Publications by authors named "Sarah Levesque"

Background: High activity of poly(ADP-ribose) polymerase-1 (PARP1) in non-small cell lung cancer (NSCLC) cells leads to an increase in immunohistochemically detectable PAR, correlating with poor prognosis in patients with NSCLC, as well as reduced tumor infiltration by cytotoxic T lymphocytes (CTLs). Intrigued by this observation, we decided to determine whether PARP1 activity in NSCLC cells may cause an alteration of anticancer immunosurveillance.

Methods: Continuous culture of mouse NSCLC cells in the presence of cisplatin led to the generation of cisplatin-resistant PAR clones.

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Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are chronic diseases in which cholangiocytes are primarily damaged. Although PSC is an inflammatory condition predisposing to CCA, CCA is almost never found in the autoimmune context of PBC.

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Salicylate, the active derivative of aspirin (acetylsalicylate), recapitulates the mode of action of caloric restriction inasmuch as it stimulates autophagy through the inhibition of the acetyltransferase activity of EP300. Here, we directly compared the metabolic effects of aspirin medication with those elicited by 48 h fasting in mice, revealing convergent alterations in the plasma and the heart metabolome. Aspirin caused a transient reduction of general protein acetylation in blood leukocytes, accompanied by the induction of autophagy.

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Hormone receptor (HR) breast cancer (BC) causes most BC-related deaths, calling for improved therapeutic approaches. Despite expectations, immune checkpoint blockers (ICBs) are poorly active in patients with HR BC, in part reflecting the lack of preclinical models that recapitulate disease progression in immunocompetent hosts. We demonstrate that mammary tumors driven by medroxyprogesterone acetate (M) and 7,12-dimethylbenz[a]anthracene (D) recapitulate several key features of human luminal B HRHER2 BC, including limited immune infiltration and poor sensitivity to ICBs.

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Article Synopsis
  • Chemotherapy remains the primary treatment for most cancer types, with some drugs triggering immune responses that can lead to tumor shrinkage.
  • Researchers used an AI-based model to analyze 50,000 compounds and discovered that dactinomycin (DACT) is an effective anticancer agent that promotes immunogenic cell death (ICD).
  • The study found that DACT and other ICD stimulators commonly inhibit RNA transcription, highlighting this as a crucial step in triggering the immune response against tumors.
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We have recently shown that chemotherapy with immunogenic cell death (ICD)-inducing agents can be advantageously combined with fasting regimens or caloric restriction mimetics (CRMs) to achieve superior tumor growth control via a T cell-dependent mechanism. Here, we show that the blockade of the CD11b-dependent extravasation of myeloid cells blocks such a combination effect as well. Based on the characterization of the myeloid and lymphoid immune infiltrates, including the expression pattern of immune checkpoint proteins (and noting a chemotherapy-induced overexpression of programmed death-ligand 1, PD-L1, on both cancer cells and leukocytes, as well as a reduced frequency of exhausted CD8 T cells positive for programmed cell death 1 protein, PD-1), we then evaluated the possibility to combine ICD inducers, CRMs and targeting of the PD-1/PD-L1 interaction.

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Local immunotherapies such as the intratumoral injection of oncolytic compounds aim at reinstating and enhancing systemic anticancer immune responses. LTX-315 is a first-in-class, clinically evaluated oncolytic peptide-based local immunotherapy that meets these criteria. Here, we show that LTX-401, yet another oncolytic compound designed for local immunotherapy, depicts a similar safety profile and that sequential local inoculation of LTX-401 was able to cure immunocompetent host from subcutaneous MCA205 and TC-1 cancers.

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Dietary interventions have a profound impact on whole body metabolism, including oncometabolism (the metabolic features allowing cancer cells to proliferate) and immunometabolism (the catabolic and anabolic reactions that regulate immune responses). Recent preclinical studies demonstrated that multiple dietary changes can improve anticancer immunosurveillance of chemo-, radio- and immunotherapy. These findings have fostered the design of clinical trials evaluating the capacity of dietary interventions to synergize with treatment and hence limit tumor progression.

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Article Synopsis
  • The article initially had a spelling mistake in the author's name, listed as Xia Lin instead of Lin Xia.
  • This error has been fixed in both the PDF and HTML formats of the article.
  • The correction ensures that the author is properly credited in the publication.
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Immunogenic cell death (ICD) converts dying cancer cells into a therapeutic vaccine and stimulates antitumor immune responses. Here we unravel the results of an unbiased screen identifying high-dose (10 µM) crizotinib as an ICD-inducing tyrosine kinase inhibitor that has exceptional antineoplastic activity when combined with non-ICD inducing chemotherapeutics like cisplatin. The combination of cisplatin and high-dose crizotinib induces ICD in non-small cell lung carcinoma (NSCLC) cells and effectively controls the growth of distinct (transplantable, carcinogen- or oncogene induced) orthotopic NSCLC models.

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The treatment of breast cancer largely depends on the utilization of immunogenic chemotherapeutics, which, as a common leitmotif, stimulate the exposure of calreticulin (CALR) on the surface of cancer cells, thereby facilitating their recognition by dendritic cells for the uptake of tumor-associated antigens and subsequent antigen cross-presentation to cytotoxic T cells. Breast cancer cells also express the calreticulin antagonist CD47, which inhibits tumor cell phagocytosis and consequently subverts anticancer immune responses. Here, we treated carcinogen-induced or transplantable mouse models of cancer by a CD47 blocking antibody that was at least as efficient as chemotherapy and that could be favorably combined with the anthracycline mitoxantrone in the context of carcinogen-induced orthotopic breast cancers.

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Article Synopsis
  • 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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The efficacy of cancer therapies strongly relies on their ability to reinstate cancer immunosurveillance. Numerous biomedical approaches with immunotherapeutic activity have been developed to reeducate the host immune system to detect and clear tumor cells. Cytotoxicants have been primarily designed to slow down malignant cell proliferation and to induce programmed cell death.

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Article Synopsis
  • Cisplatin is a common chemotherapy drug, but many cancer cells develop resistance to it, which complicates treatment.
  • Researchers studied cisplatin-resistant lung and ovarian cancer cell lines and found they were more susceptible to starvation, particularly due to their heavy reliance on glutamine.
  • By manipulating glutamine levels, they discovered that reducing glutamine restored sensitivity to cisplatin, while supplementing it helped resistant cells survive starvation, indicating a potential therapeutic strategy involving antimetabolites that disrupt nucleoside metabolism.
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Starvation is a strong physiological stimulus of macroautophagy/autophagy. In this study, we addressed the question as to whether it would be possible to measure autophagy in blood cells after nutrient deprivation. Fasting of mice for 48 h (which causes ∼20% weight loss) or starvation of human volunteers for up to 4 d (which causes <2% weight loss) provokes major changes in the plasma metabolome, yet induces only relatively minor alterations in the intracellular metabolome of circulating leukocytes.

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Cancer can be viewed in 2 rather distinct ways, namely (i) as a cell-autonomous disease in which malignant cells have escaped control from cell-intrinsic barriers against proliferation and dissemination or (ii) as a systemic disease that involves failing immune control of aberrant cells. Since macroautophagy/autophagy generally increases the fitness of cells as well as their resistance against endogenous or iatrogenic (i.e.

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Caloric restriction mimetics (CRMs) mimic the biochemical effects of nutrient deprivation by reducing lysine acetylation of cellular proteins, thus triggering autophagy. Treatment with the CRM hydroxycitrate, an inhibitor of ATP citrate lyase, induced the depletion of regulatory T cells (which dampen anticancer immunity) from autophagy-competent, but not autophagy-deficient, mutant KRAS-induced lung cancers in mice, thereby improving anticancer immunosurveillance and reducing tumor mass. Short-term fasting or treatment with several chemically unrelated autophagy-inducing CRMs, including hydroxycitrate and spermidine, improved the inhibition of tumor growth by chemotherapy in vivo.

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Objective: Food guides are important tools for nutrition education. While developing a food guide in Benin, the objective was to determine the daily number of servings per food group and the portion sizes of common foods to be recommended.

Design: Linear programming (LP) was used to determine, for each predefined food group, the optimal number and size of servings of commonly consumed foods.

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