In vitro cytotoxicity of the LDE : daunorubicin complex in acute myelogenous leukemia blast cells

Acute myelogenous leukemia (AML) blast cells show high-affinity degradation of low-density lipoprotein (LDL), suggesting an increased expression of ce llular LDL receptors. LDE is a lipid microemulsion easily synthesized in vi tro which is known to mimic the metabolic pathway of LDL. We used LDE as a carrier for daunorubicin and assayed the cytotoxicity of the complex using AML blast cells since RT-PCR analysis showed that AML cells express LDL rec eptor mRNA. The LDE:daunorubicin complex killed 46.7% of blast cells and 20 .2% of normal bone marrow cells (P <0.001; Student t-test). Moreover, this complex destroyed AML blast cells as efficiently as free daunorubicin. Thus , LDE might be a suitable carrier of chemotherapeutic agents targeting thes e drugs to neoplastic cells and protecting normal tissues.