LAUSR

Purpose To explore the effect of dextran sulfate (DS) on the angiogenesis, invasion, and migration of gastric cancer cells through interfering with the polarization of M2-type macrophages. Methods The infiltration of M2-type macrophages and microvascular density in gastric cancer and paracancerous tissues were analyzed using immunohistochemistry and immunofluorescence. The effects of DS on M2-type macrophages and the angiogenesis in metastatic tumors were investigated in the nude mice intraperitoneal metastasis model using immunohistochemistry and western blot. The differentiation and polarization of macrophage, immunocytochemistry, western blot, ELISA, and transwell migration assay were used to evaluate the effect of DS on the polarization of macrophage, Results The infiltration of M2-type macrophages and the microvascular density were highly expressed and positively correlated in the human gastric cancer tissue. DS can significantly inhibit the intraperitoneal metastases of gastric cancer in nude mice, and reduce the infiltration of M2-type macrophages and the angiogenesis in intraperitoneal metastatic tumors. Moreover, DS can prevent the polarization of M0-type macrophages to M2 type, reduce the expression of M2-type macrophage markers (CD206, CD163, IL-10, and Arg-1), down-regulate the IL-6-STAT3 pathway, and inhibit the recruitment capability of M2-type macrophages. Finally, the co-culture experiment showed that DS significantly reduced the promoting effects of M2-type macrophages on the angiogenesis, invasion, and migration of gastric cancer cells, as well as down-regulated the related expressions of proteins (VEGF, N-cadherin, MMP-2 and Vimentin) in gastric cancer cells. Conclusion DS can reduce the infiltration of M2-type macrophages and the microvascular density in intraperitoneal metastases of gastric cancer in nude mice, and inhibit the angiogenesis, invasion, and migration of gastric cancer cells by interfering with the polarization of M2-type macrophages through repression of the IL-6/STAT3 signaling pathway.