MRx102, a triptolide derivative, has potent antileukemic activity in vitro and in a murine model of AML.
Märksõnad
Abstraktne
Triptolide, isolated from the herb Tripterygium wilfordii, has been shown to potently induce apoptosis in various malignant cells by inhibiting RNA synthesis and nuclear factor-κB activity. Previously, we showed that triptolide promotes apoptosis in acute myeloid leukemia (AML) cells via the mitochondria-mediated pathway, in part, by decreasing levels of the anti-apoptotic proteins XIAP and Mcl-1. MRx102 is a triptolide derivative, currently in preclinical development. Here we show that MRx102 potently promoted apoptosis in AML cell lines, with EC(50) values of 14.5±0.6 nM and 37.0±0.9 nM at 48 h for OCI-AML3 and MV4-11 cells, respectively. MRx102, at low nanomolar concentrations, also induced apoptosis in bulk, CD34(+) progenitor, and more importantly, CD34(+)CD38(-) stem/progenitor cells from AML patients, even when they were protected by coculture with bone marrow derived mesenchymal stromal cells. MRx102 decreased XIAP and Mcl-1 protein levels and inhibited RNA synthesis in OCI-AML3 cells. In vivo, MRx102 greatly decreased leukemia burden and increased survival time in non-obese diabetic/severe combined immunodeficiency mice harboring Ba/F3-ITD cells. Collectively, we demonstrated that MRx102 has potent antileukemic activity both in vitro and in vivo, has the potential to eliminate AML stem/progenitor cells and overcome microenvironmental protection of leukemic cells, and warrants clinical investigation.