Research On The Time Window Of Vascular Normalization Marked By Serum TSP-1 In Human Colon Carcinoma Induced By Recombinant Human Endostatin

Objective Transient anti-angiogenic therapy can facilitate the normalization of tumor vessels.Firstly,to induce the tumor vascular normalization window in human colorectal by recombinant human endostatin(endostar),and analysis the relationship to plasma thrombospondin 1(TSP-1),then research its probably mechanism.Methods To build the model by the human colorectal cancer,SW620(5 x 106 cells/mouse)which were subcutaneously injected into the right groin of BALB/c female(nu/nu)mouse(4 weeks old).Before modeling,6 mice were randomly selected for plasma TSP-1acquisition as the basic line.When the tumor size was 75mm~3,another 3 mice were randomly selected to collect plasma.When the tumor size was up to 100mm~3-150mm~3,drug intervention was applied(as 0 days).The experimental group was intraperitoneally injected with recombinant human endostatin(5 mg/kg).The control group was injected with the same amount of normal saline(NS).The drug was administered continuously for 4 days,then administered every 2 days to 12 days.Plasma and nude mice tumor tissues and liver and kidney tissues were collected at 0,2,4,6 and 12 days respectively.The time window of normalization of tumor vasculature and oxygen content in tumor tissues were analyzed by immunohistochemistry,immunofluorescence and HE staining.To detect organ toxicity of liver and kidney tissue by HE staining,and further analyzes the relationship between the changes in plasma TSP-1 and the tumor vascular normalization window of human colorectal cancer.Results Anti angiogenesis treatment by Endostar,tumor vascular maturity(perivascular cell marker alpha SMA+/vascular marker CD31+)was significantly increased in 4 to 6 days compared to the other time period of experimental group(P<0.001),the control group showed no tumor vascular maturity variation.In the control group,as time goes on,internal hypoxia and necrosis of tumor tissue gradually increased(P<0.001),But in the experimental group,the hypoxia improved and necrosis decreased in the tumor tissue from 4 day to 6 day compared to 0day and 12 day,especially on the 6 day(P<0.001).Meanwhile,by analyzing the expression of hypoxia inducible factor HIF-1αin tumor tissue,the expression level in the experimental group on the 4 day and the 6 day was significantly decreased compared to that in 0 day and12day(P<0.05).There was a correlation between plasma TSP-1 and time window of tumor vasculature normalization,and plasma TSP-1 concentration decreased in time window,which was statistically significant compared to normal saline group(P<0.05).At the same time,the liver and kidney structure of mice was not significantly changed at the end of the drug use.Conclusions The endostar can induces the tumor vasculature normalization in human colorectal cancer.Plasma TSP-1 increased in human colorectal cancer when increased its hypoxia,and decreased in the time window of hypoxia improved.It can be used as a new biomarker to mark the normalization time window of tumor vasculature.