The Study Of The Effect Of Polypeptide Extract From Scorpion Venom(PESV) On Angiogenesis Of Lewis Lung Carcinomas

ObjectiveTo observe the effection of the polypeptide extract from scorpion venom (PESV) on tumor vascular endothelial growth factorⅧfactor,а-SMA, Dll4, Notch1 of Lewis lung tumor-bearing mice,tumor microvessel density (MVD) and the impact of maturity, inhibiting tumor angiogenesis and the effecting of tumor blood vessel formation and maturation, inhibiting new blood vessel function and further reveal the mechanism of PESV to anti-tumor, which will combine PESV with traditional chemotherapy drugs, and the therapeutics of inhibiting the VEGF-based blood vessel inhibition.Method1. Establishing subcutaneous Lewis lung tumor model, tumor-bearing animals were randomly divided into the control group, PESV group, positive control group, chemotherapy group, chemotherapy combined with PESV group, chemotherapy combined with the positive control group. Detecting the tumor volume and inhibition rate was calculated to observe the inhibition of tumor growth of PESV.2. Routine HE staining, observeing tumor pathology chang by light microscopy.3. DetectingⅧfactor,а-SMA, Dll4 and Notch1 protein expression of tumor tissue by immunohistochemical.4. RT-PCR for detection of tumor angiogenesis regulatory factors Dll4 and Notch1 in the gene expression levels. Results1. The effect of PESV on the growth of Lewis lungCompairing with tumor-bearing control group, Tumor volume in mice for scorpion venom group had no significant difference ( P≥0.05),the inhibition rate was 14.95%. Compairing PESV group and the positive control group,there was no significant difference (P≥0.05). Scorpion PESV and the positive control group, tumor volume was significantly different(P≤0.01). Chemotherapy combined PESV group compared with the chemotherapy group, difference is significant (P≤0.05), inhibition rate was 42.21%. Chemotherapy combined PESV group compared with chemotherapy and the positive control group, the difference was statistically significant (P≥0.05).2. The effect of PESV on tumor microvessel density and vascular maturation of Lewis lungⅧfactor expresses in microvascular endothelial cells in the cytoplasm, its expression could reflect the tumor microvessel density;а-SMA expresses of functi- onal blood vessels in the base membrane can be used to mark the function of tumor tissue blood vessels, and the microvessel number may reflect the relative ratio of ma- ture blood vessels in tumor tissue. By the semi-quantitative image analysis, com- paring PESV group with the control group, chemotherapy combined with PESV gro- up with the chemotherapy group , the tumor microvessel density and vascular matu- rity of the former were significantly lower than the latter (P≤0.05). Comparing PE- SV group with the positive control group, chemotherapy combined with PESV group with the chemotherapy combination group compared with the positive control, tumor microvessel density of the former was no significant difference than the latter (P≥0.05). PESV could educe tumor vascular maturity (P≤0.05),while the positive cant.3. The expression of Dll4 and Notch1 in Lewis lung tumor tissues effected by PESVThe results of immunohistochemical staining showed that, positive products of Dll4 and Notch1 were mainly localized in the cytoplasm and membrane of tumor cells, by the semi-quantitative image analysis, the expression of Dll4 and Notch1 in PESV groups were significantly lower than in the control group (P≤0.05).,chemotherapy combined with PESV group were significantly lower than in the chemotherapy group (P≤0.05). The expression of Dll4 and Notch1 of tumor tissues in PESV were significantly lower than in the positive control group, chemotherapy combined with PESV were lower than in the chemotherapy combined with positive control group (P≥0.05).4. The effects of PESV on the expression of Dll4 and Notch1 in Lewis lung tumor tissueThe gene level differences of Dll4, Notch1 mRNA in tumor tissue was detected by RT-PCR. According to the semi-quantitative image analysis, the expression of Dll4 and Notch1 in PESV groups were lower than in the control group,chemotherapy combined with PESV group were lower than in the chemotherapy group, the difference was statistically significant (P≤0.05). Comparing PESV group with the positive control group, chemotherapy combined with PESV group with the chemotherapy combination group compared with the positive control, the expression of Dll4 and Notch1 in the former was no significant difference than the latter in tumor tissue (P≥0.05).Conclusion1. PESV inhibit the growth of Lewis lung cancer.2. PESV can affect tumor angiogenesis.3. The mechanism of PESV affected on tumor may by Dll4/Notch1 pathway of the tumor microenvironment.