Effect Of Recombinant Human Endostatin Combined With Paclitaxel Under Different Delivery Order On Serum HIF-1? And VEGF Expression In Mice Xenograft Tumor Model

Objective: Anti-angiogenesis is the most important thing in anti-tumor.Recombinant human endostatin(rh-endostatin) is China first anti-ang iogenesis targeted drugs, It is separated and purificated from e. coli engineering bacterium fermentation, and added nine amino acid residues in the original En dostatin. make its traits more stable and higher activity. The anti angiogenesis ef fect of rh-endostatin could inhibit the proliferation and metastasis of tumor cells though reducing the migration and inducing apoptosis of the endothelial cells.Studies have reported that when rh-endostatin combined with chemotherapy dr ug, drug delivery sequence is different, the curative effect is also different. Seru m vascular endothelial growth factor(vascular endothelial groth factor, VEGF),hypoxia inducing factor(hypoxia inducible factor 1 alpha and alpha HIF- 1) hi gh level expression in a wide variety of tumor is closely related to tumor growt h and metastasis, but on the relationship with the antiangiogenesis effect is less study. This study was to observe the effect of recombinant human endostatin(r h-endostatin)combined with paclitaxel(PTX)under different delivery order on serum vascular endothelial groth factor(VEGF)and hypoxia inducible fac tor-1a(HIF-1a)expression in mice xenograft model,and to explore the application value in anti-angiogenesis therapy.Methods: Subcutaneous xenograft tumor models of lung carcinoma Lewis cells were established in C57/BL mice, and the mice were randomly divided int o six groups:(1) Control group(intraperitoneal injection with 0.9% Na Cl,d1-d14);(2) PTX group(intraperitoneal injection with PTX,d1);(3) Rh-endostati n group(intraperitoneal injection with rh-endostatin,d1-d14);(4)Combined gro up1(intraperitoneal injection with rh-endostatin d1-d14 + PTX d1);(5)Combin ed group2(intraperitoneal injection with rh-endostatin d1-d14 + PTX d4);(6)C ombined group 3(intraperitoneal injection with rh-endostatin,d1-d14 + PTX d7). Then tumor volume was measured dynamically. The serum VEGF and HIF-1? levels of the mice in each group were detected by enzyme-linked immunosor bent assay(ELISA)at 2nd,5th,8th,12 th,17th. As well as the microvascular densit y(MVD) and ?-smooth muscle actin(?-SMA) of xenograft tumor tissues were observed by immunohistochemistry. The concentration of PTX in xenograft tu mor tissues were detected by high-performance liquid chromatography(HPLC).Results: In the whole experiment process, the mental status and diet of mi ce are normal, no obvious thin and systemic adverse reactions were observed. S ince the second day of drug administration, the serum VEGF levels in rh-endost atin group and three combination groups was significantly lower than that in the control group(all P < 0.05). Since the fifth day of drug administration, HIF-1? levels in rh-endostatin group and three combination groups were also decreased significantly(all P < 0.05). On the fifth and eighth days of drug administration,MVD in rh-endostatin group and 3 combination groups was lower than that in t he control group(all P < 0.05), while the expression level of ?-SMA was signifi cantly increased(all P < 0.05). As compared with the other two combination gr oups, the most significant differences in expressions of serum VEGF, HIF-1? w ere seen between combination group 2 and the control group(all P < 0.01). Furt hermore, the concentration of PTX in xenograft tumor tissues in combination gr oup 2 was significantly higher than those in the other two combination groups(both P < 0.05), and the size of xenograft tumor was significantly smaller than t hose of the other combination groups(both P < 0.05).Conclusion: Single degree of antiangiogenesis effect briefly, Transplanted tumor mice serum VEGF, HIF-1a level change is closely related to the microva scular structure change and anti-tumor effect, The abnormal levels of serum HI F-1? and VEGF showed similar changes with tumor tissues MVD and ?-SMA expression but earlier than the change. through dynamic monitor the change of serum VEGF, HIF-1a can earlier find tumor microvascular changes in the struct ure that provide PTX a best point in time.So as to achieve the best effect of tu mor suppression.Serum HIF-1? and VEGF could be a promising indicator for monitoring the microvascular structure change and predict anti-tumor effect.