Initiation of growth arrest and apoptosis of MCF-7 mammary carcinoma cells by tributyrin, a triglyceride analogue of the short-chain fatty acid butyrate, is associated with mitochondrial activity.
We investigated the effects of tributyrin, a triglyceride analogue of the short-chain fatty acid butyrate and an approved food additive, establishing induction of growth arrest and apoptosis of MCF-7 human mammary carcinoma cells. Transient increased mitochondria-associated bax, dissipation of the mitochondrial membrane potential (delta(psi)m), and caspase-3-independent cleavage of poly(ADP-ribose) polymerase are evident as early as 4 h after treatment of cells with tributyrin. These events are followed by the transient accumulation of mitochondrial cytochrome c in the cytosol and, finally, the generation and accumulation of cells with subdiploid DNA content. During the period in which mitochondria-associated bax levels are elevated, the delta(psi)m is disrupted, and cytochrome c is detected in the cytosol, we show induction of p21WAF1/Cip1 in the absence of increased p53 and arrest of cells in G2-M. Thus, early mitochondria-associated events may play a key role in initiating and/or coordinating tributyrin-mediated growth arrest and apoptosis of wild-type p53 MCF-7 cells. Because effective chemoprevention has been associated with agents that restore or maintain the balance between proliferation and apoptosis, dietary tributyrin, particularly during the critical period of mammary gland development, may be a promising chemopreventive agent.
Heerdt
B G
BG
Albert Einstein Cancer Center, Bronx, New York 10467, USA.
Houston
M A
MA
Anthony
G M
GM
Augenlicht
L H
LH
D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000473:pathology* / Q000517:prevention & control; D002453:Cell Cycle / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000502:physiology; D003574:Cytochrome c Group / Q000378:metabolism; D005260:Female; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D014220:Trialkyltin Compounds / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D003574:Cytochrome c Group; D014220:Trialkyltin Compounds; D016159:Tumor Suppressor Protein p53; C011559:tributyltin; D011065:Poly(ADP-ribose) Polymerases