Potential Mechanisms by which Glucocorticoids Induce Breast Carcinogenesis through Nrf2 Inhibition.

Breast cancer is the most common malignancy among women worldwide. Several studies indicate that, in addition to established risk factors for breast cancer, other factors such as cortisol release related to psychological stress and drug treatment with high levels of glucocorticoids may also contribute significantly to the initiation of breast cancer. There are several possible mechanisms by which glucocorticoids might promote neoplastic transformation of breast tissue. Among these, the least known and studied is the inhibition of the nuclear erythroid factor 2-related (Nrf2)-antioxidant/electrophile response element (ARE/EpRE) pathway by high levels of glucocorticoids. Specifically, Nrf2 is a potent transcriptional activator that plays a central role in the basal and inducible expression of many cytoprotective genes that effectively protect mammalian cells from various forms of stress and reduce the propensity of tissues and organisms to develop disease or malignancy including breast cancer. Consequently, a loss of Nrf2 in response to high levels of gluco-corticoids may lead to a decrease in cellular defense against oxidative stress, which plays an important role in the initiation of human mammary carcinogenesis. In the present review, we provide a comprehensive overview of the current state of knowledge of the cellular mechanisms by which both glucocorticoid pharmacotherapy and endogenous GCs (cortisol in humans and corticosterone in rodents) may contribute to breast cancer development through inhibition of the Nrf2-ARE/EpRE pathway and the protective role of melatonin against glucocorticoid-induced apoptosis in the immune system.

The Pan-Immune-Inflammation Value in Patients with Metastatic Melanoma Receiving First-Line Therapy.

BACKGROUND: Since a non-negligible fraction of patients with metastatic melanoma does not experience long-term disease control, even with immunotherapy and targeted therapy, new biomarkers for patient stratification and treatment tailoring are needed in this setting. OBJECTIVE: We investigated the association of a novel immune-inflammatory blood-based biomarker, the Pan-Immune-Inflammation Value (PIV), with clinical outcomes of patients with metastatic melanoma receiving first-line therapy. PATIENTS AND METHODS: We retrospectively included patients treated at the Fondazione IRCCS Istituto Nazionale dei Tumori of Milan and having an available baseline complete blood cell count (CBC). PIV was calculated as: [neutrophil count (103/mm3) × platelet count (103/mm3) × monocyte count (103/mm3)]/lymphocyte count (103/mm3). RESULTS: A total of 228 patients were included: 119 (52%) had been treated with immunotherapy and 109 (48%) with targeted therapy. PIV was significantly higher in patients with ECOG PS ≥ 1, high disease burden, synchronous metastases, and elevated baseline LDH level. High baseline PIV was independently associated with poor overall survival (adjusted hazard ratio [HR]: 2.06; 95% confidence interval [CI]: 1.30-3.29; adjusted P = 0.002) and progression-free survival (adjusted HR 1.56; 95% CI 1.01-2.41; adjusted P = 0.044). High PIV was also associated with primary resistance to both immunotherapy (odds ratio [OR]: 3.98; 95% CI 1.45-12.32; P = 0.005) and targeted therapy (OR: 8.42; 95% CI 2.50-34.5; P < 0.001). PIV showed a promising discrimination ability in terms of AIC and c-index when compared with other CBC-based biomarkers. CONCLUSIONS: PIV may guide the treatment decision process and the development of novel first-line treatment strategies in melanoma, but warrants further study and validation.

Chondroitin Sulphate Proteoglycan 4 (NG2/CSPG4) Localization in Low- and High-Grade Gliomas.

BACKGROUND: Neuron glial antigen 2 or chondroitin sulphate proteoglycan 4 (NG2/CSPG4) is expressed by immature precursors/progenitor cells and is possibly involved in malignant cell transformation. The aim of this study was to investigate its role on the progression and survival of sixty-one adult gliomas and nine glioblastoma (GB)-derived cell lines. METHODS: NG2/CSPG4 protein expression was assessed by immunohistochemistry and immunofluorescence. Genetic and epigenetic alterations were detected by molecular genetic techniques. RESULTS: NG2/CSPG4 was frequently expressed in IDH-mutant/1p19q-codel oligodendrogliomas (59.1%) and IDH-wild type GBs (40%) and rarely expressed in IDH-mutant or IDH-wild type astrocytomas (14.3%). Besides tumor cells, NG2/CSPG4 immunoreactivity was found in the cytoplasm and/or cell membranes of reactive astrocytes and vascular pericytes/endothelial cells. In GB-derived neurospheres, it was variably detected according to the number of passages of the in vitro culture. In GB-derived adherent cells, a diffuse positivity was found in most cells. NG2/CSPG4 expression was significantly associated with EGFR gene amplification (p = 0.0005) and poor prognosis (p = 0.016) in astrocytic tumors. CONCLUSION: The immunoreactivity of NG2/CSPG4 provides information on the timing of the neoplastic transformation and could have prognostic and therapeutic relevance as a promising tumor-associated antigen for antibody-based immunotherapy in patients with malignant gliomas.

The Significance of Chondroitin Sulfate Proteoglycan 4 (CSPG4) in Human Gliomas.

Neuron glial antigen 2 (NG2) is a chondroitin sulphate proteoglycan 4 (CSPG4) that occurs in developing and adult central nervous systems (CNSs) as a marker of oligodendrocyte precursor cells (OPCs) together with platelet-derived growth factor receptor α (PDGFRα). It behaves variably in different pathological conditions, and is possibly involved in the origin and progression of human gliomas. In the latter, NG2/CSPG4 induces cell proliferation and migration, is highly expressed in pericytes, and plays a role in neoangiogenesis. NG2/CSPG4 expression has been demonstrated in oligodendrogliomas, astrocytomas, and glioblastomas (GB), and it correlates with malignancy. In rat tumors transplacentally induced by N-ethyl-N-nitrosourea (ENU), NG2/CSPG4 expression correlates with PDGFRα, Olig2, Sox10, and Nkx2.2, and with new vessel formation. In this review, we attempt to summarize the normal and pathogenic functions of NG2/CSPG4, as well as its potential as a therapeutic target.

Glioblastoma niches: from the concept to the phenotypical reality.

Recently, the concept of niches as sites of tumor progression, invasion, and angiogenesis in glioblastoma (GB) has been extensively debated. Niches, considered the sites in which glioblastoma stem cells (GSCs) reside, have been classified as perivascular, perinecrotic, and invasive. However, from a neuropathological point of view, it is not easy to establish when a tumor structure can be considered a niche. The relevant literature has been reviewed in the light of our recent experience on the subject. As for perinecrotic niches, the occurrence of GSCs around necrosis is interpreted as triggered by hypoxia through HIF-1α. Our alternative hypothesis is that, together with progenitors, they are the cell constituents of hyper-proliferative areas of GB, where perinecrotic niches have developed, and they would, therefore, represent the remnants of GSCs/progenitors spared by the developing necrosis. Perivascular structures originate from both transport vessels and exchange vessels, i.e., venules, arterioles, or the undefinable neo-formed small vessels, but only those in which a direct contact between GSCs/progenitors and endothelial cells occurs can be called niches. Both pericytes and microglia/macrophages play a role in niche function: Macrophages of blood origin invade GB only after the appearance of "mother vessels" with consequent blood-brain barrier disruption. Not all vessel/tumor cell structures can be considered niches, that is, crucial sites of tumor progression, invasion, and angiogenesis.

Radiotherapy of meningioma: a treatment in need of radiobiological research.

PURPOSE: Meningiomas account for one third of primary intracranial tumors; nevertheless information on meningioma cell lines and in vivo models is scant. Although radiotherapy is one of the most relevant therapeutic options for the treatment of patients with meningioma, radiobiological research to understand tumor response to this treatment is far from being thoroughly figured out. The aim of this report is to provide a comprehensive picture of the current literature on this field, so as to foster research in this regard. METHODS: We carried out a review of meningioma radiobiology based on a peer-reviewed PubMed search. RESULTS: Our findings confirm that the main limitation of radiobiological research into meningioma is the paucity of robust in vitro and in vivo models. Alternative approaches to overcome the already identified problems, and to allow better understanding of the entire histopathological spectrum of meningiomas have been explored. CONCLUSIONS: A radiobiological perspective of meningioma may help to improve clinical results both in terms of tumor control and healthy tissue sparing. Although we are far from drawing any conclusions, this review can lead researchers to identify some clues for future areas of study.