|
|
Blood, 1 September 2008, Vol. 112, No. 5, pp. 1971-1980.
Prepublished online as a Blood First Edition Paper on June 19, 2008; DOI 10.1182/blood-2007-12-126946.
Previous Article | Next Article 
Submitted December 3, 2007
Accepted April 13, 2008
Gossypol, a BH3 mimetic, induces apoptosis in
chronic lymphocytic leukemia cells
Kumudha Balakrishnan, William G Wierda, Michael J Keating, and Varsha Gandhi*
Experimental Therapeutics, M.D. Anderson Cancer Center, Houston, TX
Leukemia Department, M.D. Anderson Cancer Center, Houston, TX
* Corresponding author; email: vgandhi{at}mdanderson.org.
Gossypol, a cottonseed extract derivative, acts as a BH3-mimetic, binding to the BH3 pocket of anti-apoptotic proteins and displacing pro-death partners to induce apoptosis. However, knowledge on the molecular underpinnings of its downstream effects is limited. Since chronic lymphocytic leukemia (CLL) cells express high levels of anti-apoptotic proteins that act as a survival mechanism for these replicationally quiescent lymphocytes, we investigated whether gossypol induces apoptosis in these cells and what mechanism underlies gossypol-mediated cytotoxicity. Gossypol induced cell death in a concentration- and time-dependent manner; 24-hour incubation with 30 µM gossypol resulted in 50% cell death (median; range, 10-80%; n = 47) that was not abrogated by pan-specific caspase inhibitor. Starting at 4 hours, the mitochondrial outer membrane was significantly permeabilized (median, 77%; range, 54-93%; n = 15). Mitochondrial outer membrane permeablistaion (MOMP) was concurrent with increased production of reactive oxygen species (ROS); however, antioxidants did not abrogate gossypol-induced cell death. Mitochondrial membrane permeabilization was also associated with loss of intracellular ATP, activation of BAX, and release of cytochrome c and apoptosis-inducing factor (AIF), which was translocated to the nucleus. Blocking AIF translocation resulted in a decreased apoptosis, suggesting that AIF contributes to gossypol-mediated cytotoxicity in CLL lymphocytes.

CiteULike Connotea Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
R. Chen, W. G. Wierda, S. Chubb, R. E. Hawtin, J. A. Fox, M. J. Keating, V. Gandhi, and W. Plunkett
Mechanism of action of SNS-032, a novel cyclin-dependent kinase inhibitor, in chronic lymphocytic leukemia
Blood,
May 7, 2009;
113(19):
4637 - 4645.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. J. Kipps
Chronic Lymphocytic Leukemia: Advances in Assessing Prognosis and Therapy
ASCO Educational Book,
January 1, 2009;
2009(1):
385 - 393.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Balakrishnan, J. A. Burger, W. G. Wierda, and V. Gandhi
AT-101 induces apoptosis in CLL B cells and overcomes stromal cell-mediated Mcl-1 induction and drug resistance
Blood,
January 1, 2009;
113(1):
149 - 153.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. Gandhi, K. Balakrishnan, and L. S. Chen
Mcl-1: the 1 in CLL
Blood,
November 1, 2008;
112(9):
3538 - 3540.
[Full Text]
[PDF]
|
 |
|
|
|