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Dantzer, R.

Publications and source records attributed to Dantzer, R..

5 recordsLinked to original sources

Activation of the cGAS-STING pathway contributes to cancer-related fatigue in a murine model of head and neck cancer

Cancer-related inflammation and metabolic alterations extend beyond the tumor microenvironment, exerting systemic effects that disrupt energy homeostasis and contribute to reduced physical function and chronic fatigue. The cGAS-STING pathway has emerged as a key regulator of innate immunity and inflammation; however, its role in cancer-associated fatigue remains poorly understood. In this study, we investigated the contribution of cGAS- STING-mediated inflammation to cancer- and/or its treatment-induced fatigue using a mouse model of human papillomavirus-related head and neck cancer. Wheel running activity, along with inflammatory and metabolic changes in tumor and liver tissues, were assessed following chemoradiotherapy and pharmacological inhibition of STING in tumor-bearing and tumor-free control mice. The results revealed that tumor growth and chemoradiotherapy activated the cGAS-STING pathway, together with an upregulation of proinflammatory mediators and alterations of mitochondrial and metabolic gene expression in the liver. To inhibit STING activation, mice were administered H-151, a specific STING antagonist. This intervention attenuated hepatic inflammatory signatures and mitigated tumor and/or chemoradiotherapy-associated behavioral fatigue measured by decreased voluntary wheel running. These findings implicate for the first time the cGAS-STING signaling pathway and metabolic homeostasis in cancer- and cancer therapy-related fatigue.

cancer biology↗

Tumor-infiltrating nerves functionally alter brain circuits and modulate behavior in a male mouse model of head-and-neck cancer

Cancer patients often experience changes in mental health, prompting an exploration into whether nerves infiltrating tumors contribute to these alterations by impacting brain functions. Using a mouse model for head and neck cancer and neuronal tracing we show that tumor-infiltrating nerves connect to distinct brain areas. The activation of this neuronal circuitry altered behaviors (decreased nest-building, increased latency to eat a cookie, and reduced wheel running). Tumor-infiltrating nociceptor neurons exhibited heightened calcium activity and brain regions receiving these neural projections showed elevated Fos as well as increased calcium responses compared to non-tumor-bearing counterparts. The genetic elimination of nociceptor neurons decreased brain Fos expression and mitigated the behavioral alterations induced by the presence of the tumor. While analgesic treatment restored nesting and cookie test behaviors, it did not fully restore voluntary wheel running indicating that pain is not the exclusive driver of such behavioral shifts. Unraveling the interaction between the tumor, infiltrating nerves, and the brain is pivotal to developing targeted interventions to alleviate the mental health burdens associated with cancer. Significance StatementHead and neck cancers are infiltrated by sensory nerves which connect to a pre-existing circuit that includes areas in the brain. Neurons within this circuit are altered and mediate modifications in behavior.

cancer biology↗

Tonic Meningeal Interleukin-10 Upregulates Delta Opioid Receptor to Prevent Relapse to Pain

Chronic pain often alternates between transient remission and relapse of severe pain. While most research on chronic pain has focused on mechanisms maintaining pain, there is a critical unmet need to understand what prevents pain from re-emerging in those who recover from acute pain. We found that interleukin (IL)-10, a pain resolving cytokine, is persistently produced by resident macrophages in the spinal meninges during remission from pain. IL-10 upregulated expression and analgesic activity of {delta}-opioid receptor ({delta}OR) in the dorsal root ganglion. Genetic or pharmacological inhibition of IL-10 signaling or {delta}OR triggered relapse to pain in both sexes. These data challenge the widespread assumption that remission of pain is simply a return to the naive state before pain was induced. Instead, our findings strongly suggest a novel concept that: remission is a state of lasting pain vulnerability that results from a long-lasting neuroimmune interactions in the nociceptive system.

neuroscience↗

Enteral Activation of WR-2721 Mediates Radioprotection and Improved Survival from Lethal Fractionated Radiation

Unresectable pancreatic cancer is almost universally lethal because chemotherapy and radiation cannot completely stop the growth of the cancer. The major problem with using radiation to approximate surgery in unresectable disease is that the radiation dose required to ablate pancreatic cancer exceeds the tolerance of the nearby duodenum. WR-2721, also known as amifostine, is a well-known radioprotector, but has significant clinical toxicities when given systemically. WR-2721 is a prodrug and is converted to its active metabolite, WR-1065, by alkaline phosphatases in normal tissues. The small intestine is highly enriched in these activating enzymes, and thus we reasoned that oral administration of WR-2721 just before radiation would result in localized production of the radioprotective WR-1065 in the small intestine, providing protective benefits without the significant systemic side effects. Here, we show that oral WR-2721 is as effective as intraperitoneal WR-2721 in promoting survival of intestinal crypt clonogens after morbid irradiation. Furthermore, oral WR-2721 confers full radioprotection and survival after lethal upper abdominal irradiation of 12.5Gy x 5 fractions (total of 62.5Gy, D2EQ=140.6Gy), which would likely ablate pancreatic cancer. We find that the efficacy of oral WR-2721 stems from its selective accumulation in the intestine, but not in tumors or other normal tissues, as determined by in vivo mass spectrometry analysis. Thus, we demonstrate that oral WR-2721 is a well-tolerated, and quantitatively selective, radioprotector of the intestinal tract that is capable of enabling clinically relevant ablative doses of radiation to the upper abdomen without unacceptable gastrointestinal toxicity.

cancer biology↗

Cancer exosomes induce tumor neo-neurogenesis potentiating tumor growth

Patients with densely innervated tumors do worse than those with less innervated cancers. We hypothesize that neural elements are acquired by a tumor-induced process, called neo-neurogenesis. Here, we use PC12 cells in a simple system to test this hypothesis. PC12 cells extend processes, called neurites, only when appropriately stimulated. Using this system, we show that patient tumors release vesicles (exosomes) which induce PC12 neurite outgrowth. Using a cancer mouse model, we show that tumor cells compromised in exosome release grow slower and are less innervated than controls indicating a contribution of innervation to disease progression. We find that neo-neurogenesis is mediated in part by the axonal guidance molecule, EphrinB1, contained in exosomes. These findings support testing EphrinB1 blockers to inhibit tumor innervation and improve survival.\n\nOne Sentence SummaryTumors release exosomes which not only promote their own innervation but also potentiate their growth.

cancer biology↗