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The second most common mutation in melanoma occurs in NRAS oncogene, being a more aggressive disease that has no effective approved treatment. Besides, cellular plasticity limits better outcomes of the advanced and therapy-resistant patients. Peroxiredoxins (PRDXs) control cellular processes through direct hydrogen peroxide oxidation or by redox-relaying processes. Here, we demonstrated that PRDX2 could act as a modulator of multiple EMT markers in NRAS-mutated melanomas. PRDX2 knockdown lead to phenotypic changes towards invasion in human reconstructed skin and the treatment with a PRDX mimetic (gliotoxin), decreased migration in PRDX2-deficient cells. We also confirmed the favorable clinical outcome of patients expressing PRDX2 in a large primary melanoma cohort. This study contributes to our knowledge about genes involved in phenotype switching and opens a new perspective for PRDX2 as a biomarker and target in NRAS-mutated melanomas.
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Transição Epitelial-Mesenquimal , GTP Fosfo-Hidrolases , Melanoma , Proteínas de Membrana , Mutação , Invasividade Neoplásica , Peroxirredoxinas , Humanos , Melanoma/genética , Melanoma/patologia , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Linhagem Celular Tumoral , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Transição Epitelial-Mesenquimal/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/tratamento farmacológico , Feminino , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão GênicaRESUMO
Microenvironment and transcriptional plasticity generate subpopulations within the tumor, and the use of BRAF inhibitors (BRAFis) contributes to the rise and selection of resistant clones. We stochastically isolated subpopulations (C1, C2, and C3) from naïve melanoma and found that the clones demonstrated distinct morphology, phenotypic, and functional profiles: C1 was less proliferative, more migratory and invasive, less sensitive to BRAFis, less dependent on OXPHOS, more sensitive to oxidative stress, and less pigmented; C2 was more proliferative, less migratory and invasive, more sensitive to BRAFis, less sensitive to oxidative stress, and more pigmented; and C3 was less proliferative, more migratory and invasive, less sensitive to BRAFis, more dependent on OXPHOS, more sensitive to oxidative stress, and more pigmented. Hydrogen peroxide plays a central role in oxidative stress and cell signaling, and PRDXs are one of its main consumers. The intrinsically resistant C1 and C3 clones had lower MITF, PGC-1α, and PRDX1 expression, while C1 had higher AXL and decreased pigmentation markers, linking PRDX1 to clonal heterogeneity and resistance. PRDX2 is depleted in acquired BRAFi-resistant cells and acts as a redox sensor. Our results illustrate that decreased pigmentation markers are related to therapy resistance and decreased antioxidant defense.
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Introduction: There is an emerging body of evidence that vitamin C consumption can modulate microbiota abundance and can also impact DNA methylation in the host, and this could be a link between diet, microbiota, and immune response. The objective of this study was to evaluate common CpG sites associated with both vitamin C and microbiota phyla abundance. Methods: Six healthy women participated in this cohort study. They were divided into two groups, according to the amount of vitamin C they ingested. Ingestion was evaluated using the 24-h recall method. The Illumina 450 k BeadChip was used to evaluate DNA methylation. Singular value decomposition analyses were used to evaluate the principal components of this dataset. Associations were evaluated using the differentially methylated position function from the Champ package for R Studio. Results and discussion: The group with higher vitamin C (HVC) ingestion also had a higher relative abundance of Actinobacteria. There was a positive correlation between those variables (r = 0.84, p = 0.01). The HVC group also had higher granulocytes, and regarding DNA methylation, there were 207 CpG sites commonly related to vitamin C ingestion and the relative abundance of Actinobacteria. From these sites, there were 13 sites hypomethylated and 103 hypermethylated. The hypomethylated targets involved the respective processes: immune function, glucose homeostasis, and general cellular metabolism. The hypermethylated sites were also enriched in immune function-related processes, and interestingly, more immune responses against pathogens were detected. These findings contribute to understanding the interaction between nutrients, microbiota, DNA methylation, and the immune response.
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Exercise training emerges as a key strategy in lifestyle modification, capable of reducing the risk of developing Alzheimer's disease (AD) due to risk factors such as age, family history, genetics and low level of education associated with AD. We aim to analyze the effect of a 14-week combined exercise training (CT) on the methylation of genes associated with AD in non-alzheimer's disease women. CT sessions lasted 60 min, occurring three times a week for 14 weeks. Forty non-Alzheimer's disease women aged 50 to 70 years (60.7 ± 4.1 years) with a mean height of 1.6 ± 0.1 m, mean weight of 73.12 ± 9.0 kg and a mean body mass index of 29.69 ± 3.5 kg/m2, underwent two physical assessments: pre and post the 14 weeks. DNA methylation assays utilized the EPIC Infinium Methylation BeadChip from Illumina. We observed that 14 weeks of CT led to reductions in systolic (p = 0.001) and diastolic (p = 0.017) blood pressure and improved motor skills post-intervention. Among 25 genes linked to AD, CT induced differentially methylated sites in 12 genes, predominantly showing hypomethylated sites (negative ß values). Interestingly, despite hypomethylated sites, some genes exhibited hypermethylated sites (positive ß values), such as ABCA7, BDNF, and WWOX. A 14-week CT regimen was adequate to induce differential methylation in 12 CE-related genes in healthy older women, alongside improvements in motor skills and blood pressure. In conclusion, this study suggest that combined training can be a strategy to improve physical fitness in older individuals, especially able to induce methylation alterations in genes sites related to development of AD. It is important to highlight that training should act as protective factor in older adults.
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Doença de Alzheimer , Humanos , Feminino , Idoso , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Metilação de DNA , Exercício Físico , Processamento de Proteína Pós-Traducional , Fatores de RiscoRESUMO
INTRODUCTION: The increasing prevalence of obesity has become a major health problem worldwide. The causes of obesity are multifactorial and could be influenced by dietary patterns and genetic factors. Obesity has been associated with a decrease in micronutrient intake and consequently decreased blood concentrations. Selenium is an essential micronutrient for human health, and its metabolism could be affected by obesity, especially severe obesity. This study aimed to identify differential methylation genes associated with serum selenium concentration in women with and without obesity. METHODOLOGY: Thirty-four patients were enrolled in the study and divided into two groups: Obese (Ob) n = 20 and Non-Obese (NOb) n = 14, according to the Body Mass Index (BMI). Anthropometry, body composition, serum selenium, selenium intake, and biochemical parameters were evaluated. DNA extraction and bisulfite conversion were performed to hybridize the samples on the 450k Methylation Chip Infinium Beadchip (Illumina). Bioinformatics analysis was performed using the R program and the Champ package. The differentially methylated regions (DMRs) were identified using the Bumphunter method. In addition, logarithmic conversion was performed for the analysis of serum selenium and methylation. RESULTS: In the Ob group, the body weight, BMI, fat mass, and free fat mass were higher than in the NOb group, as expected. Interestingly, the serum selenium was lower in the Ob than in the NOb group without differences in selenium intake. One DMR corresponding to the CPT1B gene, involved in lipid oxidation, was related to selenium levels. This region was hypermethylated in the Ob group, indicating that the intersection between selenium deficiency and hypermethylation could influence the expression of the CPT1B gene. The transcriptional analysis confirmed the lower expression of the CPT1B gene in the Ob group. CONCLUSION: Studies connecting epigenetics to environmental factors could offer insights into the mechanisms involving the expression of genes related to obesity and its comorbidities. Here we demonstrated that the mineral selenium might play an essential role in lipid oxidation via epigenetic and transcriptional regulation of the CPT1B gene in obesity.
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Carnitina O-Palmitoiltransferase , Epigênese Genética , Obesidade , Selênio , Feminino , Humanos , Carnitina O-Palmitoiltransferase/metabolismo , Metilação de DNA/genética , Epigênese Genética/genética , Regulação da Expressão Gênica , Lipídeos , Obesidade/genética , Obesidade/metabolismo , Selênio/metabolismoRESUMO
Purpose: The acceleration of epigenetic age is a predictor of mortality and contributes to the increase in chronic diseases. Adherence to a healthy lifestyle is a strategy to reduce epigenetic age. The present study aimed to determine whether eight weeks of combined (aerobic and strength) training (CT) can influence the epigenetic age of women between 50 and 70 years old and the differences in sites and methylated regions. Methods: Eighteen women (AARLow: lower age acceleration residual, n = 10; AARHigh: higher age acceleration residual, n = 8) participated in a combined exercise training program (60 minutes, 3× a week) for eight weeks. DNA was extracted from whole blood using the salting out technique. DNA methylation was performed using the array technique (Illumina's Infinium Methylation BeadChip 850k). We used the DNA Methylation Age Calculator platform to calculate the biological epigenetic age. Two-way ANOVA followed by FISHER LSD posthoc was Applied, adopting p < .05. Results: After eight weeks of CT, there were no changes to the epigenetic age acceleration for the AARLow group (PRE: -2.3 ± 3.2 to POST: -2.3 ± 3.6). However, the AARHigh group significantly decreased the age acceleration (PRE: 3.6 ± 2.6 to POST: 2.2 ± 2.7) (group effect, p = .01; time effect, p = .31; group vs. time effect, p = .005). Conclusion: CT for eight weeks benefits the epigenetic clock of women with the most accelerated age.
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The endogenous estradiol derivative 2-Methoxyestradiol (2-ME) has shown good and wide anticancer activity but suffers from poor oral bioavailability and extensive metabolic conjugation. However, its sulfamoylated derivative, 2-methoxyestradiol-3,17-O,O-bis-sulfamate (STX140), has superior potential as a therapeutic agent, acts by disrupting microtubule polymerization, leading to cell cycle arrest and apoptosis in cancer cells and possesses much better pharmaceutical properties. This study investigated the antiproliferative and anti-invasive activities of STX140 in both SKMEL-28 naïve melanoma (SKMEL28-P) cells and resistant melanoma cells (SKMEL-28R). STX140 inhibited cell proliferation in the nanomolar range while having a less pronounced effect on human melanocytes. Additionally, STX140 induced cell cycle arrest in the G2/M phase and sub-G1, reduced migration, and clonogenic potential in monolayer models, and inhibited invasion in a 3D human skin model with melanoma cells. Furthermore, STX140 induced senescence features in melanoma and activated the senescence machinery by upregulating the expression of senescence genes and proteins related to senescence signaling. These findings suggest that STX140 may hold potential as a therapeutic agent for melanoma treatment.
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Estrenos , Melanoma , Humanos , 2-Metoxiestradiol/farmacologia , Estrenos/farmacologia , Proliferação de Células , Melanoma/tratamento farmacológico , Linhagem Celular Tumoral , ApoptoseRESUMO
BACKGROUND & AIMS: Obesity is associated with low grade systemic inflammation and insulin resistance. Although metabolic and immunological changes may contribute to the increased risk for COVID-19 mortality in obese, little is known about the impact of obesity in the lungs of patients with COVID-19. METHODS: We analyzed gene expression profiles of autopsy lungs of a cohort of 14 COVID-19 patients and 4 control individuals. Patients were divided into 3 groups according to their comorbidities: hypertension, type 2 diabetes (T2D) and obesity. We then identified the molecular alterations associated with these comorbidities in COVID-19 patients. RESULTS: Patients with only hypertension showed higher levels of inflammatory genes and B-cell related genes when compared to those with T2D and obesity. However, the levels of IFN-gamma, IL22, and CD274 (a ligand that binds to receptor PD1) were higher in COVID-19 patients with T2D and obesity. Several metabolic- and immune-associated genes such as G6PD, LCK and IL10 were significantly induced in the lungs of the obese group. CONCLUSION: Our findings suggest that SARS-CoV-2 infection in the lungs may exacerbate the immune response and chronic condition in obese COVID-19 patients.
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COVID-19/complicações , COVID-19/genética , Expressão Gênica/genética , Pulmão/imunologia , Obesidade/complicações , Obesidade/genética , Autopsia , COVID-19/imunologia , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/imunologia , Humanos , Hipertensão/complicações , Hipertensão/genética , Hipertensão/imunologia , Obesidade/imunologia , SARS-CoV-2RESUMO
OBJECTIVE: The present report investigated the rates of coinfections between high-rik human papillomavirus (hrHPV) and the most important human mycoplasmas including Mycoplasma hominis, M. genitalium, Ureaplasma urealyticum and U. parvum in cervical samples of asymptomatic brazilian population. METHODS: Were included a total of 283 women aged 25-64 years screened by Papanicolaou smears for determining cervical abnormalities, single-target polymerase chain reaction (PCR) and real-time PCR (rt-PCR) for hrHPV and mycoplasmas, respectively. RESULTS: A total of 273 (94.5%) women were negative for intraepithelial lesions or malignancy cytology (NILM) and 10 (3.5%) presented abnormal cytology, all low-grade intraepithelial lesions (LSIL). The prevalence of hrHPV was 12.7% and 53.7% for mycoplasmas. U. parvum was the most frequently bacteria detected, followed by Mycoplasma hominis and U. urealyticum. M. genitalium was not detected. Women positive for U. parvum presented a 5-fold increased risk of LSIL (OR = 5.33; 95% CI = 1.09-26.04, P = 0.02) and co-infections between U. parvum and hrHPV increased the risk for LSIL (OR = 3.88; 95% CI = 1.75-8.58, P = 0.0003). However, these associations were not dependent on the concentration of the bacteria. CONCLUSION: Our results reinforced the hypothesis that some mycoplasmas may play a role as cofactors in HPV-mediated cervical carcinogenesis, at least in some populations.
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