Pyrrolidine dithiocarbamate inhibition of luteolin-induced apoptosis through up-regulated phosphorylation of Akt and caspase-9 in human leukemia HL-60 cells.

Abstract

Previously, we observed that luteolin effectively inhibited cell growth and induced apoptosis in HL-60 cells. In that study, we also explored the modulatory effects and molecular mechanisms of pyrrolidine dithiocarbamate (PDTC) on the cytotoxicity of luteolin to HL-60 cells. In this study, we found that PDTC was able to inhibit luteolin-induced cell apoptosis in a dose-dependent manner. When HL-60 cells were treated with PDTC for 0.5 h before 60 microM luteolin treatment, the DNA ladder disappeared. Moreover, flow cytometry showed that PDTC had dose dependently decreased the percentage of apoptotic HL-60 cells and had not interfered with luteolin's ability to change the mitochondrial membrane potential or its ability to trigger the release of cytochrome c to cytosol. Detection by Western blotting, however, did show that PDTC had interfered with luteolin's ability to cleave poly(ADP-ribose)polymerase and DNA fragmentation of factor-45. Three hours after the PDTC-pretreated HL-60 cells were treated with 60 microM luteolin, the product cleaved from Akt started to appear. Therefore, not only was PDTC able to stop the apoptosis of HL-60 cells treated with luteolin, it was also found to increase phosphorylation of Akt and caspase-9. These results suggest that in the luteolin-induced apoptotic pathway, phosphorylation of procaspase-9 by survival signals might play an important role in the ultimate fate of HL-60 cells.

• Authors: An-Chin Cheng, Tzou-Chi Huang, Ching-Shu Lai, Jen-Min Kuo, Ying-Tang Huang, Chih-Yu Lo, Chi-Tang Ho, Min-Hsiung Pan
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) Vol. 54 Issue 12 Pg. 4215-21 (Jun 14 2006) ISSN: 0021-8561 [Print] United States
• PMID: 16756349 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antioxidants
• Apoptosis Regulatory Proteins
• Proteins
• Pyrrolidines
• Thiocarbamates
• caspase-activated DNase inhibitor
• pyrrolidine dithiocarbamic acid
• Cytochromes c
• Poly(ADP-ribose) Polymerases
• Proto-Oncogene Proteins c-akt
• CASP9 protein, human
• Caspase 9
• Caspases
• Luteolin

Topics

• Antioxidants (pharmacology)
• Apoptosis (drug effects)
• Apoptosis Regulatory Proteins
• Caspase 9
• Caspases (metabolism)
• Cytochromes c (metabolism)
• DNA Fragmentation
• Flow Cytometry
• HL-60 Cells
• Humans
• Luteolin (pharmacology)
• Membrane Potentials (drug effects)
• Mitochondria (ultrastructure)
• Phosphorylation
• Poly(ADP-ribose) Polymerases (metabolism)
• Proteins (metabolism)
• Proto-Oncogene Proteins c-akt (metabolism)
• Pyrrolidines (pharmacology)
• Thiocarbamates (pharmacology)