Psychological stress is associated with altered levels of myeloid-derived suppressor cells in breast cancer patients

Myeloid‑derived suppressor cells as targets of emerging therapies and nanotherapies (Review)

Breast cancer (BC) is the leading cause of cancer-related mortality among women worldwide. Immunotherapies are a promising approach in cancer treatment, particularly for aggressive forms of BC with high mortality rates. However, the current eligibility for immunotherapy remains limited to a limited fraction of patients with BC. Myeloid-derived suppressor cells (MDSCs), originating from myeloid cells, are known for their dual role in immunosuppression and tumor promotion, significantly affecting patient outcomes by fostering the formation of premetastatic niches. Consequently, targeting MDSCs has emerged as a promising avenue for further exploration in therapeutic interventions. Leveraging nanotechnology-based drug delivery systems, which excel in accumulating drugs within tumors via passive or active targeting mechanisms, are a promising strategy for the use of MDSCs in the treatment of BC. The present review discusses the immunosuppressive functions of MDSCs, their role in BC, and the diverse strategies for targeting them in cancer therapy. Additionally, the present review discusses future advancements in BC treatments focusing on MDSCs. Furthermore, it elucidates the mechanisms underlying MDSC activation, recruitment and differentiation in BC progression, highlighting the clinical characteristics that render MDSCs suitable candidates for the therapy and targeted nanotherapy of BC.

Interactions between MDSCs and the Autonomic Nervous System: Opportunities and Challenges in Cancer Neuroscience

Myeloid-derived suppressor cells (MDSC) are a population of heterogeneous immune cells that are involved in precancerous conditions and neoplasms. The autonomic nervous system (ANS), which is composed of the sympathetic nervous system and the parasympathetic nervous system, is an important component of the tumor microenvironment that responds to changes in the internal and external environment mainly through adrenergic and cholinergic signaling. An abnormal increase of autonomic nerve density has been associated with cancer progression. As we discuss in this review, growing evidence indicates that sympathetic and parasympathetic signals directly affect the expansion, mobilization, and redistribution of MDSCs. Dysregulated autonomic signaling recruits MDSCs to form an immunosuppressive microenvironment in chronically inflamed tissues, resulting in abnormal proliferation and differentiation of adult stem cells. The two components of the ANS may also be responsible for the seemingly contradictory behaviors of MDSCs. Elucidating the underlying mechanisms has the potential to provide more insights into the complex roles of MDSCs in tumor development and lay the foundation for the development of novel MDSC-targeted anticancer strategies.

Effects of chronic stress on cancer development and the therapeutic prospects of adrenergic signaling regulation

Long-term chronic stress is an important factor in the poor prognosis of cancer patients. Chronic stress reduces the tissue infiltration of immune cells in the tumor microenvironment (TME) by continuously activating the adrenergic signaling, inhibits antitumor immune response and tumor cell apoptosis while also inducing epithelial-mesenchymal transition (EMT) and tumor angiogenesis, promoting tumor invasion and metastasis. This review first summarizes how adrenergic signaling activates intracellular signaling by binding different adrenergic receptor (AR) heterodimers. Then, we focused on reviewing adrenergic signaling to regulate multiple functions of immune cells, including cell differentiation, migration, and cytokine secretion. In addition, the article discusses the mechanisms by which adrenergic signaling exerts pro-tumorigenic effects by acting directly on the tumor itself. It also highlights the use of adrenergic receptor modulators in cancer therapy, with particular emphasis on their potential role in immunotherapy. Finally, the article reviews the beneficial effects of stress intervention measures on cancer treatment. We think that enhancing the body's antitumor response by adjusting adrenergic signaling can enhance the efficacy of cancer treatment.

Single-Cell RNA-Seq Analysis of Patient Myeloid-Derived Suppressor Cells and the Response to Inhibition of Bruton's Tyrosine Kinase

Myeloid-derived suppressor cell (MDSC) levels are elevated in patients with cancer and contribute to reduced efficacy of immune checkpoint therapy. MDSC express Bruton's tyrosine kinase (BTK) and BTK inhibition with ibrutinib, an FDA-approved irreversible inhibitor of BTK, leads to reduced MDSC expansion/function in mice and significantly improves the antitumor activity of anti-PD-1 antibody treatments. Single-cell RNA sequencing (scRNA-seq) was used to characterize the effect of ibrutinib on gene expression of fluorescence-activated cell sorting-enriched MDSC from patients with different cancer types [breast, melanoma, head and neck squamous cell cancer (HNSCC)]. Melanoma patient MDSC were treated in vitro for 4 hours with 5 μmol/L ibrutinib or DMSO, processed for scRNA-seq using the Chromium 10× Genomics platform, and analyzed via the Seurat v4 standard integrative workflow. Baseline gene expression of MDSC from patients with breast, melanoma, and HNSCC cancer revealed similarities among the top expressed genes. In vitro ibrutinib treatment of MDSC from patients with melanoma resulted in significant changes in gene expression. GBP1, IL-1β, and CXCL8 were among the top downregulated genes whereas RGS2 and ABHD5 were among the top upregulated genes (P < 0.001). Double positive CD14+CD15+ MDSC and PMN-MDSC responded similarly to BTK inhibition and exhibited more pronounced gene changes compared with early MDSC and M-MDSC. Pathway analysis revealed significantly downregulated pathways including TREM1, nitric oxide signaling, and IL-6 signaling (P < 0.004).

IMPLICATIONS

scRNA-seq revealed characteristic gene expression patterns for MDSC from different patients with cancer and BTK inhibition led to the downregulation of multiple genes and pathways important to MDSC function and migration.

Role of stress in the pathogenesis of cancer (Review)

Stress is a state of disrupted homeostasis, triggered by intrinsic or extrinsic factors, the stressors, which are counteracted by various physiological and behavioural adaptive responses. Stress has been linked to cancer development and incidence for decades; however, epidemiological studies and clinical trials have yielded contradictory results. The present review discusses the effects of stress on cancer development and the various underlying mechanisms. Animal studies have revealed a clear link between stress and cancer progression, revealing molecular, cellular and endocrine processes that are implicated in these effects. Thus, stress hormones, their receptor systems and their intracellular molecular pathways mediate the effects of stress on cancer initiation, progression and the development of metastases. The mechanisms linking stress and cancer progression can either be indirect, mediated by changes in the cancer microenvironment or immune system dysregulation, or direct, through the binding of neuroendocrine stress‑related signalling molecules to cancer cell receptors. Stress affects numerous anti‑ and pro‑cancer immune system components, including host resistance to metastasis, tumour retention and/or immune suppression. Chronic psychological stress through the elevation of catecholamine levels may increase cancer cell death resistance. On the whole, stress is linked to cancer development and incidence, with psychological stressors playing a crucial role. Animal studies have revealed a better link than human ones, with stress‑related hormones influencing tumour development, migration, invasion and cell proliferation. Randomized controlled trials are required to further evaluate the long‑term cancer outcomes of stress and its management.

Depression and anxiety in cancer patient enrolled in clinical trials with serious adverse events

OBJECTIVE

Drug-induced side effects, particularly serious adverse events (SAEs), often affect cancer patients enrolled in clinical trials. However, little is known about anxiety and depression in cancer patients who experienced SAEs. This study evaluated the prevalence of anxiety and depression in cancer patients enrolled in clinical trials who experienced SAEs and explored the risk factors.

METHODS

A multi-center, cross-sectional survey was conducted in hospitals affiliated with the University of Science and Technology of China from December 2021 to November 2022. A total of 112 cancer patients who experienced SAEs while enrolled in clinical trials, and who completed the informed consent process and study questionnaires, were included in the final analysis.

RESULTS

The rate of moderate-severe depression in cancer patients was 38.4% and that of moderate-severe anxiety was 13.4%. Among the patients who had moderate-severe anxiety, 93.3% had concurrent moderate-severe depression. Lower cognitive function and lower global quality of life were risk factors for depression in cancer patients who experienced SAEs. Pain, low emotional function, low global quality of life, and a high Impact of Events Scale score were risk factors for anxiety.

CONCLUSIONS

Cancer patients enrolled in a clinical trial who experienced SAEs tended to be anxious and depressed, particularly the latter. These results indicate the need to evaluate anxiety and depression, and mental health treatment among cancer patients with SAEs in clinical trials.

Bakar R, Banerji D, Rokicki A, Zhang L, Mulligan CP, Osborne MT, Zarif A, Hammad B, Chan AW, Wirth LJ, Warner ET, Pitman RK, Armstrong KA, Addison D, Neilan TG. Amygdalar activity measured using FDG-PET/CT at head and neck cancer staging independently predicts survival

IMPORTANCE

The mechanisms underlying the association between chronic stress and higher mortality among individuals with cancer remain incompletely understood.

OBJECTIVE

To test the hypotheses that among individuals with active head and neck cancer, that higher stress-associated neural activity (ie. metabolic amygdalar activity [AmygA]) at cancer staging associates with survival.

DESIGN

Retrospective cohort study.

SETTING

Academic Medical Center (Massachusetts General Hospital, Boston).

PARTICIPANTS

240 patients with head and neck cancer (HNCA) who underwent 18F-FDG-PET/CT imaging as part of initial cancer staging.

MEASUREMENTS

18F-FDG uptake in the amygdala was determined by placing circular regions of interest in the right and left amygdalae and measuring the mean tracer accumulation (i.e., standardized uptake value [SUV]) in each region of interest. Amygdalar uptake was corrected for background cerebral activity (mean temporal lobe SUV).

RESULTS

Among individuals with HNCA (age 59±13 years; 30% female), 67 died over a median follow-up period of 3 years (IQR: 1.7-5.1). AmygA associated with heightened bone marrow activity, leukocytosis, and C-reactive protein (P<0.05 each). In adjusted and unadjusted analyses, AmygA associated with subsequent mortality (HR [95% CI]: 1.35, [1.07-1.70], P = 0.009); the association persisted in stratified subset analyses restricted to patients with advanced cancer stage (P<0.001). Individuals within the highest tertile of AmygA experienced a 2-fold higher mortality rate compared to others (P = 0.01). The median progression-free survival was 25 months in patients with higher AmygA (upper tertile) as compared with 36.5 months in other individuals (HR for progression or death [95%CI], 1.83 [1.24-2.68], P = 0.001).

CONCLUSIONS AND RELEVANCE

AmygA, quantified on routine 18F-FDG-PET/CT images obtained at cancer staging, independently and robustly predicts mortality and cancer progression among patients with HNCA. Future studies should test whether strategies that attenuate AmygA (or its downstream biological consequences) may improve cancer survival.

Neuro-immune interactions and immuno-oncology

The nervous system is an important component of the tumor microenvironment (TME), driving tumorigenesis and tumor progression. Neuronal cues (e.g., neurotransmitters and neuropeptides) in the TME cause phenotypic changes in immune cells, such as increased exhaustion and inhibition of effector cells, which promote immune evasion and cancer progression. Two types of immune regulation by tumor-associated nerves are discussed in this review: regulation via neuronal stimuli (i.e., by neural transmission) and checkpoint-mediated neuronal immune regulation. The latter occurs via the expression of immune checkpoints on the membranes of intratumoral nerves and glial cells. Here, we summarize novel findings regarding the neuroimmune circuits in the tumor milieu, while emphasizing the potential targets of new and affordable anticancer therapeutic approaches.

MDSCs in breast cancer: an important enabler of tumor progression and an emerging therapeutic target

Women worldwide are more likely to develop breast cancer (BC) than any other type of cancer. The treatment of BC depends on the subtype and stage of the cancer, such as surgery, radiotherapy, chemotherapy, and immunotherapy. Although significant progress has been made in recent years, advanced or metastatic BC presents a poor prognosis, due to drug resistance and recurrences. During embryonic development, myeloid-derived suppressor cells (MDSCs) develop that suppress the immune system. By inhibiting anti-immune effects and promoting non-immune mechanisms such as tumor cell stemness, epithelial-mesenchymal transformation (EMT) and angiogenesis, MDSCs effectively promote tumor growth and metastasis. In various BC models, peripheral tissues, and tumor microenvironments (TME), MDSCs have been found to amplification. Clinical progression or poor prognosis are strongly associated with increased MDSCs. In this review, we describe the activation, recruitment, and differentiation of MDSCs production in BC, the involvement of MDSCs in BC progression, and the clinical characteristics of MDSCs as a potential BC therapy target.

Depression and anxiety among hemophilia patients enrolled in clinical trials: a multi-center cohort study

Hemophilia patients enrolled in clinical trials often exhibit various physical and psychological symptoms. However, little is known about anxiety and depression among them. This study assessed the effects of depression and anxiety on hemophilia patients enrolled in clinical trials and identified risk factors for these disorders. A multi-center, cohort study was conducted from January to December 2022. Sixty-nine hemophilia patients who enrolled in clinical trials participated at baseline (T1, prior to treatment initiation) and completed the informed consent. Risk factors were measured at baseline to predict depression and anxiety at 3 months (T2). Sixty-four hemophilia patients were included in the final analysis. More hemophilia patients had moderate-severe depression (28 [43.75%]) and anxiety (16 [25.00%]) at T2 than at T1 (12 [18.75]), (5 [7.81%]). Depression was aggravated in 23 (35.94%) patients and anxiety was aggravated in 12 (18.75%) patients. Frequently acquired medical information (OR 11.378, CI 1.319-98.114, P = 0.027), baseline GAD-7 (OR 1.341, CI 1.015-1.772, P = 0. 039) and PHQ-9 (OR 1.465, CI 1.039-2.065, P = 0.029) are important factors predicting depression and anxiety in hemophilia patients. Hemophilia patients enrolled in a clinical trial have significant anxiety and depression. The frequency of acquiring medical information and the baseline PHQ-9 and GAD-7 scores were risk factors for anxiety and depression. Thus, hemophilia patients should receive education regarding clinical trials and undergo evaluations of their anxiety and depression; these changes will enable prompt detection of their psychological burden and identify potential psychological intervention strategies.

Chronic psychological stress promotes breast cancer pre-metastatic niche formation by mobilizing splenic MDSCs via TAM/CXCL1 signaling

BACKGROUND

Emerging studies have identified chronic psychological stress as an independent risk factor influencing breast cancer growth and metastasis. However, the effects of chronic psychological stress on pre-metastatic niche (PMN) formation and the underlying immunological mechanisms remain largely unknown.

METHODS

The effects and molecular mechanisms of chronic unpredictable mild stress (CUMS) on modulating tumor-associated macrophages (TAMs) and PMN formation were clarified by multiplex immunofluorescence technique, cytokine array, chromatin immunoprecipitation, the dual-luciferase reporter assay, and breast cancer xenografts. Transwell and CD8⁺ T cytotoxicity detection were used to analyze the mobilization and function of myeloid-derived suppressor cells (MDSCs). mCherry-labeled tracing strategy and bone marrow transplantation were applied to explore the crucial role of splenic CXCR2^+/+ MDSCs facilitating PMN formation under CUMS.

RESULTS

CUMS significantly promoted breast cancer growth and metastasis, accompanied by TAMs accumulation in the microenvironment. CXCL1 was identified as a crucial chemokine in TAMs facilitating PMN formation in a glucocorticoid receptor (GR)-dependent manner. Interestingly, the spleen index was significantly reduced under CUMS, and splenic MDSCs were validated as a key factor mediating CXCL1-induced PMN formation. The molecular mechanism study revealed that TAM-derived CXCL1 enhanced the proliferation, migration, and anti-CD8⁺ T cell functions of MDSCs via CXCR2. Moreover, CXCR2 knockout and CXCR2^-/-MDSCs transplantation significantly impaired CUMS-mediated MDSC elevation, PMN formation, and breast cancer metastasis.

CONCLUSION

Our findings shed new light on the association between chronic psychological stress and splenic MDSC mobilization, and suggest that stress-related glucocorticoid elevation can enhance TAM/CXCL1 signaling and subsequently recruit splenic MDSCs to promote PMN formation via CXCR2.

Here, There, and Everywhere: Myeloid-Derived Suppressor Cells in Immunology

Myeloid-derived suppressor cells (MDSCs) were initially identified in humans and mice with cancer where they profoundly suppress T cell- and NK cell-mediated antitumor immunity. Inflammation is a central feature of many pathologies and normal physiological conditions and is the dominant driving force for the accumulation and function of MDSCs. Therefore, MDSCs are present in conditions where inflammation is present. Although MDSCs are detrimental in cancer and conditions where cellular immunity is desirable, they are beneficial in settings where cellular immunity is hyperactive. Because MDSCs can be generated ex vivo, they are being exploited as therapeutic agents to reduce damaging cellular immunity. In this review, we discuss the detrimental and beneficial roles of MDSCs in disease settings such as bacterial, viral, and parasitic infections, sepsis, obesity, trauma, stress, autoimmunity, transplantation and graft-versus-host disease, and normal physiological settings, including pregnancy and neonates as well as aging. The impact of MDSCs on vaccination is also discussed.

Stress and surgical diseases of thyroid gland in environment of the armed conflict (review of literature and own observations)

Stress and surgical diseases of thyroid gland in environment of the armed conflict (review of literature and own observations)

Effect of chronic stress on tumorigenesis and development

Chronic stress activates the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis to aggravates tumorigenesis and development. Although the importance of SNS and HPA in maintaining homeostasis has already attracted much attention, there is still a lot remained unknown about the molecular mechanisms by which chronic stress influence the occurrence and development of tumor. While some researches have already concluded the mechanisms underlying the effect of chronic stress on tumor, complicated processes of tumor progression resulted in effects of chronic stress on various stages of tumor remains elusive. In this reviews we concluded recent research progresses of chronic stress and its effects on premalignancy, tumorigenesis and tumor development, we comprehensively summarized the molecular mechanisms in between. And we highlight the available treatments and potential therapies for stressed patients with tumor.

Distinctive gene expression patterns in pregnancy-associated breast cancer

Pregnancy-associated breast cancer (PABC) is diagnosed during pregnancy or within 1 year postpartum, but the unique aspects of its etiology and pathogenesis have not been fully elucidated. This study aimed to ascertain the molecular mechanisms of PABC to facilitate diagnosis and therapeutic development. The Limma package was used to characterize the differentially expressed genes in PABC as compared to non-pregnancy-associated breast cancer (NPABC) and normal breast tissue. A total of 871 dysregulated genes were identified in the PABC versus NPABC groups and 917 in the PABC versus normal groups, with notable differences in the expression of MAGE and CXCL family genes. The dysregulated genes between the PABC and normal groups were mainly associated with signal transduction and immune response, while Kyoto Encyclopedia of Genes and Genomes analysis revealed that the dysregulated genes were enriched in immune-related pathways, including the major histocompatibility complex (MHC) class II protein complex, the type I interferon signaling pathway, regulation of α-β T-cell proliferation, and the T-cell apoptotic process. Through protein-protein interaction network construction, CD44 and BRCA1 were identified as prominent hub genes with differential expression in PABC versus NPABC. Furthermore, a cluster with eleven hub genes was identified in PABC versus normal adjacent tissues, of which the expression of EGFR, IGF1, PTGS2, FGF1, CAV1, and PLCB1 were verified to be differentially expressed in an independent cohort of PABC patients. Notably, IGF1, PTGS2, and FGF1 were demonstrated to be significantly related to patient prognosis. Our study reveals a distinctive gene expression pattern in PABC and suggests that IGF1, PTGS2, and FGF1 might serve as biomarkers for diagnosis and prognosis of PABC.

Inhibiting the Priming for Cancer in Li-Fraumeni Syndrome

Simple Summary

Li-Fraumeni Syndrome (LFS) is a rare cancer pre-disposition syndrome associated with a germline mutation in the TP53 tumour suppressor gene. People with LFS have a 90% chance of suffering one or more cancers in their lifetime. No treatments exist to reduce this cancer risk. This paper reviews the evidence for how cancers start in people with LFS and proposes that a series of commonly used non-cancer drugs, including metformin and aspirin, can help reduce that lifetime risk of cancer.

Abstract

The concept of the pre-cancerous niche applies the ‘seed and soil’ theory of metastasis to the initial process of carcinogenesis. TP53 is at the nexus of this process and, in the context of Li-Fraumeni Syndrome (LFS), is a key determinant of the conditions in which cancers are formed and progress. Important factors in the creation of the pre-cancerous niche include disrupted tissue homeostasis, cellular metabolism and chronic inflammation. While druggability of TP53 remains a challenge, there is evidence that drug re-purposing may be able to address aspects of pre-cancerous niche formation and thereby reduce the risk of cancer in individuals with LFS.

Stress-Reducing Psychological Interventions as Adjuvant Therapies for Diabetic Chronic Wounds

BACKGROUND

Diabetic foot ulcers (DFUs) are a major complication of diabetes mellitus and a leading cause of lower limb amputation. Interventions to reduce psychological stress may have the potential to improve self-care and greatly reduce the morbidity and mortality associated with DFU. This review is focused on the consequences of psychological stress in wound healing and reflects on the effects of currently used psychological stress-reducing interventions in patients with DFU, proposing new applications for currently used stress-reduction interventions.

RESULTS

Stress is a natural and fundamental survival mechanism that becomes harmful when chronic. DFU is associated with high levels of anxiety and chronic psychological stress. Chronic stressinduced cortisol and adrenaline release impair wound healing, independently of the stressor. Psychological stress-reducing interventions, such as relaxation with guided imagery, biofeedback-assisted relaxation, mindfulness-based strategies, and hypnosis, can lead to a reduction in perceived stress and improve wound healing by reducing wound inflammation and pain while improving glycemic control. All stress reduction interventions also lead to pain relief and improved patient's quality of life.

CONCLUSION

Psychological stress-reducing interventions are promising adjuvant therapies for DFU. Their clinical application can improve self-care by tackling patient's expectations, anxieties, and fears. They can also help patients manage stress and pain while reducing wound inflammation and improving wound healing.

Targeting Myeloid-Derived Suppressor Cells Derived From Surgical Stress: The Key to Prevent Post-surgical Metastasis

Myeloid-derived suppressor cells (MDSCs) are known to play an essential part in tumor progression under chronic stress settings through their manipulation of adaptive and innate immune systems. Previous researches mainly focus on MDSC's role in the chronic tumor immune environment. In addition, surgery can also serve as a form of acute stress within the patient's internal environment. Nevertheless, the part that MDSCs play in post-surgical tumor development has not gained enough attention yet. Although surgery is known to be an effective definite treatment for most localized solid tumors, there are still plenty of cancer patients who experience recurrence or metastasis after radical resection of the primary tumor. It is believed that surgery has the paradoxical capability to enhance tumor growth. Many possible mechanisms exist for explaining post-surgical metastasis. We hypothesize that surgical resection of the primary tumor can also facilitate the expansion of MDSCs and their pro-tumor role since these surgery-induced MDSCs can prepare the pre-metastatic niche (the "soil") and at the same time interact with circulating tumor cells (the "seeds"). This vicious, reciprocal mechanism is a crucial point in the emergence of post-surgical metastasis. According to our hypothesis, MDSCs can be the precise target to prevent cancer patients from post-surgical recurrence and metastasis during the perioperative phase to break the wretched cycle and provide better long-term survival for these patients. Future studies are needed to validate this hypothesis.

Chronic stress promotes breast carcinoma metastasis by accumulating myeloid-derived suppressor cells through activating β-adrenergic signaling

Numerous studies have found that chronic stress could promote tumor progression and this may be related to inhibtion of immune system. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells with immunosuppressive activity. MDSCs may represent a key link between chronic stress and tumor progression. However, the role of stress-induced MDSCs in breast cancer progression is unclear. The present study showed that pre-exposure of chronic stress could lead to MDSCs elevation and facilitated breast cancer metastasis in tumor-bearing mice. Adoptive transfer of MDSCs could significantly increase lung metastatic foci. In contrast, lung metastasis could be alleviated by depleting endogenous MDSCs with Gr-1 antibody. The concentration of norepinephrine in serum and the expression of tyrosine hydroxylase in bone marrow could be significantly elevated by chronic stress. Moreover, propranolol, an inhibitor of β-adrenergic signaling, could inhibit breast carcinoma metastasis and prevent the expansion of chronic stress-induced MDSCs. Further study revealed that the expressions of IL-6 and JAK/STAT3 signaling pathways were upregulated by chronic stress in mice, and this upregulation could be inhibited by propranolol. Blocking the IL-6 signal or inhibiting the activation of the JAK/STAT3 signaling pathway could reduce tumor growth and metastasis by attenuating the accumulation of MDSCs in vivo. Besides, propranolol inhibited the expression of IL-6 in supernatant of 4T1 cells induced by isoproterenol and reduced the proportion of inducible MDSCs in vitro. Taken together, these data indicated that chronic stress may accumulate MDSCs via activation of β-adrenergic signaling and IL-6/STAT3 pathway, thereby promoting breast carcinoma metastasis.

Stress and cancer: mechanisms, significance and future directions

The notion that stress and cancer are interlinked has dominated lay discourse for decades. More recent animal studies indicate that stress can substantially facilitate cancer progression through modulating most hallmarks of cancer, and molecular and systemic mechanisms mediating these effects have been elucidated. However, available clinical evidence for such deleterious effects is inconsistent, as epidemiological and stress-reducing clinical interventions have yielded mixed effects on cancer mortality. In this Review, we describe and discuss specific mediating mechanisms identified by preclinical research, and parallel clinical findings. We explain the discrepancy between preclinical and clinical outcomes, through pointing to experimental strengths leveraged by animal studies and through discussing methodological and conceptual obstacles that prevent clinical studies from reflecting the impacts of stress. We suggest approaches to circumvent such obstacles, based on targeting critical phases of cancer progression that are more likely to be stress-sensitive; pharmacologically limiting adrenergic-inflammatory responses triggered by medical procedures; and focusing on more vulnerable populations, employing personalized pharmacological and psychosocial approaches. Recent clinical trials support our hypothesis that psychological and/or pharmacological inhibition of excess adrenergic and/or inflammatory stress signalling, especially alongside cancer treatments, could save lives.

Immunosuppressive metabolites in tumoral immune evasion: redundancies, clinical efforts, and pathways forward

Tumors accumulate metabolites that deactivate infiltrating immune cells and polarize them toward anti-inflammatory phenotypes. We provide a comprehensive review of the complex networks orchestrated by several of the most potent immunosuppressive metabolites, highlighting the impact of adenosine, kynurenines, prostaglandin E2, and norepinephrine and epinephrine, while discussing completed and ongoing clinical efforts to curtail their impact. Retrospective analyses of clinical data have elucidated that their activity is negatively associated with prognosis in diverse cancer indications, though there is a current paucity of approved therapies that disrupt their synthesis or downstream signaling axes. We hypothesize that prior lukewarm results may be attributed to redundancies in each metabolites' synthesis or signaling pathway and highlight routes for how therapeutic development and patient stratification might proceed in the future.

The current knowledge concerning solid cancer and therapy

Solid cancers comprise a large number of new cases and deaths from cancer each year globally. There are a number of strategies for addressing tumors raised from solid organs including surgery, chemotherapy, radiotherapy, targeted therapy, immunotherapy, combinational therapy, and stem cell and extracellular vesicle (EV) therapy. Surgery, radiotherapy, and chemotherapy are the dominant cures, but are not always effective, in which even in a localized tumor there is a possibility of tumor relapse after surgical resection. Over half of the cancer patients will receive radiotherapy as a part of their therapeutic schedule. Radiotherapy can cause an abscopal response for boosting the activity of the immune system outside the local field of radiation, but it may also cause an unwanted bystander effect, predisposing nonradiated cells into carcinogenesis. In the context of immunotherapy, immune checkpoint inhibition is known as the standard-of-care, but the major concern is in regard with cold cancers that show low responses to such therapy. Stem-cell therapy can be used to send prodrugs toward the tumor area; this strategy, however, has its own predicaments, such as unwanted attraction toward the other sites including healthy tissues and its instability. A substitute to such therapy and quite a novel strategy is to use EVs, by virtue of their stability and potential to cross biological barriers and long-term storage of contents. Combination therapy is the current focus. Despite advances in the field, there are still unmet concerns in the area of effective cancer therapy, raising challenges and opportunities for future investigations.

Rural-Urban Differences in Neuroimmune Biomarkers and Health Status Among Women Living With Breast Cancer

BACKGROUND

Because of chronic emotional and psychosocial stressors following breast cancer (BC) treatment, BC survivors are at risk of neuroimmune dysfunction in survivorship. Rural BC survivors experience more health disparities than urban BC survivors. Rural-urban residence as a variable on neuroimmune activity in extended BC survivorship continuum has not been explored.

OBJECTIVE

To report the feasibility of studying relationships between neuroimmune activity and perceived health in rural and urban BC survivors.

METHODS

Data from a pilot study of BC survivors (n = 41) were analyzed. Participants were rural (n = 16) and urban (n = 25). Participants completed Medical Outcomes Study Short-Form Version 2 Health Survey questionnaires and provided salivary specimens for analysis of salivary α-amylase (sAA), cortisol, and interleukin 6 (IL-6). Rural-Urban Commuting Area Codes were used to determine rural or urban residence.

RESULTS

Differences in immune activity were observed between rural and urban BC survivors (U = 34, P < .05). No rural-urban group differences in neuroendocrine activity were observed. Relationships were observed between perceptions of mental health and sAA (P < .05) in rural BC survivors and between perceptions of mental health and IL-6 (P < .05) in urban BC survivors. Interleukin 6 was positively associated with perceptions of physical health (P < .05) in rural BC survivors.

CONCLUSION

Pilot data suggest rural-urban residence may be a factor in relationships between neuroimmune function (ie, sAA and IL-6) and perceived health status, particularly social functioning in women with BC. Additional studies with powered designs are indicated.

IMPLICATIONS FOR PRACTICE

Although evidence is limited, data support the feasibility of studying relationships between sAA and IL-6 and perceptions of health in women with BC.

Targeting Myeloid-Derived Suppressor Cells for Premetastatic Niche Disruption After Tumor Resection

Surgical resection is a common therapeutic option for primary solid tumors. However, high cancer recurrence and metastatic rates after resection are the main cause of cancer related mortalities. This implies the existence of a "fertile soil" following surgery that facilitates colonization by circulating cancer cells. Myeloid-derived suppressor cells (MDSCs) are essential for premetastatic niche formation, and may persist in distant organs for up to 2 weeks after surgery. These postsurgical persistent lung MDSCs exhibit stronger immunosuppression compared with presurgical MDSCs, suggesting that surgery enhances MDSC function. Surgical stress and trauma trigger the secretion of systemic inflammatory cytokines, which enhance MDSC mobilization and proliferation. Additionally, damage associated molecular patterns (DAMPs) directly activate MDSCs through pattern recognition receptor-mediated signals. Surgery also increases vascular permeability, induces an increase in lysyl oxidase and extracellular matrix remodeling in lungs, that enhances MDSC mobilization. Postsurgical therapies that inhibit the induction of premetastatic niches by MDSCs promote the long-term survival of patients. Cyclooxygenase-2 inhibitors and β-blockade, or their combination, may minimize the impact of surgical stress on MDSCs. Anti-DAMPs and associated inflammatory signaling inhibitors also are potential therapies. Existing therapies under tumor-bearing conditions, such as MDSCs depletion with low-dose chemotherapy or tyrosine kinase inhibitors, MDSCs differentiation using all-trans retinoic acid, and STAT3 inhibition merit clinical evaluation during the perioperative period. In addition, combining low-dose epigenetic drugs with chemokine receptors, reversing immunosuppression through the Enhanced Recovery After Surgery protocol, repairing vascular leakage, or inhibiting extracellular matrix remodeling also may enhance the long-term survival of curative resection patients.

Association between cellular immune response and spleen weight in mice with hepatocellular carcinoma

The spleen is an important site for extramedullary hematopoiesis and tumor immunotolerance. Spleen weight varies with tumor progression and may be a predictor of tumor recurrence. However, to the best of our knowledge, the association between spleen weight and tumor progression remains unclear. The present study revealed a novel role for the spleen in predicting the cellular immune response in tumor-bearing mice. A murine H22 subcutaneous hepatoma model was established. The spleen weight and tumor weight were measured. The proportion of immune cells in peripheral blood and spleen were detected by flow cytometry. The results demonstrated that the spleen weight of tumor-bearing mice at day 21 was higher than that of the controls. In addition, spleen weight was identified to be positively correlated with tumor weight. The percentages of CD4⁺ and CD8⁺ T lymphocytes in the spleen were decreased at day 21 after tumor cell inoculation, while those of monocytic-like myeloid-derived suppressor cells (M-MDSCs) and CD11b⁺F4/80⁺ macrophages were increased at day 21 after tumor cell inoculation. Similarly, the percentage of polymorphonuclear-like MDSCs (PMN-MDSCs) in the spleen of tumor-bearing mice was increased at days 7, 14 and 21 after tumor cell inoculation. Notably, spleen weight was negatively correlated with the percentages of CD4⁺ and CD8⁺ T lymphocytes in the spleen, although spleen and tumor weight were positively correlated with the percentages of M-MDSCs and PMN-MDSCs in the spleen. Similarly, the percentages of CD8⁺ T lymphocytes in the peripheral blood were decreased, and programmed cell death protein 1 expression on CD8⁺ T lymphocytes was increased at day 21 after tumor cell inoculation. Furthermore, the percentages of M-MDSCs were increased at day 21 and PMN-MDSCs in the peripheral blood were increased at days 7, 14 and 21 after tumor cell inoculation. Additionally, spleen and tumor weight were also positively correlated with the percentages of M-MDSC and PMN-MDSCs in the peripheral blood of tumor-bearing mice. Collectively, the findings of the present study suggested that spleen weight may be a predictor of tumor prognosis, since it was directly correlated with tumor weight and the percentages of M-MDSC and PMN-MDSCs in tumor-bearing mice.

Depression, Anxiety, and Social Environmental Adversity as Potential Modulators of the Immune Tumor Microenvironment in Breast Cancer Patients

Background: Mounting data suggest that exposure to chronic stress is associated with worse breast cancer outcomes. This study aimed to explore the impact of social environmental adversity (SEA, e.g., child abuse, crime, sexual, and physical violence), depressive symptomatology, and anxiety on immune cell infiltration into the breast tumor microenvironment. Methods: Participants (n = 33) completed a series of surveys assessing depression and anxiety symptoms, adverse childhood events (ACE), and trauma history. Tumor-associated macrophages (CD68+), B cells (CD19+), and T cells (CD3+) were identified by immunohistochemical analyses of formalin-fixed paraffin-embedded tumor samples and quantified. Spearman rank tests were used to explore the relationships between the variables studied. Results: Exposure to SEA was high (ACE = 72%, exposure to crime = 47%, and exposure to physical/sexual assault = 73%) among participants. Moreover, 30% reported a comorbid history of depression and ACE; 39% reported one or more traumatic events, and clinically significant depression symptomatology, while 21% reported trauma history and significant anxiety symptomatology. Increased tumor-infiltrating B cells were significantly correlated with exposure to crime, anxiety symptoms, and exposure to an ACE. The ACE plus anxiety group presented the highest infiltration of B cells, T cells, and macrophages. Conclusion: These findings support a role for SEA, anxiety symptoms, and depression as potential modulators of the immune tumor microenvironment in breast cancer.

Breast cancer dormancy: need for clinically relevant models to address current gaps in knowledge

Breast cancer is the most commonly diagnosed cancer in the USA. Although advances in treatment over the past several decades have significantly improved the outlook for this disease, most women who are diagnosed with estrogen receptor positive disease remain at risk of metastatic relapse for the remainder of their life. The cellular source of late relapse in these patients is thought to be disseminated tumor cells that reactivate after a long period of dormancy. The biology of these dormant cells and their natural history over a patient's lifetime is largely unclear. We posit that research on tumor dormancy has been significantly limited by the lack of clinically relevant models. This review will discuss existing dormancy models, gaps in biological understanding, and propose criteria for future models to enhance their clinical relevance.

Myeloid-derived suppressor cells in cancer immunotherapy-clinical perspectives

Myeloid-derived suppressor cells (MDSCs) are heterogeneous and poorly mature cells of innate immunity that their population is increased substantially in cancer patients. MDSCs represent three subsets including CD14⁺ monocytic (M), CD15⁺ granulocytic (G) and Lin^- early precursor (e) cells. MDSCs release a number of factors that direct several tumorigenic-related events including immune evasion, angiogenesis and metastasis. Assessment of MDSCs can provide valuable information from cancer immunity state, and it can be an indicator of tumor prognosis. The cells can be targeted in combination with current immunotherapeutic schedules, and the outcomes were promising. The focus of this review is to provide an overview of MDSCs, their involvement in tumor-related immunosuppression, and their impact on cancer immunotherapy. Then, strategies are proposed to boost the power of immune system against MDSCs.

Serotonin/HTR1E signaling blocks chronic stress-promoted progression of ovarian cancer

Rationale: Psychological stress has been linked to cancer development and resistance to therapy by many epidemiological and clinical studies. Stress-induced immunosuppressive microenvironment by stress hormones, in particular glucocorticoids, has been extensively studied. However, the impacts of other stress-related neurotransmitters, such as serotonin (5-hydroxytryptamine, 5-HT), on cancer development just start to be revealed. Here, we aimed to identify novel neurotransmitters involved in stress-induced growth and dissemination of ovarian cancer (OC) and reveal the major underlying signaling pathway and the therapeutic significance. Methods: Through a genome-wide CRISPR/Cas9 knockout screen in the murine orthotopic model of ovarian carcinoma (OC), we identified candidate genes regulating the peritoneal dissemination of OC. Among them, we picked out HTR1E, one member of 5-HT receptor family specifically expressed in the ovary and endometrium in addition to brain. The correlation of HTR1E expression with OC progression was analyzed in OC patient specimen by quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry (IHC). Gain-of-function and loss-of-function analyses were performed to explore the functions of 5-HT/HTR1E signaling in OC growth and dissemination in vitro and in vivo. In addition, we investigated the therapeutic values of HTR1E specific agonist and small molecular inhibitors against HTR1E downstream factor SRC in a stressed murine OC xenograft model. Results: In OC patients, the HTR1E expression is dramatically decreased in peritoneal disseminated OC cells, which correlates with poor clinical outcome. Silence of HTR1E in OC cells greatly promotes cell proliferation and epithelial mesenchymal transition (EMT) by the activation of SRC-mediated downstream signaling pathways. Furthermore, chronic stress results in significantly decreased serotonin in the ovary and the enhanced OC growth and peritoneal dissemination in mice, which can be strongly inhibited by specific HTR1E agonist or the SRC inhibitor. Conclusions: We discovered the essential role of serotonin/HTR1E signaling in preventing the chronic psychological stress-promoted progression of OC, suggesting the potential therapeutic value of the HTR1E specific agonist and the SRC inhibitor for OC patients who are suffering from psychological stress.

Psychosocial stress and immunosuppression in cancer: what can we learn from new research?

It is generally believed that the physiological consequences of stress could contribute to poor outcomes for patients being treated for cancer. However, despite preclinical and clinical evidence suggesting that stress promotes increased cancer-related mortality, a comprehensive understanding of the mechanisms involved in mediating these effects does not yet exist. We reviewed 47 clinical studies published between 2007 and 2020 to determine whether psychosocial stress affects clinical outcomes in cancer: 6.4% of studies showed a protective effect; 44.6% showed a harmful effect; 48.9% showed no association. These data suggest that psychosocial stress could affect cancer incidence and/or mortality, but the association is unclear. To shed light on this potentially important relationship, objective biomarkers of stress are needed to more accurately evaluate levels of stress and its downstream effects. As a potential candidate, the neuroendocrine signalling pathways initiated by stress are known to affect anti-tumour immune cells, and here we summarise how this may promote an immunosuppressive, pro-tumour microenvironment. Further research must be done to understand the relationships between stress and immunity to more accurately measure how stress affects cancer progression and outcome.

Chronic restraint stress promotes the mobilization and recruitment of myeloid-derived suppressor cells through β-adrenergic-activated CXCL5-CXCR2-Erk signaling cascades

Myeloid-derived suppressor cells (MDSCs) play an important role in tumor immune escape. Recent studies have shown that MDSCs contribute to tumor progression under psychological stress, but the underlying mechanism of MDSCs mobilization and recruitment remains largely unknown. In the present study, a chronic restraint stress paradigm was applied to the H22 hepatocellular carcinoma (HCC) bearing mice to mimic the psychological stress. We observed that chronic restraint stress significantly promoted HCC growth, as well as the mobilization of MDSCs to spleen and tumor sites from bone marrow. Meanwhile, chronic restraint stress enhanced the expression of C-X-C motif chemokine receptor 2 (CXCR2) and pErk1/2 in bone marrow MDSCs, together with elevated chemokine (C-X-C motif) ligand 5 (CXCL5) expression in tumor tissues. In vitro, the treatments of MDSCs with epinephrine (EPI) and norepinephrine (NE) but not corticosterone (CORT)-treated H22 conditioned medium obviously inhibited T-cell proliferation, as well as enhanced CXCR2 expression and extracellular signal-regulated kinase (Erk) phosphorylation. In vivo, β-adrenergic blockade with propranolol almost completely reversed the accelerated tumor growth induced by chronic restraint stress and inactivated CXCL5-CXCR2-Erk signaling pathway. Our findings support the crucial role of β-adrenergic signaling cascade in the mobilization and recruitment of MDSCs under chronic restraint stress.

Cancer immunotherapy: Re-programming cells of the innate and adaptive immune systems

Cancers utilize multiple mechanisms to overcome immune responses. Emerging evidence suggest that immunotherapy of cancer should focus on inducing and re-programming cells of the innate and adaptive immune systems rather than focusing solely on T cells. Recently, we have shown that such a multifaceted approach can improve immunotherapy of breast cancer.

A Psychosocial Genomics Pilot Study in Oncology for Verifying Clinical, Inflammatory and Psychological Effects of Mind-Body Transformations-Therapy (MBT-T) in Breast Cancer Patients: Preliminary Results

Several studies have highlighted the key role of chronic inflammation in breast cancer development, progression, metastasis, and therapeutic outcome. These processes are mediated through a variety of cytokines and hormones that exert their biological actions either locally or distantly via systemic circulation. Recent findings suggest that positive psychosocial experiences, including psychotherapeutic interventions and therapeutic mind-body protocols, can modulate the inflammatory response by reducing the expression of genes/proteins associated with inflammation and stress-related pathways. Our preliminary results indicate that a specific mind-body therapy (MBT-T) could induce a significant reduction of the release of different cytokines and chemokines, such as SCGFβ, SDF-1α, MCP3, GROα, LIF, and IL-18, in the sera of breast cancer patients compared to a control group, suggesting that MBT-T could represent a promising approach to improve the wellness and outcome of breast cancer patients.

β3-Adrenoceptors as Putative Regulator of Immune Tolerance in Cancer and Pregnancy

Understanding the mechanisms of immune tolerance is currently one of the most important challenges of scientific research. Pregnancy affects the immune system balance, leading the host to tolerate embryo alloantigens. Previous reports demonstrated that β-adrenergic receptor (β-AR) signaling promotes immune tolerance by modulation of NK and Treg, mainly through the activation of β2-ARs, but recently we have demonstrated that also β3-ARs induce an immune-tolerant phenotype in mice bearing melanoma. In this report, we demonstrate that β3-ARs support host immune tolerance in the maternal microenvironment by modulating the same immune cells populations as recently demonstrated in cancer. Considering that β3-ARs are modulated by oxygen levels, we hypothesize that hypoxia, through the upregulation of β3-AR, promotes the biological shift toward a tolerant immunophenotype and that this is the same trick that embryo and cancer use to create an aura of immune-tolerance in a competent immune environment. This study confirms the analogies between fetal development and tumor progression and suggests that the expression of β3-ARs represents one of the strategies to induce fetal and tumor immune tolerance.

Relationship satisfaction predicts lower stress and inflammation in breast cancer survivors: A longitudinal study of within-person and between-person effects

BACKGROUND

Breast cancer survivors with elevated inflammation have a greater risk for cancer recurrence, premature mortality, and comorbid disease development. The psychological stress survivors experience when confronted with a breast cancer diagnosis and cancer treatment can heighten inflammation. Identifying factors that reduce stress and inflammation could lead to improvements in survivors' long-term health. Accordingly, this study examined the health-enhancing effects of romantic relationships-a key health determinant-on breast cancer survivors' stress and inflammation.

METHODS

Breast cancer survivors (n = 139, stages 0-IIIC) completed a baseline visit before treatment and two follow-up visits 6 and 18 months after treatment ended. Women completed self-report questionnaires assessing their romantic relationship satisfaction and perceived stress, and they provided a blood sample for serum markers of inflammation at each visit. The longitudinal design allowed for examination within and between survivors. We conducted multilevel mediation analyses to assess how changes in survivors' relationship satisfaction were related to changes in stress and inflammation from visit to visit (i.e., within-person effects), as well as how the average effects of relationship satisfaction were associated with average stress and inflammation levels throughout the study (i.e., between-person effects).

RESULTS

At the within-person level, at visits in which survivors were more satisfied with their relationships, they also perceived less stress, which in turn was related to lower than their own average levels of serum C-reactive protein and proinflammatory cytokines (tumor necrosis factor-α, interleukin-6, and interleukin-1β). At the between-person level, survivors who had greater relationship satisfaction throughout the study had lower perceived stress, which was linked to lower levels of inflammation.

CONCLUSION

Breast cancer survivors in satisfying romantic relationships felt less stressed and in turn had lower inflammation throughout cancer treatment. This study illustrates the utility of a within-person approach to not only consider the average effects of relationship satisfaction, but also how changes in their own relationship satisfaction impact stress and inflammation over time. Our findings demonstrate important psychological and immunological pathways through which satisfying relationships may promote breast cancer survivors' long-term health.

Current Therapies and New Targets to Fight Melanoma: A Promising Role for the β3-Adrenoreceptor

Melanoma is one of the most aggressive types of cancer and the most deadly skin cancer. According to World Health Organization, about 132,000 melanoma skin cancers occur globally each year. Thanks to the efficacy of new therapies, life expectation has been improved over the last years. However, some malignant melanomas still remain unresponsive to these therapies. The β-adrenergic system, among its many physiological roles, has been recognized as the main mediator of stress-related tumorigenic events. In particular, catecholamine activation of β-adrenergic receptors (β-ARs) affects several processes that sustain cancer progression. Among the β-AR subtypes, the β3-AR is emerging as an important regulator of tumorigenesis. In this review, we summarize data of different experimental studies focused on β3-AR involvement in tumor development in various types of cancer and, particularly, in melanoma. Taken together, the preclinical evidences reported in this review demonstrate the crucial role of β3-AR in regulating the complex signaling network driving melanoma progression. Therefore, a need exists to further disseminate this new concept and to investigate more deeply the role of β3-AR as a possible therapeutic target for counteracting melanoma progression at clinical level.

Neuroendocrine Regulation of Tumor-Associated Immune Cells

Mounting preclinical and clinical evidence continues to support a role for the neuroendocrine system in the modulation of tumor biology and progression. Several studies have shown data supporting a link between chronic stress and cancer progression. Dysregulation of the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in promoting angiogenesis, tumor cell proliferation and survival, alteration of the immune response and exacerbating inflammatory networks in the tumor microenvironment. Here, we review how SNS and HPA dysregulation contributes to disturbances in immune cell populations, modifies cancer biology, and impacts immunotherapy response. We also highlight several interventions aimed at circumventing the adverse effects stress has on cancer patients.

Identifying risk factors for depression and anxiety symptoms in patients with chronic lymphocytic leukemia

PURPOSE

This study assessed whether empirically supported risk factors can identify future depression and anxiety symptoms in a specific cancer type, chronic lymphocytic leukemia (CLL).

METHODS

Patients enrolled in a CLL treatment clinical trial (N = 106) participated at baseline following informed consent and prior to treatment initiation. Risk factors with empirical support (personal or family psychiatric history, recurrent, advanced or progressive disease, low socioeconomic status, gender, medical comorbidities, and single marital status) and additional risk factors (cancer-specific stress, social contacts, negative life events, absolute lymphocyte counts, treatment group, and fatigue) were measured at baseline to predict depression and anxiety symptoms at 12 months.

RESULTS

Data show 14% (n = 15) and 12% (n = 13) of patients experienced moderate-severe depression and anxiety symptoms, respectively. Multiple linear regression analyses found medical comorbidities predicted 12-month anxiety symptoms (p < 0.05). Also, negative life events predicted depression and anxiety symptoms and fatigue predicted depression symptoms (p < 0.05).

CONCLUSION

Empirically supported risk factors associated with depression and anxiety symptoms are limited in predicting future depression and anxiety symptoms beyond initial screening in patients with CLL. In addition to levels of depression and anxiety symptoms at baseline, negative life events, higher levels of fatigue, and greater medical comorbidities were associated with future depression or anxiety symptoms in patients with CLL.

Effects of anesthetic technique and surgery on myeloid-derived suppressor cells and prognosis in women who underwent breast cancer surgery: a prospective study

Background: Surgery and anesthesia-induced immunosuppression may play a critical role in tumor progression and metastasis. Myeloid-derived suppressor cells (MDSCs) are highly immunosuppressive myeloid cells, closely linked with tumor staging, clinical therapeutic efficacy and prognosis. This study aims to investigate the effect of anesthetic technique and surgery on the expression of MDSCs and prognosis in women who received breast cancer surgery. Methods: From March 2016 to January 2017, a total of 80 patients with breast cancer were prospectively enrolled and randomized into two anesthetic groups: sevoflurane-based anesthetic group (SEV; n=38) and propofol-based total intravenous anesthetic group (TIVA; n=42). The expression of MDSCs and prognosis between different anesthetic techniques and stresses of surgical methods were compared. The primary endpoint is the postoperative expression of MDSCs and prognosis between SEV and TIVA groups. The secondary endpoint is the VAS scores at 24 hr post-operation between SEV and TIVA groups. Results: There was no significant difference in postoperative expression of MDSCs (P=0.202) and prognosis (P=0.138) between SEV and TIVA groups. Compared to breast-conserving surgery (BCS), patients who underwent breast mastectomy had significantly fewer MDSCs (P=0.040) and lower VAS score at 24 hr post-operation (P=0.044), while no significant difference in prognosis was found (P=0.953). When MDSCs were classified as subtypes of granulocytic/polymorphonuclear (PMN)-MDSCs and monocytic (Mo)-MDSCs, it showed higher ratio of Mo-MDSCs (P=0.018) or lower ratio of (PMN)-MDSCs (P=0.022) correlates to later tumor stage. Conclusion: Sevoflurane and propofol-based anesthesia do not show significant difference in MDSCs expression and prognosis after breast cancer surgery. Compared to BCS, although mastectomy with high extent of surgical stress exhibits lower levels of MDSCs, there is no significant difference in prognosis. The ratio of MDSCs subtype correlates to tumor stage.

Myeloid-Derived Suppressor Cells: Not Only in Tumor Immunity

Since the realization that immature myeloid cells are powerful modulators of the immune response, many studies on “myeloid-derived suppressor cells” (MDSCs) have documented their ability to promote tumor progression in melanoma and other cancers. Whether MDSCs are induced solely pathologically in tumorigenesis, or whether they also represent physiological immune control mechanisms, is not well-understood, but is particularly important in the light of ongoing attempts to block their activities in order to enhance anti-tumor immunity. Here, we briefly review studies which explore (1) how best to identify MDSCs in the context of cancer and how this compares to other conditions in humans; (2) what the suppressive mechanisms of MDSCs are and how to target them pharmacologically; (3) whether levels of MDSCs with various phenotypes are informative for clinical outcome not only in cancer but also other diseases, and (4) whether MDSCs are only found under pathological conditions or whether they also represent a physiological regulatory mechanism for the feedback control of immunity. Studies unequivocally document that MDSCs strongly influence cancer outcomes, but are less informative regarding their relevance to infection, autoimmunity, transplantation and aging, especially in humans. So far, the results of clinical interventions to reverse their negative effects in cancer have been disappointing; thus, developing differential approaches to modulate MSDCs in cancer and other diseases without unduly comprising any normal physiological function requires further exploration.

β3 -Adrenoceptor as a potential immuno-suppressor agent in melanoma

BACKGROUND AND PURPOSE

Stress-related catecholamines have a role in cancer and β-adrenoceptors; specifically, β₂ -adrenoceptors have been identified as new targets in treating melanoma. Recently, β₃ -adrenoceptors have shown a pleiotropic effect on melanoma micro-environment leading to cancer progression. However, the mechanisms by which β₃ -adrenoceptors promote this progression remain poorly understood. Catecholamines affect the immune system by modulating several factors that can alter immune cell sub-population homeostasis. Understanding the mechanisms of cancer immune-tolerance is one of the most intriguing challenges in modern research. This study investigates the potential role of β₃ -adrenoceptors in immune-tolerance regulation.

EXPERIMENTAL APPROACH

A mouse model of melanoma in which syngeneic B16-F10 cells were injected in C57BL-6 mice was used to evaluate the effect of β-adrenoceptor blockade on the number and activity of immune cell sub-populations (Treg, NK, CD8, MDSC, macrophages, and neutrophils). Pharmacological and molecular approaches with β-blockers (propranolol and SR59230A) and specific β-adrenoceptor siRNAs targeting β₂ - or β₃ -adrenoceptors were used.

KEY RESULTS

Only β₃ -, but not β₂ -adrenoceptors, were up-regulated under hypoxia in peripheral blood mononuclear cells and selectively expressed in immune cell sub-populations including Treg, MDSC, and NK. SR59230A and β₃ -adrenoceptor siRNAs increased NK and CD8 number and cytotoxicity, while they attenuated Treg and MDSC sub-populations in the tumour mass, blood, and spleen. SR59230A and β₃ -adrenoceptor siRNAs increased the ratio of M1/M2 macrophages and N1 granulocytes.

CONCLUSIONS AND IMPLICATIONS

Our data suggest that β₃ -adrenoceptors are involved in immune-tolerance, which opens the way for new strategic therapies to overcome melanoma growth.

LINKED ARTICLES

This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

The impact of psychosocial stress and stress management on immune responses in patients with cancer

The range of psychosocial stress factors/processes (eg, chronic stress, distress states, coping, social adversity) were reviewed as they relate to immune variables in cancer along with studies of psychosocial interventions on these stress processes and immune measures in cancer populations. The review includes molecular, cellular, and clinical research specifically examining the effects of stress processes and stress-management interventions on immune variables (eg, cellular immune function, inflammation), which may or may not be changing directly in response to the cancer or its treatment. Basic psychoneuroimmunologic research on stress processes (using animal or cellular/tumor models) provides leads for investigating biobehavioral processes that may underlie the associations reported to date. The development of theoretically driven and empirically supported stress-management interventions may provide important adjuncts to clinical cancer care going forward.

Rigor and Reproducibility: A Systematic Review of Salivary Cortisol Sampling and Reporting Parameters Used in Cancer Survivorship Research

Salivary cortisol is a commonly used biomarker in cancer survivorship research; however, variations in sampling protocols and parameter reporting limit comparisons across studies. Standardized practices to provide rigor and reproducibility of diurnal salivary cortisol sampling and reporting are not well established. Previous systematic reviews examining relationships between diurnal salivary cortisol and clinical outcomes have resulted in mixed findings. It remains unclear which sampling protocols and reporting parameters offer the greatest utility for clinical research. This review examines diurnal salivary cortisol sampling protocols and reporting parameters to evaluate whether a standardized approach is recommended. A comprehensive search of intervention studies among adult cancer survivors including diurnal salivary cortisol resulted in 30 articles for review. Sampling protocols ranged from 1 to 4 days with the majority of studies sampling cortisol for 2 days. Sampling instances ranged from 2 to 7 times per day, with the majority collecting at 4 time points per day. Diurnal cortisol slope and cortisol awakening response (CAR) were the most commonly reported parameters associated with clinical outcomes. Flattened cortisol slopes, blunted CARs, and elevated evening cortisol concentrations were associated with poorer psychosocial and physiological outcomes. Based on our review, we propose that a rigorous, standardized diurnal salivary cortisol sampling protocol should include sampling at key diurnal times across ≥3 consecutive days to report diurnal cortisol parameters (i.e., CAR and slope) and objective measures of participant protocol adherence. Diminishing budgetary resources and efforts to minimize participant burden dictate the importance of standardized cortisol sampling protocols and reporting parameters.

Suppressive role of myeloid-derived suppressor cells (MDSCs) in the microenvironment of breast cancer and targeted immunotherapies

Myeloid-derived suppressor cells (MDSCs) play a pivotal role in promoting tumor growth and metastasis and can even decrease the efficacy of immunotherapy. In breast cancer, MDSCs are recruited mainly by breast cancer cells to form a tumor-favoring microenvironment to suppress the anti-tumor immune response. In addition, MDSCs can react directly with breast cancer cells. In this paper, we describe several ways to recruit MDSCs in breast cancer, including breast cancer cell-derived cytokines and chemokines. The intracellular pathways in MDSCs during recruitment are classified as the STAT3-NF-κB-IDO pathway, the STAT3/IRF-8 pathway and the PTEN/Akt pathway. MDSCs act on T cells and NK cells to suppress the body's immunity, and via IL-6 trans-signaling, promote breast cancer directly. We further describe MDSC-targeted immune therapies for breast cancer, which are classified as: preventing the formation of MDSCs, eliminating MDSDCs, and reducing the products of MDSCs. Furthermore, MDSC-targeted immunotherapy potentiates the effect of the other immunotherapies. Based on the facts that MSDCs have significant roles in breast cancer malignant behaviors and can be suppressed by various strategies, we do believe MDSC-targeted immunotherapy presents a broad prospect in the future.

β-Adrenergic Signaling in Mice Housed at Standard Temperatures Suppresses an Effector Phenotype in CD8+ T Cells and Undermines Checkpoint Inhibitor Therapy

The immune context of tumors has significant prognostic value and is predictive of responsiveness to several forms of therapy, including immunotherapy. We report here that CD8⁺ T-cell frequency and functional orientation within the tumor microenvironment is regulated by β₂-adrenergic receptor (β-AR) signaling in host immune cells. We used three strategies-physiologic (manipulation of ambient thermal environment), pharmacologic (β-blockers), and genetic (β₂-AR knockout mice) to reduce adrenergic stress signaling in two widely studied preclinical mouse tumor models. Reducing β-AR signaling facilitated conversion of tumors to an immunologically active tumor microenvironment with increased intratumoral frequency of CD8⁺ T cells with an effector phenotype and decreased expression of programmed death receptor-1 (PD-1), in addition to an elevated effector CD8⁺ T-cell to CD4⁺ regulatory T-cell ratio (IFNγ⁺CD8⁺:Treg). Moreover, this conversion significantly increased the efficacy of anti-PD-1 checkpoint blockade. These data highlight the potential of adrenergic stress and norepinephrine-driven β-AR signaling to regulate the immune status of the tumor microenvironment and support the strategic use of clinically available β-blockers in patients to improve responses to immunotherapy. Cancer Res; 77(20); 5639-51. ©2017 AACR.

Novel rodent model of breast cancer survival with persistent anxiety-like behavior and inflammation

Breast cancer survivors are an expanding population that is troubled by lasting mental health problems, including depression and anxiety. These issues reduce quality-of-life throughout survivorhood. Research indicates that tumor biology, cancer treatments, and stress contribute to these mood disturbances. Although the mechanisms underlying these various causes remain under investigation, neuroinflammation is a leading hypothesis. To date, rodent models of recurrence-free tumor survival for understanding mechanisms by which these behavioral issues persist after cancer are lacking. Here, we test the extent to which potential behavioral symptoms persist after mammary tumor removal in mice (i.e., establishment of a cancer survivor model), while also empirically testing the causal role of tumors in the development of neuroinflammatory-mediated affective-like behaviors. Complete surgical resection of a non-metastatic orthotopic, syngeneic mammary tumor reversed tumor-induced increases of circulating cytokines (IL-6, CXCL1, IL-10) and myeloid-derived cells and modulated neuroinflammatory gene expression (Cd11b, Cxcl1). Multiple anxiety-like behaviors and some central and peripheral immune markers persisted or progressed three weeks after tumor resection. Together, these data indicate that persistent behavioral changes into cancer survivorhood may be due, in part, to changes in immunity that remain even after successful tumor removal. This novel survivor paradigm represents an improvement in modeling prevalent cancer survivorship issues and studying the basic mechanisms by which cancer/cancer treatments influence the brain and behavior.

Myeloid cells in circulation and tumor microenvironment of breast cancer patients

Pathological conditions including cancers lead to accumulation of a morphological mixture of highly immunosuppressive cells termed as myeloid-derived suppressor cells (MDSC). The lack of conclusive markers to identify human MDSC, due to their heterogeneous nature and close phenotypical and functional proximity with other cell subsets, made it challenging to identify these cells. Nevertheless, expansion of MDSC has been reported in periphery and tumor microenvironment of various cancers. The majority of studies on breast cancers were performed on murine models and hence limited literature is available on the relation of MDSC accumulation with clinical settings in breast cancer patients. The aim of this study was to investigate levels and phenotypes of myeloid cells in peripheral blood (n = 23) and tumor microenvironment of primary breast cancer patients (n = 7), compared with blood from healthy donors (n = 21) and paired non-tumor normal breast tissues from the same patients (n = 7). Using multicolor flow cytometric assays, we found that breast cancer patients had significantly higher levels of tumor-infiltrating myeloid cells, which comprised of granulocytes (P = 0.022) and immature cells that lack the expression of markers for fully differentiated monocytes or granulocytes (P = 0.016). Importantly, this expansion was not reflected in the peripheral blood. The immunosuppressive potential of these cells was confirmed by expression of Arginase 1 (ARG1), which is pivotal for T-cell suppression. These findings are important for developing therapeutic modalities to target mechanisms employed by immunosuppressive cells that generate an immune-permissive environment for the progression of cancer.

Psychosocial stress on neuroinflammation and cognitive dysfunctions in Alzheimer's disease: the emerging role for microglia?

Chronic psychosocial stress is increasingly recognized as a risk factor for late-onset Alzheimer's disease (LOAD) and associated cognitive deficits. Chronic stress also primes microglia and induces inflammatory responses in the adult brain, thereby compromising synapse-supportive roles of microglia and deteriorating cognitive functions during aging. Substantial evidence demonstrates that failure of microglia to clear abnormally accumulating amyloid-beta (Aβ) peptide contributes to neuroinflammation and neurodegeneration in AD. Moreover, genome-wide association studies have linked variants in several immune genes, such as TREM2 and CD33, the expression of which in the brain is restricted to microglia, with cognitive dysfunctions in LOAD. Thus, inflammation-promoting chronic stress may create a vicious cycle of aggravated microglial dysfunction accompanied by increased Aβ accumulation, collectively exacerbating neurodegeneration. Surprisingly, however, little is known about whether and how chronic stress contributes to microglia-mediated neuroinflammation that may underlie cognitive impairments in AD. This review aims to summarize the currently available clinical and preclinical data and outline potential molecular mechanisms linking stress, microglia and neurodegeneration, to foster future research in this field.

Biobehavioral approaches to cancer progression and survival: Mechanisms and interventions

Over the last decade, there have been groundbreaking strides in our understanding of the multiple biological pathways by which psychosocial and behavioral factors can affect cancer progression. It is now clear that biobehavioral factors not only affect cellular immunity but both directly and indirectly modulate fundamental processes in cancer growth, including inflammation, angiogenesis, invasion, and metastasis. There is also an emerging understanding of how psychological and behavioral factors used in interventions can impact these physiological processes. This review outlines our current understanding of the physiological mechanisms by which psychological, social, and behavioral processes can affect cancer progression. The intervention literature is discussed, along with recommendations for future research to move the field of biobehavioral oncology forward.