Objective To study the expression of inducible nitric oxide synthase (iNOS)，endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) in human gastric cancer and their relationship with tumor angiogenesis and to investigate the interaction of NOS and VEGF in gastric cancer. Methods The expression and distribution of VEGF, iNOS and eNOS in 34 gastric cancer specimens were detected with immunohistochemistry. Microvessel density (MVD) was counted with FⅧRAg immune specific staining. Results The expression rates of iNOS, eNOS and VEGF in 34 gastric cancers were 73.5%, 82.4% and 91.2% respectively. The expression of VEGF had a significant positive relation with iNOS, but not with eNOS. The MVDs of VEGF or iNOS positive gastric cancers were obviously higher than those of VEGF or iNOS negative gastric cancers. There was no significant difference between the MVDs of eNOS positive gastric cancers and eNOS negative ones. Conclusion MVD increases with increase of expression of VEGF and iNOS in gastric cancer. It is indicated that VEGF and iNOS can promote gastric cancer angiogenesis. VEGF and iNOS have a significant positive correlation, which suggests that in human gastric cancer, iNOS plays an important role in the production and action of VEGF.
ObjectiveTo find the role of oncogene cmet and suppressor gene p53 in the process of tumor angiogenesis and their clinical significance. MethodsBy immunohistochemical method and computer image analysis technique, microvessel count and cmet, p53 protein expression were quantitatively determined in 80 cases of breast carcinoma and 20 cases of breast fibroadenoma. ResultsThe high microvessel count and the positive expression of cmet, p53 were significantly correlated with histologic grade, lymph node metastasis and the stage of the tumor (P＜0.01). The high microvessel count was significantly correlated with the positive expression of cmet and p53 (P＜0.01).ConclusionBoth oncogene cmet and suppressor gene p53 modulate tumor angiogenesis of breast carcinoma.
ObjectiveTo explore the antitumor effect of tumor vaccine fused from dendritic cells (DC) and Walker-256 cancer cells on implanted liver cancer in rats and the related mechanism of inhibition for tumor angiogenesis. MethodsWalker-256 cancer cells and mature DC were fused by 50% polyethylene glycol method for preparation of DC-Walker-256 fusion vaccines. Implanted liver cancer models were established through operations on healthy male SD rats at the age of 6－8 weeks. All the rats were divided into four groups, and rats in each group were injected subcutanely with fusion vaccine (group), mixed cultured cells (group), simple DC (group), and PBS (blank control group), respectively. On 28 d after making model, the rats were put to death, the tumor was observed and pathological essays were prepared. All rats’ spleens were collected and prepared into lymphocyte to detect antigenic specificity cytotoxic T lymphocyte (CTL) by enzymelinked immunosorbent spot (ELISPOT) method. The expressions of VEGF, ANG-1, ANG-2, and MVD were detected by immunohistochemistry. ResultsThe numbers of rats survived in the fusion vaccine group, mixed culture cells group, simple DC group, and blank control group was 8, 5, 6, and 3, respectively. The rats in the other three groups except for fusion vaccine group were manifested as inaction, anorexia, and gloomy fur in some degree as well as ascites. The tumorigenesis was found in all survival rats except for two in the fusion vaccine group. The weight of liver tumors of rats in the fusion vaccine group 〔(32.4±9.2) g〕 was significantly lighter than that in the mixed culture cells group 〔(67.3±5.1) g, P=0.031〕, simple DC group 〔(75.0±8.3) g, P=0.019〕, and blank control group 〔(86.6±10.5) g, P=0.008〕, respectively. The number of tumorspecific CTL of rats in the fusion vaccine group was also significantly higher than that in the other three groups (P=0.019, P=0.025, and P=0.001, respectively). The MVD of tumor tissue in the fusion vaccine group was (24.12±2.32) vessels/HP, which was significantly lower than that in the mixed culture cells group 〔(40.34±1.29) vessels/HP, P=0.025〕, simple DC group 〔(42.36±3.16) vessels/HP, P=0.035〕, and blank control group 〔(56.48±5.16) vessels/HP, P=0.006〕, respectively. The MVD of tumor tissue in the mixed cultured cells group and simple DC group was similar (P=0.165), however, which was significantly lower than that in the blank control group (P=0.040 and P=0.043). The positive rate of VEGFA protein expression was 23.2% in the fusion vaccine group, which was significantly lower than that in the mixed culture cells group (42.5%, P=0.031), simple DC group (61.3%, P=0.019), and blank control group (89.6%, P=0.003), respectively. The positive rate of VEGF-A protein expression in the mixed cultured cells and simple DC groups was similar (P=0.089), however, which was significantly lower than that in the blank control group (P=0.027 and P=0.038). The positive rate of ANG-1 protein expression in the fusion vaccine group (43.2%) was not different from that in the mixed culture cells group (46.3%, P=0.292), simple DC group (51.3%, P=0.183), or blank control group (49.6%, P=0.179), respectively, and the difference of pairwise comparison in latter three groups was not significant (P=0.242, P=0.347, and P=0.182). The positive rate of ANG2 protein expression was 19.2% in the fusion vaccine group, which was significantly lower than that in the mixed culture cells group (62.3%, P=0.007), simple DC group (67.3%, P=0.005), and blank control group (71.6%, P=0.004), respectively, however, the difference of pairwise comparison in latter three groups was not significant (P=0.634, P=0.483, and P=0.379). ConclusionFused vaccine can induce CD8+ CTL aiming at tumor cells and establish the effective antitumor immunity in vivo and also downregulate the level of VEGF and ANG-2 to suppress tumor angiogenesis and thereby achieve the purpose of curing tumor.