A network pharmacology approach to investigate the anticancer mechanism of cinobufagin against hepatocellular carcinoma via downregulation of EGFR-CDK2 signaling.

Hepatocellular carcinoma (HCC) is one of the deadliest cancers with high mortality and poor prognosis, and the investigation on new approaches and effective drugs for HCC therapy is of great significance. In our study, we demonstrate that treatment with cinobufagin, a natural compound isolated from traditional chinese medicine Chansu, reduces proliferation and the colony formation capacity of the human hepatoma cells in vitro, in addition, cinobufagin induces mitotic arrest in human hepatoma cells. The results of a network pharmacology-based analysis show that EGFR, MAPK1, PTK2, CDK2, MAPK3, ESR1, CDK1, PRKCA, AR, and CSNK2A1 are the key targets involved in the anti-tumor activities of cinobufagin, additionally, several signaling pathways such as proteoglycans in cancer, pathways in cancer, HIF-1 signaling pathway, VEGF signaling pathway, ErbB signaling pathway, and PI3K-AKT signaling pathway are identified as the potential pathways involved in the inhibitory effects of cinobufagin against HCC. Furthermore, at the molecular level, we find that cinobufagin decreases EGFR expression and CDK2 activity in human hepatoma cells. Inhibition of EGFR or CDK2 expression could not only suppress the growth of tumor cells but also enhance the inhibitory effects of cinobufagin on the proliferative potential of human hepatoma cells. We also demonstrate that EGFR positively regulates CDK2 expression. Furthermore, EGFR inhibitor gefitinib or CDK2 inhibitor CVT-313 synergistically enhances anticancer effects of cinobufagin in human hepatoma cells. Taken together, these findings indicate that cinobufagin may exert antitumor effects by suppressing EGFR-CDK2 signaling, and our study suggests that cinobufagin may be a novel, promising anticancer agent for the treatment of HCC.

[Change patterns of protective enzyme activities in pre-diapause, diapause, and post-diapause larvae of Sitodiplosis mosellana Gehin].

The activities of protective enzymes peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in pre-diapause, diapause, and post-diapause larvae of Sitodiplosis mosellana Gehin were determined by using protective enzyme testing kits. The results indicated that the activities of the three protective enzymes showed a decreasing trend from pre-diapause to early diapause larvae. In one-year cycle, the SOD and CAT activities of diapause larvae had the same responses to environmental temperature, i.e., increased at lower temperature but decreased at higher temperature, while POD activity was related to both environmental temperature and the development situation of the larvae. A similar seasonal variation trend was observed in the three protective enzymes of both no-cocooned and cocooned larvae in one-year cycle. The three protective enzyme activities of no-cocooned larvae were higher than those of cocooned larvae at the same diapause stage. No significant difference of the three protective enzyme activities was found between 1st and 2nd year diapause larvae. The activities of the three protective enzymes increased gradually with the development of post-diapause larvae.