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Biology subjects

Winter, J. O.

Publications and source records attributed to Winter, J. O..

3 recordsLinked to original sources

Breast Cancer-derived PDGFB Remodels the CNS Vascular Niche to Promote Brain, Spinal and Leptomeningeal Metastasis

Background: Central nervous system (CNS) metastases are a major driver of breast cancer (BC) mortality. Recently, our group demonstrated that platelet-derived growth factor-B (PDGFB) and its receptor, platelet-derived growth factor receptor-beta (PDGFR{beta}), promote BC metastasis to the brain; however, the cellular/molecular mechanisms driving this process remain unclear. Here, we investigated tumor-derived PDGFB effects on the CNS vascular niche in regulating metastatic spread. Methods: Triple-negative BC cells were engineered to overexpress PDGFB and used to evaluate endothelial sprouting, blood-brain barrier (BBB) function, vascular permeability and experimental CNS metastasis. A novel retro-orbital (RO) injection model was used to study leptomeningeal/spinal experimental metastasis. Results: PDGFB enhanced human brain microvascular endothelial cell (HBMEC) sprouting, induced cell migration in BBB spheroids, increased permeability in 3D models, and disrupted tight junction proteins in HBMECs. Notably, alterations in vascular permeability were observed in both PDGFR{beta}-positive and PDGFR{beta}-negative endothelial systems, suggesting PDGFB can remodel the CNS vasculature through multiple mechanisms. In vivo, PDGFB increased CNS metastatic burden and altered tumor vasculature in xenograft and allograft models of BC. Furthermore, PDGFB promoted robust colonization of both spinal and leptomeningeal compartments, identifying a previously underappreciated role for this signaling pathway in a clinically devastating form of CNS metastasis. Analysis of patient transcriptomic datasets revealed enrichment of angiogenesis-related pathways in PDGFB-high tumors from patients who developed CNS metastases. Conclusions: Collectively, these findings identify tumor-derived PDGFB as a key regulator of CNS vascular remodeling and metastatic tropism, while introducing a new experimental framework to study spinal metastases and leptomeningeal disease in BC.

cancer biology↗

Cooperative control of a DNA origami force sensor

Most biomolecular systems are dependent on a complex interplay of forces. Modern force spectroscopy techniques provide means of interrogating these forces. These techniques, however, are not optimized for studies in constrained or crowded environments as they typically require micron-scale beads in the case of magnetic or optical tweezers, or direct attachment to a cantilever in the case of atomic force microscopy. We implement a nanoscale force-sensing device using a DNA origami which is highly customizable in geometry, functionalization, and mechanical properties. The device, referred to as the NanoDyn, functions as a binary (open or closed) force sensor that undergoes a structural transition under an external force. The transition force is tuned with minor alterations of 1 to 3 DNA oligonucleotides and spans tens of picoNewtons (pN). This actuation of the NanoDyn is reversible and the design parameters strongly influence the efficiency of resetting the initial state, with higher stability devices ({gtrsim}10 pN) resetting more reliably during repeated force-loading cycles. Finally, we show that the opening force can be adjusted in real time by the addition of a single DNA oligonucleotide. These results establish the NanoDyn as a versatile force sensor and provide fundamental insights into how design parameters modulate mechanical and dynamic properties.

bioengineering↗

DNA-caged Nanoparticles via Electrostatic Self-Assembly

DNA-modified nanoparticles enable DNA sensing and therapeutics in nanomedicine and are also crucial for nanoparticle self-assembly with DNA-based materials. However, methods to conjugate DNA to nanoparticle surfaces are limited, inefficient, and lack control. Inspired by DNA tile nanotechnology, we demonstrate a new approach to nanoparticle modification based on electrostatic attraction between negatively charged DNA tiles and positively charged nanoparticles. This approach does not disrupt nanoparticle surfaces and leverages the programmability of DNA nanotechnology to control DNA presentation. We demonstrated this approach using a variety of nanoparticles, including polymeric micelles, polystyrene beads, gold nanoparticles, and superparamagnetic iron oxide nanoparticles with sizes ranging from 5-20 nm in diameter. DNA cage formation was confirmed through transmission electron microscopy (TEM), neutralization of zeta potential, and a series of fluorescence experiments. DNA cages present "handle" sequences that can be used for reversible target attachment or self-assembly. Handle functionality was verified in solution, at the solid-liquid interface, and inside fixed cells, corresponding to applications in biosensing, DNA microarrays, and erasable immunocytochemistry. These experiments demonstrate the versatility of the electrostatic DNA caging approach and provide a new pathway to nanoparticle modification with DNA that will empower further applications of these materials in medicine and materials science.

bioengineering↗