HOXB4-INDUCED APOPTOSIS IN REH CELLS IS NOT MEDIATED VIA THE INTRINSIC CASPASE-9 PATHWAY

Abstract

PURPOSE: Pathogenesis of primary pulmonary mucosa-associated lymphoid tumors (MALT) and lymphomas remains unknown, but is thought to involve antigen stimulation leading to immortalization, and then subsequent transformation into a more aggressive phenotype. HOXB4 is a homeobox transcription factor that is known to clonally expand hematopoietic stem cells. We have previously shown that HOXB4 is also an apoptotic agent in the pre-B acute lymphoblastic leukemia cell line REH via the extrinsic pathway that activates caspase-8 and caspase-3 leading to DNA disintegration.