Search Results (66)

Nerve Growth Factor (NGF), a member of the neurotrophin family, is currently regarded as a key regulator of ovarian physiology beyond its well-known neurotrophic functions. The mammalian ovary is one of the most highly innervated peripheral organs. Increasing evidence indicates that NGF and its receptors, TrkA and p75NTR, are widely expressed in ovarian tissues. Through the activation of the PI3K/AKT, MAPK/ERK, and PLCγ signaling pathways, NGF influences granulosa cell proliferation, steroidogenesis, and ovulation. Physiological levels of NGF are essential for primordial follicle activation, FSH receptor expression, and effective bidirectional communication between oocytes and surrounding somatic cells. As a result, NGF also regulates oocyte maturation and developmental competence. The disruption of NGF signaling can lead to serious health issues. Both low and high levels of NGF negatively affect folliculogenesis and fertility. Elevated intraovarian NGF results in sympathetic over-innervation, altered steroid production, and polycystic ovarian features. In addition, increased NGF expression has been linked to endometriosis and ovarian cancer progression. Clinical studies further suggest that follicular NGF levels may serve as indicators of ovarian reserve and reproductive outcomes in assisted reproduction. This narrative review synthesizes the current knowledge on NGF roles in ovarian physiology and disease. It highlights NGF’ dual functions as a central regulator of follicular dynamics, and as a potential biomarker and therapeutic target for common reproductive system diseases. Full article

Peripheral nerves provide a direct connection between the brain and the tumor microenvironment. This connection allows the nervous system to influence processes associated with the development, progression, and metastasis of different tumor types. Therefore, tumor innervation by peripheral nerve fibers is currently emerging as a characteristic that contributes to multiple hallmarks of cancer. Several experimental studies have shown that cancer progression involves actively inducing the ingrowth of autonomic and sensory nerve fibers into tumor tissue. In this process, known as neoaxonogenesis, cancer and other cells in the tumor microenvironment play an important role by synthesizing and releasing neurotrophic factors (e.g., nerve growth factor, brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor), axonal guidance molecules (netrins, semaphorins, ephrins, slits), exosomes (containing microRNA and axonal guidance molecules), and other molecules present in the tumor microenvironment (e.g., granulocyte colony-stimulating factor, leukemia inhibitory factor), which modulate the ingrowth of nerve fibers into the tumor. This results in an increased nerve supply to tumor tissue, which is primarily linked to its growth. However, there are also studies demonstrating the protective effects of increased nerve fiber density against processes associated with cancer progression in certain types of cancer. The findings from these studies contribute to the complexity of neuro-cancer interactions, which is probably based on the type of cancer and the physiological specializations of the nerve fibers in a given organ. Despite contrasting findings, the stimulatory effects of nerve fibers on cancer growth are supported by several studies that described reducing the negative impact of nerve fibers on tumors and thus inhibiting cancer progression. The most significant approaches to reducing neural effects appear to be denervation, the administration of neurotransmitter receptor antagonists, the administration of local anesthetics, and the administration of antibodies against neurotrophic factors. Other significant approaches include methods that improve quality of life, such as psychotherapy and heart rate variability biofeedback. Despite their therapeutic potential, there are several limitations to using approaches that manipulate cancer innervation in clinical practice. These limitations include impaired normal tissue function and nervous system function, as well as the problematic direct application of the therapeutic agent to the tumor site, dosage-dependent, cancer type-dependent, cancer stage-dependent, duration-dependent, and timing-dependent effects. Procedures that modify neoaxonogenesis and nerve fiber signaling appear to be a promising new therapeutic approach in oncology. However, more research is needed to better understand their effects on cancer progression. In the future, the assessment of the presence and density of nerve fibers in tumors, as well as the evaluation of approaches aimed at reducing their negative impact, could be part of personalized anticancer therapy. As part of this therapy, a fresh tumor sample would be collected from the patient to generate patient-derived organoid models to test and consider the possibility of using supportive therapy and to predict its efficacy. Based on these results, it would be possible to evaluate the applicability of nerve-fiber-targeted therapy for a given patient. This review article summarizes and describes the current knowledge concerning the significance of nerve fibers in cancer progression, with a particular emphasis on neoaxonogenesis in tumors and the various factors that influence this process. Full article

Background/Objectives: Increasing evidence indicates that tumors interact functionally with the nervous system. Rather than being passively innervated, many cancers establish bidirectional communication with neurons, suggesting that neural activity may represent an additional regulatory layer of tumor biology. This review aims to synthesize current knowledge on the mechanisms and consequences of tumor innervation and to discuss its implications for cancer progression and therapy. Methods: We performed a narrative synthesis of recent experimental and translational studies (2015–2026), identified through PubMed and major peer-reviewed biomedical journals. The literature was analyzed to identify key mechanisms of neural influence on tumor biology, including axonogenesis, pseudo-synaptic communication, neurotransmitter signaling, and metabolic coupling. Results: Emerging evidence indicates that neural inputs can regulate multiple hallmarks of cancer, including proliferation, invasion, angiogenesis, metabolic plasticity, and immune evasion. Tumors can actively recruit nerve fibers through axonogenic signals and establish specialized neuron–cancer interfaces that enable activity-dependent oncogenic signaling. In addition, neuronal interactions can influence tumor metabolism and therapeutic resistance through mechanisms such as mitochondrial transfer and neurotransmitter-driven signaling pathways. Conclusions: Tumor innervation represents an important and increasingly recognized dimension of cancer biology. Understanding how neural circuits interact with tumor cells and the surrounding microenvironment may reveal new biomarkers and therapeutic strategies aimed at disrupting tumor–neuron communication. Full article

Bone metastases represent a major cause of morbidity in advanced cancers, yet the neural regulation of metastatic growth within bone remains largely unexplored. The skeletal system is richly innervated by sensory and sympathetic nerve fibers that influence bone remodeling, hematopoiesis, and immune surveillance. Emerging evidence suggests that disseminated tumor cells exploit these neural circuits to create a growth-permissive microenvironment. Tumor-secreted neurotrophic factors can induce nerve sprouting, while sympathetic activation via β-adrenergic receptors promotes osteoclastogenesis, immunosuppression, and tumor proliferation. Neuropeptides such as substance P and calcitonin gene-related peptide exert dual effects on bone cells and infiltrating immune populations, further shaping the metastatic niche. The interplay between neural signals, osteolytic activity, and immune modulation positions the neuro–bone axis as a critical but underappreciated driver of metastatic progression. In this review, we synthesize current evidence on the anatomy and function of bone innervation, tumor-induced neural remodeling, and neuro–immune–osteoclast interactions. We highlight preclinical and clinical data supporting neuromodulatory strategies, including β-blockers, neurotrophin inhibitors, and targeted nerve ablation, as potential adjuncts to standard bone metastasis therapies. Finally, we identify key knowledge gaps, including the need for spatial and functional mapping of nerve–tumor interfaces and for integrating neuroimaging into bone metastasis detection. By framing the neuro–bone axis as a therapeutic target, we aim to catalyze interdisciplinary research that bridges oncology, neuroscience, and bone biology, with the goal of disrupting neural support for metastatic growth Full article

Cervical cancer (CC) remains a significant public health problem. Despite the availability of standard treatment strategies, chemotherapy-resistant tumors persist, highlighting the need to explore new therapeutic approaches or adjuvant strategies. This underscores the importance of preclinical in vivo models. Conventional models, such as murine xenografts, patient-derived xenografts (PDXs), and patient-derived organoids (PDOs), provide valuable biological relevance but are often time-consuming, costly, and resource-intensive. In this context, the chick embryo chorioallantoic membrane (CAM) assay represents a rapid, low-cost, and technically accessible in vivo platform. The CAM is a non-innervated, highly vascularized extraembryonic structure that provides a suitable environment for tumor generation from xenografts. However, despite the broad use of the CAM assay for tumor xenografts, standardized and comparative methodological optimizations specifically addressing technical variables for cervical cancer tumor induction remain limited. Therefore, the aim of this study was to optimize the CAM assay for tumor generation using the HeLa and SiHa cell lines. The generated tumors are vascularized and exhibit Ki-67 expression. The CAM assay is an excellent short-term exploratory model based on developing chicken embryos for studying the developmental biology of cervical tumors, which would accelerate the preclinical investigation of new therapeutic molecules. Full article

Organoid technology has emerged as a revolutionary tool in cancer research, offering physiologically accurate, three-dimensional models that preserve the histoarchitecture, genetic stability, and phenotypic complexity of primary tumors. These self-organizing structures, derived from adult stem cells, induced pluripotent stem cells, or patient tumor biopsies, recapitulate critical aspects of tumor heterogeneity, clonal evolution, and microenvironmental interactions. Organoids serve as powerful systems for modeling tumor progression, assessing drug sensitivity and resistance, and guiding precision oncology strategies. Recent innovations have extended organoid capabilities beyond static culture systems. Integration with microfluidic organoid-on-chip platforms, high-throughput CRISPR-based functional genomics, and AI-driven phenotypic analytics has enhanced mechanistic insight and translational relevance. Co-culture systems incorporating immune, stromal, and endothelial components now permit dynamic modeling of tumor–host interactions, immunotherapeutic responses, and metastatic behavior. Comparative analyses with conventional platforms, 2D monolayers, spheroids, and patient-derived xenografts emphasize the superior fidelity and clinical potential of organoids. Despite these advances, several challenges remain, such as protocol variability, incomplete recapitulation of systemic physiology, and limitations in scalability, standardization, and regulatory alignment. Addressing these gaps with unified workflows, synthetic matrices, vascularized and innervated co-cultures, and GMP-compliant manufacturing will be crucial for clinical integration. Proactive engagement with regulatory frameworks and ethical guidelines will be pivotal to ensuring safe, responsible, and equitable clinical translation. With the convergence of bioengineering, multi-omics, and computational modeling, organoids are poised to become indispensable tools in next-generation oncology, driving mechanistic discovery, predictive diagnostics, and personalized therapy optimization. Full article

Innervation is ubiquitous in diseased tissues, including cancer. Increasing evidence suggests that innervation not only plays a direct role in cancer pain, but is also closely related to disease progression, including cancer growth, metastasis, and drug resistance. At the molecular level, tumor-associated nerves can interact with cancer cells and the tumor microenvironment through neurotrophic factors, thereby promoting tumor occurrence and development, and represent a potential intervention for solid tumors with nerve enrichment. By dissecting the transcriptome dynamics of cancer-associated neurons with single cell resolution, numbers of novel therapeutic targets for tumor denervation have been uncovered, including a novel phenomenon—Macrophage to Neuron-like cell Transition (MNT). This review systematically summarizes the latest research findings of tumor denervation, from molecular mechanisms to the innovative denervation strategies, paving the way for novel, safe, and effective cancer treatments in the clinic. Full article

In recent years, a long list of relevant studies has highlighted the engagement of the nervous system in the fine-tuning of tumor development and progression. Several authors have shown that different types of nerve fibres (sympathetic, parasympathetic/vagal or somatosensory fibres) may contribute to tumor innervation affecting cancer initiation, progression and metastasis. A large presence of nerve fibres is frequently observed in tumors with respect to the corresponding healthy tissues. In this regard, it is worth noting that in some cases a reduced innervation may associate with slow tumor growth in a tissue-specific manner. Current studies have begun to shed light over the role played in this specific process by Schwann cells (SCs), the most abundant glial cells of the peripheral nervous system. SCs observed in cancer tissues share strong similarities with repair SCs that appear after nerve injury. A large body of research indicates that SCs may have a role in shaping the microenvironment of tumors by regulating the immune response and influencing their invasiveness. In this review, we summarize data relevant to the role of peripheral innervation in general, and of SCs in particular, in defining the progression of different tumors: melanoma that originate in the skin with mainly sensory innervation; pancreatic and liver-derived tumors (e.g., pancreatic adenocarcinoma and cholangiocarcinoma) with mainly autonomous innervation. We conclude by summarizing data regarding hepatocarcinoma (with anatomical predominance of small autonomic nerve fibres) in which the potential relationship between innervation and tumor progression has been little explored, and largely remains to be defined. Full article

Tumor cells and the tumor microenvironment (TME) produce factors, including neurotrophins, that induce axonogenesis and neurogenesis, and increase local nerve density. Proliferative growing cancer cell clusters and disseminated invasive tumor cells undergoing partial epithelial-to-mesenchymal transition (pEMT) can invade peripheral nerves. In the early stages of tumor–nerve interactions, Schwann cells (SCs) dedifferentiate, become activated and migrate to cancer cell nests; later, they induce pEMT in tumor cells and activate tumor cell migration along nerves. The SC–tumor–nerve interaction attracts myeloid-derived suppressor cells (MDSCs) and inflammatory monocytes, and the latter differentiate into macrophages. SCs and MDSCs are responsible for the activation of transforming growth factor-beta (TGF-beta) signaling. Intra-tumoral innervation is followed by perineural invasion (PNI), which has an unfavorable prognosis. What are the interventional options against PNI: local reduction in tumor nerves or inhibition of TGF-beta-related events, inhibition of downstream signaling of TGF-beta or immune activation, or intervention against immunosuppression? This systematic review is based on the Prisma 2009 search method and provides an overview of tumor–nerve interaction. Full article

Tumor innervation is a complex interaction between nerves and cancer cells that consists of axons invading tumors, and its complexity remains largely unknown in humans. Although some retrospective studies have provided important insights into the relationship between nerves and tumors, further knowledge is required about this biological process. Animal experiments have elucidated several molecular and cellular mechanisms of tumor innervation; however, no experimental models currently exist to study interactions between human cancer and nerve cells. Human pluripotent stem cells can differentiate into neurons for research purposes; however, the use of these neurons to study interactions with cancer cells remains largely unexplored. Hence, here we analyze the potential of human pluripotent stem cells to study the interaction of cancer cells and neurons derived from human pluripotent stem cells to unravel the poorly understood mechanisms of human tumor innervation. Full article

Sympathetic nerves innervate bone marrow and various immune organs, where norepinephrine—the primary sympathetic neurotransmitter—directly interacts with immune cells that express adrenergic receptors. This article reviewed the key molecular pathways triggered by sympathetic activation and explored how sympathetic activity influences immune cell migration. Norepinephrine serves as a chemoattractant for monocytes, macrophages, and stem cells, promoting the migration of myeloid cells while inhibiting the migration of lymphocytes at physiological concentrations. We also examined the role of immune cell infiltration in cardiovascular diseases and cancer. Evidence suggests that sympathetic activation increases myeloid cell infiltration into target tissues across various cardiovascular diseases, including atherosclerosis, hypertension, cardiac fibrosis, cardiac hypertrophy, arrhythmia, myocardial infarction, heart failure, and stroke. Conversely, inhibiting sympathetic activity may serve as a potential therapeutic strategy to treat these conditions by reducing macrophage infiltration. Furthermore, sympathetic activation promotes macrophage accumulation in cancer tissues, mirroring its effects in cardiovascular diseases, while suppressing T lymphocyte infiltration into cancerous sites. These changes contribute to increased cancer growth and metastasis. Thus, inhibiting sympathetic activation could help to protect against cancer by enhancing T cell infiltration and reducing macrophage presence in tumors. Full article

Background/Objectives: Many patients evaluated by shoulder specialists suffer from intractable pain, neuropathy, and weakness. The pectoralis minor (PM) remains the only scapula muscle to receive lower trunk (C8-T1) input. We propose a novel syndrome: the Human Disharmony Loop. This model portrays how this unique PM innervation causes scapular dyskinesia, which deranges the anatomy of the upper limb girdle and produces a refractory symptom complex of pain, neuropathy, and weakness. We hypothesize that certain patients with historically intractable symptoms of the upper limb girdle may benefit from PM tenotomy. Methods: Ten patients of diverse etiologies presented with a similar constellation of complaints. The patients included a female athlete, a female with macromastia, a male bodybuilder, and patients with post-radiation breast cancer, post-operative shoulder arthroplasty, interscalene block injury, cervical spine disease, persistent impingement after rotator cuff repair, direct traction injury, and occupational disorder. All patients exhibited coracoid tenderness, scapula protraction with internal rotation and anterior tilt, and pain involving the neck, shoulder, and upper back. The patients demonstrated varying degrees of arm neuropathy, subacromial impingement, and occipital headaches. The patients failed all prior treatments by multiple subspecialists, including surgery. Each patient underwent isolated open PM tenotomy. Results: In all ten patients, PM tenotomy substantially reduced shoulder, upper back, and neck pain, cleared concomitant neuropathy, restored full motion, and eradicated occipital headaches. The response to surgery was rapid, dramatic, and durable. Conclusions: The unique asymmetric neurologic innervation to the sole ventral stabilizer of the scapula, the pectoralis minor, predisposes the human shoulder to neurologic and musculoskeletal imbalance. This produces the Human Disharmony Loop: a clinical syndrome spanning from the neck to the fingertips, with chronic pain, neuropathy, and weakness. These challenging patients may benefit dramatically from isolated PM tenotomy. Full article

Both the prevalence and mortality of liver cancers continue to rise. Early surgical interventions, including liver transplantation or resection, remain the only curative treatment. Nerves in the periphery influence tumor growth within visceral organs. Emerging cancer neuroscience efforts linked parasympathetic vagus nerves with tumor pathology, underscoring the value of vagal nerve denervation methods within cancer mouse models. Here, we describe a selective hepatic vagotomy that largely maintains non-liver parasympathetic innervation in mice. To address vagal interactions in hepatic tumor pathology, we provide an adapted methodology utilizing an established liver metastatic model. We anticipate that this methodology will expand the burgeoning field of cancer neuroscience, enabling the study of the neuroimmune, neurometabolic, and/or nerve–microbiota interactions shaping liver cancer progression and treatment. Full article

Background: This short review and pictorial essay presents a morphological insight into cancer neuroscience, which is a complex and dynamic area of the pathobiology of tumors. Methods: We discuss the different methods and issues connected with structural research on tumor innervation, interactions between neoplastic cells and the nervous system, and dysregulated neural influence on cancer phenotypes. Results: Perineural invasion (PNI), the most-visible cancer–nerve relation, is briefly presented, focusing on its pathophysiology and structural diversity as well as its clinical significance. The morphological approach to cancer neurobiology further includes the analysis of neural density/axonogenesis, neural network topographic distribution, and composition of fiber types and size. Next, the diverse range of neurotransmitters and neuropeptides and the neuroendocrine differentiation of cancer cells are reviewed. Another morphological area of cancer neuroscience is spatial or quantitative neural-related marker expression analysis through different detection, description, and visualization methods, also on experimental animal or cellular models. Conclusions: Morphological studies with systematic methodologies provide a necessary insight into the structure and function of the multifaceted tumor neural microenvironment and in context of possible new therapeutic neural-based oncological solutions. Full article

Cancer is a global health challenge with rising incidence and mortality rates, posing significant concerns. The World Health Organization reports cancer as a leading cause of death worldwide, contributing to nearly one in six deaths. Cancer pathogenesis involves disruptions in cellular signaling pathways, resulting in uncontrolled cell growth and metastasis. Among emerging players in cancer biology, Transient Receptor Potential (TRP) channels, notably TRPV1, have garnered attention due to their altered expression in cancer cells and roles in tumorigenesis and progression. TRPV1, also known as the capsaicin receptor, is pivotal in cancer cell death and pain mediation, offering promise as a therapeutic target. Activation of TRPV1 triggers calcium influx and affects cell signaling linked to growth and death. Additionally, TRPV1 is implicated in cancer-induced pain and chemo-sensitivity, with upregulation observed in sensory neurons innervating oral cancers. Also, when capsaicin, a compound from chili peppers, interacts with TRPV1, it elicits a “hot” sensation and influences cancer processes through calcium influx. Understanding TRPV1’s multifaceted roles in cancer may lead to novel therapeutic strategies for managing cancer-related symptoms and improving patient outcomes. The current review elucidates the comprehensive role of capsaicin in cancer therapy, particularly through the TRPV1 channel, highlighting its effects in various cells via different signaling pathways and discussing its limitations. Full article