Inhibition of prostate cancer cell growth by activated eosinophils

Inflammation in Prostate Cancer: Exploring the Promising Role of Phenolic Compounds as an Innovative Therapeutic Approach

Prostate cancer (PCa) remains a significant global health concern, being a major cause of cancer morbidity and mortality worldwide. Furthermore, profound understanding of the disease is needed. Prostate inflammation caused by external or genetic factors is a central player in prostate carcinogenesis. However, the mechanisms underlying inflammation-driven PCa remain poorly understood. This review dissects the diagnosis methods for PCa and the pathophysiological mechanisms underlying the disease, clarifying the dynamic interplay between inflammation and leukocytes in promoting tumour development and spread. It provides updates on recent advances in elucidating and treating prostate carcinogenesis, and opens new insights for the use of bioactive compounds in PCa. Polyphenols, with their noteworthy antioxidant and anti-inflammatory properties, along with their synergistic potential when combined with conventional treatments, offer promising prospects for innovative therapeutic strategies. Evidence from the use of polyphenols and polyphenol-based nanoparticles in PCa revealed their positive effects in controlling tumour growth, proliferation, and metastasis. By consolidating the diverse features of PCa research, this review aims to contribute to increased understanding of the disease and stimulate further research into the role of polyphenols and polyphenol-based nanoparticles in its management.

Eosinophilia in cancer and its regulation by sex hormones

Gender differences in the functionality of the immune system have been attributed, in part, to direct and indirect effects of sex steroids, especially estrogens, on immune cell repertoire and activity. Notable are studies that have defined roles for estrogens in the regulation of the biology of dendritic cells (DCs), macrophages, T cells and natural killer (NK) cells. Although estrogens can modulate eosinophil function, the mechanisms by which this occurs and how it contributes to the pathobiology of different diseases remains underexplored. Furthermore, although the importance of eosinophils in infection is well established, it remains unclear as to how these innate immune cells, which are present in different tumors, impact the biology of cancer cells and/or response to therapeutics. The observation that eosinophilia influences the efficacy of immune checkpoint blockers (ICBs) is significant considering the role of estrogens as regulators of eosinophil function and recent studies suggesting that response to ICBs is impacted by gender. Thus, in this review, we consider what is known about the roles of estrogen(s) in regulating tissue eosinophilia/eosinophil function and how this influences the pathobiology of breast cancer (in particular). This information provides the context for a discussion of how estrogens/the estrogen receptor (ER) signaling axis can be targeted in eosinophils and how this would be expected to influence the activity of standard-of-care interventions and contemporary immunotherapy regimens in cancer(s).

Prostate immunology: A challenging puzzle

Mucosal immunity defines the relationship of surfaces in contact with the environment and integrates diverse tissues such as epidermis, gum, nose, gut, uterus and prostate with the immune system. Although considered part of a system, each mucosa presents specific immune features beyond the barrier and secretory functions. Information regarding the mucosal immunology of the male reproductive tract and the prostate gland in particular is scarce. In this review, we approach the prostate as an epithelial barrier and as part of the mucosal immune system. Finally, we also raise a series of questions that will improve the understanding of this gland, its role in reproduction and its sensitivity/resistance to disease.

Eosinophil accumulation predicts response to melanoma treatment with immune checkpoint inhibitors

Eosinophils have been identified as a prognostic marker in immunotherapy of melanoma and suggested to contribute to anti-tumor host defense. However, the influence of immune checkpoint inhibitors (ICI) on the eosinophil population is poorly studied. Here, we applied routine laboratory tests, multicolor flow cytometry, RNA microarray analysis, and bio-plex assay to analyze circulating eosinophils and related serum inflammatory factors in 32 patients treated with pembrolizumab or the combination of nivolumab and ipilimumab. We demonstrated that clinical responses to ICI treatment were associated with an eosinophil accumulation in the peripheral blood. Moreover, immunotherapy led to the alteration of the eosinophil genetic and activation profile. Elevated serum concentrations of IL-16 during ICI treatment were found to be associated with increased frequencies of eosinophils in the peripheral blood. Using immunohistochemistry, we observed an enhanced eosinophil degranulation and a positive correlation between eosinophil and CD8⁺ T cell infiltration of tumor tissues from melanoma patients treated with ICI. Our findings highlight additional mechanisms of ICI effects and suggest the level of eosinophils as a novel predictive marker for melanoma patients who may benefit from this immunotherapy.

Chronic oral exposure to glycated whey proteins increases survival of aged male NOD mice with autoimmune prostatitis by regulating the gut microbiome and anti-inflammatory responses

Glycated whey proteins have been shown to be protective against type 1 diabetes in our previous studies, suggesting their potential application as medical food. To determine if the protection could be extended to other autoimmune diseases, aged male non-obese diabetic (NOD) mice that develop a wide spectrum of autoimmune pathologies, including spontaneous autoimmune prostatitis, were used. After a 6-month oral exposure to whey protein-derived early glycation products (EGPs), EGP-treated NOD mice had an increased survival rate, decreased macrophage infiltration in the anterior lobe and decreased inflammation in the prostate when compared to the mice that received non-reacted controls. The systemic immunity was regulated towards anti-inflammation, evidenced by an increase in serum IL-10 level and decreases in total splenocytes, splenic M1 macrophages, CD4+ T cells, CD8+ T cells and B cells. Consistent with an overall anti-inflammatory status, the gut microbiome was altered in abundance but not diversity, with increased Allobaculum, Anaerostipes, Bacteroides, Parabacteroides and Prevotella and decreased Adlercreutzia and Roseburia at the genus level. Moreover, increased Bacteroides acidifaciens correlated with most of the immune parameters measured. Collectively, chronic oral exposure to EGPs produced an anti-inflammatory effect in aged male NOD mice, which might contribute to the protective effects against spontaneous autoimmune prostatitis and/or other organ specific autoimmune diseases.

Prognostic values of lymphocyte and eosinophil counts in resectable cervical squamous cell carcinoma

Aim: Cervical cancer is one of the leading causes of cancer mortality in women. Peripheral white blood cell parameters such as neutrophil (NE), eosinophil (EO), basophil (BA), as well as lymphocyte (LY) and monocyte (MO), are correlated with tumor outcomes. Methods: In total, 110 cervical squamous cell carcinoma patients were recruited in this study. The potential prognostic factors were evaluated by univariate and multivariate survival analysis. Results: Cox regression analysis model indicated that higher pretreatment EO level and increased post-/preradiotherapy EO ratio were independently associated with worse progression-free survival. Lower pretreatment LY or higher EO levels and increased post-/preradiotherapy EO ratio were independently associated with worse overall survival. Conclusion: LY and EO are correlated with outcomes of cervical squamous cell cancer.

Omega-3 fatty acids decrease prostate cancer progression associated with an anti-tumor immune response in eugonadal and castrated mice

BACKGROUND

Several lines of evidence suggest effects of dietary fat on prostate cancer (PCa) development and progression. Targeting omega (ω)-3:ω6 fatty acids (FA) ratio could be beneficial against PCa by favorably modulating inflammation. Here, we studied the effects of ω3- and ω6-enriched diets on prostate tumor growth and inflammatory response in androgen-deprived and non-deprived conditions.

METHODS

Immune-competent eugonadal and castrated C57BL/6 mice were injected with TRAMP-C2 prostate tumor cells and daily fed with ω3- or ω6-enriched diet. FA and cytokine profiles were measured in blood and tumors using gas chromatography and multiplex immunoassay, respectively. Immune cell infiltration in tumors was profiled by multicolor flow cytometry.

RESULTS

ω3-enriched diet decreased prostate TRAMP-C2 tumor growth in immune-competent eugonadal and castrated mice. Cytokines associated with Th1 immune response (IL-12 [p70], IFN-γ, GM-CSF) and eosinophil recruitment (eotaxin-1, IL-5, and IL-13) were significantly elevated in tumors of ω3-fed mice. Using in vitro experiments, we confirmed ω3 FA-induced eotaxin-1 secretion by tumor cells and that eotaxin-1 secretion was regulated by androgens. Analysis of immune cell infiltrating tumors showed no major difference of immune cells' abundance between ω3- and ω6-enriched diets.

CONCLUSIONS

ω3-enriched diet reduces prostate tumor growth independently of androgen levels. ω3 FA can inhibit tumor cell growth and induce a local anti-tumor inflammatory response. These findings warrant further examination of dietary ω3's potential to slow down the progression of androgen-sensitive and castrate-resistant PCa by modulating immune cell function in tumors.

Tissue eosinophilia in oral intraepithelial neoplasia as a probable indicator of invasion

OBJECTIVE

To investigate the presence of eosinophils in oral intraepithelial neoplasia (OIN) and oral squamous cell carcinoma (OSCC) lesions and its relation to invasion.

SUBJECTS AND METHODS

Ninety-nine oral biopsies were selected and subdivided into the following: OIN-1(16 cases), OIN-2 (18 cases), OIN-3 (17 cases), microinvasive OSCC (10 cases), non-metastatic OSCC (22 cases) and metastatic OSCC (16 cases). The tissue eosinophilia was evaluated histologically in slices stained with haematoxylin and eosin.

RESULTS

Eosinophil distribution was associated with diagnosis severity (p < .01). A significant difference was found between OIN-3 or microinvasive OSCC and non-metastatic or metastatic OSCC. Stromal invasion threshold was 7 eos/10 high power field (hpf) (96.1% specificity and 62.5% sensitivity). Eosinophils were absent in OIN-1; in OIN-2, two cases were positive. In OIN-3, five cases showed tissue eosinophilia, four of which had ≥3 eos/hpf or ≥7 eos/10 hpf. Three cases were suspected of invasion; two had a previous history of OSCC with elevated eosinophil infiltrate. In microinvasive OSCC, the four positive cases presented ≥3 eos/hpf and ≥7 eos/10 hpf. Although not significantly different, non-metastatic invasive OSCC had a higher number of cases (68.2%) with ≥22 eos/10 hpf contrasting with 50% in metastatic OSCC.

CONCLUSION

Our results suggest that eosinophils can be considered an indicator of invasion in OIN, helping in cases of difficult diagnosis.

Mesenchymal stem cells up-regulate the invasive potential of prostate cancer cells via the eotaxin-3/CCR3 axis

This study aimed to clarify the role of mesenchymal stem cells (MSCs) as a component of the cancer microenvironment. We investigated the homing-related chemokine expression levels of MSCs treated with a prostate cancer cell line (PC-3) -conditioned medium. Among several homing chemokines, an antibody array revealed that expression of eotaxin-3 (but not eotxin-1 and -2) was highly enhanced in MSCs treated with PC-3-conditioned medium. A gene expression array showed significantly increased expression of CCR3, a receptor of eotaxin-3, in PC-3. In a matrigel invasion assay, interferon-gamma, a specific inhibitor of eotaxin-related homing, significantly reduced the transmigration of PC-3 cells, under co-cultured condition with MSCs, in a dose-dependent manner (P < 0.05). Consistent with these results, anti-CCR3 antibody successfully reduced PC-3 migration under the co-cultured condition. These findings suggest that MSCs to modulation of the invasive potential of prostate cancer cells via the eotaxin-3/CCR3 axis.

Relationship between the inflammatory tumor microenvironment and different histologic types of canine mammary tumors

Mammary neoplasms are the tumors with higher incidence in female dogs. Among the factors that contribute for the development of this and other neoplasms, the inflammatory tumor microenvironment plays a crucial role. Several studies reported important roles for lymphocytes, macrophages, plasma cells, neutrophils, eosinophils and mast cells in this context. In the present study, our aim was to evaluate the number of profile cells of inflammatory cells and area of tumor fibrosis and the relation of these features with canine mammary tumors of different histologic and clinical presentation (benign mixed tumor, carcinoma in mixed tumor, solid carcinoma and tubular carcinoma) Counting and staining of inflammatory cells and tumor fibrosis were performed through histochemistry, while counting and staining of CD4⁺, TCD8⁺ and FOXP3⁺ lymphocytes were performed through immunohistochemistry. Statistical analysis of the association between densities of inflammatory cells, tumor fibrosis and histologic types revealed significant difference for plasma cells (p = .035), neutrophils (p = .0113), macrophages (p = .0047), and tumor fibrosis (p = .05). The found data suggest associations between high number of neutrophils and aggressive mammary tumors, between high densities of plasma cells, macrophages and CD8⁺ cells and between low number of profile cells of CD4⁺ cells and less aggressive tumors. Larger areas of tumor fibrosis showed relation to more aggressive canine mammary tumors.

Inflammation and Prostate Cancer

Chronic inflammation resulting from infections, altered metabolism, inflammatory diseases or other environmental factors can be a major contributor to the development of several types of cancer. In fact around 20% of all cancers are linked to some form of inflammation. Evidence gathered from genetic, epidemiological and molecular pathological studies suggest that inflammation plays a crucial role at various stages of prostatic carcinogenesis and tumor progression. These include initiation, promotion, malignant conversion, invasion, and metastasis. Detailed basic and clinical research in these areas, focused towards understanding the etiology of prostatic inflammation, as well as the exact roles that various signaling pathways play in promoting tumor growth, is critical for understanding this complex process. The information gained would be useful in developing novel therapeutic strategies such as molecular targeting of inflammatory mediators and immunotherapy-based approaches.

Eosinophils: The unsung heroes in cancer?

Prolonged low-grade inflammation or smoldering inflammation is a hallmark of a cancer. Eosinophils are components of the immune microenvironment that modulates tumor initiation and progression. Although canonically associated with a detrimental role in allergic disorders, these cells can induce a protective immune response against helminthes, viral and bacterial pathogens. Eosinophils are a source of anti-tumorigenic (e.g., TNF-α, granzyme, cationic proteins, and IL-18) and protumorigenic molecules (e.g., pro-angiogenic factors) depending on the milieu. In several neoplasias (e.g., melanoma, gastric, colorectal, oral and prostate cancer) eosinophils play an anti-tumorigenic role, in others (e.g., Hodgkin's lymphoma, cervical carcinoma) have been linked to poor prognosis, whereas in yet others they are apparently innocent bystanders. These seemingly conflicting results suggest that the role of eosinophils and their mediators could be cancer-dependent. The microlocalization (e.g., peritumoral vs intratumoral) of eosinophils could be another important aspect in the initiation/progression of solid and hematological tumors. Increasing evidence in experimental models indicates that activation/recruitment of eosinophils could represent a new therapeutic strategy for certain tumors (e.g., melanoma). Many unanswered questions should be addressed before we understand whether eosinophils are an ally, adversary or neutral bystanders in different types of human cancers.

Asthma and risk of lethal prostate cancer in the Health Professionals Follow-Up Study

Inflammation, and more generally, the immune response are thought to influence the development of prostate cancer. To determine the components of the immune response that are potentially contributory, we prospectively evaluated the association of immune-mediated conditions, asthma and hayfever, with lethal prostate cancer risk in the Health Professionals Follow-up Study. We included 47,880 men aged 40-75 years with no prior cancer diagnosis. On the baseline questionnaire in 1986, the men reported diagnoses of asthma and hayfever and year of onset. On the follow-up questionnaires, they reported new asthma and prostate cancer diagnoses. We used Cox proportional hazards regression to estimate relative risks (RRs). In total, 9.2% reported ever having been diagnosed with asthma. In all, 25.3% reported a hayfever diagnosis at baseline. During 995,176 person-years of follow-up by 2012, we confirmed 798 lethal prostate cancer cases (diagnosed with distant metastases, progressed to distant metastasis or died of prostate cancer [N = 625]). Ever having a diagnosis of asthma was inversely associated with risk of lethal (RR = 0.71, 95% confidence interval [CI] = 0.51-1.00) and fatal (RR = 0.64, 95% CI = 0.42-0.96) disease. Hayfever with onset in the distant past was possibly weakly positively associated with risk of lethal (RR = 1.10, 95% CI = 0.92-1.33) and fatal (RR = 1.12, 95% CI = 0.91-1.37) disease. Men who were ever diagnosed with asthma were less likely to develop lethal and fatal prostate cancer. Our findings may lead to testable hypotheses about specific immune profiles in the etiology of lethal prostate cancer.

Eosinophilia in routine blood samples as a biomarker for solid tumor development - A study based on the Copenhagen Primary Care Differential Count (CopDiff) Database

BACKGROUND

Eosinophilia may represent an early paraclinical sign of malignant disease and a host anti-tumor effect. The association between eosinophilia and the development of solid tumors has never before been examined in an epidemiological setting. The aim of the present study was to investigate eosinophilia in routine blood samples as a potential biomarker of solid tumor development in a prospective design.

MATERIAL AND METHODS

From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356 196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count during 2000-2007. From these, one DIFF was randomly chosen and categorized according to no (< 0.5 × 10(9)/l), mild (≥ 0.5-1.0 × 10(9)/l) or severe (≥ 1.0 × 10(9)/l) eosinophilia. From the Danish Civil Registration System and the Danish Cancer Registry we ascertained all-cause death and solid tumors within the first three years following the DIFF. Using multivariable logistic regression, odds ratios (OR) were calculated and adjusted for previous eosinophilia, sex, age, year, month, C-reactive protein, previous cancer and Charlson's Comorbidity Index.

RESULTS

The risk of bladder cancer was increased with mild eosinophilia [OR 1.93 (CI 1.29-2.89), p = 0.0013]. No associations with eosinophilia were observed for the remaining solid cancers.

CONCLUSION

We demonstrate that eosinophilia in routine blood samples associates with an increased risk of bladder cancer. Our data emphasize that additional preclinical studies are needed in order to shed further light on the role of eosinophils in carcinogenesis, where it is still unknown whether the cells contribute to tumor immune surveillance or neoplastic evolution.

Eosinophilia in routine blood samples and the subsequent risk of hematological malignancies and death

Eosinophilia may represent an early paraclinical sign of hematological malignant disease, but no reports exist on its predictive value for hematological malignancies. From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356,196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count during 2000-2007. From these, one DIFF was randomly chosen and categorized according to no (<0.5 × 10(9) /L), mild (≥ 0.5-1.0 × 10(9) /L) or severe (≥ 1.0 × 10(9) /L) eosinophilia. From the Danish Cancer Registry and the Danish Civil Registration System, we ascertained hematological malignancies and death within 3 years following the DIFF. Using multivariable logistic regression odds ratios (ORs) were calculated and adjusted for previous eosinophilia in a DIFF, sex, age, year, month, C-reactive protein, previous cancer, and comorbidity. ORs for developing Hodgkin's lymphoma (HL) was significantly increased in individuals exhibiting severe eosinophilia, OR = 9.09 (C.I. 2.77-29.84), P = 0.0003. The association with classical myeloproliferative neoplasms (cMPNs) showed an increasing risk with OR = 1.65 (1.04-2.61) P = 0.0322 and OR = 3.87 (1.67-8.96) P = 0.0016 for mild and severe eosinophilia. Eosinophilia was in a similar fashion associated with chronic lymphatic leukemia (CLL), OR = 2.57 (1.50-4.43), P = 0.0006 and OR = 5.00 (1.57-15.94), P = 0.0065, and all-cause death, OR of 1.16 (1.09-1.24), P < 0.0001 and 1.60 (1.35-1.91), P < 0.0001. We confirm associations between eosinophilia and HL and cMPNs, and in addition for the first time demonstrate a dose-dependent association between eosinophilia and CLL as well as death. Unexplained eosinophilia should prompt clinicians to consider conditions where early diagnosis may improve prognosis.

Eosinophils in innate immunity: an evolving story

Eosinophils are innate immune leukocytes found in relatively low numbers within the blood. Terminal effector functions of eosinophils, deriving from their capacity to release their content of tissue-destructive cationic proteins, have historically been considered primary effector mechanisms against specific parasites, and are likewise implicated in tissue damage accompanying allergic responses such as asthma. However, the past decade has seen dramatic advancements in the field of eosinophil immunobiology, revealing eosinophils to also be key participants in many other facets of innate immunity, from bridging innate and adaptive immune responses to orchestrating tissue remodeling events. Here, we review the multifaceted functions of eosinophils in innate immunity that are currently known, and discuss new avenues in this evolving story.

Th2-mediated anti-tumour immunity: friend or foe?

The concept that the immune system can recognise tumour cells and either eliminate them (tumour immune surveillance) or select for immunologically resistant variants (immunoediting) is gaining general acceptance by immunologists. In terms of an adaptive immune response to cancer, however, much of the research has focused on the response of cytotoxic CD8+ T lymphocytes to tumour-specific antigens and the production of Th1 cytokines by CD4+ and CD8+ T cells. In contrast, Th2-mediated immunity has traditionally been viewed as favouring tumour growth, both by promoting angiogenesis and by inhibiting cell-mediated immunity and subsequent tumour cell killing. While there is evidence that components of type 2 inflammation, such as B cells and interleukin-10, do promote tumour growth, there are also many studies demonstrating the anti-tumour activity of CD4+ Th2 cells, particularly in collaboration with tumour-infiltrating granulocytes, such as eosinophils. In this review, we examine all the components of type 2 immunity and their effects on tumour growth. Collectively, from this analysis, we conclude that there is a great potential for the development of Th2-mediated immunotherapies that harness the cytotoxic activity of eosinophils.

Prevention of de novo prostate cancer by immunization with tumor-derived vaccines

Since advanced prostate cancer is difficult to treat, we have chosen a very different approach: the development of vaccines to prevent initial de novo tumor formation. To test the hypothesis that prostate cancer can be prevented by vaccination, Lobund-Wistar (LW) rats were vaccinated subcutaneously with complete Freund's adjuvant (CFA) plus glutaraldehyde-fixed (GFT) whole cell or potassium thiocyanate extract (PTE) preparations derived from in vivo tumors, or with media and CFA (media-vaccinated). Rats were vaccinated each month substituting incomplete Freund's adjuvant for CFA, from age 3 to 12 months, and methylnitrosourea (30 mg/kg) was administered intravenously at 4 months of age. Groups of 30 GFT cell-vaccinated rats showed a 90% reduction, and PTE-vaccinated rats, a 50% reduction in the occurrence of de novo prostate tumors compared with media-vaccinated controls. When splenocytes from vaccinated rats were incubated with tumor cells prior to subcutaneous implantation, PTE-vaccinated rats showed a 80% reduction, and GFT cell-vaccinated rats showed a 40% reduction in the occurrence of tumors, demonstrating a role for the spleen in the protective response. The inflammatory responses in tumors from GFT cell-vaccinated rats and PTE-vaccinated rats were distinguished by an influx of eosinophils compared with the responses in tumors from media-vaccinated rats. These results demonstrate the possibility that prostate cancer can be prevented by immunization with vaccines based on whole tumor-derived vaccines.

Éosinophiles et réponse antitumorale

PURPOSE

Immune response probably plays a role in the tumour control. Cytotoxic T-lymphocyte response is antigen-specific and requires previous encounter with the antigen to develop an efficient immune response. Regarding the innate immunity, natural killer (NK) cells can destroy neoplastic cells lacking HLA class I molecules. In addition to these effector cells, eosinophils are granulocytes usually involved in allergic diseases or response to parasitic infections. Many types of cancer, however, are associated with eosinophilia, either in the tumour itself and/or in peripheral blood. We will focus our attention on the putative involvement of eosinophils in the antitumour response.

CURRENT KNOWLEDGE AND KEY POINTS

Recent studies on the relationship between tumour and eosinophils have mainly focused on the << tumour-associated tissue eosinophilia >> (TATE), which seems to be more relevant than peripheral blood eosinophilia. Most studies show that TATE is a favourable prognostic marker, except in Hodgkin's disease, since eosinophils probably deliver in this case an antiapoptotic and proliferative signal for Reed-Sternberg cells via the release of soluble CD30L.

FUTURE PROSPECTS AND PROJECTS

The putative anti-tumour effect of eosinophils relies on their tight contact with tumour cells. As a consequence, future immunotherapy studies aiming at an anti-tumour eosinophilic reaction might attract and activate eosinophils within the tumour itself. This could be obtained via direct injection of cytokines (IL-3, IL-5, GM-CSF...) at tumour site or by the use of expression vectors encoding for these molecules.