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Biology subjects

Corn, K. C.

Publications and source records attributed to Corn, K. C..

5 recordsLinked to original sources

Radiotherapy-induced vascular dysfunction alters neutrophil phenotype to promote tumor cell colonization of mammary adipose tissue

Recurrence remains a significant clinical challenge for triple-negative breast cancer patients and radiotherapy (RT) is a key therapeutic tool that significantly reduces the risk of relapse. Despite this, patients with chronic lymphopenia and a high neutrophil:lymphocyte ratio (NLR) experience recurrence at significantly higher rates than those whose hematological biomarkers return to baseline post-RT, and there are currently no treatments to prevent this relapse. Here, we utilized in vivo mouse models of lymphocyte-deficiency to identify the mechanism behind systemic immune status and recurrence. Using a model of RT-induced circulating tumor cell (CTC) colonization, we found that neutrophils are sustained in the irradiated, lymphocyte-deficient mammary tissue up to 10 days post-RT. Persistent neutrophil accumulation was accompanied by excessive vascular remodeling and tumor cell colonization of the mammary tissue, both of which were abated upon systemic neutrophil depletion. Neutrophils in the colonization-permissive microenvironment exhibited a state of pathological activation consistent with a polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) phenotype that was not seen in systemic compartments, highlighting a microenvironment-induced phenotype shift. This phenotype was recapitulated in vitro when naive neutrophils were exposed to the secretome of RT-induced senescent endothelial cells (ECs). We found that these activated neutrophils then regulated the dysfunction of irradiated ECs in a canonical NF-kB-dependent manner, increasing their barrier permeability and activating downstream inflammatory signals. Our findings not only establish neutrophils as a critical component of tumor cell colonization in lymphocyte-deficient subjects but also uncover a positive feedback loop between neutrophils and irradiated vasculature that leads to aberrant tissue remodeling and ultimately tumor cell colonization. This work deepens our understanding of how systemic factors influence treatment-damaged microenvironments, which could ultimately lead to identification of molecular targets for prevention of RT failure.

cancer biology↗

Encoded cell-material interactions to reroute cytokine signaling for regenerative medicine

Regenerative engineering harnesses materials science and stem cell biology to develop strategies to repair damaged and diseased tissue. Despite advances in designer materials, few techniques effectively provide auto-regulated feedback mechanisms that govern how cells sense and respond to discrete microenvironmental changes. Here, we demonstrate that the artificial, juxtacrine-like receptor synthetic Notch (synNotch) can be activated by endogenous multimeric cytokines in solution, without immobilizing materials, revealing a previously unreported activation modality and yielding up to 24-fold dynamic range. To broaden synNotch sensing to monomeric cytokines, we developed nMATRIX, a co-engineered material-cell platform that detects endogenous, soluble ligands and routes them to programmed gene circuits with spatially confined effects. nMATRIX can be tuned to recognize the interleukins IL-1{beta} and IL-6 using synNotch receptors plus cognate biomaterials, yielding up to 68-fold dynamic range and converting these inflammatory inputs into orthogonal outputs that reprogram nearby cell phenotypes. nMATRIX functions across multiple cell types and can incorporate the synNotch-related SNIPR synthetic receptor platform. nMATRIX repurposed inflammatory signals and converted them into anti-inflammatory cues to polarize macrophages (increased CD163, CD206; decreased CD86). Thus, nMATRIX couples native soluble cues to customized cellular responses with tunable sensitivity, offering a flexible materials-based approach for self-regulating regenerative therapies.

bioengineering↗

miR-100 and miR-125b Contribute to Enhanced Growth and Invasiveness

Extracellular communication via the transfer of vesicles and nanoparticles is now recognized to play an important role in tumor microenvironment interactions. Cancer cells upregulate and secrete abundant levels of miR-100 and miR-125b that can alter gene expression by both cell- and non-cell-autonomous mechanisms. We previously showed that these miRNAs activate Wnt signaling in colorectal cancer (CRC) through noncanonical pairing with 5 negative regulators of Wnt signaling. To identify additional targets of miR-100 and miR-125b, we used bioinformatic approaches comparing multiple CRC cell lines, including knockout lines lacking one or both of these miRNAs. From an initial list of 96 potential mRNA targets, we tested 15 targets with 8 showing significant downregulation in the presence of miR-100 and miR-125b. Among these, Cingulin (CGN) and Protein tyrosine phosphatase receptor type-R (PTPRR) are downregulated in multiple cancers, consistent with regulation by increased levels of miR-100 and miR-125b. We also show that increased cellular levels of miR-100 and miR-125b enhance 3D growth and invasiveness in CRC and glioblastoma cell lines. Lastly, we demonstrate that extracellular transfer of miR-100 and miR-125b can silence both reporter and endogenous mRNA targets in recipient cells and also increase the invasiveness of recipient spheroid colonies when grown under 3D conditions in type I collagen.

cancer biology↗

Radiation-Induced Metabolic Reprogramming of Fibroblasts Regulates the Breast Cancer Microenvironment

Patients with triple-negative breast cancer (TNBC) experience high recurrence rates despite current interventions, which includes radiation therapy (RT). Tumor cells thought to be involved in recurrence survive in part due to their interactions with irradiated fibroblasts following treatment. How fibroblasts metabolically respond to RT and influence the behavior of TNBC cells is poorly understood. In this study, we demonstrate that irradiated fibroblasts undergo a mitochondrial stress response that is regulated by autophagy, resulting in a metabolic profile characterized by high levels of mitochondrial respiration and fatty acid oxidation. This stress response in fibroblasts induces an aggressive phenotype in TNBC cells that is mitigated when fibroblast autophagy is blocked. Our work reveals how a metabolic stress response in irradiated fibroblasts and crosstalk with TNBC cells leads to a microenvironment conducive to recurrence. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/492249v3_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@181680aorg.highwire.dtl.DTLVardef@d58a1forg.highwire.dtl.DTLVardef@15f04eforg.highwire.dtl.DTLVardef@13cf5f9_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Mammary Tissue-Derived Extracellular Matrix Hydrogels Reveal the Role of the Irradiated Microenvironment in Breast Cancer Recurrence

Radiation therapy (RT) is essential for triple negative breast cancer (TNBC) treatment. However, patients with TNBC continue to experience recurrence after RT. The role of the extracellular matrix (ECM) of irradiated breast tissue in tumor recurrence is still unknown. In this study, we evaluated the structure, molecular composition, and mechanical properties of irradiated murine mammary fat pads (MFPs) and developed ECM hydrogels from decellularized tissues (dECM) to assess the effects of RT-induced ECM changes on breast cancer cell behavior. Irradiated MFPs were characterized by increased ECM deposition and fiber density compared to unirradiated controls, which may provide a platform for cell invasion and proliferation. ECM component changes in collagens I, IV, and VI, and fibronectin were observed following irradiation in both MFPs and dECM hydrogels. Encapsulated TNBC cell proliferation and invasive capacity was enhanced in irradiated dECM hydrogels. In addition, TNBC cells co-cultured with macrophages in irradiated dECM hydrogels induced M2 macrophage polarization and exhibited further increases in proliferation. Our study establishes that the ECM in radiation-damaged sites promotes TNBC invasion and proliferation as well as an immunosuppressive microenvironment. This work represents an important step toward elucidating how changes in the ECM after RT contribute to breast cancer recurrence.

cancer biology↗