Bone marrow stromal cells regulate caspase 3 activity in leukemic cells during chemotherapy

The interaction between leukemic cells and stromal cells of the bone marrow microenvironment has been shown to enhance leukemic cell survival during e xposure to chemotherapeutic agents. In the current study we investigated wh ether association of B lineage acute lymphoblastic leukemic cells with huma n bone marrow stromal cells altered caspase activation during chemotherapy treatment. Following treatment with Ara-C or VP-16 in vitro, caspase 3 acti vity in leukemic cells was consistently reduced by co-culture of leukemic c ells with human bone marrow stromal cell layers. These observations suggest that the protective effect of the bone marrow microenvironment on leukemic cells may be due, in part, to regulation of caspase 3 activity. (C) 2001 E lsevier Science Ltd. All rights reserved.