Curcumin suppresses lymphatic vessel density in an in vivo human gastric cancer model

This study aimed to assess the effects of curcumin on lymphatic vessel density (LVD) in an in vivo model of gastric cancer using the gastric cancer cell line, SGC-7901. Gastric tumor-bearing nude mice were treated with saline or 40, 80, or 160 mg kg(-1) day(-1) curcumin for 8 weeks. The results indicated that the tumor volumes were significantly lower in mice treated with 80 and 160 mg kg(-1) day(-1) curcumin as compared with that of the control group (both P<0.001). In addition, both 80 and 160 mg kg(-1) day(-1) curcumin significantly reduced LVD (both P<0.01). Although immunohistochemical analysis showed that curcumin did not significantly alter the expression of prospero homeobox 1 (Prox-1), podoplanin, and vascular endothelial growth factor receptor 3 (VEGFR-3), 160 mg kg(-1) day(-1) curcumin significantly decreased the expression of Prox-1, podoplanin, and VEGFR-3 levels as detected by Western blot analysis (P <= 0.03). Downregulation of lymphatic vessel endothelial receptor 1 (LYVE-1), Prox-1, podoplanin, and VEGFR-3 mRNA expression by curcumin was also detected (all P<0.05). Furthermore, the apoptosis rates of tumor cells increased with curcumin in a concentration-dependent manner (all P<0.001). Thus, curcumin may inhibit gastric cancer lymph node metastasis. Our findings provide theoretical evidence and an experimental basis for further analysis of the clinical application of curcumin in the therapy of gastric cancer.