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1.
Cell ; 167(5): 1385-1397.e11, 2016 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-27863250

RESUMEN

The association of histone modification changes with autism spectrum disorder (ASD) has not been systematically examined. We conducted a histone acetylome-wide association study (HAWAS) by performing H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) on 257 postmortem samples from ASD and matched control brains. Despite etiological heterogeneity, ≥68% of syndromic and idiopathic ASD cases shared a common acetylome signature at >5,000 cis-regulatory elements in prefrontal and temporal cortex. Similarly, multiple genes associated with rare genetic mutations in ASD showed common "epimutations." Acetylome aberrations in ASD were not attributable to genetic differentiation at cis-SNPs and highlighted genes involved in synaptic transmission, ion transport, epilepsy, behavioral abnormality, chemokinesis, histone deacetylation, and immunity. By correlating histone acetylation with genotype, we discovered >2,000 histone acetylation quantitative trait loci (haQTLs) in human brain regions, including four candidate causal variants for psychiatric diseases. Due to the relative stability of histone modifications postmortem, we anticipate that the HAWAS approach will be applicable to multiple diseases.


Asunto(s)
Trastorno del Espectro Autista/genética , Cerebelo/metabolismo , Código de Histonas , Corteza Prefrontal/metabolismo , Sitios de Carácter Cuantitativo , Lóbulo Temporal/metabolismo , Acetilación , Trastorno del Espectro Autista/metabolismo , Autopsia , Inmunoprecipitación de Cromatina , Elementos de Facilitación Genéticos , Humanos , Regiones Promotoras Genéticas , Factores de Transcripción/metabolismo
2.
EMBO Rep ; 24(8): e56335, 2023 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-37341560

RESUMEN

While there is growing evidence that many epigenetically silenced genes in cancer are tumour suppressor candidates, their significance in cancer biology remains unclear. Here, we identify human Neuralized (NEURL), which acts as a novel tumour suppressor targeting oncogenic Wnt/ß-catenin signalling in human cancers. The expression of NEURL is epigenetically regulated and markedly suppressed in human colorectal cancer. We, therefore, considered NEURL to be a bona fide tumour suppressor in colorectal cancer and demonstrate that this tumour suppressive function depends on NEURL-mediated oncogenic ß-catenin degradation. We find that NEURL acts as an E3 ubiquitin ligase, interacting directly with oncogenic ß-catenin, and reducing its cytoplasmic levels in a GSK3ß- and ß-TrCP-independent manner, indicating that NEURL-ß-catenin interactions can lead to a disruption of the canonical Wnt/ß-catenin pathway. This study suggests that NEURL is a therapeutic target against human cancers and that it acts by regulating oncogenic Wnt/ß-catenin signalling.


Asunto(s)
Neoplasias del Colon , beta Catenina , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Vía de Señalización Wnt , Neoplasias del Colon/genética , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas con Repetición de beta-Transducina/genética , Proteínas con Repetición de beta-Transducina/metabolismo , Línea Celular Tumoral
3.
Curr Issues Mol Biol ; 46(3): 2402-2443, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38534769

RESUMEN

Gliomas constitute a diverse and complex array of tumors within the central nervous system (CNS), characterized by a wide range of prognostic outcomes and responses to therapeutic interventions. This literature review endeavors to conduct a thorough investigation of gliomas, with a particular emphasis on glioblastoma (GBM), beginning with their classification and epidemiological characteristics, evaluating their relative importance within the CNS tumor spectrum. We examine the immunological context of gliomas, unveiling the intricate immune environment and its ramifications for disease progression and therapeutic strategies. Moreover, we accentuate critical developments in understanding tumor behavior, focusing on recent research breakthroughs in treatment responses and the elucidation of cellular signaling pathways. Analyzing the most novel transcriptomic studies, we investigate the variations in gene expression patterns in glioma cells, assessing the prognostic and therapeutic implications of these genetic alterations. Furthermore, the role of epigenetic modifications in the pathogenesis of gliomas is underscored, suggesting that such changes are fundamental to tumor evolution and possible therapeutic advancements. In the end, this comparative oncological analysis situates GBM within the wider context of neoplasms, delineating both distinct and shared characteristics with other types of tumors.

4.
Cell Commun Signal ; 22(1): 36, 2024 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-38216942

RESUMEN

Prostate cancer, as one of the most prevalent malignancies in males, exhibits an approximate 5-year survival rate of 95% in advanced stages. A myriad of molecular events and mutations, including the accumulation of oncometabolites, underpin the genesis and progression of this cancer type. Despite growing research demonstrating the pivotal role of oncometabolites in supporting various cancers, including prostate cancer, the root causes of their accumulation, especially in the absence of enzymatic mutations, remain elusive. Consequently, identifying a tangible therapeutic target poses a formidable challenge. In this review, we aim to delve deeper into the implications of oncometabolite accumulation in prostate cancer. We center our focus on the consequential epigenetic alterations and impacts on cancer stem cells, with the ultimate goal of outlining novel therapeutic strategies.


Asunto(s)
Neoplasias , Neoplasias de la Próstata , Masculino , Humanos , Epigénesis Genética , Microambiente Tumoral , Neoplasias de la Próstata/genética , Neoplasias/patología , Mutación , Células Madre Neoplásicas/patología
5.
Int J Toxicol ; 43(3): 253-290, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38204208

RESUMEN

The ten key characteristics (KCs) of carcinogens are based on characteristics of known human carcinogens and encompass many types of endpoints. We propose that an objective review of the large amount of cancer mechanistic evidence for the chemical bisphenol A (BPA) can be achieved through use of these KCs. A search on metabolic and mechanistic data relevant to the carcinogenicity of BPA was conducted and web-based software tools were used to screen and organize the results. We applied the KCs to systematically identify, organize, and summarize mechanistic information for BPA, and to bring relevant carcinogenic mechanisms into focus. For some KCs with very large data sets, we utilized reviews focused on specific endpoints. Over 3000 studies for BPA from various data streams (exposed humans, animals, in vitro and cell-free systems) were identified. Mechanistic data relevant to each of the ten KCs were identified, with receptor-mediated effects, epigenetic alterations, oxidative stress, and cell proliferation being especially data rich. Reactive and bioactive metabolites are also associated with a number of KCs. This review demonstrates how the KCs can be applied to evaluate mechanistic data, especially for data-rich chemicals. While individual entities may have different approaches for the incorporation of mechanistic data in cancer hazard identification, the KCs provide a practical framework for conducting an objective examination of the available mechanistic data without a priori assumptions on mode of action. This analysis of the mechanistic data available for BPA suggests multiple and inter-connected mechanisms through which this chemical can act.


Asunto(s)
Compuestos de Bencidrilo , Carcinógenos , Fenoles , Fenoles/toxicidad , Compuestos de Bencidrilo/toxicidad , Humanos , Animales , Carcinógenos/toxicidad , Neoplasias/inducido químicamente
6.
Toxicol Mech Methods ; 34(2): 109-121, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37794599

RESUMEN

Nanoparticles (NPs) are particles of matter that are between 1 to 100 nm in diameter. They are suggested to cause toxic effects in both humans and environment thorough different mechanisms. However, their toxicity profile may be different from the parent material. Titanium dioxide (TiO2) NPs are widely used in cosmetic, pharmaceutical and food industries. As a white pigment, the use of TiO2 is used in food coloring, industrial paints, clothing and UV filters has increased tremendously in recent years. Melatonin, on the other hand, is a well-known antioxidant and may prevent oxidative stress caused by a variety of different substances, including NPs. In the current study, we aimed to comparatively investigate the effects of normal-sized TiO2 (220 nm) and nano-sized TiO2 (21 nm) on cytopathology, cytotoxicity, oxidative damage (lipid peroxidation, protein oxidation and glutathione), genotoxicity (8-hydroxydeoxyguanosine), apoptosis (caspase 3, 8 and 9) and epigenetic alterations (global DNA methylation, H3 acetylation) on 3T3 fibroblast cells. In addition, the possible protective effects of melatonin, which is known to have strong antioxidant effects, against the toxicity of TiO2 were also evaluated. Study groups were: a. the control group; b. melatonin group; c. TiO2 group; d. nano-sized TiO2 group; e. TiO2 + melatonin group and f. nano-sized TiO2 + melatonin group. We observed that both normal-sized and nano-sized TiO2 NPs showed significant toxic effects. However, TiO2 NPs caused higher DNA damage and global DNA methylation compared to normal-sized TiO2 whereas normal-sized TiO2 led to lower H3 acetylation vs. TiO2 NPs. Melatonin showed partial protective effect against the toxicity caused by TiO2 NPs.


Asunto(s)
Melatonina , Nanopartículas del Metal , Nanopartículas , Humanos , Melatonina/farmacología , Nanopartículas del Metal/toxicidad , Nanopartículas/toxicidad , Estrés Oxidativo , Antioxidantes/farmacología , Antioxidantes/metabolismo , Titanio/toxicidad , Daño del ADN
7.
EMBO J ; 38(12)2019 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-31088843

RESUMEN

Human pluripotent stem cells (hPSCs) are being increasingly utilized worldwide in investigating human development, and modeling and discovering therapies for a wide range of diseases as well as a source for cellular therapy. Yet, since the first isolation of human embryonic stem cells (hESCs) 20 years ago, followed by the successful reprogramming of human-induced pluripotent stem cells (hiPSCs) 10 years later, various studies shed light on abnormalities that sometimes accumulate in these cells in vitro Whereas genetic aberrations are well documented, epigenetic alterations are not as thoroughly discussed. In this review, we highlight frequent epigenetic aberrations found in hPSCs, including alterations in DNA methylation patterns, parental imprinting, and X chromosome inactivation. We discuss the potential origins of these abnormalities in hESCs and hiPSCs, survey the different methods for detecting them, and elaborate on their potential consequences for the different utilities of hPSCs.


Asunto(s)
Epigénesis Genética/fisiología , Células Madre Pluripotentes/fisiología , Diferenciación Celular/genética , Reprogramación Celular/genética , Metilación de ADN/fisiología , Impresión Genómica/genética , Humanos , Células Madre Pluripotentes Inducidas/fisiología , Inactivación del Cromosoma X/fisiología
8.
Environ Res ; 225: 115577, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-36871939

RESUMEN

Endocrine-disrupting compounds (EDC) are a group of exogenous chemicals that structurally mimic hormones and interfere with the hormonal signaling cascade. EDC interacts with hormone receptors, transcriptional activators, and co-activators, altering the signaling pathway at both genomic and non-genomic levels. Consequently, these compounds are responsible for adverse health ailments such as cancer, reproductive issues, obesity, and cardiovascular and neurological disorders. The persistent nature and increasing incidence of environmental contamination from anthropogenic and industrial effluents have become a global concern, resulting in a movement in both developed and developing countries to identify and estimate the degree of exposure to EDC. The U.S. Environment Protection Agency (EPA) has outlined a series of in vitro and in vivo assays to screen potential endocrine disruptors. However, the multidisciplinary nature and concerns over the widespread application demand alternative and practical techniques for identifying and estimating EDC. The review chronicles the state-of-art 20 years (1990-2023) of scientific literature regarding EDC's exposure and molecular mechanism, highlighting the toxicological effects on the biological system. Alteration in signaling mechanisms by representative endocrine disruptors such as bisphenol A (BPA), diethylstilbestrol (DES), and genistein has been emphasized. We further discuss the currently available assays and techniques for in vitro detection and propose the prominence of designing nano-architectonic-sensor substrates for on-site detection of EDC in the contaminated aqueous environment.


Asunto(s)
Disruptores Endocrinos , Neoplasias , Humanos , Disruptores Endocrinos/toxicidad , Dietilestilbestrol , Hormonas , Neoplasias/inducido químicamente , Transducción de Señal , Compuestos de Bencidrilo
9.
Int J Mol Sci ; 24(12)2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37373000

RESUMEN

Bladder cancer (BLCA) is one of the most common types of malignant tumors of the urogenital system in adults. Globally, the incidence of BLCA is more than 500,000 new cases worldwide annually, and every year, the number of registered cases of BLCA increases noticeably. Currently, the diagnosis of BLCA is based on cystoscopy and cytological examination of urine and additional laboratory and instrumental studies. However, cystoscopy is an invasive study, and voided urine cytology has a low level of sensitivity, so there is a clear need to develop more reliable markers and test systems for detecting the disease with high sensitivity and specificity. Human body fluids (urine, serum, and plasma) are known to contain significant amounts of tumorigenic nucleic acids, circulating immune cells and proinflammatory mediators that can serve as noninvasive biomarkers, particularly useful for early cancer detection, follow-up of patients, and personalization of their treatment. The review describes the most significant advances in epigenetics of BLCA.


Asunto(s)
Neoplasias de la Vejiga Urinaria , Adulto , Humanos , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Citodiagnóstico , Cistoscopía , Técnicas Citológicas , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/orina , Epigénesis Genética , Sensibilidad y Especificidad
10.
Int J Mol Sci ; 24(9)2023 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-37175926

RESUMEN

This review explores the application of in vitro cell transformation assays (CTAs) as a screening platform to assess the carcinogenic potential of nanomaterials (NMs) resulting from continuously growing industrial production and use. The widespread application of NMs in various fields has raised concerns about their potential adverse effects, necessitating safety evaluations, particularly in long-term continuous exposure scenarios. CTAs present a realistic screening platform for known and emerging NMs by examining their resemblance to the hallmark of malignancy, including high proliferation rates, loss of contact inhibition, the gain of anchorage-independent growth, cellular invasion, dysregulation of the cell cycle, apoptosis resistance, and ability to form tumors in experimental animals. Through the deliberate transformation of cells via chronic NM exposure, researchers can investigate the tumorigenic properties of NMs and the underlying mechanisms of cancer development. This article examines NM-induced cell transformation studies, focusing on identifying existing knowledge gaps. Specifically, it explores the physicochemical properties of NMs, experimental models, assays, dose and time requirements for cell transformation, and the underlying mechanisms of malignancy. Our review aims to advance understanding in this field and identify areas for further investigation.


Asunto(s)
Nanoestructuras , Neoplasias , Animales , Carcinógenos/toxicidad , Carcinogénesis/inducido químicamente , Transformación Celular Neoplásica/inducido químicamente , Nanoestructuras/toxicidad , Nanoestructuras/química
11.
Saudi Pharm J ; 30(8): 1065-1078, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36164575

RESUMEN

Mitochondria are double-membraned cytoplasmic organelles that are responsible for the production of energy in eukaryotic cells. The process is completed through oxidative phosphorylation (OXPHOS) by the respiratory chain (RC) in mitochondria. Thousands of mitochondria may be present in each cell, depending on the function of that cell. Primary mitochondria disorder (PMD) is a clinically heterogeneous disease associated with germline mutations in mitochondrial DNA (mtDNA) and/or nuclear DNA (nDNA) genes, and impairs mitochondrial structure and function. Mitochondrial dysfunction can be detected in early childhood and may be severe, progressive and often multi-systemic, involving a wide range of organs. Understanding epigenetic factors and pathways mutations can help pave the way for developing an effective cure. However, the lack of information about the disease (including age of onset, symptoms, clinical phenotype, morbidity and mortality), the limits of current preclinical models and the wide range of phenotypic presentations hamper the development of effective medicines. Although new therapeutic approaches have been introduced with encouraging preclinical and clinical outcomes, there is no definitive cure for PMD. This review highlights recent advances, particularly in children, in terms of etiology, pathophysiology, clinical diagnosis, molecular pathways and epigenetic alterations. Current therapeutic approaches, future advances and proposed new therapeutic plans will also be discussed.

12.
Andrologia ; 53(1): e13799, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33099803

RESUMEN

The molecular mechanisms of drug use on sexual health are largely unknown. We investigated, the relationship between heroin use disorder and epigenetic factors influencing histone acetylation in sperm cells. The volunteers included twenty-four 20- to 50-year-old men with a normal spermogram who did not consume any drugs and twenty-four age- to BMI-matched men who consume only the drug heroin for more than last four months. HDAC1 and HDAC11 mRNA expression levels in spermatozoa and miR-34c-5p and miR-125b-5p expression levels in seminal plasma were measured. The heroin-user group showed significantly increased white blood cell counts and decreased sperm motility and survival rates (8.61 ± 1.73, 21.50 ± 3.11, 69.90 ± 4.69 respectively) as compared to the control group (1.49 ± 0.32, 38.82 ± 3.05, 87.50 ± 0.99 respectively) (p ≤ .001). An increase in DNA fragmentation index (DFI) (heroin-user group: 41.93 ± 6.59% and control group: 10.14 ± 1.43%, p = .003), a change in frequency of HDAC1 (heroin-user group: 1.69 ± 0.55 and control group: 0.45 ± 0.14, p = .045) and HDAC11 (heroin-user group: 0.29 ± 0.13 and control group: 2.36 ± 0.76, p = .019) in spermatozoa and a significant decrease in seminal miR-125b-5p abundance (heroin-user group: 0.37 ± 0.11 and control group: 1.59 ± 0.47, p = .028) were reported in heroin consumers. Heroin use can lead to male infertility by causing leukocytospermia, asthenozoospermia, DFI elevation in sperm cells and alterations in seminal RNA profile.


Asunto(s)
Heroína , Infertilidad Masculina , Adulto , Fragmentación del ADN , Epigénesis Genética , Heroína/toxicidad , Histona Desacetilasas , Humanos , Infertilidad Masculina/genética , Masculino , Persona de Mediana Edad , Semen , Motilidad Espermática , Espermatozoides , Adulto Joven
13.
Int J Urol ; 28(2): 140-149, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33111429

RESUMEN

Prostate cancer is a major cause of cancer-related deaths among men worldwide. In addition to genomic alterations, epigenetic alterations accumulated in prostate cancer have been elucidated. While aberrant deoxyribonucleic acid hypermethylation in promoter CpG islands inactivates crucial genes associated with deoxyribonucleic acid repair, cell cycle, apoptosis or cell adhesion, aberrant deoxyribonucleic acid hypomethylation can lead to oncogene activation. Acetylation of histone is also deregulated in prostate cancer, which could cause aberrant super-enhancer formation and activation of genes associated with cancer development. Deregulations of histone methylation, such as an increase of trimethylation at position 27 of histone H3 by enhancer of zeste homolog2 overexpression, or other modifications, such as phosphorylation and ubiquitination, are also involved in prostate cancer development, and inhibitors targeting these epigenomic aberrations might be novel therapeutic strategies. In this review, we provide an overview of epigenetic alterations in the development and progression of prostate cancer, focusing on deoxyribonucleic acid methylation and histone modifications.


Asunto(s)
Epigénesis Genética , Neoplasias de la Próstata , Islas de CpG , Metilación de ADN , Histonas/genética , Histonas/metabolismo , Humanos , Masculino , Neoplasias de la Próstata/genética
14.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-34445557

RESUMEN

Renal cell carcinomas (RCC) account for 2-3% of the global cancer burden and are characterized by the highest mortality rate among all genitourinary cancers. However, excluding conventional imagining approaches, there are no reliable diagnostic and prognostic tools available for clinical use at present. Liquid biopsies, such as urine, serum, and plasma, contain a significant amount of tumor-derived nucleic acids, which may serve as non-invasive biomarkers that are particularly useful for early cancer detection, follow-up, and personalization of treatment. Changes in epigenetic phenomena, such as DNA methylation level, expression of microRNAs (miRNAs), and long noncoding RNAs (lncRNAs), are observed early during cancer development and are easily detectable in biofluids when morphological changes are still undetermined by conventional diagnostic tools. Here, we reviewed recent advances made in the development of liquid biopsy-derived DNA methylation-, miRNAs- and lncRNAs-based biomarkers for RCC, with an emphasis on the performance characteristics. In the last two decades, a mass of circulating epigenetic biomarkers of RCC were suggested, however, most of the studies done thus far analyzed biomarkers selected from the literature, used relatively miniature, local, and heterogeneous cohorts, and suffered from a lack of sufficient validations. In summary, for improved translation into the clinical setting, there is considerable demand for the validation of the existing pool of RCC biomarkers and the discovery of novel ones with better performance and clinical utility.


Asunto(s)
Biomarcadores de Tumor/genética , Carcinoma de Células Renales/diagnóstico , Epigénesis Genética , Neoplasias Renales/diagnóstico , Carcinoma de Células Renales/genética , Humanos , Neoplasias Renales/genética , Biopsia Líquida
15.
Medicina (Kaunas) ; 57(5)2021 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-34066975

RESUMEN

Background andObjective: Epigenetic modifications are believed to play a significant role in the development of cancer progression, growth, differentiation, and cell death. One of the most popular histone deacetylases inhibitors (HDACIs), suberoylanilide hydroxamic acid (SAHA), also known as Vorinostat, can directly activate p21WAF1/CIP1 gene transcription through hyperacetylation of histones by a p53 independent mechanism. In the present investigation, we evaluated the correlation between histone modifications and DNA methyltransferase enzyme levels following SAHA treatments in A2780 ovarian cancer cells. Materials and Methods: Acetylation of histones and methyltransferases levels were analyzed using RT2 profiler PCR array, immunoblotting, and immunofluorescence methods in 2D and 3D cell culture systems. Results: The inhibition of histone deacetylases (HDAC) activities by SAHA can reduce DNA methyl transferases / histone methyl transferases (DNMTs/HMTs) levels through induction of hyperacetylation of histones. Immunofluorescence analysis of cells growing in monolayers and spheroids revealed significant up-regulation of histone acetylation preceding the above-described changes. Conclusions: Our results depict an interesting interplay between histone hyperacetylation and a decrease in methyltransferase levels in ovarian cancer cells, which may have a positive impact on the overall outcomes of cancer treatment.


Asunto(s)
Inhibidores de Histona Desacetilasas , Neoplasias Ováricas , Acetilación , Línea Celular Tumoral , Femenino , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Histonas/metabolismo , Humanos , Metiltransferasas , Neoplasias Ováricas/tratamiento farmacológico
16.
Saudi Pharm J ; 29(12): 1361-1373, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35002373

RESUMEN

Chronic obstructive pulmonary disease (COPD) is a progressive lung dysfunction caused mainly by inhaling toxic particles and cigarette smoking (CS). The continuous exposure to ruinous molecules can lead to abnormal inflammatory responses, permanent damages to the respiratory system, and irreversible pathological changes. Other factors, such as genetics and aging, influence the development of COPD. In the last decade, accumulating evidence suggested that mitochondrial alteration, including mitochondrial DNA damage, increased mitochondrial reactive oxygen species (ROS), abnormal autophagy, and apoptosis, have been implicated in the pathogenesis of COPD. The alteration can also extend to epigenetics, namely DNA methylation, histone modification, and non-coding RNA. This review will discuss the recent progressions in COPD pathology, pathophysiology, and molecular pathways. More focus will be shed on mitochondrial and epigenetic variations related to COPD development and the role of nanomedicine as a potential tool for the prevention and treatment of this disease.

17.
Biochim Biophys Acta Rev Cancer ; 1868(2): 439-448, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28939182

RESUMEN

Colorectal cancer (CRC) is a heterogeneous disease with distinct molecular and clinical features, which reflects the wide range of prognostic outcomes and treatment responses observed among CRC patients worldwide. Our understanding of the CRC epigenome has been largely developed over the last decade and it is now believed that among thousands of epigenetic alterations present in each tumor, a small subgroup of these may be considered as a CRC driver event. DNA methylation profiles have been the most widely studied in CRC, which includes a subset of patients with distinct molecular and clinical features now categorized as CpG island methylator phenotype (CIMP). Major advances have been made in our capacity to detect epigenetic alterations, providing us with new potential biomarkers for diagnostic, prognostic and therapeutic purposes. This review aims to summarize our current knowledge about epigenetic alterations occurring in CRC, underlying their potential future clinical implications in terms of diagnosis, prognosis and therapeutic strategies for CRC patients.


Asunto(s)
Neoplasias Colorrectales/genética , Metilación de ADN , Inestabilidad Cromosómica , Neoplasias Colorrectales/terapia , Islas de CpG , Humanos , MicroARNs/fisiología , Inestabilidad de Microsatélites , Fenotipo
18.
Int J Mol Sci ; 21(24)2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33353068

RESUMEN

Breast cancer is one of the most frequently diagnosed malignancies and common causes of cancer death in women. Recent studies suggest that environmental exposures to certain chemicals, such as 7,12-Dimethylbenzanthracene (DMBA), a chemical present in tobacco, may increase the risk of developing breast cancer later in life. The first-line treatments for breast cancer (surgery, chemotherapy or a combination of both) are generally invasive and frequently associated with severe side effects and high comorbidity. Consequently, novel approaches are strongly required to find more natural-like experimental models that better reflect the tumors' etiology, physiopathology and response to treatments, as well as to find more targeted, efficient and minimally invasive treatments. This study proposes the development and an in deep biological characterization of an experimental model using DMBA-tumor-induction in Sprague-Dawley female rats. Moreover, a photothermal therapy approach using a near-infrared laser coupled with gold nanoparticles was preliminarily assessed. The gold nanoparticles were functionalized with Epidermal Growth Factor, and their physicochemical properties and in vitro effects were characterized. DMBA proved to be a very good and selective inductor of breast cancer, with 100% incidence and inducing an average of 4.7 tumors per animal. Epigenetic analysis showed that tumors classified with worst prognosis were hypomethylated. The tumor-induced rats were then subjected to a preliminary treatment using functionalized gold nanoparticles and its activation by laser (650-900 nm). The treatment outcomes presented very promising alterations in terms of tumor histology, confirming the presence of necrosis in most of the cases. Although this study revealed encouraging results as a breast cancer therapy, it is important to define tumor eligibility and specific efficiency criteria to further assess its application in breast cancer treatment on other species.


Asunto(s)
5-Metilcitosina/metabolismo , 9,10-Dimetil-1,2-benzantraceno/toxicidad , Hipertermia Inducida , Neoplasias Mamarias Experimentales/terapia , Nanopartículas del Metal/administración & dosificación , Modelos Teóricos , Animales , Peso Corporal , Femenino , Oro/química , Neoplasias Mamarias Experimentales/inducido químicamente , Neoplasias Mamarias Experimentales/patología , Nanopartículas del Metal/química , Ratas , Ratas Sprague-Dawley
19.
Int J Mol Sci ; 21(9)2020 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-32370233

RESUMEN

Cancer is one of the main causes of death worldwide. Despite the significant development of methods of cancer healing during the past decades, chemotherapy still remains the main method for cancer treatment. Depending on the mechanism of action, commonly used chemotherapeutic agents can be divided into several classes (antimetabolites, alkylating agents, mitotic spindle inhibitors, topoisomerase inhibitors, and others). Multidrug resistance (MDR) is responsible for over 90% of deaths in cancer patients receiving traditional chemotherapeutics or novel targeted drugs. The mechanisms of MDR include elevated metabolism of xenobiotics, enhanced efflux of drugs, growth factors, increased DNA repair capacity, and genetic factors (gene mutations, amplifications, and epigenetic alterations). Rapidly increasing numbers of biomedical studies are focused on designing chemotherapeutics that are able to evade or reverse MDR. The aim of this review is not only to demonstrate the latest data on the mechanisms of cellular resistance to anticancer agents currently used in clinical treatment but also to present the mechanisms of action of novel potential antitumor drugs which have been designed to overcome these resistance mechanisms. Better understanding of the mechanisms of MDR and targets of novel chemotherapy agents should provide guidance for future research concerning new effective strategies in cancer treatment.


Asunto(s)
Antineoplásicos/uso terapéutico , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Animales , Antineoplásicos/clasificación , Antineoplásicos/farmacología , Resistencia a Múltiples Medicamentos/genética , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Neoplasias/genética , Neoplasias/patología , Farmacogenética/métodos
20.
J Biomed Sci ; 26(1): 28, 2019 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-31014351

RESUMEN

Cervical cancer is the fourth most frequent cancer in women worldwide and a major cause of mortality in developing countries. Persistent infection with high-risk human papillomavirus (HPV) is a necessary cause for the development of cervical cancer. In addition, genetic and epigenetic alterations in host cell genes are crucial for progression of cervical precancerous lesions to invasive cancer. Although much progress has been made in understanding the life cycle of HPV and it's role in the development of cervical cancer, there is still a critical need for accurate surveillance strategies and targeted therapeutic options to eradicate these cancers in patients. Given the widespread nature of HPV infection and the type specificity of currently available HPV vaccines, it is crucial that molecular details of the natural history of HPV infection as well as the biological activities of viral oncoproteins be elucidated. A better understanding of the mechanisms involved in oncogenesis can provide novel insights and opportunities for designing effective therapeutic approaches against HPV-associated malignancies. In this review, we briefly summarize epigenetic alterations and events that cause alterations in host genomes inducing cell cycle deregulation, aberrant proliferation and genomic instability contributing to tumorigenesis.


Asunto(s)
Carcinogénesis , Papillomaviridae/fisiología , Infecciones por Papillomavirus , Carcinogénesis/genética , Ciclo Celular , Proliferación Celular , Epigénesis Genética , Femenino , Inestabilidad Genómica/genética , Humanos , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/fisiopatología , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/fisiopatología
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