Rapid evolving into acute myeloid leukemia in a patient with multiple myeloma and concurrent myelodysplasia after VTD therapy.

The association of Myelodysplasia (MDS) and multiple myeloma (MM) has been usually described not only as a complication of chemotherapy but also in the absence of preceding chemotherapy or together at the time of diagnosis. Optimal therapies of a coexisting MM and MDS have not been well established up to now. We report a case of MDS diagnosed simultaneously with MM.

Overexpression of glucosylceramide synthase in associated with multidrug resistance of leukemia cells.

Ceramide, as a second messenger, initiates one of the major signal transduction pathways in tumor apoptosis. Glucosylceramide synthase (GCS) catalyzes glycosylation of ceramide and produces glucosylceramide. Through GCS, ceramide glycosylation allows cellular escape from ceramide-induced programmed cell death.

[Relation between glucosylceramide synthase and multidrug resistance in leukemia cells].

This study was purposed to explore the expression of glucosylceramide synthase (GCS) in human leukemia cells and its relationship with multidrug resistance. RT-PCR was used to analyze peripheral blood samples from 53 leukemia patients with multidrug resistance/non-resistance, and to detect the expression level of GCS gene in HL-60 cells and HL-60/ADR cells, the expression level was compared with the level of mdr-1. The expressions of GCS protein and P-gp protein in HL-60 cells and HL-60/ADR cells were assayed by Western blot analysis.