenesis: Efficacy of caffeic acid.

Macrophage polarization is a process when macrophage expresses different functional programs in response to microenvironmental signals and two extreme forms exist; M1 and M2 macrophages. M1 macrophages are highly microbicidal and anticancer with enhanced ability to kill and phagocytose pathogens, upregulate pro-inflammatory cytokines and reactive molecular species, and present antigens; M2 macrophages and the related tumour associated macrophages (TAMs) regulate tissue remodelling and promote tissue repair and angiogenesis and can amplification of metabolic pathways that can suppress adaptive immune responses. It is demonstrated that ROS production, critical for the activation and functions of M1 macrophages, is necessary for the differentiation of M2 macrophages and TAMs, and that antioxidant therapy blocks TAMs differentiation and tumorigenesis in mouse models of cancer. In order to study how caffeic acid (CA), a natural antioxidant, affects macrophage function, polarization, angiogenesis and tumour growth we injected mice with Ehrlich ascites tumour (EAT) cells and treated them for 10 days with CA in a dose of 40 and/or 80 mg kg(-1.) Macrophage polarization was further characterized by quantifying secreted pro- and anti-inflammatory cytokines, nitric oxide and arginase 1 activity. CA may increase the cytotoxic actions of M1 macrophages and inhibit tumour growth; inhibitory activity on TAMs may be mediated through its antioxidative activity. Taken together, we conclude that the antitumour activity of CA was the result of the synergistic activities of different mechanisms by which CA acts on proliferation, angiogenesis, immunomodulation and survival. The continuous administration of CA efficiently blocked the occurrence of TAMs and markedly suppressed tumorigenesis in mouse cancer models. Targeting TAMs by antioxidants can be a potentially effective method for cancer treatment.

Chronic Dietary Administration of the Glycolytic Inhibitor 2-Deoxy-D-Glucose (2-DG) Inhibits the Growth of Implanted Ehrlich's Ascites Tumor in Mice.

BACKGROUND: Dietary energy restriction (DER) has been well established as a potent anticancer strategy. Non-adoption of restricted diet for an extended period has limited its practical implementation in humans with a compelling need to develop agents that mimic effects similar to DER, without reduction in actual dietary intake. Glycolytic inhibitor, 2-deoxy-D-glucose (2-DG), has recently been shown to possess potential as an energy restriction mimetic agent (ERMA). In the present study we evaluated the effect of dietary 2-DG administration on a mouse tumor model, with a focus on several potential mechanisms that may account for the inhibition of tumorigenesis. METHODOLOGY/PRINCIPAL FINDINGS: Swiss albino strain 'A' mice were administered with 0.2% and 0.4% w/v 2-DG in drinking water for 3 months prior to tumor implantation (Ehrlich's ascites carcinoma; EAC) and continued till the termination of the study with no adverse effects on general physiology and animal growth. Dietary 2-DG significantly reduced the tumor incidence, delayed the onset, and compromised the tumor growth along with enhanced survival. We observed reduced blood glucose and serum insulin levels along with decreased proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine positive (BrdU+) tumor cells in 2-DG fed mice. Also, reduced levels of certain key players of metabolic pathways such as phosphatidylinositol 3-kinase (PI3K), phosphorylated-Akt and hypoxia inducible factor-1 alpha (HIF-1α) were also noted in tumors of 2-DG fed mice. Further, decrease in CD4+/CD8+ ratio and T-regulatory cells observed in 2-DG fed mice suggested enhanced antitumor immunity and T cell effector function. CONCLUSION/SIGNIFICANCE: These results strongly suggest that dietary 2-DG administration in mice, at doses easily achievable in humans, suitably modulates several pleotrophic factors mimicking DER and inhibits tumorigenesis, emphasizing the use of ERMAs as a promising cancer preventive strategy.

Thymus in experimental carcinogenesis of the prostate gland.

We studied structural changes in the prostate gland, thymus, and lymph nodes in CBA mice after transplantation of Ehrlich ascites tumor cells into the prostate gland. On experimental day 5, the number of blood and lymph vessels decreased in the gland; the percentage of connective tissue elements and glandular tissue and the number of immunoblasts in the thymus increased. On day 18, the number of blood vessels in the tumor decreased; the width of the cortex and glandular tissue increased in the thymus, while the number of immunoblasts was reduced. On day 28, tumor infiltration and increased number of lymphatic vessels in its stroma were observed; parenchyma was reduced, and the area of the connective tissue increased in the thymus. These structural changes indicated the development of accidental involution of the thymus during carcinogenesis of the prostate.

Chloroquine synergizes sunitinib cytotoxicity via modulating autophagic, apoptotic and angiogenic machineries.

Tyrosine kinases play a pivotal role in oncogenesis. Although tyrosine kinase inhibitors as sunitinib malate are used in cancer therapy, emerging studies report compromised cytotoxicity when used as monotherapy and thus combinations with other anti-cancer agents is recommended. Chloroquine is a clinically available anti-malarial agent which has been shown to exhibit anti-cancer activity. In the current study, we questioned whether chloroquine can modulate sunitinib cytotoxicity. We found that chloroquine synergistically augmented sunitinib cytotoxicity on human breast (MCF-7 and T-47D), cervical (Hela), colorectal (Caco-2 and HCT116), hepatocellular (HepG2), laryngeal (HEp-2) and prostate (PC3) cancer cell lines as indicated by combination and concentration reduction indices. These results were also consistent with that of Ehrlich ascites carcinoma (EAC) Swiss albino mice models as confirmed by tumor volume, weight, histopathological examination and PCNA expression. Sunitinib induced autophagy via upregulating beclin-1 expression which was blocked by chloroquine as evidenced by accumulated SQTSM1/p62 level. Furthermore, chloroquine augmented sunitinib-induced apoptosis by decreasing survivin level and increasing caspase 3 activity. Chloroquine also enhanced the antiangiogenic capacity of sunitinib as indicated by decreased CD34 expression and peritoneal/skin angiogenesis. Sunitinib when combined with chloroquine also increased reactive nitrogen species production via increasing inducible nitric oxide synthase expression and nitric oxide level whilst reduced reactive oxygen species production by increasing GSH level, activities of glutathione peroxidase and catalase and reducing lipid peroxides compared to sunitinib-only treated group. Taken together, these findings suggest that chloroquine enhanced sunitinib cytotoxicity in a synergistic manner via inducing apoptosis while switching off autophagic and angiogenic machineries. Nevertheless, further studies are required to elucidate the efficacy and safety profile of such combination.

Synthesis, angiopreventive activity, and in vivo tumor inhibition of novel benzophenone-benzimidazole analogs.

AIM: The development of anticancer drugs with specific targets is of prime importance in modern biology. This study investigates the angiopreventive and in vivo tumor inhibition activities of novel synthetic benzophenone-benzimidazole analogs. MAIN METHODS: The multistep synthesis of novel benzophenone-benzimidazole analogs (8a-n) allowing substitution with methoxy, methyl and halogen groups at different positions on the identical chemical backbone and the variations in the number of substituents were synthesized and characterized. The newly synthesized compounds were further evaluated for cytotoxic and antiproliferative effects against Ehrlich ascites carcinoma (EAC) cells. The potent lead compounds were further assessed for antiangiogenic effects in a CAM model and a tumor-induced vasculature in vivo model. The effect of angioprevention on tumor growth was verified in a mouse model. KEY FINDINGS: The cytotoxicity studies revealed that compounds 8f and 8n are strongly cytotoxic. Analyzing the structure-activity relationship, we found that an increase in the number of methyl groups in addition to methoxy substitution at the para position of the benzoyl ring in compound 8n resulted in higher potency compared to 8f. Furthermore, neovessel formation in in vivo systems, such as the chorioallantoic membrane (CAM) and tumor-induced mice peritoneum models, was significantly suppressed and reflected the tumor inhibition observed in mice. SIGNIFICANCE: These results suggest the potential clinical application of compound 8n as an antiangiogenic drug for cancer therapy.

Brucine, an indole alkaloid from Strychnos nux-vomica attenuates VEGF-induced angiogenesis via inhibiting VEGFR2 signaling pathway in vitro and in vivo.

In this study, we investigated the mechanism of brucine in tumor angiogenesis. We found that brucine inhibits VEGF-induced cell proliferation, chemotactic motility, and the formation of capillary-like structures in HUVECs in a dose-dependent manner. Brucine suppresses VEGF- induced p-VEGFR2 kinase activity and inhibits neovascularization in vivo. Brucine inhibits the downstream protein kinases of VEGFR2, including Src, FAK, ERK, AKT and mTOR. And further downregulates levels of VEGF, NO, IL-6, IL-8, TNF-α and IFN-γ in HUVECs. Taken together, our study suggests that brucine potently suppresses angiogenesis by targeting VEGFR2 activation and may be a viable drug candidate in anti-angiogenesis and anti-cancer therapies.

Bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex a new apoptotic agent through Flk-1 down regulation, caspase-3 activation and oligonucleosomes DNA fragmentation.

New bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex was synthesized and characterized. In vivo anti-angiogenic activities of bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex against Ehrlich ascites carcinoma (EAC) cells are described. The newly synthesized complex resulted in inhibition of proliferation of EAC cells and ascites formation. The anti-tumor effect was found to be through anti-angiogenic activity as evident by the reduction of microvessel density in EAC solid tumors. The anti-angiogenic effect is mediated through down-regulation of VEGF receptor type-2 (Flk-1). The complex was also found to significantly increase the level of caspase-3 in laboratory animals compared to the acridine ligand and to the control group. This was also consistent with the DNA fragmentation detected by capillary electrophoresis that proved the apoptotic effect of the new complex. Our complex exhibited anti-angiogenic and apoptotic activity in vivo, a thing that makes it a potential effective chemotherapeutic agent. The interaction of calf thymus DNA (ct-DNA) with bis(acridine-9-carboxylate)-nitro-europium(III) dihydrate complex has been investigated using fluorescence technique. A competitive experiment of the europium(III)-acridine complex with ethidium bromide (EB) to bind DNA revealed that interaction between the europium(III)-acridine and DNA was via intercalation. The interaction of the synthesized complex with tyrosine kinases was also studied using molecular docking simulation to further substantiate its mode of action.

A novel anti-tumor agent, Ln(III) 2-thioacetate benzothiazole induces anti-angiogenic effect and cell death in cancer cell lines.

New complexes with a potent DNA-binding anti-tumor agent, europium(III)- and terbium(III)-2-thioacetate benzothiazole were synthesized and characterized. These complexes showed strong binding affinity to calf thymus DNA using fluorometric and electronic absorption spectroscopy. The synthesized complexes resulted in inhibition of proliferation of EAC cells and ascites formation. Their anti-tumor effect was found to be through anti-angiogenic activity as was evident by the reduction of microvessel density and down-regulation of VEGF receptor type-2 (Flk-1). It was found that EAC cells had distinct DNA fragmentation patterns analyzed by capillary electrophoresis in the treated animals. Moreover, the synthesized complexes exhibited significant cytotoxic activity against HepG2 and MCF7 cell lines. Furthermore, complexes showed a potent anti-bacterial activity against two pathogenic bacteria Escherichia coli and Salmonella.

Cytotoxic and antitumor effects of brucine on Ehrlich ascites tumor and human cancer cell line.

AIMS: Brucine (BRU), a natural plant alkaloid is reported to possess cytotoxic and antiproliferative activities. In this study we aimed to investigate its in vitro and in vivo antitumor and antiangiogenic effects. MAIN METHODS: Cell proliferation and viability was assessed using microculture tetrazolium tests (MTT). As predictive markers we determined intracellular levels of vascular endothelial growth factor (VEGF), Interleukin-12 (IL-12), tumor necrosis factor (TNF-α), caspase-3, -8 and -9 by ELISA and enzymatic activity assays. In addition, anti-VEGF neutralization effect was evaluated to assess whether it could result in augmented anticancer efficacy than the single agent. Antitumor activity was evaluated against Ehrlich ascites and solid tumor models. 15×10(6) EAC cells were implanted intraperitoneally (i.p., ascites tumor) and subcutaneous (s.c., solid tumor) in Swiss albino mice. Mice with established tumors received brucine i.p. at 12.5, 25, and 50mg/kg for 14days in ascites tumor and 50mg/kg in solid tumor for 30days. Tumor volume, cell viability, angiogenic, anti-angiogenic, anti-inflammatory factors and antioxidant parameters were determined. Immunohistochemistry analysis for VEGF and CD-31 was also performed. KEY FINDINGS: BRU produced time and dose-dependent inhibition of MCF-7 in vitro and EAC tumors in vivo. The anti-angiogenic effects were accompanied with decreased VEGF and TNF-α and increased IL-12 expression. BRU reduced peritoneal angiogenesis and microvessel density in vivo. CONCLUSION: Our findings suggest that BRU possesses antitumor and anti-angiogenic activities in vitro and in vivo. The above results showed that BRU can be used as a potential anticancer agent as an antimetastatic and anti-angiogenic agent.

[Therapeutic features of endostar, a modified endostatin, on ascites tumor in mice].

OBJECTIVE: To investigate the effect of endostar in controlling ascites tumor formation in mice. METHODS: Mouse models bearing ascites tumors were established via intraperitoneal injection of H22 and S180 cell lines. Eighty-eight ICR mice were randomly assigned into 4 groups, namely the control group (0.9% normal saline) and 3 endostar groups with 8 mg/kg endostar administration daily, every other day or every two days. The peritoneal membrane permeability of the mice was assessed using Evan blue staining. The body weight curve of mice was drawn, and the cumulative ascites volume and number of red cells and tumor cells in the malignant ascites were determined. The survival of the mice was evaluated to assess the therapeutic effect of endostar. RESULTS: Compared with the control group, the mice receiving daily endostar injection showed obviously lower ascites accumulation and peritoneal capillary permeability (P<0.05) with reduced count of ascites tumor cells and red cells and tumor burden of the abdominal cavity. The mice with daily endostar injection also showed longer survival than the control group. CONCLUSIONS: Continuous intraperitoneal injection can be the optimal means for endostar administration for treatment of malignant ascites.

Platelet-activating factor receptor (PAF-R)-dependent pathways control tumour growth and tumour response to chemotherapy.

BACKGROUND: Phagocytosis of apoptotic cells by macrophages induces a suppressor phenotype. Previous data from our group suggested that this occurs via Platelet-activating factor receptor (PAF-R)-mediated pathways. In the present study, we investigated the impact of apoptotic cell inoculation or induction by a chemotherapeutic agent (dacarbazine, DTIC) on tumour growth, microenvironmental parameters and survival, and the effect of treatment with a PAF-R antagonist (WEB2170). These studies were performed in murine tumours: Ehrlich Ascitis Tumour (EAT) and B16F10 melanoma. METHODS: Tumour growth was assessed by direct counting of EAT cells in the ascitis or by measuring the volume of the solid tumour. Parameters of the tumour microenvironment, such as the frequency of cells expressing cyclo-oxygenase-2 (COX-2), caspase-3 and galectin-3, and microvascular density, were determined by immunohistochemistry. Levels of vascular endothelium growth factor (VEGF) and prostaglandin E2 (PGE2) were determined by ELISA, and levels of nitric oxide (NO) by Griess reaction. PAF-R expression was analysed by immunohistochemistry and flow cytometry. RESULTS: Inoculation of apoptotic cells before EAT implantation stimulated tumour growth. This effect was reversed by in vivo pre-treatment with WEB2170. This treatment also reduced tumour growth and modified the microenvironment by reducing PGE2, VEGF and NO production. In B16F10 melanoma, WEB2170 alone or in association with DTIC significantly reduced tumour volume. Survival of the tumour-bearing mice was not affected by WEB2170 treatment but was significantly improved by the combination of DTIC with WEB2170. Tumour microenvironment elements were among the targets of the combination therapy since the relative frequency of COX-2 and galectin-3 positive cells and the microvascular density within the tumour mass were significantly reduced by treatment with WEB2170 or DTIC alone or in combination. Antibodies to PAF-R stained the cells from inside the tumour, but not the tumour cells grown in vitro. At the tissue level, a few cells (probably macrophages) stained positively with antibodies to PAF-R. CONCLUSIONS: We suggest that PAF-R-dependent pathways are activated during experimental tumour growth, modifying the microenvironment and the phenotype of the tumour macrophages in such a way as to favour tumour growth. Combination therapy with a PAF-R antagonist and a chemotherapeutic drug may represent a new and promising strategy for the treatment of some tumours.

Inhibitory effect of caffeic acid phenethyl ester on mice bearing tumor involving angiostatic and apoptotic activities.

UNLABELLED: This study aims at investigating the anti-tumor effect of caffeic acid phenethyl ester (CAPE) against animal carcinogenesis. In order to substantiate this fact implanted tumor Ehrlich carcinoma cells were assessed in vivo to Swiss mice strain. We found that administrating of CAPE (15 mg/kg S.C.) showed that the tumor volume decreased significantly by 51%. As a result, it improved animal chances of survival and they became healthier. An anti-angiogenic effect of CAPE in vivo was observed, as determined by a significant serum matrix metalloproteinase (MMP-9) reduction (142.1 ng/ml), activation of endostatin serum level (1.9 ng/ml), as well as DNA fragmentation in tumor treated mice when compared with untreated ones. CONCLUSION: CAPE has a significant inhibitory effect on tumor in vivo. This inhibition may be related to its angiostatic and apoptotic effects. It also reduced angiogenic factors which may shift the equilibrium to the angiostatic effect of CAPE. These findings provide the possibility for the future use of CAPE as tumor therapy in human clinical trials.

Vascular endothelial growth factor immunoneutralization in combination with cisplatin reduces EAC tumor growth.

In the present study, we evaluated the effects of a neutralizing anti-Vascular Endothelial Growth Factor (VEGF) polyclonal antibody on murine EAC tumor growth both in vitro and in vivo. Furthermore, we investigated if in the presence of effective VEGF blockade, a conventional chemotherapeutic drug Cisplatin could be effective, and if so would there be an additive effect of the combination regimen. An in vitro cell proliferation assay using MTT kit showed that VEGF antibody alone inhibited proliferation of EAC cells significantly in all the three time intervals (p<0.05). But cisplatin treatment in combination with VEGF antibody resulted in highly significant inhibition (p<0.001) of cell proliferation. Apoptosis assay by FACS analysis showed that VEGF antibody-cisplatin combination treatment induced apoptosis in cultured EAC cells. Intraperitoneal administration of VEGF antibody (100 mug/dose) and cisplatin (0.5 mg/kg/dose) combination was observed to be more effective in reducing tumor burden and increasing life span when compared to VEGF antibody or cisplatin treatment alone in EAC solid tumor bearing mice. In EAC ascites tumor model, all the three types of treatment inhibited tumor burden and increased life span, but the inhibition was less compared to EAC solid tumor bearing mice. VEGF antibody singly and in combination with cisplatin reduced neoangiogenesis and vascular hyperpermeability. However, it is clear from the results that the combination treatment had no additive effect in reducing vascular hyperpermeability. Serum VEGF was not reduced significantly after treatment in EAC ascites tumor bearing mice, whereas in EAC solid tumor bearing mice it was reduced significantly after treatment. The results clearly show that though alone cisplatin showed antitumor efficacy but it had no significant inhibitory effect on neoangiogenesis and vascular hyperpermeability. Thus the present study suggests that anti-VEGF agent can be combined with traditional treatment modalities to ensure more effectiveness.

Angiogenic and proliferative effects of the cytokine VEGF in Ehrlich ascites tumor cells is inhibited by Glycyrrhiza glabra.

Blood vessel plays a crucial role in solid tumor development. It has been suggested that blocking of angiogenesis and the action of the cytokine VEGF could be possible in cancer therapy. In a screen for naturally occurring angiogenic inhibitors, we have identified an extract from the roots of Glycyrrhiza glabra, which has potent antiangiogenic and antitumor activity. The aqueous extract inhibits the in vivo and in vitro proliferation of Ehrlich ascites tumor cells. The angioinhibitory activity of G. glabra was confirmed by its inhibition of angiogenesis in in vivo assays, peritoneal and chorioallantoic membrane assay. Reduction in the levels of the cytokine VEGF and microvessel density count in the peritoneum of mice treated with G. glabra indicated that the plant extract decreased VEGF production and the cytokine induced neovascularization. Our results suggest that the extract from the roots of G. glabra may be a potential supplemental source for cancer therapy.

Butyrate-induced proapoptotic and antiangiogenic pathways in EAT cells require activation of CAD and downregulation of VEGF.

Butyrate, a short-chain fatty acid produced in the colon, induces cell cycle arrest, differentiation, and apoptosis in transformed cell lines. In this report, we study the effects of butyrate (BuA) on the growth of Ehrlich ascites tumor (EAT) cells in vivo. BuA, when injected intraperitoneally (i.p) into mice, inhibited proliferation of EAT cells. Further, induction of apoptosis in EAT cells was monitored by nuclear condensation, annexin-V staining, DNA fragmentation, and translocation of caspase-activated DNase into nucleus upon BuA-treatment. Ac-DEVD-CHO, a caspase-3 inhibitor, completely inhibited BuA-induced apoptosis, indicating that activation of caspase-3 mediates the apoptotic pathway in EAT cells. The proapoptotic effect of BuA also reflects on the antiangiogenic pathway in EAT cells. The antiangiogenic effect of BuA in vivo was demonstrated by the downregulation of the secretion of VEGF in EAT cells. CD31 immunohistochemical staining of peritoneum sections clearly indicated a potential angioinhibitory effect of BuA in EAT cells. These results suggest that BuA, besides regulating other fundamental cellular processes, is able to modulate the expression/secretion of the key angiogenic growth factor VEGF in EAT cells.

Mechanism of inhibition of ascites tumor growth in mice by curcumin is mediated by NF-kB and caspase activated DNase.

One of the most clinically relevant biological activities of curcumin is its anti-cancer property, implicating multiple intracellular pathways in the process. In the present report, we investigated the effect of curcumin on the activation of apoptotic and anti-angiogenic pathways in Ehrlich Ascites Tumor (EAT) cells. Treatment with curcumin in vivo resulted in inhibition of proliferation of EAT cells and ascites formation. Further, we demonstrate that the induction of apoptosis in EAT cells showed nuclear condensation, DNA fragmentation and translocation of caspase-activated DNase (CAD) to nucleus upon curcumin treatment. Curcumin-induced apoptosis is mediated through activation of caspase-3, which is specifically inhibited by the caspase-3 inhibitor, Ac-DEVD-CHO. On the other hand, the decreased secretion of ascites by EAT cells is corroborated by reduction in VEGF secretion upon curcumin treatment. Further, CD31 immunohistological staining of peritoneum sections in curcumin-treated mice suggests its efficacy in acting as anti-angiogenic compound in EAT cells by inhibiting proliferation of endothelial cells in mouse peritoneum. However, immunoflurescence studies of NF-kB revealed that the inhibition of nuclear translocation of NF-kB p65, a transcription factor required for VEGF gene expression, in curcumin-treated EAT cells. These results suggest a further possible clinical application of this diet-derived compound curcumin, as both proapoptotic and anti-angiogenic compound in association with conventional chemotherapeutic agents.