Gamabufogenin and Liver-Neoplasms

Hepatocellular carcinoma (HCC) is a malignant tumor with a high rate of recurrence and a poor prognosis. Here, we investigated the effect and the potential antitumor mechanism of Gamabufotalin (CS-6) against HCC. Our results show that CS-6 strikingly reduced cell viability, inhibited colony formation, and promoted apoptosis in Hep3B and Huh7 cells. In vivo, CS-6 inhibited HCC xenograft tumor growth with no toxicity to normal tissues. Mechanistically, we found that CS-6 could induce cytoprotective autophagy through the mTOR-ULK1 signaling pathway through downregulation of p62 and upregulation of LC3 II/LC3 I. Meanwhile, CS-6 activated caspase-3 and PARP mediated apoptosis, and the caspase inhibitor Z-VAD-FMK blocked the CS-6-induced cell death in HCC cells. Moreover, autophagy and apoptosis were found to have antagonistic effects in Hep3B and Huh7 cells. Both the autophagy inhibitor chloroquine (CQ) and the mTOR activator MHY1485 blocked autophagy and further enhanced CS-6-induced apoptosis. Taken together, we demonstrated for the first time that CS-6 promotes apoptosis and cytoprotective autophagy through the mTOR signaling pathway in HCC, which proposes a novel strategy for HCC therapy.

Topics: Apoptosis; Autophagy; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Humans; Liver Neoplasms; Signal Transduction; TOR Serine-Threonine Kinases

QSAR analysis has been used to identify the essential structural requirements for increasing the inhibitory activities of selected bufadienolides from the Chinese drug Ch'an Su (and other sources) against the primary liver carcinoma cell line PLC/PRF/5 (PLC) and the derived colchicine-resistant line (COL). The variable substituent domain of the proposed pharmacophore of the bufadienolides was investigated using a Comparative Molecular Field Analysis (CoMFA) approach. A model with considerable predictive ability was obtained. In addition, the CoMFA results agreed well with the pharmacophore bufadienolide model for the parent PLC line proposed earlier.

Topics: Antineoplastic Agents; Bufanolides; Colchicine; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Humans; Liver Neoplasms; Models, Molecular; Quantitative Structure-Activity Relationship; Tumor Cells, Cultured