VEGF antibody plus cisplatin reduces angiogenesis and tumor growth in a xenograft model of ovarian cancer.

In our previous study, PAb, a VEGF polyclonal antibody was found to inhibit murine tumor growth significantly. The main objective of this study was to investigate the efficacy of combination therapy of (PAb) and cisplatin on human ovarian cancer xenograft. Effect of VEGF, PAb, PAb-cisplatin combination, and cisplatin alone on cultured human ovarian teratocarci-noma cell line PA-1 were assessed by measuring cell proliferation, matrigel invasion, MMP-9 expression, and MMP-9 secretion. In vivo, effect of PAb was observed in a xenograft model of ovarian cancer. Antitumor efficacy was monitored by assessment of tumor volume, MVD, serum NO, serum VEGF, and p53 expression. VEGF increased proliferation of PA-1 cell in a dose-dependent manner while addition of PAb inhibited cell proliferation, cell invasion as well as MMP-9 secretion in vitro. Tumor burden in PAb and PAb-cisplatin combination group was reduced by 41% (p < 0.05) and 66% (p < 0.01), respectively. A significant decrease in MVD, serum NO, serum VEGF, and p53 expression was also observed after PAb and PAb-cisplatin combination treatment when compared to normal mouse serum IgG-treated control mice. Thus, it was concluded that VEGF immunoneutralization may enhance cisplatin-in-duced apoptosis in human ovarian cancer and thus may be an effective way to reduce tumor growth in ovarian carcinoma.

Acivicin with glutaminase regulates proliferation and invasion of human MCF-7 and OAW-42 cells--an in vitro study.

Tumor cells intensely utilize glutamine as the major source of respiratory fuel. Glutamine-analogue acivicin inhibits tumor growth and tumor-induced angiogenesis in Ehrlich ascites carcinoma. In the present study, antitumor properties of acivicin in combination with glutaminase enzyme is reported. Acivicin along with E. coli glutaminase synergistically reduced in vitro proliferation and matrigel invasion of human MCF-7 and OAW-42 cells. Effects of single and combined treatments with acivicin and glutaminase on angiogenic factors were also analyzed in these cell lines. Co-administration of the treatment agents inhibits the release of VEGF and MMP-9 by cells in culture supernatant significantly than single agent treatments. The result suggests that combination of acivicin with glutaminase may provide a better therapeutic option than either of them given separately for treating human breast and ovarian cancer. However, further studies are required to be conducted in vivo for its confirmation.

Augmented antitumor effects of combination therapy with VEGF antibody and cisplatin on murine B16F10 melanoma cells.

Our previous studies with EAC tumor model demonstrated that a VEGF polyclonal antibody combined with cisplatin inhibited tumor growth. Here we report the antitumor effect of VEGF antibody plus cisplatin on a murine metastatic tumor model specially emphasizing its effect on different angiogenic parameters both in vitro and in vivo. Mouse B16F10 melanoma cells were cultured in vitro in DMEM media containing 10% FBS, nonessential amino acids and antibiotics in a 5% CO(2) incubator at 37 degrees C and the effect of VEGF antibody singly and in combination with cisplatin on this cell was assessed by MTT assay, matrigel invasion study and MMP-9 expression study in vitro. In vivo studies were performed by two tumor models viz B16F10 solid tumor model and B16LuF10 lung tumor model. The mice treated with VEGF antibody (PAb) alone, cisplatin alone and combination of VEGF antibody and cisplatin on alternative days from the next day of tumor transplantation. Antitumor as well as antiangiogenic efficacy was monitored by measuring tumor burden, survivability, MVD measurement, serum NO value measurement and bcl-2 expression study. It was observed that administration of combined therapy with VEGF antibody and cisplatin augmented antitumor activity in B16F10 melanoma models than the either agents alone. Thus our experiments show a successful VEGF antibody based combination therapy with cisplatin and suggests that the enhancement of antitumor activity could be explained by a concomitant effect on both endothelial and tumor cell compartment.

Modulation of metastatic potential of B16F10 melanoma cells by acivicin: synergistic action of glutaminase and potentiation of cisplatin cytotoxicity.

Treatment for metastatic melanoma has mostly been unsatisfactory despite advances in ongoing medical research. Here we investigated the role of acivicin, a glutamine analogue, singly and in combination with either E. coli glutaminase or cisplatin, on the growth, angiogenic activity and invasiveness of B16F10 cells in vitro and after allografting in C57BL/6 mice. B16F10 melanoma colonization in the lungs of mice was measured by monitoring colony counts. Host toxicity was assessed with reference to tumor bearing host's weight and survivability. Acivicin promoted melanoma dormancy and reduced melanoma associated angiogenic factors like VEGF level and vessel diameter. Acivicin in combination with glutaminase significantly suppressed tumor growth by 66.7% and increased life-span by 43.5% without host toxicity. Tumor VEGF content was significantly lowered by combination therapy as assessed by ELISA. Accelerated cytotoxicity, reduced invasion and enhanced apoptosis of melanoma cells were exhibited in vitro by combined than by single agent treatment. Moreover, invasion of melanoma cells through matrigel chambers was reduced in presence of acivicin and glutaminase combination. These findings support future studies of acivicin in combination with other anticancer agents for prevention of melanoma metastasis.

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.

Effect of glutamine analogue-acivicin on tumor induced angiogenesis in Ehrlich ascites carcinoma.

The inhibition of tumor growth and tumor induced angiogenesis by the glutamine antimetabolite acivicin was evaluated in 6-7 weeks old male Swiss albino mice bearing Ehrlich ascites carcinoma (EAC) transplanted by intraperitoneal (ip) injections of EAC cells. Treatment involving ip injections with two different doses of acivicin (0.05 and 0.41microg/g body weight/day) in saline revealed decrease in tumor volumes and reduced number of blood vessels on peritoneal wall after 10 and 15 days of treatment when compared to control (i.e. injected with saline only). Vascular hyperpermeability was found to be lesser in the treated groups of mice than the control as indicated by the FITC- D and colloidal carbon assay. Serum VEGF level was found to decrease in the drug treated groups both after 10 and 15 days of treatment. The results thus suggest that acivicin may suppress tumoral angiogenesis through regulation of VEGF level.

Isolation and purification of vascular endothelial growth factor (VEGF) from ascitic fluid of ovarian cancer patients.

Vascular Endothelial Growth Factor (VEGF) or Vascular Permeability Factor (VPF) is an angiogenic cytokine expressed by many human and animal tumors. Because of the importance of VEGF in animal tumors, we purified VEGF/VPF from ascitic fluid of ovarian cancer patients with heparin sepharose column. The purified protein gave protein bands of 37 and 26 kD, respectively in 12% SDS PAGE. The specificity of the purified protein was determined with dot blot, trans-immunoblot and ELISA using polyclonal goat anti-VEGF antibody (Santa Cruz Biotechnology). The vasodilatatory effect of the purified protein was confirmed by a vascular permeability assay on mouse. A polyclonal mouse antibody was raised against the purified protein, which recognized the same protein by ELISA, transimmunoblot and dot-blot analysis. It has been also found that the raised polyclonal antibody in mouse- and the commercial VEGF polyclonal antibody (Santa Cruz Biotechnology) both inhibited in vitrocell proliferation of human MCF-7 cell line. This study shows for the first time an effort to purify VEGF from human source.