The Influence Of Interstitial Brachytherapy With ¹²⁵I Seeds On VEGF-C And COX-2 Expressions Of Lewis Lung Carcinoma In C57BL Mice

Objective:To explore the influence of interstitial brachytherapy with(125)I seeds on VEGF-C and COX-2 expressions of lewis lung carcinoma in C57BL mice. Methods:Lewis lung cell(LLC) was planted intomodelmice of C57BL,in each mouse of the treatment group(n=17),two BT-125-IModel ¹²⁵I seeds with apparent activity of 9.25MBq were implanted into the tumor;whereas in each mouse of the control group(n=16) two dummy seeds were implanted.The mice survival rates of both groups were recorded after 21 days.The tumorweights and dimensions of survived mice were measured,and the tumor volume inhibition rate was calculated.T-test was performed to compare differences of tumor weights and volumes between these two groups.Routine pathological slides of tumor tissue were observed under light microscope.The expression of VEGF-C and COX-2 was detected by immunohist ochemical method.Results:The survival rates were 82.35%in the treatment group and 62.50%in the control group,the difference had no statistical significance(χ²=1.6368,P>0.05).The tumor volume inhibition rate was 70.98%.Pathological examination showed degeneration and necrosis of cancer cell at the site nearby the seed in the treated group,but the tumor cells alive were still presented nearby the seed in the control group.The expressions of COX-2(χ²=6.523,P<0.01) and VEGF-C(χ²=9.447 P<0.01) in the treated group were highter than those in the control group.Conclusion:The interstitial brachytherapy with ¹²⁵I seeds could inhibit the growth of lewis lung cacinoma of mice.The possible mechanism may be that ¹²⁵I interstitial brachytherapy can inhibit the activity of COX-2,by which expression of VEGF-C and tumor angiogenesis and metastasis are decreased.