Phase II pilot study of oral dasatinib in patients with higher-risk myelodysplastic syndrome (MDS) who failed conventional therapy.

Given evidence for the role of Src family kinases, especially Lyn kinase, in myeloblast proliferation and the in vitro inhibitory activity of dasatinib on Src and Lyn, we conducted a phase II study to assess overall response to 100mg/day dasatinib in patients with higher-risk myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia, or acute myeloid leukemia arising from MDS and who had failed prior treatment with azanucleoside analogs. Among 18 patients treated, 3 responded, 4 had stable disease, and 10 experienced disease progression. Toxicities were limited and consistent with previous reports.

The role of lenalidomide in the treatment of patients with chromosome 5q deletion and other myelodysplastic syndromes.

Purpose Of Review: The aim of this article is to discuss the relevant pathobiologic effects of lenalidomide and the most recent clinical evidence to support its use in patients with myelodysplastic syndrome.

Recent Findings: Lenalidomide is an immunomodulatory agent with biological activity in several hematologic malignancies, including myelodysplastic syndrome. The precise mechanism yielding benefit in patients with myelodysplastic syndrome and 5q- syndrome is not clear, but various molecular and pathogenic targets have been identified.

Immunomodulatory drugs (IMiDs): a new treatment option for myelodysplastic syndromes.

The IMiDs represent a new proprietary class of thalidomide analogues that possess greater potency and less toxicity than the parent compound. As a group, these agents share the pharmacologic property of modulating cellular response to ligand activation, the precise biologic effect of which is cell lineage and stimulant-dependent. Lenalidomide (CC-5013; Revlimid), a second generation IMiD, has shown significant erythropoietic activity in patients with lower risk MDS that have failed or are not candidates for recombinant erythropoietin treatment.

Mature vascular endothelium can give rise to smooth muscle cells via endothelial-mesenchymal transdifferentiation: in vitro analysis.

Though in the past believed to be a rare phenomenon, endothelial-mesenchymal transdifferentiation has been described with increasing frequency in recent years. It is believed to be important in embryonic vascular development, yet less is known regarding its role in the adult vasculature. Using FACS and immunomagnetic (Dynabeads) purification techniques (based on uptake of DiI-acetylated low-density lipoproteins and/or PECAM-1 expression) and double-label indirect immunostaining (for endothelial and smooth muscle [SM] markers), we demonstrate that mature bovine vascular endothelium contains cells of an endothelial phenotype (defined by VE-cadherin, von Willebrand factor, PECAM-1, and elevated uptake of acetylated low-density lipoproteins) that can undergo endothelial-mesenchymal transdifferentiation and further differentiate into SM cells (as defined by expression of alpha-SM-actin, SM22alpha, calponin, and SM-myosin).