Biology subjects

McCall, S.

Publications and source records attributed to McCall, S..

3 recordsLinked to original sources

bioRxiv2025

Multiscale Modeling Uncovers Macrophage Infiltration and TNF-α Signaling Networks for Targeting in Inflammatory Breast Cancer Tumor Emboli

Inflammatory breast cancer (IBC) tumors are characterized by diffuse clusters of cells found in dermal tissue and lymphatic vessels, known as tumor emboli. Thus, IBC needs a novel treatment because it is the most aggressive breast cancer subtype. We hypothesized that the interaction between tumor emboli and the tumor immune microenvironment (TiME) fosters survival signaling, leading to the aggressiveness of the IBC. In this study, ex vivo tumor emboli were generated from patient-derived cell lines cultured in a lymphatic-like environment, which was compared to 2D monolayer cultures, revealing upregulation of TNFR signaling networks, CXCL8, and immune cell chemotaxis genes. Spatial immunophenotyping of IBC patient tumors demonstrated high levels of CD163+ tumor-associated macrophages (TAMs). Furthermore, intravital imaging of CX3cr1GFP mice confirmed macrophage movement toward tumor cell clusters. Finally, targeting macrophage-associated TNF--signaling using Birinapant, a SMAC mimetic, inhibited the tumor emboli phenotype in vivo, identifying Birinapant as a potential therapeutic agent to disrupt this signaling axis.

cancer biology↗

bioRxiv2023

A dirofilariasis mouse model for heartworm preclinical research

Use of experimental cats and dogs in veterinary heartworm preclinical drug research is increasing. As a potential alternative primary in vivo heartworm preventative drug screen, we assessed lymphopenic mice with ablation of the interleukin-2/7 common gamma chain ({gamma}c) as susceptible to the larval development phase of D. immitis. Non-obese diabetic (NOD) Severe Combined ImmunoDeficient (SCID){gamma}c-/-(NSG / NXG) mice consistently yielded viable D. immitis larvae at 2-4 weeks post-infection across multiple experiments, different batches of infectious larvae inoculates, different isolates of D. immitis and at independent laboratories. Mice did not display any overt clinical signs associated with infection up to 4 weeks. Developing larvae were found in subcutaneous and muscle fascia tissues, the natural site of this stage of heartworm in dogs. Larvae retrieved from NSG / NXG mice were mid-L4 stage of development. Compared with 14-day in vitro propagated larvae, in vivo derived L4 were significantly larger and contained expanded Wolbachia endobacteria titres, determined by QPCR and Fluorescent in situ Hybridisation (FISH). We established an ex vivo 6-day L4 paralytic screening system against nematodicidal agents (moxidectin, levamisole) which highlighted discrepancies in relative drug sensitivities in comparison with in vitro reared L4 D. immitis. We demonstrated effective depletion of Wolbachia by 70-90% in D. immitis L4 following 2-7 day oral in vivo exposures of NSG / NXG infected mice with doxycycline or the rapid-acting investigational anti-Wolbachia drug, AWZ1066S. We validated the NSG / NXG mouse model as a filaricide drug screen by in vivo treatments with single injections of moxidectin, which mediated 60-88% reduction in L4 larvae at 14-28 days. Future adoption of the mouse model as a first-line efficacy screen will benefit end-user laboratories conducting research and development of novel heartworm preventatives via increased access, rapid turnaround and reduced costs whilst simultaneously decreasing need for experimental cat or dog use.

microbiology↗

bioRxiv2020

A cross-species drug discovery pipeline to identify and validate new treatments for osteosarcoma

PurposeOsteosarcoma is a rare but aggressive bone cancer that occurs primarily in children. Like other rare cancers, treatment advances for osteosarcoma have stagnated, with little improvement in survival for the past several decades. Developing new treatments has been hampered by extensive genomic heterogeneity and limited access to patient samples to study the biology of this complex disease. Experimental designTo overcome these barriers, we combined the power of comparative oncology with patient-derived models of cancer and high-throughput chemical screens in a cross-species drug discovery pipeline. ResultsCoupling in vitro high-throughput drug screens on low-passage and established cell lines with in vivo validation in patient-derived xenografts we identify the proteasome and CRM1 nuclear export pathways as therapeutic sensitivities in osteosarcoma, with dual inhibition of these pathways inducing synergistic cytotoxicity. ConclusionsThese collective efforts provide an experimental framework and set of new tools for osteosarcoma and other rare cancers to identify and study new therapeutic vulnerabilities.

cancer biology↗