Chronic stress induces pulmonary epithelial cells to produce acetylcholine that remodels lung pre-metastatic niche of breast cancer by enhancing NETosis

Lung-specific metastasis: the coevolution of tumor cells and lung microenvironment

The vast majority of cancer-related deaths are attributed to metastasis. The lung, being a common site for cancer metastasis, is highly prone to being a target for multiple cancer types and causes a heavy disease burden. Accumulating evidence has demonstrated that tumor metastasis necessitates continuous interactions between tumor cells and distant metastatic niches. Nevertheless, a comprehensive elucidation of the underlying mechanisms governing lung-specific metastasis still poses a formidable challenge. In this review, we depict the lung susceptibility and the molecular profiles of tumors with the potential for lung metastasis. Under the conceptual framework of "Reciprocal Tumor-Lung Metastatic Symbiosis" (RTLMS), we mechanistically delineate the bidirectional regulatory dynamics and coevolutionary adaptation between tumor cells and distal pulmonary niches during lung-specific metastasis, including the induction of pre-metastatic-niches, positive responses of the lung, tumor colonization, dormancy, and reawakening. An enhanced understanding of the latest mechanisms is essential for developing targeted strategies to counteract lung-specific metastasis.

α5-nAChR/NETO2 contributed to chronic stress-promoted lung adenocarcinoma progression

BACKGROUND

α5-nicotinic acetylcholine receptor (α5-nAChR) participates in chronic stress-promoted lung adenocarcinoma (LUAD) progression. Neuropilin and tolloid-like 2 (NETO2) contributes to fear expression and extinction, which is related to tumorigenesis. CHRNA5 (encoding α5-nAChR) gene profiling revealed a reduction in NETO2 expression following CHRNA5 knockdown. Nevertheless, the connection between α5-nAChR and NETO2 in LUAD progression induced by chronic stress remains unclear.

METHODS

RNA-Seq and bioinformatics database were used for analyzing the expression as well as correlation of α5-nAChR, together with NETO2 in LUAD. α5-nAChR and NETO2 expression were detected using immunohistochemistry in LUAD tissue microarrays, chronic restraint stress (CRS) and chronic unpredictable stress (CUMS) mice tissues. In lung adenocarcinoma A549 and H1299 cells, the expression of α5-nAChR, NETO2, p-CAMKII, p-STAT3 and vimentin induced by acetylcholine/nicotine was examined by western blot. The interaction of α5-nAChR with NETO2 in lung adenocarcinoma cells was detected by Co-immunoprecipitation assay and modeled using molecular docking. EdU assay and colony formation assay were conducted to evaluate cell proliferation, while wound healing assay as well as transwell assay assessed the migration and invasion of lung adenocarcinoma cells.

RESULTS

α5-nAChR expression was related to NETO2 expression, low survival rate, staging as well as smoking status in LUAD dataset as well as tissue microarrays. The correlation between α5-nAChR and NETO2 was validated in nude mice xenograft tissues. α5-nAChR as well as NETO2 expression correlated in CRS and CUMS mice tissues. In vitro, acetylcholine/nicotine mediated NETO2, p-CAMKII, p-STAT3 and vimentin expression via α5-nAChR. α5-nAChR interacted with NETO2 as well as CAMKII in LUAD cells. α5-nAChR/NETO2 signaling contributed to LUAD cell proliferation, migration and invasion.

CONCLUSIONS

The above results uncover a new chronic stress-promoted LUAD signaling pathway: α5-nAChR/NETO2 axis contributes to chronic stress-promoted LUAD cell proliferation, migration and invasion.

SIRT-2 inhibition by AK-7 orchestrates fibrotic cascades in airways through neuroimmune interaction via TRPA1, TRPM8 and TGF-β signalling

Chronic obstructive pulmonary diseases (COPD) is characterized by airflow limitation, chronic inflammation and airway remodeling (AR) in airways and lung parenchyma. AR, a lung response, involves mucus production, airflow issues, and structural changes. It is exacerbated by neurogenic inflammation from activated sensory nerves, highlighting the interplay between neuronal and immune regulation in COPD. Sirtuins play a crucial role in lung remodeling, with SIRT-2 being the least studied. Present study explores how SIRT-2 regulates neurogenic inflammation and fibrosis in experimental BALB/c mice with cigarette smoke-induced COPD. Mice from each group, except the control, were exposed to CS for 60 days and AK-7 (100ug/kg and 200ug/kg) was administered intranasally. The study evaluated lung injury and inflammation marked by increased Cortisol, ACTH, COX-2 and LDH in COPD group with its attenuation by SIRT-2 inhibition. Additionally, CS exposure exhibited neurogenic inflammation represented by activated TPRV1 and TRPM8, elevated neuromediators levels (dopamine, acetylcholine, substance P, serotonin) and their respective receptors which were mitigated by AK-7. CS exposure enhanced fibrosis by targeting the fibrotic cascade, enhancing MMP-9, total collagen, hydroxyproline, and upregulating αSMA, MUC5AC, TGF-β, PKA, GATA-3, FOXO3, and STAT-6. SIRT-2 inhibition effectively reversed all these factors suppressing fibrosis further supported by downregulated SIRT-2 expression and histopathological studies where collagen deposition and mucus production were also attenuated by AK-7. Molecular docking revealed strong binding affinity of certain protein such as COX-2, D5DR and 5HT with AK-7. Overall, targeting SIRT-2 to modulate neuro-immune interplay presents a promising therapeutic approach for addressing AR in COPD.

Influence of the ERK/CHGB pathway in breast cancer progression under chronic stress

BACKGROUND

Breast cancer is one of the most common malignancies among women, and its development involves a variety of complex molecular mechanisms. Extracellular signal-regulated kinase (ERK) and Chromogranin B (CHGB) are known to play key roles in various cancers. This study aims to explore the impact of the ERK/CHGB pathway in a chronic stress environment simulated by salbutamol on the development of breast cancer.

METHODS

This study utilized female BALB/c mice to establish a breast cancer model, dividing them into control, salbutamol-treated, and salbutamol-inhibitor-treated groups. Cell culture, immunohistochemistry, Western Blot, real-time fluorescent quantitative PCR, and Transwell migration assays were employed to assess the effects of salbutamol and the ERK/CHGB pathway.

RESULTS

Salbutamol treatment significantly enhanced the proliferation, migration, and invasiveness of breast cancer cells, associated with the activation of the ERK pathway and the inhibition of CHGB. The salbutamol-inhibitor-treated group exhibited a marked suppression of these effects. Additionally, the interaction of the ERK/CHGB pathway in an extracellular stress environment provided advantages for the survival and proliferation of breast cancer cells.

CONCLUSION

This study demonstrates that a chronic stress environment simulated by salbutamol can promote malignant behaviors in breast cancer cells through the ERK/CHGB pathway. These findings offer new molecular targets for breast cancer treatment and highlight the potential importance of managing chronic stress and blocking specific molecular pathways in cancer therapy.

Adaptations of neutrophils in cancer

There is a renewed interest in neutrophil biology, largely instigated by their prominence in cancer. From an immunologist's perspective, a conceptual breakthrough is the realization that prototypical inflammatory, cytotoxic leukocytes can be tamed to promote the survival and growth of other cells. This has sparked interest in defining the biological principles and molecular mechanisms driving the adaptation of neutrophils to cancer. Yet, many questions remain: is this adaptation mediated by reprogramming mature neutrophils inside the tumoral mass, or rather by rewiring granulopoiesis in the bone marrow? Why, in some instances, are neutrophils beneficial and in others detrimental to cancer? How many different functional programs can be induced in neutrophils by tumors, and is this dependent on the type of tumor? This review summarizes what we know about these questions and discusses therapeutic strategies based on our incipient knowledge of how neutrophils adapt to cancer.

Chronic Stress-Induced and Tumor Derived SP1+ Exosomes Polarizing IL-1β+ Neutrophils to Increase Lung Metastasis of Breast Cancer

Chronic stress can significantly promote breast cancer progression. When exposed to chronic stress, exosomes released from neural and neuroendocrine cells in the central nervous system are enhanced and modified. However, whether tumor-derived exosomes (TDEs) are influenced by chronic stress and participate in chronic stress-mediated distant metastasis remains unclear. Here, it is shown that chronic stress remarkably facilitates the secretion of TDEs and modifies the contents of exosomes by activating the adrenergic β receptor in 4T1 tumor-bearing mice. Exosomes injection and blockade experiments indicate that exosomes play a crucial role in chronic stress-mediated lung metastasis of breast cancer. Chronic stress-induced TDEs are internalized by pulmonary neutrophils and strengthen neutrophil recruitment via the CXCL2 autocrine. In addition, the level of SP1 in TDEs increases, which favors the secretion of IL-1β by neutrophils through the activation of the TLR4-NFκβ pathway, ultimately aggravating lung metastasis of breast cancer. Collectively, this study provides a novel mechanism by which neutrophils within a pre-metastatic niche acquire their inflamed phenotype and establishes an important link among neuroendocrine changes, exosomes, immunity, and metastasis.

Effect of neutrophils on tumor immunity and immunotherapy resistance with underlying mechanisms

Neutrophils are key mediators of the immune response and play essential roles in the development of tumors and immune evasion. Emerging studies indicate that neutrophils also play a critical role in the immunotherapy resistance in cancer. In this review, firstly, we summarize the novel classification and phenotypes of neutrophils and describe the regulatory relationships between neutrophils and tumor metabolism, flora microecology, neuroendocrine and tumor therapy from a new perspective. Secondly, we review the mechanisms by which neutrophils affect drug resistance in tumor immunotherapy from the aspects of the immune microenvironment, tumor antigens, and epigenetics. Finally, we propose several promising strategies for overcoming tumor immunotherapy resistance by targeting neutrophils and provide new research ideas in this area.

The Association Between Neutrophil-Percentage-to-Albumin Ratio (NPAR) and Mortality Among Individuals With Cancer: Insights From National Health and Nutrition Examination Survey

BACKGROUND

Neutrophils interact with tumor cells, potentially exacerbating cancer progression. Additionally, decreased albumin levels are a marker of poor cancer prognosis. The neutrophil-percentage-to-albumin ratio (NPAR) has been used for prognostic assessment in non-cancerous diseases, but its relationship with mortality risk in cancer patients has not been explored. Therefore, we utilized data from the National Health and Nutrition Examination Survey (NHANES) to investigate the correlation between NPAR and the risks of all-cause mortality and cancer-related mortality among cancer patients.

METHODS

This study leveraged comprehensive NHANES data spanning 2005-2016. We analyzed the relationship between NPAR and the risks of cancer incidence, all-cause mortality, and cancer-related mortality using weighted Logistic and Cox regression models, as well as trend tests. Restricted cubic spline analysis was employed to investigate NPAR's nonlinear relationship with mortality risk. Furthermore, Kaplan-Meier survival analysis was utilized to assess patient prognoses across varying NPAR levels.

RESULTS

Elevated NPAR was associated with an increased risk of all-cause mortality and cancer-related mortality in cancer patients (p < 0.05), with higher NPAR values correlating with greater risk (p-trend < 0.05). However, no significant association between NPAR and cancer incidence was observed (p > 0.05). Our analysis further identified a non-linear relationship between NPAR and all-cause mortality risk (p-nonlinear < 0.05), while no non-linear relationship was found with cancer-related mortality risk. The relationship is characterized by an optimal NPAR value, correlating with the lowest hazard ratio (HR). Deviations from this optimal NPAR result in increased all-cause mortality risk (p < 0.05). Kaplan-Meier analysis indicated superior survival rates in patients with lower NPAR values compared to those with higher NPAR values (p < 0.05).

CONCLUSIONS

According to our study, higher NPAR was associated with an increased risk of all-cause mortality and cancer-related mortality in cancer patients.

Multi-stage mechanisms of tumor metastasis and therapeutic strategies

The cascade of metastasis in tumor cells, exhibiting organ-specific tendencies, may occur at numerous phases of the disease and progress under intense evolutionary pressures. Organ-specific metastasis relies on the formation of pre-metastatic niche (PMN), with diverse cell types and complex cell interactions contributing to this concept, adding a new dimension to the traditional metastasis cascade. Prior to metastatic dissemination, as orchestrators of PMN formation, primary tumor-derived extracellular vesicles prepare a fertile microenvironment for the settlement and colonization of circulating tumor cells at distant secondary sites, significantly impacting cancer progression and outcomes. Obviously, solely intervening in cancer metastatic sites passively after macrometastasis is often insufficient. Early prediction of metastasis and holistic, macro-level control represent the future directions in cancer therapy. This review emphasizes the dynamic and intricate systematic alterations that occur as cancer progresses, illustrates the immunological landscape of organ-specific PMN creation, and deepens understanding of treatment modalities pertinent to metastasis, thereby identifying some prognostic and predictive biomarkers favorable to early predict the occurrence of metastasis and design appropriate treatment combinations.

The intersection of the nervous system and breast cancer

Breast cancer (BC) represents a paradigm of heterogeneity, manifesting as a spectrum of molecular subtypes with divergent clinical trajectories. It is fundamentally characterized by the aberrant proliferation of malignant cells within breast tissue, a process modulated by a myriad of factors that govern its progression. Recent endeavors outline the interplay between BC and the nervous system, illuminate the complex symbiosis between neural structures and neoplastic cells, and elucidate nerve dependence as a cornerstone of BC progression. This includes the neural modulations on immune response, neurovascular formation, and multisystem interactions. Such insights have unveiled the critical impact of neural elements on tumor dynamics and patient prognosis. This revelation beckons a deeper exploration into the neuro-oncological interface, potentially unlocking novel therapeutic vistas. This review endeavors to delineate the intricate mechanisms between the nervous system and BC, aiming to accentuate the implications and therapeutic strategies of this intersection for tumor evolution and the formulation of innovative therapeutic approaches.

Neutrophil extracellular traps in cancer

Neutrophil extracellular traps (NETs), which consist of chromatin DNA studded with granule proteins, are released by neutrophils in response to both infectious and sterile inflammation. Beyond the canonical role in defense against pathogens, the extrusion of NETs also contributes to the initiation, metastasis, and therapeutic response of malignant diseases. Recently, NETs have been implicated in the development and therapeutic responses of various types of tumors. Although extensive work regarding inflammation in tumors has been reported, a comprehensive summary of how these web-like extracellular structures initiate and propagate tumor progression under the specific microenvironment is lacking. In this review, we demonstrate the initiators and related signaling pathways that trigger NETs formation in cancers. Additionally, this review will outline the current molecular mechanisms and regulatory networks of NETs during dormant cancer cells awakening, circulating tumor cells (CTCs) extravasation, and metastatic recurrence of cancer. This is followed by a perspective on the current and potential clinical potential of NETs as therapeutic targets in the treatment of both local and metastatic disease, including the improvement of the efficacy of existing therapies.

Neutrophil Extracellular Traps in Breast Cancer: Roles in Metastasis and Beyond

Despite advances in the treatment of breast cancer, the disease continues to exhibit high global morbidity and mortality. The importance of neutrophils in cancer development has been increasingly recognized. Neutrophil extracellular traps (NETs) are web-like structures released into the extracellular space by activated neutrophils, serving as a potential antimicrobial mechanism for capturing and eliminating microorganisms. The roles played by NETs in cancer development have been a subject of intense research in the last decade. In breast cancer, current evidence suggests that NETs are involved in various stages of cancer development, particularly during metastasis. In this review, we try to provide an updated overview of the roles played by NETs in breast cancer metastasis. These include: 1) facilitating systemic dissemination of cancer cells; 2) promoting cancer-associated inflammation; 3) facilitating cancer-associated thrombosis; 4) facilitating pre-metastatic niche formation; and 5) awakening dormant cancer cells. The translational implications of NETs in breast cancer treatment are also discussed. Understanding the relationship between NETs and breast cancer metastasis is expected to provide important insights for developing new therapeutic strategies for breast cancer patients.

Alpha5 nicotine acetylcholine receptor subunit promotes intrahepatic cholangiocarcinoma metastasis

Neurotransmitter-initiated signaling pathway were reported to play an important role in regulating the malignant phenotype of tumor cells. Cancer cells could exhibit a "neural addiction" property and build up local nerve networks to achieve an enhanced neurotransmitter-initiated signaling through nerve growth factor-mediated axonogenesis. Targeting the dysregulated nervous systems might represent a novel strategy for cancer treatment. However, whether intrahepatic cholangiocarcinoma (ICC) could build its own nerve networks and the role of neurotransmitters in the progression ICC remains largely unknown. Immunofluorescence staining and Enzyme-linked immunosorbent assay suggested that ICC cells and the infiltrated nerves could generate a tumor microenvironment rich in acetylcholine that promotes ICC metastasis by inducing epithelial-mesenchymal transition (EMT). Acetylcholine promoted ICC metastasis through interacting with its receptor, alpha 5 nicotine acetylcholine receptor subunits (CHRNA5). Furthermore, acetylcholine/CHRNA5 axis activated GSK3β/β-catenin signaling pathway partially through the influx of Ca2+-mediated activation of Ca/calmodulin-dependent protein kinases (CAMKII). In addition, acetylcholine signaling activation also expanded nerve infiltration through increasing the expression of Brain-Derived Neurotrophic Factor (BDNF), which formed a feedforward acetylcholine-BDNF axis to promote ICC progression. KN93, a small-molecule inhibitor of CAMKII, significantly inhibited the migration and enhanced the sensitivity to gemcitabine of ICC cells. Above all, Acetylcholine/CHRNA5 axis increased the expression of β-catenin to promote the metastasis and resistance to gemcitabine of ICC via CAMKII/GSK3β signaling, and the CAMKII inhibitor KN93 may be an effective therapeutic strategy for combating ICC metastasis.

Role of stress in skin diseases: A neuroendocrine-immune interaction view

Psychological stress is a crucial factor in the development of many skin diseases, and the stigma caused by skin disorders may further increase the psychological burden, forming a vicious cycle of psychological stress leading to skin diseases. Therefore, understanding the relationship between stress and skin diseases is necessary. The skin, as the vital interface with the external environment, possesses its own complex immune system, and the neuroendocrine system plays a central role in the stress response of the body. Stress-induced alterations in the immune system can also disrupt the delicate balance of immune cells and inflammatory mediators in the skin, leading to immune dysregulation and increased susceptibility to various skin diseases. Stress can also affect the skin barrier function, impair wound healing, and promote the release of pro-inflammatory cytokines, thereby exacerbating existing skin diseases such as psoriasis, atopic dermatitis, acne, and urticaria. In the present review, we explored the intricate relationship between stress and skin diseases from a neuroendocrine-immune interaction perspective. We explored the occurrence and development of skin diseases in the context of stress, the stress models for skin diseases, the impact of stress on skin function and diseases, and relevant epidemiological studies and clinical trials. Understanding the relationship between stress and skin diseases from a neuroendocrine-immune interaction perspective provides a comprehensive framework for targeted interventions and new insights into the diagnosis and treatment of skin diseases.