Strain elastography was used to monitor response to neoadjuvant chemotherapy (NAC) in 92 patients with biopsy-proven, locally advanced breast cancer. Strain elastography data were collected before, during, and after NAC. Relative changes in tumor strain ratio (SR) were calculated over time, and responder status was classified according to tumor size changes. Statistical analyses determined the significance of changes in SR over time and between response groups. Machine learning techniques, such as a naïve Bayes classifier, were used to evaluate the performance of the SR as a marker for Miller-Payne pathological endpoints. With pathological complete response (pCR) as an endpoint, a significant difference ( P < .01) in the SR was observed between response groups as early as 2 weeks into NAC. Naïve Bayes classifiers predicted pCR with a sensitivity of 84%, specificity of 85%, and area under the curve of 81% at the preoperative scan. This study demonstrates that strain elastography may be predictive of NAC response in locally advanced breast cancer as early as 2 weeks into treatment, with high sensitivity and specificity, granting it the potential to be used for active monitoring of tumor response to chemotherapy.
Background: Pyroptosis is a type of proinflammatory regulated cell death (RCD) in which caspase-1 proteolytically cleaves gasdermin D (GSDMD) to yield a cytotoxic pore-forming protein. Recent studies have suggested that additional cell death pathways may interact with GSDMD under certain circumstances to execute pyroptosis. Microglia/macrophages in the central nervous system (CNS) undergo GSDMD-associated pyroptosis in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) but the contribution of other cell death pathways to this phenomenon is unknown. Herein, we tested the hypothesis that multiple RCD pathways underlie microglial pyroptosis in the context of neuroinflammation. Methods: A siRNA screen of genes with known RCD functions was performed in primary human microglia to evaluate their role in nigericin-induced pyroptosis using supernatant lactate dehydrogenase activity as a read-out of cell lysis. Activation of apoptotic executioner proteins and their contribution to pyroptosis was assessed using semiquantitative confocal microscopy, high-sensitivity ELISA, immunoblot, cell lysis assays, and activity-based fluorescent probes. Quantification of pyroptosis-related protein expression was performed in CNS lesions from patients with progressive MS and mice with MOG 35-55-induced EAE, and in matched controls. Results: Among progressive MS patients, activated caspase-3 was detected in GSDMD immunopositive pyroptotic microglia/macrophages within demyelinating lesions. In the siRNA screen, suppression of caspase-3/7, caspase-1, or GSDMD expression prevented plasma membrane rupture during pyroptosis. Upon exposure to pyroptotic stimuli (ATP or nigericin), human microglia displayed caspase-3/7 activation and cleavage of caspase-3/7-specific substrates (e.g., DFF45, ROCK1, and PARP), with accompanying features of pyroptosis including GSDMD immunopositive pyroptotic bodies, IL-1β release, and membrane rupture. Pyroptosis-associated nuclear condensation and pyroptotic body formation were suppressed by caspase-3/7 inhibition. Pharmacological and siRNA-mediated inhibition of caspase-1 diminished caspase-3/7 activation during pyroptosis. In mice with EAE-associated neurological deficits, activated caspase-3 colocalized with GSDMD immunopositivity in lesion-associated macrophages/microglia.
Results from QUS analysis presented in this study confirm that acute tumor response is linked to a vascular effect following high doses of radiation therapy. Overall, this is in agreement with previous reports suggesting that acute tumor radiation response is regulated by a vascular-driven response. Data also suggest that Sunitinib may enhance tumor radiosensitivity through a vascular remodeling process, and that QUS may be sensitive to changes in tissue properties associated with vascular remodeling. Finally, the work also demonstrates the ability of QUS methods to monitor response to radiation-based vascular strategies.
Inflammatory demyelination and axonal injury in the central nervous system (CNS) are cardinal features of progressive multiple sclerosis (MS), and linked to activated brain macrophage-like cells (BMCs) including resident microglia and trafficking macrophages. Caspase-1 is a pivotal mediator of inflammation and cell death in the CNS. We investigated the effects of caspase-1 activation and its regulation in models of MS. Brains from progressive MS and non-MS patients, as well as cultured human oligodendrocytes were examined by transcriptomic and morphological methods. Next generation transcriptional sequencing of progressive MS compared to non-MS patients' normal appearing white matter (NAWM) showed induction of caspase-1 as well as other inflammasome-associated genes with concurrent suppression of neuron-specific genes. Oligodendrocytes exposed to TNFα exhibited upregulation of caspase-1 with myelin gene suppression in a cell differentiation state-dependent manner. Brains from cuprizone-exposed mice treated by intranasal delivery of the caspase-1 inhibitor, VX-765 or its vehicle, were investigated in morphological and molecular studies, as well as by fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging. Cuprizone exposure resulted in BMC and caspase-1 activation accompanied by demyelination and axonal injury, which was abrogated by intranasal VX-765 treatment. FDG-PET imaging revealed suppressed glucose metabolism in the thalamus, hippocampus and cortex of cuprizone-exposed mice that was restored with VX-765 treatment. These studies highlight the caspase-1 dependent interactions between inflammation, demyelination, and glucose metabolism in progressive MS and associated models. Intranasal delivery of an anti-caspase-1 therapy represents a promising therapeutic approach for progressive MS and other neuro-inflammatory diseases.
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