Pathogenetics of alveolar capillary dysplasia with misalignment of pulmonary veins.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal lung developmental disorder caused by heterozygous point mutations or genomic deletion copy-number variants (CNVs) of FOXF1 or its upstream enhancer involving fetal lung-expressed long noncoding RNA genes LINC01081 and LINC01082. Using custom-designed array comparative genomic hybridization, Sanger sequencing, whole exome sequencing (WES), and bioinformatic analyses, we studied 22 new unrelated families (20 postnatal and two prenatal) with clinically diagnosed ACDMPV. We describe novel deletion CNVs at the FOXF1 locus in 13 unrelated ACDMPV patients. Together with the previously reported cases, all 31 genomic deletions in 16q24.1, pathogenic for ACDMPV, for which parental origin was determined, arose de novo with 30 of them occurring on the maternally inherited chromosome 16, strongly implicating genomic imprinting of the FOXF1 locus in human lungs. Surprisingly, we have also identified four ACDMPV families with the pathogenic variants in the FOXF1 locus that arose on paternal chromosome 16. Interestingly, a combination of the severe cardiac defects, including hypoplastic left heart, and single umbilical artery were observed only in children with deletion CNVs involving FOXF1 and its upstream enhancer. Our data demonstrate that genomic imprinting at 16q24.1 plays an important role in variable ACDMPV manifestation likely through long-range regulation of FOXF1 expression, and may be also responsible for key phenotypic features of maternal uniparental disomy 16. Moreover, in one family, WES revealed a de novo missense variant in ESRP1, potentially implicating FGF signaling in the etiology of ACDMPV

SKI-178: A multitargeted inhibitor of sphingosine kinase and microtubule dynamics demonstrating therapeutic efficacy in acute myeloid leukemia models

Aim: To further characterize the selectivity, mechanism of action, and therapeutic efficacy of the novel small molecule inhibitor, SKI-178. Methods: We used the state-of-the-art cellular thermal shift assay technique to detect “direct target engagement” of proteins in intact cells. In vitro and in vivo assays, pharmacological assays, and multiple mouse models of acute myeloid leukemia (AML) were also used. Results: Herein, we demonstrate that SKI-178 directly target engages both sphingosine kinase 1 and 2 (SphK1 and 2). We also present evidence that, in addition to its actions as a sphingosine kinase inhibitor, SKI-178 functions as a microtubule network disrupting agent both in vitro and in intact cells. Interestingly, we separately demonstrate that simultaneous SphK inhibition and microtubule disruption synergistically induce apoptosis in AML cell lines. Furthermore, we demonstrate that SKI-178 is well tolerated in normal healthy mice. Most importantly, we demonstrate that SKI-178 has therapeutic efficacy in several mouse models of AML. Conclusion: SKI-178 is a multitargeted agent that functions both as an inhibitor of the SphKs as well as a disruptor of the microtubule network. SKI-178-induced apoptosis arises from a synergistic interaction of these two activities. SKI-178 is safe and effective in mouse models of AML, supporting its further development as a multitargeted anticancer therapeutic agent