Genetic and epigenetic underpinnings of neurodegenerative disorders
Pluripotent cells, including embryonic stem (ES) and induced pluripotent stem (iPS) cells, are used to investigate the genetic and epigenetic underpinnings of human diseases such as Parkinson’s, Alzheimer’s, autism, and cancer. Mechanisms of somatic cell reprogramming to an embryonic pluripotent state are explored, utilizing patient-specific pluripotent cells to model and analyze neurodegenerative diseases.
Mechanisms Underlying the Persistence of Cancer-Related Fatigue
Cancer-related fatigue is a prominent and debilitating side effect of cancer and its treatment. It can develop prior to diagnosis, generally peaks during cancer treatment, and can persist long after treatment completion. Its mechanisms are multifactorial, and its expression is highly variable. Unfortunately, treatment options are limited. Our research uses syngeneic murine models of cancer and cisplatin-based chemotherapy to better understand these mechanisms. Our data indicate that both peripherally and centrally processes may contribute to the developmental of fatigue. These processes include metabolic alterations, mitochondrial dysfunction, pre-cachexia, and inflammation. However, our data has revealed that behavioral fatigue can persist even after the toxicity associated with cancer and its treatment recover. For example, running during cancer treatment attenuates kidney toxicity while also delaying recovery from fatigue-like behavior. Additionally, administration of anesthetics known to disrupt memory consolidation at the time treatment can promote recovery, and treatment-related cues can re-instate fatigue after recovery. Cancer-related fatigue can also promote habitual behavioral patterns, as observed using a devaluation task. We interpret this data to suggest that limit metabolic resources during cancer promote the utilization of habit-based behavioral strategies that serve to maintain fatigue behavior into survivorship. This line of work is exciting as it points us toward novel interventional targets for the treatment of persistent cancer-related fatigue.
Aging promotes reactivation from metastatic melanoma dormancy
How does the primary tumor imprint a dormancy signature in disseminated tumor cells?
T cells specific for alpha-myosin drive immunotherapy-related myocarditis
CD8+ T cell activation in cancer comprises an initial activation phase in lymph nodes followed by effector differentiation within the tumor
Effect of the intratumoral microbiota on spatial and cellular heterogeneity in cancer
Metastatic recurrence in colorectal cancer arises from residual EMP1+ cells
PHGDH heterogeneity potentiates cancer cell dissemination and metastasis
Malignant synaptic plasticity in pediatric high-grade gliomas
Pediatric high-grade gliomas (pHGG) are a devastating group of diseases that urgently require novel therapeutic options. We have previously demonstrated that pHGGs directly synapse onto neurons and the subsequent tumor cell depolarization, mediated by calcium-permeable AMPA channels, promotes their proliferation. The regulatory mechanisms governing these postsynaptic connections are unknown. Here, we investigated the role of BDNF-TrkB signaling in modulating the plasticity of the malignant synapse. BDNF ligand activation of its canonical receptor, TrkB (which is encoded for by the gene NTRK2), has been shown to be one important modulator of synaptic regulation in the normal setting. Electrophysiological recordings of glioma cell membrane properties, in response to acute neurotransmitter stimulation, demonstrate in an inward current resembling AMPA receptor (AMPAR) mediated excitatory neurotransmission. Extracellular BDNF increases the amplitude of this glutamate-induced tumor cell depolarization and this effect is abrogated in NTRK2 knockout glioma cells. Upon examining tumor cell excitability using in situ calcium imaging, we found that BDNF increases the intensity of glutamate-evoked calcium transients in GCaMP6s expressing glioma cells. Western blot analysis indicates the tumors AMPAR properties are altered downstream of BDNF induced TrkB activation in glioma. Cell membrane protein capture (via biotinylation) and live imaging of pH sensitive GFP-tagged AMPAR subunits demonstrate an increase of calcium permeable channels at the tumors postsynaptic membrane in response to BDNF. We find that BDNF-TrkB signaling promotes neuron-to-glioma synaptogenesis as measured by high-resolution confocal and electron microscopy in culture and tumor xenografts. Our analysis of published pHGG transcriptomic datasets, together with brain slice conditioned medium experiments in culture, indicates the tumor microenvironment as the chief source of BDNF ligand. Disruption of the BDNF-TrkB pathway in patient-derived orthotopic glioma xenograft models, both genetically and pharmacologically, results in an increased overall survival and reduced tumor proliferation rate. These findings suggest that gliomas leverage normal mechanisms of plasticity to modulate the excitatory channels involved in synaptic neurotransmission and they reveal the potential to target the regulatory components of glioma circuit dynamics as a therapeutic strategy for these lethal cancers.
Retinoblastoma: Canadian global leadership
“Discovery of Novel Gain-of-Function Mutations Guided by Structure-Based Deep Learning”
Life of biological molecules spans time and length scales relevant at atomic to cellular time and length scales. Hence, novel molecular modeling approaches are required to be inherently multi-scale. Here we describe multiple methodologies developed in our laboratory: rapid discrete molecular dynamics simulation algorithm, protein design and structural refinement tools. Using these methodologies, we describe therapeutic strategies to combat this HIV and cancer, as well as design novel approaches for controlling proteins in living cells and organisms.