Effects of NM-3 on Lymphatic Vessel Density and Vascular Endothelial Growth Factor of Colon Cancer in Orthotopic Implantation Model of a Severe Combined Immune Deficiency Mice

The molecular mechanisms involved colon cancer tumorigenesis and development of colon cancer remain unclear. The aim of this study is to explore the inhibitive effects of NM-3 on lymphatic vessel density and vascular endothelial growth factor of micrometastatic lesion of orthotopic implantated colon cancer in the severe combined immune deficiency (SCID) nude mice. Human colon cancer SW1116 cells were orthotopically implantated into the colon of the nude mice. Twenty-eight SCID nude mice were randomly divided into four groups (7 mice for each group) after one week feeding and then the nude mice were treated with carboplatin and NM-3 via intraperitoneal injection twice a week for 8 weeks. The mice were sacrificed after 8 weeks and the vascular endothelial growth factor-C (VEGF-C), VEGF-D, VEGF-R-3 and lymphatic vessel density (LVD) were analyzed using immunohistochemistry staining assay. LVD in NM-3 treated mice was significantly lower than that of control (normal saline treated) mice. The expression of VEGF-C, VEGF-D, and VEGF-R-3 and the expression of mRNA of VEGF-C, VEGF-D, and VEGF-R-3 in NM-3 treated mice were significantly lower than that of control mice. The NM-3 inhibited the growth of colon cancer in the SCID mice of orthotopic implantatation model, and this effect may be related to the inhibitive effects of NM-3 on the lymphangiogenesis and vascular endothelial growth factor in colon cancer. NM-3 and carboplatin played a synergistic role in inhibiting lymphangiogenesis of human colon cancer in SCID nude mice and the further investigation of molecular mechanisms involved in colon cancer metastasis will provide an important evidence for understanding of lymphangiogenesis of human colon cancer.