KIF11 and KIF15 mitotic kinesins are potential therapeutic vulnerabilities for malignant peripheral nerve sheath tumors.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) constitutes the leading cause of neurofibromatosis type 1-related mortality. MPNSTs contain highly rearranged hyperploid genomes and exhibit a high division rate and aggressiveness. We have studied in vitro whether the mitotic kinesins KIF11, KIF15, and KIF23 have a functional role in maintaining MPNST cell survival and can represent potential therapeutic vulnerabilities. METHODS: We studied the expression of kinesin mRNAs and proteins in tumors and cell lines and used several in vitro functional assays to analyze the impact of kinesin genetic suppression (KIF15, KIF23) and drug inhibition (KIF11) in MPNST cells. We also performed in vitro combined treatments targeting KIF11 together with other described MPNST targets. RESULTS: The studied kinesins were overexpressed in MPNST samples. KIF15 and KIF23 were required for the survival of MPNST cell lines, which were also more sensitive than benign control fibroblasts to the KIF11 inhibitors ispinesib and ARRY-520. Co-targeting KIF11 and BRD4 with ARRY-520 and JQ1 reduced MPNST cell viability, synergistically killing a much higher proportion of MPNST cells than control fibroblasts. In addition, genetic suppression of KIF15 conferred an increased sensitivity to KIF11 inhibitors alone or in combination with JQ1. CONCLUSIONS: The mitotic spindle kinesins KIF11 and KIF15 and the cytokinetic kinesin KIF23 play a clear role in maintaining MPNST cell survival and may represent potential therapeutic vulnerabilities. Although further in vivo evidences are still mandatory, we propose a simultaneous suppression of KIF11, KIF15, and BRD4 as a potential therapy for MPNSTs.

Macrophage-derived IL-10 mediates mucosal repair by epithelial WISP-1 signaling.

In response to injury, epithelial cells migrate and proliferate to cover denuded mucosal surfaces and repair the barrier defect. This process is orchestrated by dynamic crosstalk between immune cells and the epithelium; however, the mechanisms involved remain incompletely understood. Here, we report that IL-10 was rapidly induced following intestinal mucosal injury and was required for optimal intestinal mucosal wound closure. Conditional deletion of IL-10 specifically in CD11c-expressing cells in vivo implicated macrophages as a critical innate immune contributor to IL-10-induced wound closure. Consistent with these findings, wound closure in T cell- and B cell-deficient Rag1-/- mice was unimpaired, demonstrating that adaptive immune cells are not absolutely required for this process. Further, following mucosal injury, macrophage-derived IL-10 resulted in epithelial cAMP response element-binding protein (CREB) activation and subsequent synthesis and secretion of the pro-repair WNT1-inducible signaling protein 1 (WISP-1). WISP-1 induced epithelial cell proliferation and wound closure by activating epithelial pro-proliferative pathways. These findings define the involvement of macrophages in regulating an IL-10/CREB/WISP-1 signaling axis, with broad implications in linking innate immune activation to mucosal wound repair.

Protein-engineered scaffolds for in vitro 3D culture of primary adult intestinal organoids.

Though in vitro culture of primary intestinal organoids has gained significant momentum in recent years, little has been done to investigate the impact of microenvironmental cues provided by the encapsulating matrix on the growth and development of these fragile cultures. In this work, the impact of various in vitro culture parameters on primary adult murine organoid formation and growth are analyzed with a focus on matrix properties and geometric culture configuration. The air-liquid interface culture configuration was found to result in enhanced organoid formation relative to a traditional submerged configuration. Additionally, through use of a recombinantly engineered extracellular matrix (eECM), the effects of biochemical and biomechanical cues were independently studied. Decreasing mechanical stiffness and increasing cell adhesivity were found to increase organoid yield. Tuning of eECM properties was used to obtain organoid formation efficiency values identical to those observed in naturally harvested collagen I matrices but within a stiffer construct with improved ease of physical manipulation. Increased ability to remodel the surrounding matrix through mechanical or enzymatic means was also shown to enhance organoid formation. As the engineering and tunability of recombinant matrices is essentially limitless, continued property optimization may result in further improved matrix performance and may help to identify additional microenvironmental cues that directly impact organoid formation, development, differentiation, and functional behavior. Continued culture of primary organoids in recombinant matrices could therefore prove to be largely advantageous in the field of intestinal tissue engineering for applications in regenerative medicine and in vitro tissue mimics.