Homeostatic chemokines increase survival of B-chronic lymphocytic leukemia cells through inactivation of transcription factor FOXO3a

Oncogene. 2007 Nov 1;26(50):7081-91. doi: 10.1038/sj.onc.1210519. Epub 2007 May 14.


B-chronic lymphocytic leukemia (B-CLL) cell is characterized by the accumulation of long-lived CD5+ B lymphocytes, whose survival in vivo is in part dependent on exogenous factors such as cytokines and/or extracellular matrix proteins. Homeostatic chemokines are critical mediators of lymphoid cell trafficking. However, how they function in cell signaling and survival remains ill-defined. In this study, we have investigated the role of the homeostatic chemokines, CXCL12, CCL21, CCL19 and CXCL13, in B-CLL cell survival. Using primary leukemic cells isolated from 26 patients, we observed that each chemokine enhances cell survival. Chemokines induced the phosphorylation of ERK1/2 and p90RSK, and of Akt and its effectors GSK3 and FOXO3a. Consistently, inhibitors against mitogen-activated protein kinase/extracellular signal-regulated kinase and phosphatidylinositol 3-kinase inhibited chemokine-induced survival. Moreover, using a constitutively active mutated form of FOXO3a or siRNAs against FOXO3a in transfection experiments performed in primary B-CLL cells, we directly demonstrated the critical role of FOXO3a in both spontaneous and chemokine-induced B-CLL cell survival. Overall, our data support the notion that homeostatic chemokines contribute to B-CLL resistance to cell death through inactivation of the transcription factor FOXO3a, which may represent a novel therapeutic target in this hematopoietic malignancy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Apoptosis / genetics
  • Apoptosis / immunology
  • Cell Death / genetics
  • Cell Death / immunology
  • Cell Survival / immunology
  • Chemokines / physiology*
  • Female
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors / antagonists & inhibitors*
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / physiology
  • Homeostasis / genetics
  • Homeostasis / immunology*
  • Humans
  • Leukemia, Lymphocytic, Chronic, B-Cell / metabolism*
  • Leukemia, Lymphocytic, Chronic, B-Cell / pathology*
  • Male
  • Middle Aged
  • Transcriptional Activation / genetics
  • Transcriptional Activation / immunology


  • Chemokines
  • FOXO3 protein, human
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors