Apoptotic effects of mahanine on human leukemic cells are mediated through crosstalk between Apo-1/Fas signaling and the Bid protein and via mitochondrial pathways

Biochem Pharmacol. 2010 Feb 1;79(3):361-72. doi: 10.1016/j.bcp.2009.09.007. Epub 2009 Sep 12.

Abstract

Apo-1 (Fas/CD95), a cell surface receptor, triggers apoptosis after binding to its physiological ligand, Apo-1L (FasL/CD95L). This study reports that mahanine, purified from the leaves of Murraya koenigii, has a dose- and time-dependent anti-proliferative activity in acute lymphoid (MOLT-3) and chronic myeloid (K562) leukemic cell lines and in the primary cells of leukemic and myeloid patients, with minimal effect on normal immune cells including CD34(+) cells. Leukemic cells underwent phosphatidylserine externalization and DNA fragmentation, indicating mahanine-induced apoptosis. An increase in reactive oxygen species suggests that the mahanine-induced apoptosis was mediated by oxidative stress. A significant drop in the Bcl2/Bax ratio, the loss of mitochondrial transmembrane potential as well as cytochrome c release from the mitochondria to the cytosol suggested involvement of the mitochondrial pathway of apoptosis. Cytochrome c release was followed by the activation of caspase-9, caspase-3 and caspase-7, and cleavage of PARP in both MOLT-3 and K562 cells. In MOLT-3 cells, formation of the Fas-FasL-FADD-caspase-8 heterotetramer occurred, leading to the cleavage of Bid to its truncated form, which consequently resulted in formation of the mitochondrial transmembrane pore. The incubation of MOLT-3 cells with mahanine in the presence of caspase-8 inhibitor or FasL-neutralizing NOK-2 antibody resulted in the decrease of mahanine-induced cell death. Mahanine was also a potent inhibitor of K562 xenograft growth, which was evident in an athymic nude mice model. In summary, these results provide evidence for involvement of the death receptor-mediated extrinsic pathway of apoptosis in the mahanine-induced anticancer activity in MOLT-3 cells, but not in K562 cells, which are deficient in Fas/FasL.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemistry
  • Alkaloids / pharmacology*
  • Animals
  • Antineoplastic Agents, Phytogenic / chemistry
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • BH3 Interacting Domain Death Agonist Protein / metabolism*
  • Carbazoles / chemistry
  • Carbazoles / pharmacology*
  • Cell Line, Tumor
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Infant, Newborn
  • K562 Cells
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Mitochondria / drug effects*
  • Mitochondria / physiology
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology
  • Plant Leaves
  • Receptor Cross-Talk / drug effects*
  • Receptor Cross-Talk / physiology
  • Signal Transduction / drug effects*
  • Signal Transduction / physiology
  • Xenograft Model Antitumor Assays / methods
  • fas Receptor / physiology*

Substances

  • Alkaloids
  • Antineoplastic Agents, Phytogenic
  • BH3 Interacting Domain Death Agonist Protein
  • Carbazoles
  • Plant Extracts
  • fas Receptor
  • mahanine