Chronic Inflammation, Oxidative Stress and Metabolic Plasticity: Three Players Driving the Pro-Tumorigenic Microenvironment in Malignant Mesothelioma

Fibrous erionite modifications following THP-1 macrophage phagocytosis: An insight into the mechanisms of interaction with biological systems

Erionite is a ubiquitous natural zeolite, often occurring with fibrous habit, whose strong tumorigenic activity to humans has been certified by its inclusion in the Group 1 Human-Carcinogenic list by the International Agency for Research on Cancer. To date, the reason(s) of erionite toxicity are still unclear, albeit several hypotheses have been proposed. The present work, based on the combined analysis of the chemical and structural modifications of erionite fibres following incubation in human THP-1 macrophages and evaluation of cellular response, indicates that, upon macrophage phagocytosis, a large release of cations is counterbalanced by a significant sequestration of hydronium ions from lysosomes provoking a quick pH dysregulation. This would be restored by the hyperactivation of ATP-dependent proton pumps with significant energy expenditure for the cell, ultimately causing mitochondrial suffering, leading to chronic inflammation and eventually cancer development.

Malignant mesothelioma-associated inflammatory microenvironment promotes tumor progression via GPNMB

BACKGROUND

Tumor-Associated Macrophages (TAMs) are the main immune component of the tumor stroma with heterogeneous functional activities, predominantly suppressing the immune response and promoting tumor progression, also via secretion of different factors. Among these, GPNMB (Glycoprotein non-metastatic B) is usually associated with disease progression in several tumor types. Malignant pleural mesothelioma (MPM) a severe neoplasia with poor prognosis, is characterized by an abundancy of TAMs, testifying the presence of a long-lasting inflammation which is pathogenetic of the disease. However, the role of GPNMB in MPM is unclear.

METHODS

Clinical samples from patients with MPM were used to measure RNA and protein levels of GPNMB. The functional role of GPNMB in vivo was studied in an orthotopic mouse model of mesothelioma using the murine cell lines AB1 and AB22. Experiments included in vivo tumor growth in wild type and in GPNMB-deficient mice and blocking of GPNMB-induced signaling with anti-CD44 antibodies.

RESULTS

We show that in human and murine MPM tissues the protein GPNMB is mainly produced by infiltrating TAMs. Gpnmb RNA levels in MPM patients from TCGA are significantly associated with lower survival. Using an orthotopic mouse model of mesothelioma we observed that in GPNMB-defective mice (DBA2/J mice) unable to produce the protein, tumors formed by AB1 and AB22 mesothelioma cells grow significantly less than in GPNMB-proficient mice (DBA2/J-Gpnmb+ mice), indicating that host GPNMB is involved in tumor progression. Likewise, the ectopic expression of GPNMB in AB1 and AB22 cells causes an acceleration of tumor growth in vivo, significantly different compared to mock-transduced cells. Treatment of tumor-bearing mice with blocking anti-CD44 (a major receptor for GPNMB) results in a significant reduction of tumor growth.

CONCLUSIONS

Overall, these results indicate that the protein GPNMB, a product and marker gene of TAMs, is a driver of mesothelioma progression and may constitute a promising therapeutic target.

Pretreatment platelet level is associated with tumor proliferation and prognosis in malignant pleural mesothelioma

OBJECTIVE

The present study aimed to investigate the relationship between serum-based inflammatory biomarkers and MPM tumor biology and prognosis.

METHODS

A total of 83 patients with MPM who were diagnosed and started treatment between January 1998 and December 2010 were studied. Clinicopathological variables were evaluated, including age, sex, clinical stage, histology, surgical resection, and chemotherapy. The cut-off values for pretreatment levels of white blood cell count, neutrophil count, lymphocyte count, platelet count, C-reactive protein, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index were determined using receiver operating characteristic curve analysis for predicting 5-year survival. Univariate and multivariate Cox regression analyses were performed to estimate the prognostic impact on 5-year overall survival.

RESULTS

The mean Ki-67 proliferation index in MPM cells was 35.1 ± 29.5% and the median overall survival of patients was 15.0 months. The Ki-67 proliferation index in MPM cells was significantly higher in the platelet-high group compared with that in the platelet-low group (42.1 ± 31.9 vs. 27.7 ± 25.1%; P = 0.027). Multivariate Cox regression analyses identified platelet count (hazard ratio = 1.929; P = 0.022) and PLR (hazard ratio = 1.776; P = 0.040) as significant prognostic factors.

CONCLUSION

Pretreatment platelet level may be a useful prognostic marker for 5-year overall survival related to tumor proliferation in patients with MPM.

Haptoglobin phenotype: A germline risk factor for malignant pleural mesothelioma? A case-control study

PURPOSE

The pathogenesis of malignant pleural mesothelioma (MPM) is linked to asbestos-induced chronic inflammation, oxidant formation, hemolysis and subsequent hemoglobin (Hb) release, potentiating oxidative injury. Haptoglobin (Hp) serves as a major antioxidant by binding free Hb in order to prevent its harmful effects. Dependent on the Hp-phenotype, this complexing can be divergent, leading to additional formation of reactive oxygen species (ROS) above those directly induced by asbestos or released by inflammatory cells. In order to determine the Hp-phenotype as a risk factor in MPM, this case-control study compared the Hp-phenotype distribution in MPM patients with asymptomatic persons with former occupational asbestos exposure (AEx) and controls from a European population.

MATERIALS AND METHODS

Hp-phenotyping was done on serum samples of 118 MPM patients and 96 AEx subjects by starch gel electrophoresis. The frequencies of Hp phenotypes (Hp 1-1, Hp 2-1 and Hp 2-2) and alleles (Hp1, Hp2) were compared with those from 918 healthy control subjects.

RESULTS

The Hp 1-1 phenotype was overrepresented in MPM patients compared to AEx persons (P = 0.001) and healthy controls (P = 0.005). The relative risk for developing MPM when having the Hp 1-1 phenotype was 3.05 (1.47-6.34) for AEx subjects and 1.74 (1.19-2.54) for healthy controls compared to other phenotypes.

CONCLUSION

Our results indicate an important role of the Hp-phenotype in MPM pathogenesis suggesting that Hp 1-1 phenotypic persons are more prone for MPM development. Apart from the asbestos-induced radical formation, this finding confirms the role of oxidative stress in cancer development.

Partial Inhibition of Epithelial-to-Mesenchymal Transition (EMT) Phenotypes by Placenta-Derived DBMSCs in Human Breast Cancer Cell Lines, In Vitro

Stem cell-based therapies hold significant potential for cancer treatment due to their unique properties, including migration toward tumor niche, secretion of bioactive molecules, and immunosuppression. Mesenchymal stem cells (MSCs) from adult tissues can inhibit tumor progression, angiogenesis, and apoptosis of cancer cells. We have previously reported the isolation and characterization of placenta-derived decidua basalis mesenchymal stem cells (DBMSCs), which demonstrated higher levels of pro-migratory and anti-apoptotic genes, indicating potential anti-cancer effects. In this study, we analyzed the anti-cancer effects of DBMSCs on human breast cancer cell lines MDA231 and MCF7, with MCF 10A used as control. We also investigated how these cancer cells lines affect the functional competence of DBMSCs. By co-culturing DBMSCs with cancer cells, we analyzed changes in functions of both cell types, as well as alterations in their genomic and proteomic profile. Our results showed that treatment with DBMSCs significantly reduced the functionality of MDA231 and MCF7 cells, while MCF 10A cells remained unaffected. DBMSC treatment decreased epithelial-to-mesenchymal transition (EMT)-related protein levels in MDA231 cells and modulated expression of other cancer-related genes in MDA231 and MCF7 cells. Although cancer cells reduced DBMSC proliferation, they increased their expression of anti-apoptotic genes. These findings suggest that DBMSCs can inhibit EMT-related proteins and reduce the invasive characteristics of MDA231 and MCF7 breast cancer cells, highlighting their potential as candidates for cell-based cancer therapies.

ROS: A "booster" for chronic inflammation and tumor metastasis

Reactive oxygen species (ROS) are a group of highly active molecules produced by normal cellular metabolism and play a crucial role in the human body. In recent years, researchers have increasingly discovered that ROS plays a vital role in the progression of chronic inflammation and tumor metastasis. The inflammatory tumor microenvironment established by chronic inflammation can induce ROS production through inflammatory cells. ROS can then directly damage DNA or indirectly activate cellular signaling pathways to promote tumor metastasis and development, including breast cancer, lung cancer, liver cancer, colorectal cancer, and so on. This review aims to elucidate the relationship between ROS, chronic inflammation, and tumor metastasis, explaining how chronic inflammation can induce tumor metastasis and how ROS can contribute to the evolution of chronic inflammation toward tumor metastasis. Interestingly, ROS can have a "double-edged sword" effect, promoting tumor metastasis in some cases and inhibiting it in others. This article also highlights the potential applications of ROS in inhibiting tumor metastasis and enhancing the precision of tumor-targeted therapy. Combining ROS with nanomaterials strategies may be a promising approach to enhance the efficacy of tumor treatment.

Hesperidin attenuates radiation-induced ovarian failure in rats: Emphasis on TLR-4/NF-ĸB signaling pathway

Young women suffering from premature ovarian failure after radiotherapy carry a huge burden in the field of cancer therapy including reproductive loss, emotional stress, and physical troubles that reduce their long-term quality of life. Hesperidin (HSP) exhibited antioxidant, anti-inflammatory, and anti-apoptotic properties. HSP enhanced in vitro follicular maturation and preserved in vivo ovarian stockpile. In this research, the role of HSP in radiation-induced POF in rats was investigated besides ascertaining its underlying mechanisms. Female Sprague-Dawley rats were arbitrarily allocated into four groups: control-group, ϒ-irradiated-group (3.2 Gy once on the 7th day), HSP-group (100 mg/kg, orally for 10 days), and HSP/ϒ-irradiated-group (ϒ-radiation was applied one hour after HSP). At the end of experiment, the whole ovaries were collected for histological and biochemical analyses. Administration of HSP preserved the ovarian histoarchitecture and follicular stock, retained ovarian weight, and conserved serum estradiol and AMH levels following radiation exposure. HSP ameliorated the ovarian oxidative damage mediated by radiation through augmenting the activities of glutathione peroxidase, glutathione reductase, and catalase antioxidant enzymes. HSP exhibited remarkable anti-inflammatory activity by downregulating the expression of ovarian TLR-4, NF-ĸB, and TNF-α. Moreover, HSP suppressed the apoptotic machinery triggered by radiation by reducing p53 and Bax while increasing Bcl-2 mRNA expressions alongside diminishing caspase-3 expression. Additionally, HSP regulated estrous cycle disorder of irradiated rats and improved their reproductive capacity reflected by enhancing pregnancy outcomes. Therefore, HSP represents an appealing candidate as an adjunct remedy for female cancer patients during radiotherapy protocols owing to its antioxidant, anti-inflammatory, anti-apoptotic, and hormone-regulatory effects.

The intricate interplay between ferroptosis and efferocytosis in cancer: unraveling novel insights and therapeutic opportunities

The complex interplay between ferroptosis and efferocytosis in cancer has attracted significant interest recently. Efferocytosis, the process of eliminating apoptotic cells, is essential for preserving tissue homeostasis and reducing inflammation. However, dysregulation of efferocytosis can have profound effects on cancer. Apoptotic cells accumulate because of impaired efferocytosis, which triggers chronic inflammation and the release of pro-inflammatory chemicals. Surprisingly, accumulating evidence suggests that dysregulation of ferroptosis- a form of controlled cell death characterized by lipid peroxidation and the buildup iron-dependent reactive oxygen species (ROS)-can influence efferocytic activities within the tumor microenvironment. Dysfunctional iron metabolism and increased lipid peroxidation, are associated with ferroptosis, resulting in inadequate apoptotic cell clearance. Conversely, apoptotic cells can activate ferroptotic pathways, increasing oxidative stress and inducing cell death in cancer cells. This reciprocal interaction emphasizes the complex relationship between efferocytosis and ferroptosis in cancer biology. Understanding and managing the delicate balance between cell clearance and cell death pathways holds significant therapeutic potential in cancer treatment. Targeting the efferocytosis and ferroptosis pathways may offer new opportunities for improving tumor clearance, reducing inflammation, and sensitizing cancer cells to therapeutic interventions. Further research into the interaction between efferocytosis and ferroptosis in cancer will provide valuable insights for the development of novel therapies aimed at restoring tissue homeostasis and improving patient outcomes.

Microgravity as a Tool to Investigate Cancer Induction in Pleura Mesothelial Cells

The present work shows that the exposure of mesothelial cells to simulated microgravity changes their cytoskeleton and adhesion proteins, leading to a cell switch from normal towards tumoral cells. Immunohistochemical and molecular data were obtained from both MeT-5A exposed to simulated microgravity and BR95 mesothelioma cell lines. Simulated microgravity was found to affect the expression of actin, vinculin, and connexin-43, altering their quantitative and spatial distribution pattern inside the cell. The analysis of the tumoral markers p27, CD44, Fibulin-3, and NANOG and the expression of genes related to cancer transformation such as NANOG, CDH-1, and Zeb-1 showed that the simulated microgravity environment led to expression patterns in MeT-5A cells similar to those observed in BR95 cells. The alteration in both quantitative expression and structural organization of the cytoskeleton and adhesion/communication proteins can thus be considered a pivotal mechanism involved in the cellular shift towards tumoral progression.

Diagnosis of Pleural Mesothelioma: Is Everything Solved at the Present Time?

Ranked high in worldwide growing health issues, pleural diseases affect approximately one million people globally per year and are often correlated with a poor prognosis. Among these pleural diseases, malignant pleural mesothelioma (PM), a neoplastic disease mainly due to asbestos exposure, still remains a diagnostic challenge. Timely diagnosis is imperative to define the most suitable therapeutic approach for the patient, but the choice of diagnostic modalities depends on operator experience and local facilities while bearing in mind the yield of each diagnostic procedure. Since the analysis of pleural fluid cytology is not sufficient in differentiating historical features in PM, histopathological and morphological features obtained via tissue biopsies are fundamental. The quality of biopsy samples is crucial and often requires highly qualified expertise. Since adequate tissue biopsy is essential, medical or video-assisted thoracoscopy (MT or VATS) is proposed as the most suitable approach, with the former being a physician-led procedure. Indeed, MT is the diagnostic gold standard for malignant pleural pathologies. Moreover, this medical or surgical approach can allow diagnostic and therapeutic procedures: it provides the possibility of video-assisted biopsies, the drainage of high volumes of pleural fluid and the administration of sterile calibrated talcum powder under visual control in order to achieve pleurodesis, placement of indwelling pleural catheters if required and in a near future potential intrapleural therapy. In this context, dedicated diagnostic pathways remain a crucial need, especially to quickly and properly diagnose PM. Lastly, the interdisciplinary approach and multidisciplinary collaboration should always be implemented in order to direct the patient to the best customised diagnostic and therapeutic pathway. At the present time, the diagnosis of PM remains an unsolved problem despite MDT (multidisciplinary team) meetings, mainly because of the lack of standardised diagnostic work-up. This review aims to provide an overview of diagnostic procedures in order to propose a clear strategy.

The influence of cation exchange on the possible mechanism of erionite toxicity: A synchrotron-based micro-X-ray fluorescence study on THP-1-derived macrophages exposed to erionite-Na

Fibrous erionite is the only zeolite classified as Group 1 carcinogen by the International Agency for Research on Cancer (IARC). Carcinogenesis induced by erionite is thought to involve several factors as biopersistence, the iron role and cation exchange processes. To better understand these mechanisms, a detailed investigation at the micro scale was performed, collecting elemental information on iron and cation release and their distribution in biological systems by synchrotron micro-X-ray fluorescence mapping (SR-micro-XRF) and synchrotron micro-X-ray absorption spectroscopy (SR-micro-XANES) at the TwinMic beamline (Elettra synchrotron) and at the ID21 beamline of the European Synchrotron Radiation Facility (ESRF). By microscopy and chemical mapping, highly detailed maps of the chemical and morphological interaction of biological systems with fibres could be produced. In detail, THP-1 cell line derived macrophages, used as in vitro model, were analysed during erionite-Na phagocytosis at different time intervals, after single dose exposure. For comparison, cellular fluorescent probes were also used to evaluate the intracellular free sodium and calcium concentrations. Synchrotron analyses visualised the spatial distribution of both fibre and mineral particle associated metals during the phagocytosis, describing the mechanism of internalisation of erionite-Na and its accessory mineral phases. The intracellular distribution of metals and other cations was mapped to evaluate metal release, speciation changes and/or cation exchange during phagocytosis. The fluorescent probes complemented microchemical data clarifying, and confirming, the cation distribution observed in the SR-micro-XRF maps. The significant cytoplasmic calcium decrease, and the concomitant sodium increase, after the fibre phagocytosis seemed due to activation of plasma membrane cations exchangers triggered by the internalisation while, surprisingly, the ion-exchange capacity of erionite-Na could play a minor role in the disruption of the two cations intracellular homeostasis. These results help to elucidate the role of cations in the toxicity of erionite-treated THP-1 macrophages and add knowledge to its carcinogenicity process.

Alkaptonuria: From Molecular Insights to a Dedicated Digital Platform

Alkaptonuria (AKU) is a genetic disorder that affects connective tissues of several body compartments causing cartilage degeneration, tendon calcification, heart problems, and an invalidating, early-onset form of osteoarthritis. The molecular mechanisms underlying AKU involve homogentisic acid (HGA) accumulation in cells and tissues. HGA is highly reactive, able to modify several macromolecules, and activates different pathways, mostly involved in the onset and propagation of oxidative stress and inflammation, with consequences spreading from the microscopic to the macroscopic level leading to irreversible damage. Gaining a deeper understanding of AKU molecular mechanisms may provide novel possible therapeutical approaches to counteract disease progression. In this review, we first describe inflammation and oxidative stress in AKU and discuss similarities with other more common disorders. Then, we focus on HGA reactivity and AKU molecular mechanisms. We finally describe a multi-purpose digital platform, named ApreciseKUre, created to facilitate data collection, integration, and analysis of AKU-related data.

Unraveling colorectal cancer prevention: The vitamin D - gut flora - immune system nexus

Colorectal cancer (CRC) is one of the most common cancers diagnosed in the world. Although environmental and genetic factors play a major role in the pathogenesis of CRC, extensive research has suggested that vitamin D may play a pivotal role in the development of CRC. Vitamin D, primarily obtained through sunlight exposure, dietary sources, and supplements, has long been recognized for its essential functions in maintaining health, including immune regulation. This article delves into the intricate relationship between vitamin D, the immune system, gut flora, and the prevention of CRC. It presents a synthesis of epidemiological data, experimental studies, and clinical trials, highlighting the mechanisms by which vitamin D influences immune cell function, cytokine production, and inflammation. By enhancing the immune system’s surveillance and anti-tumor activity, vitamin D may offer a promising avenue for CRC prevention. Furthermore, this comprehensive review delves into the prospective clinical applications of vitamin D supplementation and delineates the forthcoming avenues of research in this dynamic domain. Additionally, the paper tentatively outlines a spectrum of prophylactic impacts of vitamin D on CRC, emphasizing its significant potential in reducing CRC risk through shedding light on its mechanisms, encompassing antineoplastic mechanisms, influences on the immune system, and modulation of the gut microbiome.

Unraveling colorectal cancer prevention: The vitamin D - gut flora - immune system nexus

Colorectal cancer (CRC) is one of the most common cancers diagnosed in the world. Although environmental and genetic factors play a major role in the pathogenesis of CRC, extensive research has suggested that vitamin D may play a pivotal role in the development of CRC. Vitamin D, primarily obtained through sunlight exposure, dietary sources, and supplements, has long been recognized for its essential functions in maintaining health, including immune regulation. This article delves into the intricate relationship between vitamin D, the immune system, gut flora, and the prevention of CRC. It presents a synthesis of epidemiological data, experimental studies, and clinical trials, highlighting the mechanisms by which vitamin D influences immune cell function, cytokine production, and inflammation. By enhancing the immune system's surveillance and anti-tumor activity, vitamin D may offer a promising avenue for CRC prevention. Furthermore, this comprehensive review delves into the prospective clinical applications of vitamin D supplementation and delineates the forthcoming avenues of research in this dynamic domain. Additionally, the paper tentatively outlines a spectrum of prophylactic impacts of vitamin D on CRC, emphasizing its significant potential in reducing CRC risk through shedding light on its mechanisms, encompassing antineoplastic mechanisms, influences on the immune system, and modulation of the gut microbiome.