Publications by authors named "Derek Clements"

The recruitment of monocytes and their differentiation into immunosuppressive cells is associated with the low efficacy of preclinical nonconformal radiotherapy (RT) for tumors. However, nonconformal RT (non-CRT) does not mimic clinical practice, and little is known about the role of monocytes after RT modes used in patients, such as conformal RT (CRT). Here, we investigated the acute immune response induced by after CRT.

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  • The development of transgenic mouse models has become easier with the introduction of a new system called SELECTIV, which efficiently expresses genes in specific cell types.
  • This system uses adeno-associated virus (AAV) vectors combined with Cre-inducible overexpression of the AAV receptor (AAVR), significantly improving the transduction process in various cells, including muscle stem cells that normally resist AAV.
  • SELECTIV also enhances specificity by using a whole-body knockout approach to remove the endogenous AAVR, offering better targeting in different tissues, which can lead to improved mouse models and gene delivery methods.
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  • - CD8 T cells are crucial for fighting viruses, and type I interferons quickly activate them after viral exposure, leading to changes in their behavior.
  • - The study reveals that exposure to reovirus activates naïve CD8 T cells within 24 hours, highlighting a previously overlooked role of these cells in the immune response.
  • - The activation of naïve CD8 T cells is dependent on a protein called STAT1 and is influenced by a metabolic process involving nicotinamide phosphoribosyl transferase (NAMPT), suggesting new insights into immune responses to viruses.
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Background: Immunotherapy with checkpoint inhibitors has shown impressive results in patients with melanoma, but still many do not benefit from this line of treatment. A lack of tumor-infiltrating T cells is a common reason for therapy failure but also a loss of intratumoral dendritic cells (DCs) has been described.

Methods: We used the transgenic tg(Grm1)EPv melanoma mouse strain that develops spontaneous, slow-growing tumors to perform immunological analysis during tumor progression.

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The efficacy of oncolytic viruses (OVs), such as reovirus, is dictated by host immune responses, including those mediated by the pro- versus anti-inflammatory macrophages. As such, a detailed understanding of the interaction between reovirus and different macrophage types is critical for therapeutic efficacy. To explore reovirus-macrophage interactions, we performed tandem mass tag (TMT)-based quantitative temporal proteomics on mouse bone marrow-derived macrophages (BMMs) generated with two cytokines, macrophage colony stimulating factor (M-CSF) and granulocytic-macrophage colony stimulating factor (GM-CSF), representing anti- and proinflammatory macrophages, respectively.

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Little is known about how genetic variations in viruses affect their success as therapeutic agents. The type 3 Dearing strain of (T3D) is undergoing clinical trials as an oncolytic virotherapy. Worldwide, studies on reovirus oncolysis use T3D stocks propagated in different laboratories.

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  • * A study using reovirus in a mouse model of ovarian cancer revealed that reovirus alters the tumor's MHC-I ligand expression, which represents new tumor antigens presented to the immune system.
  • * The MHC-I ligands generated by reovirus treatment not only appeared in tumor tissues but also triggered effective immune responses in CD8 T cells, suggesting they could enhance the effectiveness of OV-based cancer therapies.
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  • * The study revealed that cancer cells' response to reovirus infection is linked to changes in their metabolism, particularly involving pyruvate and oxidative stress, which influences their overall susceptibility to the virus.
  • * Therapeutically, enhancing the activity of an enzyme called pyruvate dehydrogenase (PDH) in cancer cells can make them more vulnerable to reovirus treatment, suggesting that modifying cancer cell metabolism could be an effective strategy to improve oncolytic virus therapies.
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Background/aims: The oxidative stress sensor transient receptor potential melastatin-2 (TRPM2) ion channel has recently gained attention in many types of cancer. The lung tissue is highly susceptible to oxidative stress-mediated injury and diseases; therefore, we aimed to determine whether TRPM2 plays an essential role in protecting lung cancer cells from oxidative damage while promoting cancer cell survival and metastasis.

Methods: We used two non-small cell lung (NSCLC) cell lines A549 and H1299 as a lung cancer model.

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Transient Receptor Potential Melastatin-2 (TRPM2) ion channel is emerging as a great therapeutic target in many types of cancer, including gastric cancer - a major health threat of cancer related-death worldwide. Our previous study demonstrated the critical role of TRPM2 in gastric cancer cells bioenergetics and survival; however, its role in gastric cancer metastasis, the major cause of patient death, remains unknown. Here, using molecular and functional assays, we demonstrate that TRPM2 downregulation significantly inhibits the migration and invasion abilities of gastric cancer cells, with a significant reversion in the expression level of metastatic markers.

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  • MHC-I peptides, which are important for activating CD8 T cells in the immune response, are often not well understood, especially regarding the specific ligands involved in antitumor responses.
  • Researchers developed a new multiplexing platform using tandem mass tags (TMTs) to quantify changes in MHC-I ligands following cancer therapies.
  • Their study focused on doxorubicin, showing it induces MHC-I peptides from proteins involved in cell cycle and mitosis, potentially enhancing the effectiveness of CD8 T-cell-based immunotherapies.
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  • Oncolytic viruses can specifically attack and destroy cancer cells while also triggering an immune response that enhances tumor-specific immunity.
  • In 2015, the FDA approved T-VEC, an oncolytic herpes simplex virus, for the treatment of advanced melanoma.
  • Numerous trials have since been launched to evaluate the safety and effectiveness of different oncolytic viruses for various types of cancer.
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NAD is a key metabolic redox cofactor that is regenerated from nicotinamide through the NAD salvage pathway. Here, we find that inhibiting the NAD salvage pathway depletes serine biosynthesis from glucose by impeding the NAD-dependent protein, 3-phosphoglycerate dehydrogenase (PHGDH). Importantly, we find that PHGDH breast cancer cell lines are exquisitely sensitive to inhibition of the NAD salvage pathway.

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  • Reticulon-4 (RTN4), known as Nogo, is linked to cancer progression, with lower levels correlating to better survival rates in patients with various cancers like lung and breast cancer.
  • Research using mass spectrometry revealed that knocking down RTN4 affects key processes like lipid homeostasis and AKT signaling, which are important for cancer cell survival and growth.
  • RTN4 deficiency not only inhibited cancer cell proliferation in lab tests and animal models but also enhanced the effectiveness of chemotherapy, suggesting it could be a potential target for cancer treatment.
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Avoiding detection and destruction by immune cells is key for tumor initiation and progression. The important role of cancer stem cells (CSCs) in tumor initiation has been well established, yet their ability to evade immune detection and targeting is only partly understood. To investigate the ability of breast CSCs to evade immune detection, we identified a highly tumorigenic population in a spontaneous murine mammary tumor based on increased aldehyde dehydrogenase activity.

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Proteoglycans are promising therapeutic targets in Multiple Sclerosis (MS), because they regulate many aspects of the immune response. This was studied using surfen, an agent that binds both heparan sulphate proteoglycans (HSPGs) and chondroitin sulphate proteoglycans (CSPGs). Initial cell culture work on bone marrow derived macrophages (BMDMs) found that surfen reduced concentrations of the chemokines CCL2, CCL4 and CCL5, with reduced messenger (m)RNA expression for Tumor Necrosis Factor, IL-6, IL-1β and inducible nitric oxide synthase.

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  • Myeloid cells are crucial for fighting viral infections, but their differentiation during acute infections is not well understood.
  • The study introduced a new method called quantitative temporal in vivo proteomics (QTiPs) to analyze the changes in these cells during viral infections, focusing on their interactions with the host.
  • Findings revealed that inflammatory CD11b, Ly6G, and Ly6C cells transition into M2-like macrophages later in the infection, enhancing their ability to present antigens and respond metabolically.
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  • The effectiveness of CD8 T cells, crucial for T-cell immunotherapies, relies on the peptide ligands presented by Class I MHC (MHC-I) molecules, whose identification has been advanced by mass spectrometry (MS).
  • Current methods face challenges in matching MS spectra to reference proteomes due to large search spaces, which hampers the discovery of MHC ligands efficiently.
  • The authors introduced a targeted database search tool called SpectMHC, improving peptide identification over 2-fold in mouse and human studies, thereby enhancing the discovery of new T-cell epitopes for potential therapeutic applications.
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Pluripotency is an important feature of cancer stem cells (CSCs) that contributes to self-renewal and chemoresistance. The maintenance of pluripotency of CSCs under various pathophysiological conditions requires a complex interaction between various cellular pathways including those involved in homeostasis and energy metabolism. However, the exact mechanisms that maintain the CSC pluripotency remain poorly understood.

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Breast cancer subtyping, based on the expression of hormone receptors and other genes, can determine patient prognosis and potential options for targeted therapy. Among breast cancer subtypes, tumors of basal-like and claudin-low subtypes are typically associated with worse patient outcomes, are primarily classified as triple-negative breast cancers (TNBC), and cannot be treated with existing hormone-receptor-targeted therapies. Understanding the molecular basis of these subtypes will lead to the development of more effective treatment options for TNBC.

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Oncolytic viruses (OVs), a novel class of anticancer therapeutic agents, can overturn cancer-mediated immunosuppression and initiate antitumor immunity. Contrary to this paradigm, our recent study illustrates that oncolytic reovirus transiently augments cancer-associated immunosuppression immediately following its therapeutic administration. To achieve the optimum efficacy for OV-based anticancer therapies, the pathophysiological as well as clinical implications of this phenomenon need to be considered.

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Dendritic cells (DCs) are specialized antigen-presenting cells that have a notable role in the initiation and regulation of innate and adaptive immune responses. In the context of cancer, appropriately activated DCs can induce anti-tumor immunity by activating innate immune cells and tumor-specific lymphocytes that target cancer cells. However, the tumor microenvironment (TME) imposes different mechanisms that facilitate the impairment of DC functions, such as inefficient antigen presentation or polarization into immunosuppressive DCs.

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Tumor-associated immunosuppression aids cancer cells to escape immune-mediated attack and subsequent elimination. Recently, however, many oncolytic viruses, including reovirus, have been reported to overturn such immunosuppression and promote the development of a clinically desired antitumor immunity, which is known to promote favorable patient outcomes. Contrary to this existing paradigm, in this article we demonstrate that reovirus augments tumor-associated immunosuppression immediately following its therapeutic administration.

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Introduction: Incisional biopsies, including the diagnostic core needle biopsy (CNB), routinely performed before surgical excision of breast cancer tumors are hypothesized to increase the risk of metastatic disease. In this study, we experimentally determined whether CNB of breast cancer tumors results in increased distant metastases and examine important resultant changes in the primary tumor and tumor microenvironment associated with this outcome.

Method: To evaluate the effect of CNB on metastasis development, we implanted murine mammary 4T1 tumor cells in BALB/c mice and performed CNB on palpable tumors in half the mice.

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