Nanosized zingerone-triggered anti-angiogenesis contributes to tumor suppression in human hepatocellular carcinoma

Abstract

Suppression of tumor angiogenesis has become one of the most important means of antitumorigenesis, tumor development, and metastasis. Therefore, developing novel anti-angiogenic agents for tumor therapeutics is an important issue. Phytochemicals possess numerous effective antitumorigenesis properties and can inhibit cell growth and metastasis and are thus regarded as promising candidates for use as chemopreventive agents and chemotherapeutic adjuvants. In our previous study, we fabricated phytochemical-derived carbon dot-zingerone nanoparticles (zingerone NPs) and demonstrated their potent antitumorigenesis in vivo and in vitro against human hepatocellular carcinoma (HCC). In this study, we further validated the roles of zingerone NPs in antitumor angiogenesis. Here, two human endothelial cell lines, EA.hy293 and HUVECs, and two hepatocellular carcinoma cell lines, SK-Hep-1 and Huh7, were utilized to investigate the effects of zingerone NPs on antitumor angiogenesis. Our data demonstrated that zingerone NPs significantly inhibited the viability of human endothelial EA.hy296 cells and HUVECs. Moreover, zingerone NPs revealed superior anti-angiogenic effects on cell invasiveness, in vitro tube formation, and ex vivo rat aorta ring angiogenesis. By verifying zingerone NP-mediated molecular mechanisms of anti-angiogenesis, we found that zingerone NPs significantly decreased the protein expression of VEGF and VEGFR in endothelial cells. Moreover, zingerone NPs downregulated VEGF expression in hepatoma cell lines. The hepatoma Huh7 xenograft model also showed that zingerone NPs markedly attenuated tumor angiogenesis through inhibition of VEGF and CD31 expression. In addition, we also demonstrated that zingerone NPs significantly suppressed tumorigenesis by inhibiting VEGF-mediated PI3K/Akt/mTOR axis signaling and Akt/eNOS signaling in endothelial and hepatocellular carcinoma cells. These results suggest that the phytochemical-derived carbon dots-zingerone NPs possess superior characteristics in antitumor angiogenesis and antitumorigenesis. Altogether, our study provides recent advances in zingerone NPs as anti-angiogenic agents to enhance chemopreventive and anticancer effects for future tumor therapeutic strategies.