Expression Of VEGI In Human Ovarian Cancer And Mechanism Study

Objective:To detect the expression of VEGI, VEGF in human normal ovary and ovarian cancer specimens. To explore the effects and mechanisms of VEGF on HUVEC. The results of the study will make the basement for further study.Methods:1. The expression of VEGI, VEGF and the value of microvessel density (MVD) were detected by the method of immunohistochemistry in human normal ovary and ovarian cancer specimens.2. HUVEC were cultured in specialized EGM-2medium. HUVEC were treated with recombinant human VEGF at concentration of1,5or10ng/ml for24h,48h or72h respectively. At indicated timepoints, the supernatants were collected and the concentrations of VEGI were detected by ELISA.3.OVCAR3(one kind of human ovarian cancer cell line) cells were incubated at37℃in21%O2and5%CO2(normoxic condition) or in1%O2,94%N2and5%CO2(hypoxic condition). Conditioned media (CM) were collected at indicated timepoints and the concentrations of VEGF in the OVCAR3-CM were detected by ELISA. In this testing, HUVEC were treated with0VCAR3-CM, VEGFR1pAb+0VCAR3-CM, VEGFR2mAb+OVCAR3-CM and VEGFmAb+OVCAR3-CM respectively. After72h incubation, the supernatants were collected and the concentrations of VEGI were measured by ELISA.4. Expression of NF-kB protein in HUVEC after treatment with10ng/ml recombinant human VEGF was evaluated by western blot assay.Results:1. The expression of VEGI decreased markedly in the ovarian cancer specimens, and VEGI protein levels in stages III and IV were lower than those of the stages I and II. Compared to the normal ovary tissues, the values of MVD increased significantly as the disease progressed based on FIGO stages and accompanied with the lower expression of VEGI. The expression of VEGF increased markedly in the ovarian cancer specimens, and the expression of VEGI decreased markedly accompanied with the higher expression of VEGF.2. Recombinant human VEGF could inhibit the production of VEGI by HUVEC, the inhibition was in a dose-and time-dependent manner.3. Compared to the normoxic group, the content of VEGF produced by OVCAR3cell increased significantly in hypoxic condition. Compared to the only HUVEC group, the level of VEGI decreased significantly in OVCAR3-CM group; however, the pretreatment with VEGFRlpAb, VEGFR2mAb or VEGFmAb could restore the level of VEGI downregulated by the OVCAR3-CM.4. No significant differences in protein levels of NF-kB were observed between VEGF treated group and the control group.Conclusion:1. Compared to the normal ovary tissues, the expression of VEGI decreased markedly in the ovarian cancer specimens. However, the expression of VEGF increased markedly in the ovarian cancer specimens, and the expression of VEGI decreased markedly accompanied with the higher expression of VEGF.2. Recombinant human VEGF could inhibit the production of VEGI by HUVEC.3. The level of VEGF produced by OVCAR3cells was much higher in the hypoxic condition than that in normoxic condition, and the VEGF could specifically inhibit the production of VEGI by HUVEC.4. VEGF downregulated VEGI production in HUVEC possibly via other signaling pathways rather than NF-kB pathway.