Cancer cachexia, responsible for up to 30% of cancer deaths, has transitioned conceptually from a mere nutritional deficit into a highly coordinated, multi-organ immunometabolic network that systematically dismantles host homeostasis. This review synthesizes the paradigm-shifting discoveries that position the immune system as the central conductor of tissue wasting. We delineate how redundant inflammatory cascades, neuro-immune circuits, and local cellular plasticity converge to drive muscle and adipose catabolism. Furthermore, we dissect the metabolic competition for nutrients between tumor cells and host immunity, which accelerates structural degradation. Finally, we highlight how single-cell multiomics, spatial transcriptomics, and artificial intelligence are redefining clinical stratification, shifting the therapeutic horizon toward individualized, multi-node immunometabolic interventions, thereby providing a theoretical framework for the management of cachectic wasting syndrome.

Peripheral nerves are emerging regulators of the tumor microenvironment, but how sensory innervation shapes breast cancer immunity remains poorly defined. Here we show that triple-negative breast cancers (TNBCs) co-opt nociceptor neurons to suppress antitumor immunity and promote disease progression. Across orthotopic TNBC models, we found that primary tumors and tumor-draining lymph nodes were densely innervated by CGRP⁺ sensory fibers. Tumor-derived cues directly activated dorsal root ganglion neurons, increased calcium responsiveness, induced Ngfr and Atf3, and triggered release of CGRP and substance P. Mechanistically, a tumor-derived proNGF-NGFR axis reprogrammed nociceptors and promoted neuropeptide secretion. Soluble mediators from activated nociceptors suppressed CD8⁺ T cell-mediated tumor-cell killing, whereas sensory-neuron silencing or ablation curtailed tumor growth and remodeled the immune microenvironment toward dendritic-cell activation, myeloid reprogramming, and enhanced CD8⁺ T cell and NK-cell effector states. Subset-specific analysis revealed nonredundant sensory control of immune states, with MrgD⁺ neurons selectively shaping macrophage-centered programs. Finally, blockade of CGRP signaling through RAMP1 reduced tumor growth and markedly enhanced PD-1 blockade, nearly eliminating primary tumor burden and lung metastasis in vivo. T cell-specific Ramp1 deletion similarly restrained tumor growth, and RAMP1⁺ CD8⁺ T cells in human TNBC displayed an exhaustion-associated phenotype. Together, these findings define a tumor-promoting proNGF-nociceptor-CGRP-RAMP1 axis and identify neuroimmune signaling as a therapeutically actionable vulnerability in TNBC.

Tumor-infiltrating nerves play critical roles in promoting tumor growth and progression; however, the mechanisms that drive tumor innervation remain unclear. Upon transformation, tumors recruit surrounding peripheral nerves into the tumor microenvironment (TME) to obtain their own innervation, a process called axonogenesis. While in vitro studies suggest tumor cell-derived neurotrophins, such as brain-derived neurotrophic factor (BDNF), drive axonogenesis, this has yet to be demonstrated in vivo. During wound healing, macrophages are the primary source of neurotrophins. Given the critical role of macrophages in breast cancer growth, we investigated whether these immune cells drive tumor axonogenesis in breast tumors in vivo. Syngeneic Py230 mouse triple-negative breast cancer (TNBC) cells were transplanted into intact mice and mice lacking immune-derived BDNF. Bone marrow-derived macrophages from either wild-type or immune-BDNF-deficient mice were transplanted into tumor-bearing recipients to determine if macrophage-derived BDNF was sufficient to restore tumor growth and innervation. We found that transplanted TNBC cannot grow in the absence of immune-derived BDNF, and that depletion of macrophages from the TME compromises tumor innervation. Remarkably, the introduction of wild-type macrophages restores tumor growth and innervation in mice lacking immune-derived BDNF, demonstrating that macrophages are both necessary and sufficient for tumor axonogenesis in vivo. In the absence of sensory tumor innervation, tumor growth was significantly reduced. Moreover, targeting BDNF signaling diminished TNBC growth and innervation. Our findings identify macrophages as the critical source of BDNF driving axonogenesis in breast cancer and suggest that selectively targeting BDNF signaling could provide a novel therapeutic strategy for treating TNBC through compromising tumor innervation.

This study aimed the standardization of detection, isolation, titration, replication kinetics, and virus neutralization assay protocols for DENV-2 (New Guinea C strain) with the C6/36 mosquito-derived cell line. DENV-2 was isolated, titrated by TCID₅₀, and quantified via molecular assays using serially diluted viral RNA to generate a standard curve using the C6/36 cell line. The serum neutralization assay was optimized in 96-well plates based on visual scoring of cytopathic effect (CPE). Optimized serum dilutions effectively reduced nonspecific cytotoxicity caused by residual complement, preventing misinterpretation and enabling reliable detection of serum neutralizing activity in C6/36 cells. RT-qPCR assays calibrated using a TCID₅₀-titrated DENV-2 viral stock showed high amplification efficiency (90–100

Takotsubo cardiomyopathy (TTC) is an acute stress-induced cardiac syndrome that predominantly affects women and is driven by surges in catecholamines that excessively activate β-adrenergic receptors (βARs). Although β1AR signaling mediates much of the injury, β2ARs have recognized cytoprotective roles in other cardiac settings, yet their contribution to TTC-associated remodeling remains unclear. To address this gap, we induced a TTC-like phenotype in female wild-type (WT) and β2AR-deficient (β2AR-/-) mice with a single high dose of isoproterenol (ISO). After ISO injection, β2AR-/- mice exhibited exacerbated myocardial injury, characterized by greater hypertrophy and higher levels of apoptosis and necrosis compared with WT/ISO mice. This heightened injury was accompanied by a more robust inflammatory response, including increased inflammatory score, enhanced CD68+ macrophage infiltration, and marked recruitment of CCR2+MHC-IIlow monocytes. β2AR-/-/ISO hearts also displayed more extensive interstitial fibrosis. Because fibrosis is a key driver of long-term functional decline, we isolated cardiac fibroblasts (CFs) and characterized their activation state. CFs from β2AR-/-/ISO hearts displayed a significantly higher percentage of α-SMA+ cells, increased Collagen 3 and MMP-2 staining, along with upregulation of profibrotic genes (Col1a1, Col3a1, Fap). Functionally, β2AR-/-/ISO CFs exhibited an activated molecular signature enriched in cytokines and growth factors, and their conditioned media induced greater hypertrophy in neonatal cardiomyocytes, revealing a potent paracrine contribution to the remodeling process. These findings demonstrate that the female heart relies on β2AR signaling to limit acute catecholamine-induced injury, underscoring the potential of β2AR-targeted interventions as therapeutic strategies in a Takotsubo-like setting.NEW & NOTEWORTHY Takotsubo cardiomyopathy (TTC) disproportionately affects women and is driven by excessive β-adrenergic receptor (βAR) activation. We show that loss of β2AR signaling exacerbates myocardial injury, creating a proinflammatory and profibrotic milieu that amplifies fibroblast activation and reshapes their paracrine profile. These activated cardiac fibroblasts (CFs) further sustain cardiomyocyte hypertrophy, perpetuating the injury loop in β2AR-deficient hearts. These findings establish β2AR as a determinant of cardiac resilience and support β2AR-directed strategies as interventions in the acute phase of TTC.

Photobiomodulation (PBMT) speeds up wound healing, partly by attracting pericytes. However, its specific mechanisms in a diabetic setting are still not well understood. We studied tissue regeneration after PBMT using a transgenic mouse model (NG2+DsRed/Nestin+GFP) with streptozotocin-induced Type 1 diabetes. PBMT was applied daily (660 nm, 20 mW, 7 s, 0.14 J, 0.71 W/cm2, 5 J/cm2). Our results showed increased lumen area of pericyte-covered vessels and significant flow of perivascular and neural progenitor cells in PBMT-treated wounds. We also saw an increase in the pro-resolving cytokine IL-1RA after irradiation. PBMT did not change levels of GLUT1, TNF, IL-1α, or NF-κB in the chronic inflammatory environment. Diabetic cells treated with PBMT showed limited proliferation and migration but had improved ability for adipogenic differentiation. Despite only modest changes in the inflammatory microenvironment, photobiomodulation notably accelerates tissue repair by directly encouraging pericyte and neural progenitors entry into the wound bed.

The nervous system drives tumor growth directly through intra-tumoral axons and indirectly through the systemic action of hormones. Yet contexts where the nervous system inhibits tumor growth are less defined. Here, we performed optical reconstruction of axonal innervation in mouse models of cutaneous melanoma, revealing progressive innervation by sympathetic axons. Local depletion of these axons accelerates while local optogenetic activation slows melanoma growth, together consistent with these axons acting as a physiological growth brake. The sympathetic nervous system is typically associated with driving tumor growth through activation of β-adrenergic receptors (ARs). Here, we find that the initial tumor seeding conditions sensitize melanomas from βAR-driven growth promotion toward α2-AR-driven growth inhibition. Mechanistically, the axonal activation of α2 ARs restricts the number and distribution of pro-tumor myeloid cells, independently of T cell activity. Together, our data reveal context-dependent, bidirectional neural control of tumor progression.

Pseudogenes, gene copies presumed nonfunctional, are widespread products of genome evolution, yet their retention under selection and functional significance across vertebrate diversity remain poorly understood. Here, by analyzing 244 high-quality, chromosome-scale genomes from the Vertebrate Genomes Project spanning seven major vertebrate lineages, we show that the most abundant class of pseudogenes, processed pseudogenes (retrocopies), is a dynamic substrate for evolutionary innovation rather than an inert relic. Retrocopy abundance varies by more than an order of magnitude across lineages, closely tracks autonomous retrotransposon content, and a considerable fraction retains intact open reading frames under purifying selection. We establish a two-stage model in which a conserved formation bias toward highly expressed housekeeping genes is followed by lineage-specific selective filtering that shapes distinct functional repertoires. Testing this model, we show that the mammalian X chromosome exports retrocopies to autosomes at significantly elevated rates enriched for functionally constrained copies, establishing meiotic sex chromosome inactivation as the selective driver. Furthermore, tumor suppressor gene retrocopies accumulate preferentially over oncogene retrocopies in large-bodied and long-lived mammalian lineages, identifying retrocopy-mediated tumor suppressor dosage expansion as a previously unrecognized genomic correlate of Peto's paradox. Beyond cancer-related dynamics, retrocopy abundance itself correlates with key mammalian life-history traits, including brain mass, generation length, and reproductive timing, which suggests that retrocopy turnover is broadly coupled to organismal pace-of-life. These findings recast retrocopies as a major axis of vertebrate genome evolution and provide a comprehensive resource for studying gene duplicate innovation.

Increasing evidence suggests that the sympathetic nervous system profoundly interacts with skeletal muscle, influencing both muscle fiber function and composition. β2-ARs, the predominant adrenergic receptor subtype in muscle fibers, have been shown to enhance protein synthesis, reduce protein degradation, facilitate muscle contraction and relaxation, and improve neuromuscular junction (NMJ) transmission upon activation. In this study, we investigated the effects of Formoterol, a highly selective β2-adrenoceptors (β2-AR) agonist, on the presynaptic terminal of motor neurons. We used myography, FM1-43 fluorescent dye assays, and transmission electron microscopy (TEM) to evaluate the NMJ following β2-AR activation. We demonstrated that β2-AR activation by Formoterol enhances muscle contractility and both spontaneous and evoked exocytosis of acetylcholine (ACh)-containing synaptic vesicles at the mouse diaphragm NMJ. Formoterol-induced morphological changes in diaphragmatic NMJs were consistent with increased exo-endocytic activity. Notably, Formoterol-evoked exocytosis displayed sexual dimorphism, with females showing a significantly milder response compared to males. In females, Formoterol-induced synaptic vesicles exocytosis was mediated solely by P/Q-type voltage-activated Ca2+ channels, whereas in males, it involved both P/Q-type channels, transient receptor potential channel of the vanilloid subtype (TRPV) 1 calcium channels, and an additional, yet unidentified, component. Orchiectomized males exhibited responses to Formoterol similar to the females, whereas ovariectomy did not modify female drug responses, indicating that male hormonal environment orchestrates the sex-differences herein described. These findings not only highlight the importance of sex-specific mechanisms but also reveal a novel effect of β2-AR activation directly on presynaptic terminals by Formoterol, enhancing exocytosis at the NMJ and thereby increasing neuromuscular transmission.

Bone pain is a presenting feature of bone cancers such as osteosarcoma (OS), relayed by skeletal-innervating peripheral afferent neurons. Potential functions of tumor-associated sensory neurons in bone cancers beyond pain sensation are unknown. To uncover neural regulatory functions, a chemical-genetic approach in mice with a knock-in allele for TrkA was used to functionally perturb sensory nerve innervation during OS growth and disease progression. TrkA inhibition in transgenic mice led to significant reductions in sarcoma-associated sensory innervation and vascularization, skewed tumor associated macrophage polarization, reduced tumor growth and metastasis, and prolonged overall survival. Single-cell transcriptomics revealed that sarcoma denervation was associated with phenotypic alterations in both OS tumor cells and cells within the tumor microenvironment, and with reduced calcitonin gene-related peptide (CGRP) and vascular endothelial growth factor (VEGF) signaling. Multimodal and multiomics analyses of human OS bone samples further implicated peripheral innervation and neurotrophin signaling in OS tumor biology. Next and in two parallel approaches to inhibit nerve ingrowth, we repurposed FDA-approved bupivacaine liposomes and separately blocked CGRP signaling using FDA-approved Rimegepant. Both strategies led to significant reductions in sarcoma growth, vascularity, and sarcoma-induced hyperalgesia. In sum, TrkA-expressing peripheral neurons positively regulate key aspects of OS progression and sensory neural inhibition disrupts CGRP signaling within the sarcoma microenvironment leading to significantly reduced tumor growth and improved survival. These data suggest that interventions to prevent pathological innervation of OS represent an adjunctive therapy to improve clinical outcomes and survival.

The emerging field of cancer neuroscience is rapidly evolving, driven by novel technologies and tools. These include advances in single-cell and spatial transcriptomics; genetic mouse models paired with automated high-throughput; and innovative optical electrophysiological approaches, optogenetics, chemogenetics, engineered viruses, and new methods for visualizing neuronal activity. Collectively, these technologies are revolutionizing how we investigate, manipulate, and characterize distinct components that contribute to the nervous system-cancer interface. In the present review, we discuss the key technologies that are closing the gap between oncology and neuroscience, highlighting the innovations that are propelling the cancer neuroscience field forward.

Breast cancer (BC) is a heterogeneous disease that can be molecularly classified based on the expression of the ERBB2 receptor (also known as HER2) and hormone receptors. Targeted therapies for HER2-positive BC, such as trastuzumab, antibody-drug conjugates (ADCs) and tyrosine kinase inhibitors, have improved patient outcomes, but primary/acquired resistance still poses challenges that can limit treatments' long-term efficacy. Addressing these obstacles is vital for enhancing therapeutic strategies and patient care. Alternative splicing, a post-transcriptional mechanism that enhances transcript diversity (isoforms), can produce proteins with varied functions, cellular localizations, or binding properties. Here, we comprehensively characterize the HER2 alternative splicing isoforms, assess their expression in primary BC patients and cell lines, and explore their role in resistance to anti-HER2 therapies. We expand the catalog of known HER2 protein-coding isoforms from 13 to 90, revealing distinct patterns of protein domains, cellular localizations, and protein structures, along with their antibody-binding sites. By profiling expression in 561 primary BC samples and mass spectrometry data, we discover a complex landscape of HER2 isoform, revealing novel transcripts that were previously unrecognized and are not assessed in routine clinical practice. Finally, the assessment of HER2 isoform expression in BC cell cultures sensitive or resistant to trastuzumab and ADCs reveals that drug-resistant cells shift their expression toward isoforms lacking antibody-binding domains. Our results broaden the understanding of HER2 isoforms, revealing distinct mechanisms of potential resistance to anti-HER2 therapies, particularly ADCs. This expanded landscape of HER2 isoforms emphasizes the crucial role of alternative splicing investigations in advancing precision-targeted cancer therapies.

Photobiomodulation therapy (PBMT) is a rapidly advancing approach for restoring damaged tissues, particularly in skin and mucosal wounds. While its application is promising, the role of mature adipocytes in regenerating mesenchymal tissues after PBMT remains largely unexplored. This study demonstrates that PBMT applied to skin wounds significantly reduces the number and size of mature adipocytes. Additionally, PBMT modulates the upregulation of peroxisome proliferator-activated receptor γ (PPARγ), increasing the gene expression of fatty acid binding protein 4 (Fabp4) and perilipin 1, which are linked to enhanced lipolysis. The molecular activation of neural/glial antigen 2 (NG2) indicates the recruitment of progenitor cells following mature adipocytes lipolysis. In vitro, PBMT improved dermal skin cell proliferation, migration, inflammatory regulation, and differentiation capacities. These findings reveal a novel mechanistic pathway for skin regeneration, emphasizing the therapeutic potential of PBMT in modulating dermal fat tissue to facilitate wound healing. Collectively, this emerging knowledge provides valuable insights into managing dermal fat tissue to support wound healing.

Peripheral sensory neurons, once regarded merely as a passive route for nociceptive signals, are now acknowledged as active participants in solid tumor progression. This review explores how sensory neurons influence and are influenced by the tumor microenvironment (TME) through both chemical and electrical signaling, underscoring their pivotal role in the emerging field of cancer neuroscience. We summarize recent findings indicating that cancer-neuron interactions vary among different organs and experimental models, highlighting the ways in which various tumors recruit and reprogram sensory neurons to establish mutual communication loops that foster malignancy. Clinically, the degree of sensory innervation and the level of neuropeptide signaling show promise as diagnostic and prognostic biomarkers, while targeting these pathways may enhance the efficacy of standard cancer treatments. This review also highlights current knowledge gaps and proposes future research directions aimed at disrupting sensory neuron-tumor interactions, with the ultimate goal of improving clinical outcomes across multiple cancer types.

Skeletal stem cells (SSCs) have been isolated from various tissues, including periosteum and bone marrow, where they exhibit key functions in bone biology and hematopoiesis, respectively. The role of periosteal SSCs (P-SSCs) in bone regeneration and healing has been extensively studied, but their ability to contribute to the bone marrow stroma is still under debate. In the present study, we characterized a mouse whole bone transplantation model that mimics the initial bone marrow necrosis and fatty infiltration seen after injury. Using this model and a lineage tracing approach, we observed the migration of P-SSCs into the bone marrow after transplantation. Once in the bone marrow, P-SSCs are phenotypically and functionally reprogrammed into bone marrow mesenchymal stem cells (BM-MSCs) that express high levels of hematopoietic stem cell niche factors such as Cxcl12 and Kitl. In addition, using ex vivo and in vivo approaches, we found that P-SSCs are more resistant to acute stress than BM-MSCs. These results highlight the plasticity of P-SSCs and their potential role in bone marrow regeneration after bone marrow injury.

Non-small cell lung cancer (NSCLC) exhibits substantial cellular and molecular heterogeneity, partly due to the presence of cancer stem cells (CSCs). CSCs can arise from a coordinated process known as epithelial-mesenchymal transition (EMT). EMT promotes a more aggressive phenotype, contributing significantly to tumor heterogeneity and drug resistance. Here, using state-of-the-art techniques-including confocal microscopy, flow cytometry, and transcript analysis-we investigated the cisplatin response of the LL/2 (LLC1) cell line cultured in both monolayer and tumorsphere (3D) models. Strikingly, LL/2 (LLC1) tumorspheres represent a model of cisplatin resistance, showing a remarkable increase in EMT and pluripotency mRNA regulators such as Zeb1, Zeb2, Snail, Twist, Tgfb1, Vimentin, FoxA2, Nanog, and Pou5f1 (Oct-4). Moreover, pseudotime trajectory analysis demonstrated that cisplatin treatment modulates a CSC-like phenotype differently in cells grown as monolayer versus tumorsphere. Our findings provide important insights into the role of cisplatin in NSCLC and highlight potential targets within the lung cancer microenvironment.

Circulating tumor cells (CTCs) can provide non-invasive insight into how a cancer patient responds to therapy. Their role in disease monitoring of advanced melanoma patients treated with immune checkpoint inhibitors (ICI) is unknown. CTC protein expression of human leukocyte antigen class-I (HLA I) and programmed death ligand-1 (PD-L1) may give insight into how a patient's disease evolves over the course of treatment. In our study, we utilize microfluidic Exclusion-based Sample Preparation (ESP) technology to isolate and characterize CTCs from patients with advanced-stage melanoma. CTC samples from melanoma patients are collected, captured, and stained. A range of 2 to 35 CTCs is observed in a cohort of 16 samples from 10 advanced-stage melanoma patients treated with ICI therapy. Single-cell protein expression data is generated from image cytometry analysis and used to calculate mean HLA I and PD-L1 expression. Using our ESP capture approach, we successfully detect phenotypic and numerical heterogeneity in CTCs from melanoma patients. Our assay shows sufficient capture sensitivity and promising prognostic and predictive information, as we illustrate in our case example. A greater clinical sample size will be necessary to confirm the diagnostic sensitivity and specificity of the assay in predicting clinical outcomes for patients with advanced-stage melanoma.

Background Older adults, as the population considered at increased risk for severe COVID-19, were the most impacted by social isolation. Thus, this study aimed to assess the salivary immune/inflammatory response of older adults before and during the COVID-19 pandemic. Methods A cohort of 11 older adults (mean age 66.8 ± 6.1) was followed at three different time points: before (S1) and after 6 (S2) and 20 months (S3) of the beginning of the COVID-19 pandemic in Brazil. Unstimulated saliva samples were obtained to assess the levels of antibodies (secretory IgA, IgG and IgM) by ELISA and cytokines (IL-2, IL-5, IL-6, IL-8 and IL-10, TSLP, IFN-γ, TNF-α) by multiplex analysis. Significant differences were evaluated using the Kruskal–Wallis test with Dunn's post-test. Results None volunteer presented periodontal disease or caries. All volunteers received at least two doses of the COVID-19 vaccines after S2 and before S3. A tendency to increase salivary levels of SIgA and IgM at S2 and of IgG at S3 were observed compared to the values found at S1 and S2. Significantly decreased levels of IL-2 and IL-5 were found at S2 and S3 ( p < 0.001) time points. Lower levels of IFN-γ were found at S2 as compared to the values observed at S1 ( p < 0.01). A significant decrease in the IFN-γ/IL-10 ratio was found at S2 ( p < 0.01). When assessing the Th1/Th2 ratios, a significant decrease was found in the IFN-γ/TSLP ratio at S2 ( p < 0.001) and S3 ( p < 0.001) when compared to the values at S1. In addition, a significant increase was observed in the TNF-α/IL-5 ratio at S2 ( p < 0.001) and S3 ( p < 0.001) in comparison to the values at S1. In a similar way, an increase in the TNF-α/IL-6 ratio (Fig. 5E) was observed at S3 ( p < 0.001) when compared to the values at S1. Conclusions Overall, this study provides valuable insights into the impact of COVID-19-induced social isolation on immune/inflammatory responses in the upper airway mucosa, particularly those present in oral cavity, of older adults. It demonstrates that a controlled shift in Th1 and Th2 immune responses, both during infection and post-vaccination, can create favorable conditions to combat viral infections without exacerbating the immune response or worsening the pathology.

Pericytes (PCs) are located surrounding the walls of small blood vessels, particularly capillaries and microvessels. In addition to their functions in maintaining vascular integrity, participating in angiogenesis, and regulating blood flow, PCs also serve as a reservoir for multi-potent stem/progenitor cells in white, brown, beige, and bone marrow adipose tissues. Due to the complex nature of this cell population, the identification and characterization of PCs has been challenging. A comprehensive understanding of the heterogeneity of PCs may enhance their potential as therapeutic targets for metabolic syndromes or bone-related diseases. This mini-review summarizes multiple PC markers commonly employed in lineage-tracing studies, with an emphasis on their contribution to adipogenesis and functions in different adipose depots under diverse metabolic conditions.