FES Kinase Promotes Mast Cell Recruitment to Mammary Tumors via the Stem Cell Factor/KIT Receptor Signaling Axis

Abstract

KIT receptor is required for mast cell development, survival, and migration toward its ligand stem cell factor (SCF). Many solid tumors express SCF and this leads to mast cell recruitment to tumors and release of mediators linked to tumor angiogenesis, growth, and metastasis. Here, we investigate whether FES protein-tyrosine kinase, a downstream effector of KIT signaling in mast cells, is required for migration of mast cells toward SCF-expressing mammary tumors. Using a novel agarose drop assay for chemotaxis of bone marrow-derived mast cells (BMMC) toward SCF, we found that defects in chemotaxis of fes-null BMMCs correlated with disorganized microtubule networks in polarized cells. FES displayed partial colocalization with microtubules in polarized BMMCs and has at least two direct microtubule binding sites within its N-terminal F-BAR and SH2 domains. An oligomerizationdisrupting mutation within the Fer/CIP4 homology-Bin/Amphiphysin/Rvs (F-BAR) domain had no effect on microtubule binding, whereas microtubule binding to the SH2 domain was dependent on the phosphotyrosinebinding pocket. FES involvement in mast cell recruitment to tumors was tested using the AC2M2 mouse mammary carcinoma model. These tumor cells expressed SCF and promoted BMMC recruitment in a KIT-and FESdependent manner. Engraftment of AC2M2 orthotopic and subcutaneous tumors in control or fes-null mice, revealed a key role for FES in recruitment of mast cells to the tumor periphery. This may contribute to the reduced tumor growth and metastases observed in fes-null mice compared with control mice. Taken together, FES is a potential therapeutic target to limit the progression of tumors with stromal mast cell involvement. Mol Cancer Res; 10(7); 881-91. Ó2012 AACR.

SHP2 Phosphatase Promotes Mast Cell Chemotaxis toward Stem Cell Factor via Enhancing Activation of the Lyn/Vav/Rac Signaling Axis

“…1A, 1B). To extend on these findings, we analyzed WT and KO BMMC chemotaxis toward SCF-embedded agarose drops by time-lapse microscopy, as described previously (13). To simultaneously analyze WT and KO BMMCs under identical conditions, WT and KO cells were stained with CellTracker Orange (WT) or Green (KO) and mixed briefly prior to addition to wells containing fibronectin-coated coverslips containing SCF-embedded agarose drops (Fig.…”

“…In case of Baf/3-KIT cells, migrating cells within the lower chamber were scored using an automated cell counter. Agarose drop chemotaxis assays using SCF-embedded agarose was described recently (13). Briefly, SCF (30 ng/ml) was embedded in a drop containing 0.5% low-melt agarose and allowed to solidify on dried coverslips previously coated with fibronectin (20 μg/ml) and stabilized at 4°C for 15 min.…”

Improving the design of the agarose spot assay for eukaryotic cell chemotaxis

“…Avoiding replacement of the medium would be preferable. To this effect, culture conditions that promote cell adhesion, such as coating the substrate with collagen or fibronectin, 13 may facilitate plating cells directly into the desired assay medium.…”

Electroporation-mediated delivery of the FER gene in the resolution of trauma-related fatal pneumonia

“…It has been described in normal tissues to be a downstream integrator of membrane and cytosolic signaling pathways(13–15) boasting a beneficial participation in cell survival, cytoskeleton re-arrangement, epithelial maintenance and leukocyte differentiation and chemotaxis. However in several cancer models, FER has been implied to be involved in mechanisms of malignant cell transformation, tumoral invasion and metastatic potential(16–19). FER overexpression is a negative predictor of survival in Non-Small Cell Lung Cancer (NSCLC)(20).…”