MiR-486-5p Attenuates Tumor Growth And Lymphangiogenesis By Targeting Neuropilin-2 In Colorectal Carcinoma

Objective: Previous experiments have show that miRNA-486-5p can inhibit the ability of colorectal carcinoma cell SW620, included proliferation and migration and also can accelerate its apoptosis. This experiment aims to investigate the effect of miRNA-486-5p on the growth of human colorectal cancer xenograft in nude mice and to explore the possible mechanism of the action.Methods: Fifteen nude mice were randomly divided into three groups, the experimental group, the negative control group and the blank control group, each group has 5 mice. The SW620 cell was inoculated subcutaneously into nude mice to establish the model of human colorectal cancer xenografts. peritumora inject miRNA-486-5p overexpression plasmid, blank vector or PBS every 3 days,comparing the volume and weight of subcutaneous tumor each group of inocuLated mice, which were sacrificed after been infected 3 weeks. Immunohistochemistry were used to measure the expression of neuropilin-2 (NRP2) and lymphatic vessel density.Results : The growth rate of tumor in the experimental group was significantly lower than the negative control group and the blank control group; after 21 days, the size of transplanted tumor in the experimental group was (0.32 ± 0.12) cm3,the negative control group was (0.77 ± 0.31) cm3, blank control group was (0.82 ± 0.18)cm3. The average mass of the experimental group was significantly smaller than the other two groups (P = 0.006 < 0.05); the experimental group tumor mass was (0.40±0.08) g, significantly lower than the negative control group (0.75 ± 0.18) g and the blank group (0.79 ± 0.18) g (P = 0.008 < 0.05). Lymphatic vessel density in the experimental group is (1.80 ± 0.84) which is lower than negative control group(6.90 ± 0.70) and blank group (7.20 ± 0.84). Compared with the expression of NRP2 in other groups, the level in the experimental group was declined (P = 0.000 < 0.05).Conclusion: Colorectal cancer cell line SW620 transfected with miRNA-486-5p in nude mice can be suppressed not only in tumor growth but also includ lymphangiogenesis, and the which may be by reducing the expression of NRP2 implemented.