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Stress has been well-documented to have a significant role in the etiopathogenesis of bruxism. Activation of the hypothalamic-pituitary-adrenal axis (HPA) and subsequent release of corticosteroids lead to increased muscle activity. Neurological studies have demonstrated that chronic stress exposure induces neurodegeneration of important neuronal structures and destabilization of the mesocortical dopaminergic pathway. These disruptions impair the abilities to counteract the overactivity of the HPA axis and disinhibit involuntary muscle activity, while at the same time, there is activation of the amygdala. Recent evidence shows that overactivation of the amygdala under stressful stimuli causes rhythmic jaw muscle activity by over activating the mesencephalic and motor trigeminal nuclei. The present review aimed to discuss the negative effects of certain vitamin and mineral deficiencies, such as vitamin D, magnesium, and omega-3 fatty acids, on the central nervous system. It provides evidence on how such insufficiencies may increase stress sensitivity and neuromuscular excitability and thereby reduce the ability to effectively respond to the overactivation of the sympathetic nervous system, and also how stress can in turn lead to these insufficiencies. Finally, the positive effects of individualized supplementation are discussed in the context of diminishing anxiety and oxidative stress, neuroprotection and in the reversal of neurodegeneration, and also in alleviating/reducing neuromuscular symptoms.
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Complex signaling interactions between cancer cells and their microenvironments drive the clonal selection of cancer cells. Opposing forces of antitumor and tumorigenic potential regulate the survival of the fittest clones, while key genetic and epigenetic alterations in healthy cells force them to transform, overcome cell senescence, and proliferate in an uncontrolled manner. Both clinical samples and cancer cell lines provide researchers with an insight into the complex structure and hierarchy of cancer. Intratumor heterogeneity allows for multiple cancer cell subpopulations to simultaneously coexist within tumors. One category of these cancer cell subpopulations is cancer stem cells (CSCs), which possess stem-like characteristics and are not easily detectable. In the case of breast cancer, which is the most prevalent cancer type among females, such subpopulations of cells have been isolated and characterized via specific stem cell markers. These stem-like cells, known as breast cancer stem cells (BCSCs), have been linked to major events during tumorigenesis including invasion, metastasis and patient relapse following conventional therapies. Complex signaling circuitries seem to regulate the stemness and phenotypic plasticity of BCSCs along with their differentiation, evasion of immunosurveillance, invasiveness and metastatic potential. Within these complex circuitries, new key players begin to arise, with one of them being a category of small non-coding RNAs, known as miRNAs. Here, we review the importance of oncogenic miRNAs in the regulation of CSCs during breast cancer formation, promotion and metastasis, in order to highlight their anticipated usage as diagnostic and prognostic tools in the context of patient stratification and precision medicine.
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Head and neck cancer (HNC) is a term collectively used to describe a heterogeneous group of tumors that arise in the oral cavity, larynx, nasopharynx, oropharynx, and hypopharynx, and represents the sixth most common type of malignancy worldwide. Despite advances in multimodality treatment, the disease has a recurrence rate of around 50%, and the prognosis of metastatic patients remains poor. HNCs are characterized by a high degree of genomic instability, which involves a vicious circle of accumulating DNA damage, defective DNA damage repair (DDR), and replication stress. Nonetheless, the damage that is induced on tumor cells by chemo and radiotherapy relies on defective DDR processes for a successful response to treatment, and may play an important role in the development of novel and more effective therapies. This review summarizes the current knowledge on the genes and proteins that appear to be deregulated in DDR pathways, their implication in HNC pathogenesis, and the rationale behind targeting these genes and pathways for the development of new therapies. We give particular emphasis on the therapeutic targets that have shown promising results at the pre-clinical stage and on those that have so far been associated with a therapeutic advantage in the clinical setting.
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Neoplasias de Cabeça e Pescoço , Humanos , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/terapia , Terapia Combinada , Dano ao DNARESUMO
Head and neck squamous cell carcinoma (HNSCC) is a term collectively used to describe all cancers that develop in the oral and nasal cavities, the paranasal sinuses, the salivary glands, the pharynx, and the larynx. The majority (75%) of all newly diagnosed cases are observed in patients with locally advanced and aggressive disease, associated with significant relapse rates (30%) and poor prognostic outcomes, despite advances in multimodal treatment. Consequently, there is an unmet need for the identification and application of tools that would enable diagnosis at the earliest possible stage, accurately predict prognostic outcomes, contribute to the timely detection of relapses, and aid in the decision for therapy selection. Recent evidence suggests that DNA methylation can alter the expression of genes in a way that it favors tumorigenesis and tumor progression in HNSCC, and therefore represents a potential source for biomarker identification. This study summarizes the current knowledge on how abnormally methylated DNA profiles in HNSCC patients may contribute to the pathogenesis of HNSCC and designate the methylation patterns that have the potential to constitute clinically valuable biomarkers for achieving significant advances in the management of the disease and for improving survival outcomes in these patients.
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Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Metilação de DNA , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Prognóstico , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Recidiva Local de Neoplasia/genética , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/genéticaRESUMO
The cancer immunoediting theory describes the dual ability of endogenous antitumor immunity to inhibit or promote progressing cancers. Tumor-specific neoantigens arising from somatic mutations serve as targets for the endogenous T-cell-mediated antitumor immunity and therefore possess a crucial role for tumor development. Additionally, targeting these molecules is conceptually appealing because neoantigens are not expressed in healthy tissue and therefore confer less toxicity and greater specificity when used in therapeutic interventions. Moreover, intratumor neo-antigenic heterogeneity is believed to play a pivotal role in the activation of adaptive immunity and in the efficacy of immunotherapies that are based on immune checkpoint inhibition. In this respect, mutual interactions between tumor cells and immune lymphocytes regulate the levels of antitumor immunity, but also shape tumor heterogeneity through the selective outgrowth of tumor subclones. Therefore, the exploration of the mechanistic pathways and the identification of the genomic aberrations underlying the clonal evolution of tumors is considered mandatory for improving the clinical outcomes of therapies, as it will assist in the selection of the appropriate therapeutic decisions so as to delay, avoid, or overcome resistance through the identification of the most effective therapeutic strategies.
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COVID19 patients with severe infection have been observed to have elevated autoantibodies (AAs) against angiotensin II receptor type 1 (AT1R) and endothelin (ET) 1 receptor type A (ETAR), compared with healthy controls and patients with favorable (mild) infection. AT1R and ETAR are G proteincoupled receptors, located on vascular smooth muscle cells, fibroblasts, immune and endothelial cells, and are activated by angiotensin II (Ang II) and ET1 respectively. AAs that are specific for these receptors have a functional role similar to the natural ligands, but with a more prolonged vasoconstrictive effect. They also induce the production of fibroblast collagen, the release of reactive oxygen species and the secretion of proinflammatory cytokines (including IL6, IL8 and TNFα) by immune cells. Despite the presence of AAs in severe COVID19 infected patients, their contribution and implication in the severity of the disease is still not well understood and further studies are warranted. The present review described the major vascular homeostasis systems [ET and reninangiotensinaldosterone system (RAAS)], the vital regulative role of nitric oxide, the AAs, and finally the administration of angiotensin II receptor blockers (ARBs), so as to provide more insight into the interplay that exists among these components and their contribution to the severity, prognosis and possible treatment of COVID19.
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COVID-19 , Doenças Vasculares , Angiotensina II , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Colágeno , Células Endoteliais , Endotelinas , Humanos , Interleucina-6 , Interleucina-8 , Óxido Nítrico , Espécies Reativas de Oxigênio , Receptor Tipo 1 de Angiotensina , Receptor de Endotelina A , Receptores de Angiotensina , Fator de Necrose Tumoral alfaRESUMO
Head and neck cancers (HNCs) comprise a heterogeneous group of tumors that extend from the oral cavity to the upper gastrointestinal tract. The principal etiologic factors for oral tumors include tobacco smoking and alcohol consumption, while human papillomavirus (HPV) infections have been accused of a high incidence of pharyngeal tumors. Accordingly, HPV detection has been extensively used to categorize carcinomas of the head and neck. The diverse nature of HNC highlights the necessity for novel, sensitive, and precise biomarkers for the prompt diagnosis of the disease, its successful monitoring, and the timely prognosis of patient clinical outcomes. In this context, the identification of certain microRNAs (miRNAs) and/or the detection of alterations in their expression patterns, in a variety of somatic fluids and tissues, could serve as valuable biomarkers for precision oncology. In the present review, we summarize some of the most frequently studied miRNAs (including miR-21, -375, -99, -34a, -200, -31, -125a/b, -196a/b, -9, -181a, -155, -146a, -23a, -16, -29, and let-7), their role as biomarkers, and their implication in HNC pathogenesis. Moreover, we designate the potential of given miRNAs and miRNA signatures as novel diagnostic and prognostic tools for successful patient stratification. Finally, we discuss the currently ongoing clinical trials that aim to identify the diagnostic, prognostic, or therapeutic utility of miRNAs in HNC.
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Neoplasias de Cabeça e Pescoço , MicroRNAs , Infecções por Papillomavirus , Biomarcadores , Biomarcadores Tumorais/genética , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Medicina de PrecisãoRESUMO
Radiotherapy (RT) is a therapeutic modality that aims to eliminate malignant cells through the induction of DNA damage in the irradiated tumor site. In addition to its cytotoxic properties, RT also induces mechanisms that result in the promotion of antitumor immunity both locally within the irradiation field but also at distant tumor lesions, a phenomenon that is known as the "abscopal" effect. Because the immune system is capable of sensing the effects of RT, several treatment protocols have been assessing the synergistic role of radiotherapy combined with immunotherapy, collectively referred to as radioimmunotherapy. Herein, we discuss mechanistic insights underlying RT-based immunomodulation, which also enhance our understanding of how RT regulates antitumor T-cell-mediated immunity. Such knowledge is essential for the discovery of predictive biomarkers and for the improvement of clinical trials investigating the efficacy of radio-immunotherapeutic modalities in cancer patients.
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Radiation therapy (RT) is an essential component in the therapeutic treatment of patients with localized prostate cancer (LPCa). Besides its local effects, ionizing radiation has been linked to mechanisms leading to systemic immune activation. The present study explored the effect of RT on the Tcell receptor variable ß (TCR Vß) chain repertoire of peripheral blood T cells in patients with LPCa. Highthroughput TCR Vß sequencing was performed on 20 blood samples collected from patients with LPCa at baseline and 3 months postRT. The diversity index was altered, as were TCR Vß clonal evenness and convergence before and postRT; however, these findings were not significant. Notably, marked changes in the frequencies among the top 10 TCR Vß clonotypes were detected and some patients developed new clonotypes of high abundance. These data provided initial evidence that RT in patients with LPCa may induce systemic immune changes, which could be exploited by future therapies for improved clinical results.
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Neoplasias da Próstata , Receptores de Antígenos de Linfócitos T alfa-beta , Humanos , Masculino , Neoplasias da Próstata/genética , Neoplasias da Próstata/radioterapia , Receptores de Antígenos de Linfócitos T alfa-beta/genéticaRESUMO
Cancer is the second leading cause of death globally. One of the main hallmarks in cancer is the functional deregulation of crucial molecular pathways via driver genetic events that lead to abnormal gene expression, giving cells a selective growth advantage. Driver events are defined as mutations, fusions and copy number alterations that are causally implicated in oncogenesis. Molecular analysis on tissues that have originated from a wide range of anatomical areas has shown that mutations in different members of several pathways are implicated in different cancer types. In recent decades, significant efforts have been made to incorporate this knowledge into daily medical practice, providing substantial insight towards clinical diagnosis and personalized therapies. However, since there is still a strong need for more effective drug development, a deep understanding of the involved signaling mechanisms and the interconnections between these pathways is highly anticipated. Here, we perform a systemic analysis on cancer patients included in the Pan-Cancer Atlas project, with the aim to select the ten most highly mutated signaling pathways (p53, RTK-RAS, lipids metabolism, PI-3-Kinase/Akt, ubiquitination, b-catenin/Wnt, Notch, cell cycle, homology directed repair (HDR) and splicing) and to provide a detailed description of each pathway, along with the corresponding therapeutic applications currently being developed or applied. The ultimate scope is to review the current knowledge on highly mutated pathways and to address the attractive perspectives arising from ongoing experimental studies for the clinical implementation of personalized medicine.
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Since its outbreak, in December, 2019, in the Chinese city of Wuhan, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into an ongoing global pandemic. Due to the novel antigenic properties of this virus, the world population could not develop immunity effectively and this led to the subsequent spread of COVID-19. This caused an unprecedented emergency situation with significant negative effects on health and well-being both on an individual and societal level. Apart from health, economic and social consequences, the impact of this pandemic on mental health is increasingly being reported in the scientific literature. The present review aimed to provide a comprehensive discussion of the possible neurological and neuropsychiatric manifestations of SARS-CoV-2, together with the related underlying molecular pathways. In addition, the present review focused on populations which are at a higher risk of developing psychiatric disturbances due to the COVID-19 pandemic and discussed possible routes of clinical management and therapeutics to minimize the burden associated with psychiatric disorders. Moreover, research findings exploring the prevalence of COVID-19-related post-traumatic stress disorder (PTSD) symptoms across vulnerable groups, including children, adolescents and COVID-19 survivors are presented, with particular emphasis on those with severe disease who required hospitalization and/or intensive care unit admission. Based on the available literature, the identification of potential determinants associated with PTSD across the different populations is underlined. Lessons learnt from the pandemics across the globe together with the ongoing research on COVID-19 and its impact on mental health, highlight the utmost importance for evidence-based, proactive and targeted interventions in high-risk groups aiming to mitigate the risks and manage vulnerabilities.
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Prostate cancer (PCa) is one of the most commonly diagnosed malignancies and among the leading causes of cancer-related death worldwide. It is a highly heterogeneous disease, ranging from remarkably slow progression or inertia to highly aggressive and fatal disease. As therapeutic decision-making, clinical trial design and outcome highly depend on the appropriate stratification of patients to risk groups, it is imperative to differentiate between benign versus more aggressive states. The incorporation of clinically valuable prognostic and predictive biomarkers is also potentially amenable in this process, in the timely prevention of metastatic disease and in the decision for therapy selection. This review summarizes the progress that has so far been made in the identification of the genomic events that can be used for the classification, prediction and prognostication of PCa, and as major targets for clinical intervention. We include an extensive list of emerging biomarkers for which there is enough preclinical evidence to suggest that they may constitute crucial targets for achieving significant advances in the management of the disease. Finally, we highlight the main challenges that are associated with the identification of clinically significant PCa biomarkers and recommend possible ways to overcome such limitations.
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Biomarcadores Tumorais , Neoplasias da Próstata , Biomarcadores Tumorais/genética , Genômica , Humanos , Masculino , Prognóstico , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genéticaRESUMO
Taurine is a fundamental mediator of homeostasis that exerts multiple roles to confer protection against oxidant stress. The development of hypertension, muscle/neuroâassociated disorders, hepatic cirrhosis, cardiac dysfunction and ischemia/reperfusion are examples of some injuries that are linked with oxidative stress. The present review gives a comprehensive description of all the underlying mechanisms of taurine, with the aim to explain its antioxidant actions. Taurine is regarded as a cytoprotective molecule due to its ability to sustain normal electron transport chain, maintain glutathione stores, upregulate antioxidant responses, increase membrane stability, eliminate inflammation and prevent calcium accumulation. In parallel, the synergistic effect of taurine with other potential therapeutic modalities in multiple disorders are highlighted. Apart from the results derived from research findings, the current review bridges the gap between bench and bedside, providing mechanistic insights into the biological activity of taurine that supports its potential therapeutic efficacy in clinic. In the future, further clinical studies are required to support the ameliorative effect of taurine against oxidative stress.
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Antioxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Taurina/farmacologia , Animais , Antioxidantes/fisiologia , Antioxidantes/uso terapêutico , Cardiopatias/tratamento farmacológico , Homeostase/efeitos dos fármacos , Homeostase/fisiologia , Humanos , Hepatopatias/tratamento farmacológico , Doenças Musculares/tratamento farmacológico , Doenças do Sistema Nervoso/tratamento farmacológico , Taurina/fisiologia , Taurina/uso terapêuticoRESUMO
Prostate cancer (PCa) is the most frequently diagnosed type of cancer among Caucasian males over the age of 60 and is characterized by remarkable heterogeneity and clinical behavior, ranging from decades of indolence to highly lethal disease. Despite the significant progress in PCa systemic therapy, therapeutic response is usually transient, and invasive disease is associated with high mortality rates. Immunotherapy has emerged as an efficacious and non-toxic treatment alternative that perfectly fits the rationale of precision medicine, as it aims to treat patients on the basis of patient-specific, immune-targeted molecular traits, so as to achieve the maximum clinical benefit. Antibodies acting as immune checkpoint inhibitors and vaccines entailing tumor-specific antigens seem to be the most promising immunotherapeutic strategies in offering a significant survival advantage. Even though patients with localized disease and favorable prognostic characteristics seem to be the ones that markedly benefit from such interventions, there is substantial evidence to suggest that the survival benefit may also be extended to patients with more advanced disease. The identification of biomarkers that can be immunologically targeted in patients with disease progression is potentially amenable in this process and in achieving significant advances in the decision for precision treatment of PCa.
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Glucocorticoids (GCs) are still first-line drugs for the treatment of childhood acute lymphoblastic leukemia (ALL). Prednisolone is a corticosteroid and one of the most important agents in the treatment of ALL. We report here a study of Prednisolone treatment using as a model a leukemia cell line with subsequent investigation of resistance-related gene expression. Gene silencing has been used in order to identify significant targets of resistance to GC-induced apoptosis in ALL cells. We analyzed effects of increasing doses of Prednisolone on ALL cell survival and growth, and we monitored immediate effects on gene expression through gene expression assays. We determined Prednisolone cytotoxicity and cell cycle distribution as well as DNA content. Upon treatment with escalating Prednisolone concentration, we observed a gradual decline in cell survival. MCL1 and GRIM19 were investigated as possible genes for the intrinsic capacity of this cell line to respond to corticosteroid and a snapshot of early changes was examined. Early MCL1 and GRIM19 expression correlated significantly to late GC-induced apoptosis. Prednisolone competitively induces MCL1 expression. Consistently with previous studies on primary leukemia blasts, cells are sensitive to proteasome inhibitor MG132; no interference of Prednisolone with MG132 effects on this cell line was noted. The inherent plasticity of clinically evolving cancer justifies approaches to characterize and prevent undesirable activation of early oncogenic pathways. Study of the pattern of intracellular signal pathway activation by anticancer drugs can lead to development of efficient treatment strategies by reducing detrimental secondary effects.
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Leucemia-Linfoma Linfoblástico de Células Precursoras , Prednisolona , Apoptose , Linhagem Celular , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Prednisolona/farmacologia , Linfócitos TRESUMO
To develop novel therapeutic methods for both diabetic and renal disorders, scientists had initially focused on elucidating the molecular mechanisms of taurine in established cell lines and mouse models. Although a large amount of data have been revealed, taurine has been confirmed to be the next step of novel promising therapeutic interventions against diabetic disorders. Taurine appears to ameliorate diabetes 1-related complications in various organs through its antioxidant, anti-inflammatory and anti-hormonal actions. In type 2 diabetes, taurine has been positively implicated in glucose homeostasis, exerting potent hypoglycemic, anti-obesity, hypotensive and hypolipidemic effects. Of particular interest is that taurine provides protection against renal dysfunction, including hypertension and proteinuria, specific glomerular and tubular disorders, acute and chronic renal conditions, and diabetic nephropathy. The ameliorative effects of taurine against renal disorders are based on its osmoregulatory properties, its association with signaling pathways and its association with the renin-angiotensin-aldosterone system (RAAS). Further clinical studies are required to ensure the importance of research findings.
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BACKGROUND: Resistance to glucocorticoid (GC)-induced apoptosis in Acute Lymphoblastic Leukemia (ALL), is considered one of the major prognostic factors for the disease. Prednisolone is a corticosteroid and one of the most important agents in the treatment of acute lymphoblastic leukemia. The mechanics of GC resistance are largely unknown and intense ongoing research focuses on this topic. AIM: The aim of the present study is to review some aspects of GC resistance in ALL, and in particular of Prednisolone, with emphasis on previous and present knowledge on gene expression and signaling pathways playing a role in the phenomenon. METHODS: An electronic literature search was conducted by the authors from 1994 to June 2019. Original articles and systematic reviews selected, and the titles and abstracts of papers screened to determine whether they met the eligibility criteria, and full texts of the selected articles were retrieved. RESULTS: Identification of gene targets responsible for glucocorticoid resistance may allow discovery of drugs, which in combination with glucocorticoids may increase the effectiveness of anti-leukemia therapies. The inherent plasticity of clinically evolving cancer justifies approaches to characterize and prevent undesirable activation of early oncogenic pathways. CONCLUSION: Study of the pattern of intracellular signal pathway activation by anticancer drugs can lead to development of efficient treatment strategies by reducing detrimental secondary effects.
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Apoptose/efeitos dos fármacos , Glucocorticoides/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Prednisolona/farmacologia , Transdução de Sinais/efeitos dos fármacosRESUMO
BAFF, APRIL and their receptors regulate the survival, maturation and homeostasis of mature B-cells. Despite the lack of a functional role of BAFF/APRIL system during normal early B-cell development, previous studies indicated a contribution of these molecules in the pathogenesis of B-lineage acute lymphoblastic leukemia (B-ALL). Here, we evaluated the expression of this system in B-ALL and its involvement in spontaneous and drug-induced apoptosis of B-lymphoblasts, taking into consideration the distinct disease subtypes. We found that BAFFR is the most predominant aberrantly expressed receptor in B-ALL and that its expression, along with BCMA and APRIL, positively correlates with the maturation stage of B-lymphoblasts. Moreover, the binding of the E2A-PBX1 chimeric protein to the BAFFR promoter suggests that the transcriptional activator promotes the increase in BAFFR expression observed in about 50% of pre-B-ALL patients carrying the t (1, 19) translocation. BAFF binding to BAFFR led to the processing of NF-κB2 p100 in pre-B ALL cells suggesting that BAFFR can activate the NF-κB2 pathway in pre-B ALL cells. Surprisingly, we found that BAFF treatment promotes the cell death of primary BCR-ABL+ BAFFR+ pre-B-lymphoblasts in adult B-ALL. It also enhances glucocorticoid-induced apoptosis in the E2A-PBX1+ pre-B-ALL cell line 697. These data suggest that BAFF/BAFFR signaling in B-ALL cells differs from normal B cells and that it may affect the pathogenesis of the disease.
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Cytokines are pivotal mediators of the immune response, and their coordinated expression protects host tissue from excessive damage and oxidant stress. Nevertheless, the development of lung pathology, including asthma, chronic obstructive pulmonary disease, and ozone-induced lung injury, is associated with oxidant stress; as evidence, there is a significant increase in levels of the modified guanine base 7,8-dihydro-8-oxoguanine (8-oxoG) in the genome. 8-OxoG is primarily recognized by 8-oxoguanine glycosylase 1 (OGG1), which catalyzes the first step in the DNA base excision repair pathway. However, oxidant stress in the cell transiently halts enzymatic activity of substrate-bound OGG1. The stalled OGG1 facilitates DNA binding of transactivators, including NF-κB, to their cognate sites to enable expression of cytokines and chemokines, with ensuing recruitments of inflammatory cells. Hence, defective OGG1 will modulate the coordination between innate and adaptive immunity through excessive oxidant stress and cytokine dysregulation. Both oxidant stress and cytokine dysregulation constitute key elements of oncogenesis by KRAS, which is mechanistically coupled to OGG1. Thus, analysis of the mechanism by which OGG1 modulates gene expression helps discern between beneficial and detrimental effects of oxidant stress, exposes a missing functional link as a marker, and yields a novel target for lung cancer.
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DNA Glicosilases/imunologia , Neoplasias Pulmonares/imunologia , Animais , Humanos , Imunidade Inata , NF-kappa B/imunologia , Prognóstico , Espécies Reativas de Oxigênio/imunologiaRESUMO
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease characterized by debilitating fatigue, lasting for at least 6 months, with associated malaise, headaches, sleep disturbance, and cognitive impairment, which severely impacts quality of life. A significant percentage of ME/CFS patients remain undiagnosed, mainly due to the complexity of the disease and the lack of reliable objective biomarkers. ME/CFS patients display decreased metabolism and the severity of symptoms appears to be directly correlated to the degree of metabolic reduction that may be unique to each individual patient. However, the precise pathogenesis is still unknown, preventing the development of effective treatments. The ME/CFS phenotype has been associated with abnormalities in energy metabolism, which are apparently due to mitochondrial dysfunction in the absence of mitochondrial diseases, resulting in reduced oxidative metabolism. Such mitochondria may be further contributing to the ME/CFS symptomatology by extracellular secretion of mitochondrial DNA, which could act as an innate pathogen and create an autoinflammatory state in the hypothalamus. We propose that stimulation of hypothalamic mast cells by environmental, neuroimmune, pathogenic and stress triggers activates microglia, leading to focal inflammation in the brain and disturbed homeostasis. This process could be targeted for the development of novel effective treatments.