Cepharanthine activates caspases and induces apoptosis in Jurkat and K562 human leukemia cell lines

• Published in: Journal of cellular biochemistry 2001-01, Vol.82 (2), p.200-214
• Main Authors: Wu, Jianghong, Suzuki, Haruhiko, Zhou, Yan-Wen, Liu, Wei, Yoshihara, Motoi, Kato, Masashi, Akhand, Anwarul A., Hayakawa, Akemi, Takeuchi, Kei, Hossain, Khaled, Kurosawa, Mio, Nakashima, Izumi
• Format: Article
• Language: English
• Subjects: Alkaloids - pharmacology; Amino Acid Chloromethyl Ketones - pharmacology; Antineoplastic Agents, Phytogenic - pharmacology; apoptosis; Apoptosis - drug effects; Apoptosis Regulatory Proteins; Bcr-Abl; Benzoquinones; Benzylisoquinolines; BH3 Interacting Domain Death Agonist Protein; Carrier Proteins - metabolism; caspase; Caspases - metabolism; cepharanthine; Cysteine Proteinase Inhibitors - pharmacology; DNA Fragmentation; Drug Screening Assays, Antitumor; Drug Synergism; Enzyme Activation - drug effects; Enzyme Inhibitors - pharmacology; Fas; Fas Ligand Protein; fas Receptor - physiology; Fusion Proteins, bcr-abl - antagonists & inhibitors; Fusion Proteins, bcr-abl - metabolism; herbimycin A; human leukemia cells; Humans; Intracellular Membranes - drug effects; Intracellular Membranes - ultrastructure; Jurkat Cells - cytology; Jurkat Cells - drug effects; Jurkat Cells - enzymology; K562 Cells - cytology; K562 Cells - drug effects; K562 Cells - enzymology; Lactams, Macrocyclic; Lamin Type B; Lamins; Membrane Glycoproteins - physiology; Mitochondria - drug effects; Mitochondria - ultrastructure; Neoplasm Proteins - metabolism; Nuclear Proteins - metabolism; Poly(ADP-ribose) Polymerases - metabolism; Protein Serine-Threonine Kinases; Proteins - metabolism; Proto-Oncogene Proteins - antagonists & inhibitors; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-akt; Quinones - pharmacology; Rifabutin - analogs & derivatives; signal transduction
• ISSN: 0730-2312; 1097-4644
• DOI: 10.1002/jcb.1155

Cepharanthine (CEP) is a known membrane stabilizer that has been widely used in Japan for the treatment of several disorders such as anticancer therapy‐provoked leukopenia. We here report that apoptosis was induced by low concentrations (1–5 μM) of CEP in a human leukemia T cell line, Jurkat, and by slightly higher concentrations (5–10 μM) in a human chronic myelogenous leukemia (CML) cell line K562, which expresses a p210 antiapoptotic Bcr‐Abl fusion protein. Induction of apoptosis was confirmed in both Jurkat and K562 cells by DNA fragmentation and typical apoptotic nuclear change, which were preceded by disruption of mitochondrial membrane potential and were induced through a Fas‐independent pathway. CEP treatment induced activation of caspase‐9 and ‐3 accompanied by cleavage of PARP, Bid, lamin B1, and DFF45/ICAD in both Jurkat and K562 cells, whereas caspase‐8 activation and Akt cleavage were observed only in Jurkat cells. The CEP‐induced apoptosis was completely blocked by zVAD‐fmk, a broad caspase inhibitor. Interestingly, CEP treatment induced remarkable degradation of the Bcr‐Abl protein in K562 cells, and this degradation was prevented partially by zVAD‐fmk. When used in combination with a nontoxic concentration of herbimycin A, lower concentrations (2–5 μM) of CEP induced obvious apoptosis in K562 cells with rapid degradation or decrease in the amount of Bcr‐Abl and Akt proteins. Our results suggest that CEP, which does not have bone marrow toxicity, may possess therapeutic potential against human leukemias, including CML, which is resistant to anticancer drugs and radiotherapy. J. Cell. Biochem. 82: 200–214, 2001. © 2001 Wiley‐Liss, Inc.