No abstract

Genomic characterization is beginning to define a molecular taxonomy for breast cancer; however, the molecular basis of invasion and metastasis remains poorly understood. We report a pivotal role for the fibroblast growth factor -inducible 14 (Fn14) receptor in this process. We examined whether Fn14 and its ligand tumor necrosis factor -like weak inducer of apoptosis (TWEAK) were expressed in breast tumors and whether deregulation of Fn14 levels affected malignant behavior of breast cancer cell lines. Analysis of TWEAK and Fn14 in publicly available gene expression data indicated that high Fn14 expression levels significantly correlated with several poor prognostic indicators (P < 0.05).

Flexor tendon injuries are often encountered clinically and typically require surgical repair. Return of function after repair is limited due to adhesion formation, which leads to reduced tendon gliding, and due to a lack of repair site strength, which leads to repair site gap formation or rupture. The application of the growth factors basic fibroblastic growth factor (bFGF) and platelet derived growth factor BB (PDGF-BB) has been shown to have the potential to enhance tendon healing. The objectives of this study were to examine: (1) the conditions over which delivery of bFGF can be controlled from a heparin-binding delivery system (HBDS) and (2) the effect of bFGF and PDGF-BB released from this system on tendon fibroblast proliferation and matrix gene expression in vitro over a 10-day interval. Delivery of bFGF was controlled using a HBDS. Fibrin matrices containing the HBDS retained bFGF better than did matrices lacking the delivery system over the 10-day period studied. Delivery of bFGF and PDGF-BB using the HBDS stimulated tendon fibroblast proliferation and promoted changes in the expression of matrix genes related to tendon gliding, strength, and remodeling. Both growth factors may be effective in enhancing tendon healing in vivo.

Little is known about the effects of muscle and tendon unloading on the molecular response of the rotator cuff. Tendon unloading following rupture of one of the rotator cuff tendons can induce alterations in muscle physiology and tendon structure, which can subsequently affect reparability and healing potential. The goals of the current study were to determine the effect of mechanical unloading on gene expression and morphology of (1) healthy supraspinatus tendons and muscles, and (2) supraspinatus tendons and muscles after acute injury and repair. Mechanical unloading was achieved by tenotomy and/or botulinum toxin A (BTX) chemical denervation in a rat rotator cuff model of injury and repair. Gene expression profiles varied across regions of the muscle, with the greatest changes seen in the distal aspect of the muscle for most genes. Myogenic and adipogenic genes were upregulated in muscle when unloaded (tenotomy and BTX). Tendon injury, with and without repair, resulted in upregulation of fibrosis- and tendon-specific gene expression. The expression of scleraxis, a transcription factor necessary for tendon development, was upregulated in response to injury and repair. In summary, tendon detachment and repair had the greatest effect on tendon gene expression, while unloading had the greatest effect on muscle gene expression.

The process of conducting cell-based phenotypic screens can result in datasets from small libraries or portions of large libraries, making accurate hit picking from multiple datasets important for efficient drug discovery. Here, we describe a screen design and data analysis approach that allows for normalization not only between quadrants and plates but also between screens or batches in a robust, quantitative fashion enabling hit-selection from multiple datasets. We independently screened the Microsource Spectrum and NCI Diversity Set II libraries using a cell-based phenotypic HTS assay that uses interferon stimulated response element (ISRE)-driven luciferase-reporter assay to identify interferon (IFN) signal enhancers. Inclusion of a per-plate, per-quadrant IFN dose-response standard curve enabled conversion of ISRE activity to effective IFN concentrations. We identified 45 hits based on a combined z-score ≥ 2.5 from the two libraries, and 25 of 35 available hits were validated in a compound concentration-response assay when tested using fresh compound. The results provide a basis for further analysis of chemical structure in relation to biological function. Together, the results establish an HTS method that can be extended to screening for any class of compounds that influence a quantifiable biological response for which a standard is available.

Supplementary Figure S1 from The Fibroblast Growth Factor–Inducible 14 Receptor Is Highly Expressed in HER2-Positive Breast Tumors and Regulates Breast Cancer Cell Invasive Capacity

Supplementary Figure S1 from The Fibroblast Growth Factor–Inducible 14 Receptor Is Highly Expressed in HER2-Positive Breast Tumors and Regulates Breast Cancer Cell Invasive Capacity