ABSTRACT
The etiology for liver cancer has been clearly defined. Unfortunately, therapeutic approaches for liver cancer are rather limited, and liver cancer is insensitive to chemotherapy and radiotherapy. Traditional Chinese medicine (TCM) has become a promising strategy for cancer treatment as TCM elicits broad spectrum anticancer activity. In the present study, we evaluated the anticancer efficacy of AB4, an extract from the medical herb Pulsatilla chinensis (Bunge) Regel, in liver cancer in vitro and in vivo. We found that AB4 readily dose and timedependently inhibited liver cancer HepG2 and Huh7 cell proliferation and colony formation. Western blot and flow cytometry analyses suggested that AB4 treatment induced liver cancer cell apoptosis. Moreover, these findings could be readily recaptured in vivo, in which the AB4 regimen resulted in tumor suppression and cancer cell apoptosis in xenograft tumorbearing nude mice. Importantly, we noted that treatment with a Notch signaling inhibitor DAPT produced very similar anticancer efficacy in both HepG2 and Huh7 cell lines, and administration of DAPT also efficiently suppressed HepG2 xenograft outgrowth. To this end, we anticipated that AB4 and DAPT may act on the same signaling pathway, probably through inhibition of the Notch pathway. Indeed, we found decreased expression of Notch1 protein, as well as downstream targets Hes1 and Hey1, after AB4 treatment. Immunohistochemistry analysis further confirmed the suppression of Notch signaling in HepG2 xenograftbearing mice. Taken together, our study highlighted the anticancer efficacy of AB4 in liver cancer. We also provided preliminary data showing Notch as a therapeutic target of AB4. It would be interesting to investigate the anticancer efficacy of AB4 in other types of cancer with elevated Notch activity.
Subject(s)
Drugs, Chinese Herbal/pharmacology , Liver Neoplasms/drug therapy , Pulsatilla/chemistry , Animals , Apoptosis/drug effects , Dose-Response Relationship, Drug , Drugs, Chinese Herbal/therapeutic use , Hep G2 Cells , Humans , Liver Neoplasms/pathology , Male , Mice , Receptors, Notch/antagonists & inhibitors , Receptors, Notch/metabolism , Signal Transduction/drug effects , Specific Pathogen-Free Organisms , Xenograft Model Antitumor AssaysABSTRACT
Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide and novel therapeutic approaches are urgently required. Anemoside B4 (AB4) is a compound extracted from Pulsatilla chinensis (P. chinensis). Previous studies have indicated that P. chinensis extract P. chinensis saponins has anti-cancer activity. However, the pharmacological effect of AB4 in cancer is largely unknown. In this study, we investigated the anti-cancer efficacy of AB4 in HCC. We used CCK-8 assay and colony formation assay to evaluate the cytotoxicity of AB4 and found that this agent markedly inhibited SMMC7721 cell proliferation. By using a panel of morphological and molecular experiments, we reported that AB4 induced HCC SMMC7721 cell apoptosis and autophagy. Notably, AB4 treatment acts on the Bcl-2-caspase-3 pathway and Beclin-1-LC3-p62 pathway, thereby regulates both apoptosis and autophagy. Finally, we showed that AB4-induced apoptosis and autophagy converges at the PI3K/Akt/mTOR signaling. AB4 treatment inhibits this signaling transduction pathway and leads to HCC cell death. Collectively, our study highlighted the anti-cancer efficacy of AB4 and suggested that AB4 might be a novel way to treat HCC.
