RESUMO
Hepatocellular carcinoma (HCC) has become the sixth highly diagnosed cancer and the fourth main reason of cancer deaths worldwide. HuaChanSu, an extract from dried toad skin, exhibits good anticancer effects and has been widely used in the treatment of liver cancer. The reprogramming of glucose metabolism is one remarkable feature of hepatocellular carcinoma, and the effects of HuaChanSu on the abnormal glucose metabolism of cancer cells have not been elucidated. In our study, we investigate the effects of HuaChanSu on glucose metabolism of hepatocellular carcinoma cells and tumor growth in vivo. The results show that HuaChanSu inhibits the tumor growth of hepatoma H22-bearing mice and prolongs the survival time of tumor-bearing mice, additionally, HuaChanSu has no obvious adverse effects in these mice. In vitro, HuaChanSu restrains the proliferation, induces apoptosis and cell cycle arrest of human hepatoma cells. HuaChanSu also promotes ROS production and causes mitochondrial damage. Furthermore, HuaChanSu inhibits glucose uptake and lactate release in human hepatoma cells. Mechanistically, we find that HuaChanSu downregulates Hexokinase-2 (HK2) expression, and using RNA interference, we confirm that HuaChanSu suppresses the growth of HepG2 cells by interfering with glucose metabolism through downregulation of Hexokinase-2. However, knockdown of Hexokinase-2 has no obvious effect on the proliferation of SK-HEP-1 cells, although glucose uptake and lactate release are reduced in siHK2-transfected SK-HEP-1 cells, subsequently, we illustrate that two human hepatoma cell lines exhibit glucose metabolism heterogeneity, which causes the different cell proliferation responses to the inhibition of Hexokinase-2. Taken together, our study indicates that HuaChanSu could inhibit tumor growth and interfere with glucose metabolism via suppression of Hexokinase-2, and these findings provide a new insight into the anti-hepatoma mechanisms of HuaChanSu and lay a theoretical foundation for the further clinical application of HuaChanSu.
Assuntos
Carcinoma HepatocelularRESUMO
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.
