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Colorectal cancer (CRC) is the third most common and deadliest cancer globally. Regimens using 5-fluorouracil (5FU) and Oxaliplatin (OXA) are the first-line treatment for CRC, but tumor recurrence is frequent. It is plausible to hypothesize that differential cellular responses are triggered after treatments depending on the genetic background of CRC cells and that the rational modulation of cell tolerance mechanisms like autophagy may reduce the regrowth of CRC cells. This study proposes investigating the cellular mechanisms triggered by CRC cells exposed to 5FU and OXA using a preclinical experimental design mimicking one cycle of the clinical regimen (i.e., 48 h of treatment repeated every 2 weeks). To test this, we treated CRC human cell lines HCT116 and HT29 with the 5FU and OXA, combined or not, for 48 h, followed by analysis for two additional weeks. Compared to single-drug treatments, the co-treatment reduced tumor cell regrowth, clonogenicity and stemness, phenotypes associated with tumor aggressiveness and poor prognosis in clinics. This effect was exerted by the induction of apoptosis and senescence only in the co-treatment. However, a week after treatment, cells that tolerated the treatment had high levels of autophagy features and restored the proliferative phenotype, resembling tumor recurrence. The pharmacologic suppression of early autophagy during its peak of occurrence, but not concomitant with chemotherapeutics, strongly reduced cell regrowth. Overall, our experimental model provides new insights into the cellular mechanisms that underlie the response and tolerance of CRC cells to 5FU and OXA, suggesting optimized, time-specific autophagy inhibition as a new avenue for improving the efficacy of current treatments.
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Neoplasias Colorrectales , Humanos , Oxaliplatino/farmacología , Oxaliplatino/uso terapéutico , Neoplasias Colorrectales/genética , Recurrencia Local de Neoplasia , Células HT29 , Fluorouracilo/farmacología , Fluorouracilo/uso terapéutico , Apoptosis , Autofagia , Línea Celular Tumoral , Resistencia a Antineoplásicos/genéticaRESUMEN
Cellular senescence (CS) is the state when cells are no longer capable to divide even after stimulation with grown factors. Cells that begin to undergo CS stop in the cell cycle and enter a suspended state without committing to programmed cell death. These cells assume a specific phenotype and influence their microenvironment by secreting molecules and extracellular vesicles that are part of the so-called senescent cell-associated secretory phenotype (SASP). Cellular senescence is intertwined with physiological and pathological conditions in the human organism. In terms of reproduction, senescent cells are present from reproductive tissues and germ cells to gestational tissues, and participate from fertilization to delivery, going through adverse reproductive outcomes such as pregnancy losses. Furthermore, various SASP molecules are enriched in gestational tissues throughout pregnancy. Thus, the aim of this review is to provide a basis about the features and potential roles played by CS throughout the reproductive process, encompassing its implication in each step of it and proposing a way to manage it in adverse reproductive contexts.
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Senescencia Celular , Vesículas Extracelulares , Humanos , Senescencia Celular/fisiología , Fenotipo , Vesículas Extracelulares/metabolismo , Transporte Biológico , ReproducciónRESUMEN
Morphometry of striated muscle fibres is critical for monitoring muscle health and function. Here, we evaluated functional parameters of skeletal and cardiac striated muscle in two experimental models using the Morphometric Analysis of Muscle Fibre tool (MusMA). The collagen-induced arthritis model was used to evaluate the function of skeletal striated muscle and the non-alcoholic fatty liver disease model was used for cardiac striated muscle analysis. After euthanasia, we used haeamatoxylin and eosin stained sections of skeletal and cardiac muscle to perform muscle fibre segmentation and morphometric analysis. Morphometric analysis classified muscle fibres into six subpopulations: normal, regular hypertrophic, irregular hypertrophic, irregular, irregular atrophic and regular atrophic. The percentage of atrophic fibres was associated with lower walking speed (p = 0.009) and lower body weight (p = 0.026), respectively. Fibres categorized as normal were associated with maximum grip strength (p < 0.001) and higher march speed (p < 0.001). In the evaluation of cardiac striated muscle fibres, the percentage of normal cardiomyocytes negatively correlated with cardiovascular risk markers such as the presence of abdominal adipose tissue (p = .003), miR-33a expression (p = .001) and the expression of miR-126 (p = .042) Furthermore, the percentage of atrophic cardiomyocytes correlated significantly with the Castelli risk index II (p = .014). MusMA is a simple and objective tool that allows the screening of striated muscle fibre morphometry, which can complement the diagnosis of muscle diseases while providing functional and prognostic information in basic and clinical research.
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Fibras Musculares Esqueléticas , Animales , Masculino , Pronóstico , Fibras Musculares Esqueléticas/patología , Enfermedades Cardiovasculares/patología , Enfermedades Cardiovasculares/fisiopatología , Miocitos Cardíacos/patología , Factores de Riesgo de Enfermedad CardiacaRESUMEN
Metabolic adaptations are central for carcinogenesis and response to therapy, but little is known about the contribution of mitochondrial dynamics to the response of glioma cells to the standard treatment with temozolomide (TMZ). Glioma cells responded to TMZ with mitochondrial mass increased and the production of round structures of dysfunctional mitochondria. At single-cell level, asymmetric mitosis contributed to the heterogeneity of mitochondrial levels. It affected the fitness of cells in control and treated condition, indicating that the mitochondrial levels are relevant for glioma cell fitness in the presence of TMZ.
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Neoplasias Encefálicas , Glioma , Humanos , Temozolomida/farmacología , Temozolomida/uso terapéutico , Dacarbazina/farmacología , Dacarbazina/metabolismo , Dacarbazina/uso terapéutico , Apoptosis , Línea Celular Tumoral , Glioma/tratamiento farmacológico , Glioma/metabolismo , Mitocondrias/metabolismo , Antineoplásicos Alquilantes/farmacología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/metabolismo , Resistencia a AntineoplásicosRESUMEN
Senescence is a cellular state in which the cell loses its proliferative capacity, often irreversibly. Physiologically, it occurs due to a limited capacity of cell division associated with telomere shortening, the so-called replicative senescence. It can also be induced early due to DNA damage, oncogenic activation, oxidative stress, or damage to other cellular components (collectively named induced senescence). Tumor cells acquire the ability to bypass replicative senescence, thus ensuring the replicative immortality, a hallmark of cancer. Many anti-cancer therapies, however, can lead tumor cells to induced senescence. Initially, this response leads to a slowdown in tumor growth. However, the longstanding accumulation of senescent cells (SnCs) in tumors can promote neoplastic progression due to the enrichment of numerous molecules and extracellular vesicles that constitutes the senescence-associated secretory phenotype (SASP). Among other effects, SASP can potentiate or unlock the tumor plasticity and phenotypic transitions, another hallmark of cancer. This review discusses how SnCs can fuel mechanisms that underlie cancer plasticity, like cell differentiation, stemness, reprogramming, and epithelial-mesenchymal transition. We also discuss the main molecular mechanisms that make SnCs resistant to cell death, and potential strategies to target SnCs. At the end, we raise open questions and clinically relevant perspectives in the field.
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Tracking individual cells has allowed a new understanding of cellular behavior in human health and disease by adding a dynamic component to the already complex heterogeneity of single cells. Technically, despite countless advances, numerous experimental variables can affect data collection and interpretation and need to be considered. In this review, we discuss the main technical aspects and biological findings in the analysis of the behavior of individual cells. We discuss the most relevant contributions provided by these approaches in clinically relevant human conditions like embryo development, stem cells biology, inflammation, cancer and microbiology, along with the cellular mechanisms and molecular pathways underlying these conditions. We also discuss the key technical aspects to be considered when planning and performing experiments involving the analysis of individual cells over long periods. Despite the challenges in automatic detection, features extraction and long-term tracking that need to be tackled, the potential impact of single-cell bioimaging is enormous in understanding the pathogenesis and development of new therapies in human pathophysiology.
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Células Madre , Diferenciación Celular , HumanosRESUMEN
As alterations in purinergic signaling have been observed in bladder diseases, we aimed to assess the potential prognostic role of purinergic receptors in bladder cancer in a translational approach based on clinical databases and in vitro data. The prognostic role of purinergic receptors in the survival of patients with bladder cancer and the expression profile of the altered P2 receptors in normal and in tumor samples were determined using The Cancer Genome Atlas databank. In T24 and RT4 human bladder cancer cell lines, the P2 purinergic receptors were characterized by RT-PCR and RT-qPCR analysis including radiotherapy exposure as treatment. The cell number and the cumulative population doubling were also assessed. The expression profile of P2X6 receptor in the cancer pathological stage and in the nodal metastasis status was in agreement with Kaplan-Meier analysis, indicating that high expression of this receptor was related to an increased survival rate in patients with bladder cancer. Of all the P2 receptors expressed on T24 cell line, P2X6 presented high expression after radiotherapy, while it was not altered in RT4 cells. In addition, irradiation promoted a decrease of T24 cell number, but did not change the cell number of RT4 after the same time and radiation dose. Along 7 days after irradiation exposure, both cells regrew. However, while P2X6 receptor was downregulated in T24 cells, it was upregulated in RT4 cells. Our findings indicated that high P2X6 receptor expression induced by radiation in T24 cell line may predict a good survival prognostic factor.
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Neoplasias de la Vejiga Urinaria , Línea Celular Tumoral , Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Transducción de Señal , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
Glioblastoma (GBM) is the most aggressive and lethal among the primary brain tumors, with a low survival rate and resistance to radio and chemotherapy. The P2Y12 is an adenosine diphosphate (ADP) purinergic chemoreceptor, found mainly in platelets. In cancer cells, its activation has been described to induce proliferation and metastasis. Bearing in mind the need to find new treatments for GBM, this study aimed to investigate the role of the P2Y12R in the proliferation and migration of GBM cells, as well as to evaluate the expression of this receptor in patients' data obtained from the TCGA data bank. Here, we used the P2Y12R antagonist, ticagrelor, which belongs to the antiplatelet agent's class. The different GBM cells (cell line and patient-derived cells) were treated with ticagrelor, with the agonist, ADP, or both, and the effects on cell proliferation, colony formation, ADP hydrolysis, cell cycle and death, migration, and cell adhesion were analyzed. The results showed that ticagrelor decreased the viability and the proliferation of GBM cells. P2Y12R antagonism also reduced colony formation and migration potentials, with alterations on the expression of metalloproteinases, and induced autophagy in GBM cells. Changes were observed at the cell cycle level, and only the U251 cell line showed a significant reduction in the ADP hydrolysis profile. TCGA data analysis showed a higher expression of P2Y12R in gliomas samples when compared to the other tumors. These data demonstrate the importance of the P2Y12 receptor in gliomas development and reinforce its potential as a pharmacological target for glioma treatment.
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Glioblastoma , Humanos , Ticagrelor/metabolismo , Ticagrelor/farmacología , Adenosina Difosfato/metabolismo , Glioblastoma/tratamiento farmacológico , Plaquetas , Autofagia , Proliferación Celular , Receptores Purinérgicos P2Y12/metabolismo , Antagonistas del Receptor Purinérgico P2Y/metabolismoRESUMEN
Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of hamartoma development, an effect that seems to be associated with the paradoxical role of autophagy in tumor establishment. Under normal conditions, autophagy is directly inhibited by mTORC1. In situations of bioenergetics stress, mTORC1 releases the Ulk1 complex and initiates the autophagy process. In this way, autophagy promotes the survival of established tumors by supplying metabolic precursors during nutrient deprivation; paradoxically, excessive autophagy has been associated with cell death in some situations. In spite of its paradoxical role, autophagy is an alternative therapeutic strategy that could be explored in TSC. This review compiles the findings related to autophagy and the new therapeutic strategies targeting this pathway in TSC.
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Tuberous sclerosis complex (TSC) is an autosomal dominant cancer predisposition disorder caused by heterozygous mutations in TSC1 or TSC2 genes and characterized by mTORC1 hyperactivation. TSC-associated tumors develop after loss of heterozygosity mutations and their treatment involves the use of mTORC1 inhibitors. We aimed to evaluate cellular processes regulated by mTORC1 in TSC cells with different mutations before tumor development. Flow cytometry analyses were performed to evaluate cell viability, cell cycle and autophagy in non-tumor primary TSC cells with different heterozygous mutations and in control cells without TSC mutations, before and after treatment with rapamycin (mTORC1 inhibitor). We did not observe differences in cell viability and cell cycle between the cell groups. However, autophagy was reduced in mutated cells. After rapamycin treatment, mutated cells showed a significant increase in the autophagy process (p=0.039). We did not observe differences between cells with distinct TSC mutations. Our main finding is the alteration of autophagy in non-tumor TSC cells. Previous studies in literature found autophagy alterations in tumor TSC cells or knock-out animal models. We showed that autophagy could be an important mechanism that leads to TSC tumor formation in the haploinsufficiency state. This result could guide future studies in this field.
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BACKGROUND: Chemotherapeutics can stimulate immune antitumor response by inducing immunogenic cell death (ICD), which is activated by Damage-Associated Molecular Patterns (DAMPs) like the exposure of calreticulin (CRT) on the cell surface, the release of ATP and the secretion of High Mobility Group Box 1 (HMGB1). METHODS: Here, we investigated the levels of ICD-associated DAMPs induced by chemotherapeutics commonly used in the clinical practice of non-small cell lung cancer (NSCLC) and the association of these DAMPs with apoptosis and autophagy. A549 human lung adenocarcinoma cells were treated with clinically relevant doses of cisplatin, carboplatin, etoposide, paclitaxel and gemcitabine. We assessed ICD-associated DAMPs, cell viability, apoptosis and autophagy in an integrated way. RESULTS: Cisplatin and its combination with etoposide induced the highest levels of apoptosis, while etoposide was the less pro-apoptotic treatment. Cisplatin also induced the highest levels of ICD-associated DAMPs, which was not incremented by co-treatments. Etoposide induced the lower levels of ICD and the highest levels of autophagy, suggesting that the cytoprotective role of autophagy is dominant in relation to its pro-ICD role. High levels of CRT were associated with better prognosis in TCGA databank. In an integrative analysis we found a strong positive correlation between DAMPs and apoptosis, and a negative correlation between cell number and ICD-associated DAMPs as well as between autophagy and apoptosis markers. We also purpose a mathematical integration of ICD-associated DAMPs in an index (IndImunnog) that may represent with greater biological relevance this process. Cisplatin-treated cells showed the highest IndImmunog, while etoposide was the less immunogenic and the more pro-autophagic treatment. CONCLUSIONS: Cisplatin alone induced the highest levels of ICD-associated DAMPs, so that its combination with immunotherapy may be a promising therapeutic strategy in NSCLC.
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Adenocarcinoma del Pulmón/metabolismo , Alarminas/metabolismo , Antineoplásicos/farmacología , Muerte Celular Inmunogénica , Neoplasias Pulmonares/metabolismo , Células A549 , Adenocarcinoma del Pulmón/tratamiento farmacológico , Adenocarcinoma del Pulmón/mortalidad , Adenocarcinoma del Pulmón/patología , Adenosina Trifosfato/metabolismo , Alarminas/efectos de los fármacos , Apoptosis , Autofagia , Calreticulina/metabolismo , Carboplatino/farmacología , Caspasa 3/metabolismo , Supervivencia Celular , Cisplatino/farmacología , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Etopósido/farmacología , Proteína HMGB1/metabolismo , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Paclitaxel/farmacología , Pronóstico , GemcitabinaRESUMEN
Acridine Orange is a cell-permeable green fluorophore that can be protonated and trapped in acidic vesicular organelles (AVOs). Its metachromatic shift to red fluorescence is concentration-dependent and, therefore, Acridine Orange fluoresces red in AVOs, such as autolysosomes. This makes Acridine Orange staining a quick, accessible and reliable method to assess the volume of AVOs, which increases upon autophagy induction. Here, we describe a ratiometric analysis of autophagy using Acridine Orange, considering the red-to-green fluorescence intensity ratio (R/GFIR) to quantify flow cytometry and fluorescence microscopy data of Acridine-Orange-stained cells. This method measured with accuracy the increase in autophagy induced by starvation or rapamycin, and the reduction in autophagy produced by bafilomycin A1 or the knockdown of Beclin1 or ATG7. Results obtained with Acridine Orange, considering R/GFIR, correlated with the conversion of the unlipidated form of LC3 (LC3-I) into the lipidated form (LC3-II), SQSTM1 degradation and GFP-LC3 puncta formation, thus validating this assay to be used as an initial and quantitative method for evaluating the late step of autophagy in individual cells, complementing other methods.
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Ácidos/metabolismo , Naranja de Acridina/metabolismo , Autofagia , Técnicas Citológicas/métodos , Orgánulos/metabolismo , Animales , Tamaño de la Célula , Citometría de Flujo , Fluorescencia , Células HEK293 , Humanos , Microscopía Confocal , Ratas Wistar , Espectrometría de FluorescenciaRESUMEN
Mesenchymal stem cells (MSC) are considered multipotent stromal, non-hematopoietic cells with properties of self-renovation and differentiation. Optimal conditions for culture of MSC have been under investigation. The oxygen tension used for cultivation has been studied and appears to play an important role in biological behavior of mesenchymal cells. The aim is characterize MSC in hypoxia and normoxia conditions comparing their morphological and functional characteristics. Bone marrow-derived mesenchymal stem cells obtained from 15 healthy donors and cultured. MSC obtained from each donor were separated into two cultivation conditions normoxia (21% O2 ) and hypoxia (three donors at 1%, three donors at 2%, five donors at 3%, and four donors at 4% O2 ) up to second passage. MSC were evaluated for proliferation, differentiation, immunophenotyping, size and cell complexity, oxidative stress, mitochondrial activity, and autophagy. Culture conditions applied did not seem to affect immunophenotypic features and cellular plasticity. However, cells subjected to hypoxia showed smaller size and greater cellular complexity, besides lower proliferation (P < 0.002). Furthermore, cells cultured in low O2 tension had lower mitochondrial activity (P < 0.03) and a reduced tendency to autophagy, although oxidative stress did not vary among groups (P < 0.39). Oxygen tension seems to be a key regulator of cellular adaptation in vitro, and metabolic effects underlying this variable remain undescribed. Heterogeneity or even lack of results on the impact of oxygen concentration used for expanding MSC highlights the need for further research, in order to optimize conditions of cultivation and expansion and achieve greater safety and therapeutic efficacy. J. Cell. Biochem. 118: 3072-3079, 2017. © 2017 Wiley Periodicals, Inc.
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Células de la Médula Ósea/metabolismo , Células Madre Mesenquimatosas/metabolismo , Mitocondrias/metabolismo , Consumo de Oxígeno , Células de la Médula Ósea/citología , Técnicas de Cultivo de Célula , Hipoxia de la Célula , Femenino , Humanos , Masculino , Células Madre Mesenquimatosas/citología , Factores de TiempoRESUMEN
Chemotherapy acts on cancer cells by producing multiple effects on a cell population including cell cycle arrest, necrosis, apoptosis and senescence. However, often a subpopulation of cells survives and the behavior of this subpopulation, which is responsible for cancer recurrence, remains obscure. Here we investigated the in vitro short- and long-term responses of six glioblastoma cell lines to clinically relevant doses of temozolomide for 5 days followed by 23 days of recovery, mimicking the standard schedule used in glioblastoma patient for this drug. These cells presented different profiles of sensitivity to temozolomide with varying levels of cell cycle arrest, autophagy and senescence, followed by a regrowth of the surviving cells. The initial reduction in cell number and the subsequent regrowth was analyzed with four new parameters applied to Cumulative Population Doubling (CPD) curves that describe the overall sensitivity of the population and the characteristic of the regrowth: the relative end point CPD (RendCPD); the relative Area Under Curve (rAUC); the Relative Time to Cross a Threshold (RTCT); and the Relative Proliferation Rate (RPR). Surprisingly, the kinetics of regrowth were not predicted by the mechanisms activated after treatment nor by the acute or overall sensitivity. With this study we added new parameters that describe key responses of glioblastoma cell populations to temozolomide treatment. These parameters can also be applied to other cell types and treatments and will help to understand the behavior of the surviving cancer cells after treatment and shed light on studies of cancer resistance and recurrence.
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Dacarbazina/análogos & derivados , Glioblastoma/patología , Animales , Recuento de Células , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Dacarbazina/farmacología , Humanos , Cinética , Ratones , TemozolomidaRESUMEN
Autophagy is a catabolic process that is largely regulated by extracellular and intracellular signaling pathways that are central to cellular metabolism and growth. Mounting evidence has shown that ion channels and transporters are important for basal autophagy functioning and influence autophagy to handle stressful situations. Besides its role in cell proliferation and apoptosis, intracellular Ca(2+) is widely recognized as a key regulator of autophagy, acting through the modulation of pathways such as the mechanistic target of rapamycin complex 1, calcium/calmodulin-dependent protein kinase kinase 2, and protein kinase C. Proper spatiotemporal Ca(2+) availability, coupled with a controlled ionic flow among the extracellular milieu, storage compartments, and the cytosol, is critical in determining the role played by Ca(2+) on autophagy and on cell fate. The crosstalk between Ca(2+) and autophagy has a central role in cellular homeostasis and survival during several physiologic and pathologic conditions. Here we review the main findings concerning the mechanisms and roles of Ca(2+)-modulated autophagy, focusing on human disorders ranging from cancer to neurologic diseases and immunity. By identifying mechanisms, players, and pathways that either induce or suppress autophagy, new promising approaches for preventing and treating human disorders emerge, including those based on the modulation of Ca(2+)-mediated autophagy.
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Autofagia , Señalización del Calcio , Enfermedad , Calcio/metabolismo , Sistema Nervioso Central/metabolismo , Humanos , Modelos BiológicosRESUMEN
Cellular senescence is an irreversible block of cellular division, and induction of senescence is being considered for treatment of many cancer types, mainly those resistant to classical pro-apoptotic therapies. Resveratrol (Rsv) and quercetin (Quer), two natural polyphenols, are able to induce senescence in different cancer models, including gliomas, the most common and aggressive primary brain tumor. These polyphenols modulate the activity of several proteins involved in cell growth and death in cancer cells, including histone deacetylases (HDAC), but the role of HDAC in senescence induced by Rsv and Quer is unclear. The HDAC inhibitor sodium butyrate (NaB) potentiated the pro-senescent effect of Rsv and Quer in human and rat glioma cell lines but not in normal rat astrocytes. Furthermore, the increment of Quer-induced senescence by NaB was accompanied by an increase of reactive oxygen species levels and an increment of the number of cells with nuclear abnormalities. Altogether, these data support a positive role of HDAC inhibition on the senescence induced by these polyphenols, and therefore co-treatment of HDAC inhibitors and polyphenols emerges as a potential alternative for gliomas.
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Antineoplásicos/farmacología , Ácido Butírico/farmacología , Senescencia Celular/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Quercetina/farmacología , Estilbenos/farmacología , Animales , Línea Celular Tumoral , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Glioma , Humanos , Ratas , Especies Reactivas de Oxígeno , ResveratrolRESUMEN
Several researchers have recently used C6 cells to evaluate functional properties of high-affinity glutamate transporters. However, it has been demonstrated that this lineage suffers several morphological and biochemical alterations according to the number of passages in culture. Currently, there are no reports showing whether functional properties of high-affinity glutamate transporters comply with these sub culturing-dependent modifications. The present study aimed to compare the functional properties of high-affinity glutamate transporters expressed in early (EPC6) and late (LPC6) passage C6 cells through a detailed pharmacological and biochemical characterization. Between 60-180 min of L-[(3)H]glu incubation, LPC6 presented an intracellular [(3)H] 55% lower than EPC6. Both cultures showed a time-dependent increase of intracellular [(3)H] reaching maximal levels at 120 min. Cultures incubated with D-[(3)H]asp showed a time-dependent increase of [(3)H] until 180 min. Moreover, LPC6 have a D-[(3)H]asp-derived intracellular [(3)H] 30-45% lower than EPC6 until 120 min. Only EAAT3 was immunodetected in cultures and its total content was equal between them. PMA-stimulated EAAT3 trafficking to membrane increased 50% of L-[(3)H]glu-derived intracellular [(3)H] in EPC6 and had no effect in LPC6. LPC6 displayed characteristics that resemble senescence, such as high ß-Gal staining, cell enlargement and increase of large and regular nuclei. Our results demonstrated that LPC6 exhibited glutamate uptake impairment, which may have occurred due to its inability to mobilize EAAT3 to cell membrane. This profile might be related to senescent process observed in this culture. Our results suggest that LPC6 cells are an inappropriate glial cellular model to investigate the functional properties of high-affinity glutamate transporters.
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Ácido Aspártico/metabolismo , Senescencia Celular/fisiología , Ácido Glutámico/metabolismo , Animales , Glioma/metabolismo , Ratas Wistar , Tritio , Células Tumorales CultivadasRESUMEN
Cellular senescence is a state of permanent growth arrest. It can be triggered by telomere shortening (replicative senescence) or prematurely induced by stresses such as DNA damage, oncogene overactivation, loss of tumor suppressor genes, oxidative stress, tissue factors, and others. Advances in techniques and experimental designs have provided new evidence about the biology of senescent cells (SnCs) and their importance in human health and disease. This review aims to describe the main aspects of SnCs phenotype focusing on alterations in subcellular compartments like plasma membrane, cytoskeleton, organelles, and nuclei. We also discuss the heterogeneity, dynamics, and plasticity of SnCs' phenotype, including the SASP, and pro-survival mechanisms. We advance on the multiple layers of phenotypic heterogeneity of SnCs, such as the heterogeneity between inducers, tissues and within a population of SnCs, discussing the relevance of these aspects to human health and disease. We also raise the main challenges as well alternatives to overcome them. Ultimately, we present open questions and perspectives in understanding the phenotype of SnCs from the perspective of basic and applied questions.
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Senescencia Celular , Acortamiento del Telómero , Humanos , Senescencia Celular/genética , Fenotipo , Células Cultivadas , Estrés OxidativoRESUMEN
Less than 15% of patients with esophageal squamous cell carcinoma (ESCC) survive 5 years after diagnosis. A better understanding of the biology of these tumors and the development of clinical biomarkers is needed. Autophagy is a physiological mechanism involved in the turnover of cellular components that plays a key role in cancer. This study evaluated the differential levels of three key regulators of autophagy (SQSTM1, MAP1LC3B, and BECN1) in patients with ESCC, associating autophagy with histopathologic features, including the grade of differentiation, mitotic rate, inflammation score, and the intensity of tumor-infiltrating lymphocytes. Nuclear morphometry of the tumor parenchyma was also assessed, associating it with autophagy and histopathology. All three markers significantly increased in patients with ESCC compared to the control group. Based on the mean expression of each protein in the control group, 57% of patients with ESCC had high levels of all three markers compared to control patients (14%). The most frequent profiles found in ESCC were BECNhigh/MAP1LC3high and BECNhigh/SQSTM1high. According to the TCGA database, we found that the main autophagy genes were upregulated in ESCC. Moreover, high levels of autophagy markers were associated with a poor prognosis. Considering nuclear morphometry, ESCC samples showed a significant reduction in nuclear area, which was strongly negatively correlated with autophagy. Finally, the percentage of normal nuclei was associated with tumor differentiation, while poorly differentiated tumors showed lower SQSTM1 levels. ESCC progression may involve increased autophagy and changes in nuclear structure, associated with clinically relevant histopathological features. KEY MESSAGES: Autophagy markers are co-increased in primary ESCC. Autophagy negatively correlates with nuclear morphometry in ESCC parenchyma. Autophagy and nuclear morphometry are associated with histopathological features. Autophagy is increased in ESCC-TCGA database and associated with poor prognosis.
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Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Humanos , Carcinoma de Células Escamosas de Esófago/patología , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas/patología , Proteína Sequestosoma-1/genética , Proteína Sequestosoma-1/metabolismo , Biomarcadores de Tumor/genética , AutofagiaRESUMEN
BACKGROUND: Prevalence of hepatocellular carcinoma (HCC) is increasing, especially in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). AIM: To investigate rifaximin (RIF) effects on epigenetic/autophagy markers in animals. METHODS: Adult Sprague-Dawley rats were randomly assigned (n = 8, each) and treated from 5-16 wk: Control [standard diet, water plus gavage with vehicle (Veh)], HCC [high-fat choline deficient diet (HFCD), diethylnitrosamine (DEN) in drinking water and Veh gavage], and RIF [HFCD, DEN and RIF (50 mg/kg/d) gavage]. Gene expression of epigenetic/autophagy markers and circulating miRNAs were obtained. RESULTS: All HCC and RIF animals developed metabolic-dysfunction associated steatohepatitis fibrosis, and cirrhosis, but three RIF-group did not develop HCC. Comparing animals who developed HCC with those who did not, miR-122, miR-34a, tubulin alpha-1c (Tuba-1c), metalloproteinases-2 (Mmp2), and metalloproteinases-9 (Mmp9) were significantly higher in the HCC-group. The opposite occurred with Becn1, coactivator associated arginine methyltransferase-1 (Carm1), enhancer of zeste homolog-2 (Ezh2), autophagy-related factor LC3A/B (Map1 Lc3b), and p62/sequestosome-1 (p62/SQSTM1)-protein. Comparing with controls, Map1 Lc3b, Becn1 and Ezh2 were lower in HCC and RIF-groups (P < 0.05). Carm1 was lower in HCC compared to RIF (P < 0.05). Hepatic expression of Mmp9 was higher in HCC in relation to the control; the opposite was observed for p62/Sqstm1 (P < 0.05). Expression of p62/SQSTM1 protein was lower in the RIF-group compared to the control (P = 0.024). There was no difference among groups for Tuba-1c, Aldolase-B, alpha-fetoprotein, and Mmp2 (P > 0.05). miR-122 was higher in HCC, and miR-34a in RIF compared to controls (P < 0.05). miR-26b was lower in HCC compared to RIF, and the inverse was observed for miR-224 (P < 0.05). There was no difference among groups regarding miR-33a, miR-143, miR-155, miR-375 and miR-21 (P > 0.05). CONCLUSION: RIF might have a possible beneficial effect on preventing/delaying liver carcinogenesis through epigenetic modulation in a rat model of MASLD-HCC.