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BACKGROUND/AIMS: Adipose-derived Stem Cells (ASCs) are used in Regenerative Medicine, including fat grafting, recovery from local tissue ischemia and scar remodeling. The aim of this study was to evaluate hyaluronan based gel effects on ASCs differentiation and proliferation. METHODS: Comparative analyses using high (H) and low (L) molecular weight hyaluronans (HA), hyaluronan hybrid cooperative complexes (HCCs), and high and medium cross-linked hyaluronan based dermal fillers were performed. Human ASCs were characterized by flow cytometry using CD90, CD34, CD105, CD29, CD31, CD45 and CD14 markers. Then, cells were treated for 7, 14 and 21 days with hyaluronans. Adipogenic differentiation was evaluated using Oil red-O staining and expression of leptin, PPAR-γ, LPL and adiponectin using qRT-PCR. Adiponectin was analyzed by immunofluorescence, PPAR-γ and adiponectin were analyzed using western blotting. ELISA assays for adiponectin and leptin were performed. RESULTS: HCCs highly affected ASCs differentiation by up-regulating adipogenic genes and related proteins, that were also secreted in the culture medium. H-HA and L-HA induced a lower level of ASCs differentiation. CONCLUSION: HCCs-based formulations clearly enhance adipogenic differentiation and proliferation, when compared with linear HA and cross-linked hyaluronans. Injection of HCCs in subdermal fat compartment may recruit and differentiate stem cells in adipocytes, and considerably improving fat tissue renewal.
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Diferenciación Celular/efectos de los fármacos , Ácido Hialurónico/farmacología , Adipogénesis/efectos de los fármacos , Adiponectina/análisis , Adiponectina/metabolismo , Tejido Adiposo/citología , Adulto , Antígenos CD/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Ácido Hialurónico/química , Leptina/análisis , Leptina/metabolismo , Lipoproteína Lipasa/metabolismo , Microscopía Fluorescente , Persona de Mediana Edad , Peso Molecular , PPAR gamma/metabolismo , Fenotipo , Células Madre/citología , Células Madre/metabolismo , Cirugía PlásticaRESUMEN
Human dental pulp stem cells (hDPSCs) are mesenchymal stem cells that have been successfully used in human bone tissue engineering. To establish whether these cells can lead to a bone tissue ready to be grafted, we checked DPSCs for their osteogenic and angiogenic differentiation capabilities with the specific aim of obtaining a new tool for bone transplantation. Therefore, hDPSCs were specifically selected from the stromal-vascular dental pulp fraction, using appropriate markers, and cultured. Growth curves, expression of bone-related markers, calcification and angiogenesis as well as an in vivo transplantation assay were performed. We found that hDPSCs proliferate, differentiate into osteoblasts and express high levels of angiogenic genes, such as vascular endothelial growth factor and platelet-derived growth factor A. Human DPSCs, after 40 days of culture, give rise to a 3D structure resembling a woven fibrous bone. These woven bone (WB) samples were analysed using classic histology and synchrotron-based, X-ray phase-contrast microtomography and holotomography. WB showed histological and attractive physical qualities of bone with few areas of mineralization and neovessels. Such WB, when transplanted into rats, was remodelled into vascularized bone tissue. Taken together, our data lead to the assumption that WB samples, fabricated by DPSCs, constitute a noteworthy tool and do not need the use of scaffolds, and therefore they are ready for customized regeneration.
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Sustitutos de Huesos , Pulpa Dental/citología , Células Madre/citología , Ingeniería de Tejidos/métodos , Adulto , Animales , Trasplante Óseo/métodos , Calcificación Fisiológica/fisiología , Diferenciación Celular/fisiología , Proliferación Celular , Separación Celular/métodos , Células Cultivadas , Quimiotaxis , Humanos , Ratones Desnudos , Neovascularización Fisiológica/fisiología , Osteocalcina/metabolismo , Osteogénesis/fisiología , Microtomografía por Rayos X/métodos , Adulto JovenRESUMEN
Adult mesenchymal stem cells, such as dental pulp stem cells, are of great interest for cell-based tissue engineering strategies because they can differentiate into a variety of tissue-specific cells, above all, into osteoblasts. In recent years, epigenetic studies on stem cells have indicated that specific histone alterations and modifying enzymes play essential roles in cell differentiation. However, although several studies have reported that valproic acid (VPA)-a selective inhibitor of histone deacetylases (HDAC)-enhances osteoblast differentiation, data on osteocalcin expression-a late-stage marker of differentiation-are limited. We therefore decided to study the effect of VPA on dental pulp stem cell differentiation. A low concentration of VPA did not reduce cell viability, proliferation, or cell cycle profile. However, it was sufficient to significantly enhance matrix mineralization by increasing osteopontin and bone sialoprotein expression. In contrast, osteocalcin levels were decreased, an effect induced at the transcriptional level, and were strongly correlated with inhibition of HDAC2. In fact, HDAC2 silencing with shRNA produced a similar effect to that of VPA treatment on the expression of osteoblast-related markers. We conclude that VPA does not induce terminal differentiation of osteoblasts, but stimulates the generation of less mature cells. Moreover, specific suppression of an individual HDAC by RNA interference could enhance only a single aspect of osteoblast differentiation, and thus produce selective effects.
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Pulpa Dental/efectos de los fármacos , Histona Desacetilasa 1/metabolismo , Histona Desacetilasa 2/metabolismo , Inhibidores de Histona Desacetilasas/farmacología , Células Madre Mesenquimatosas/efectos de los fármacos , Osteoblastos/efectos de los fármacos , Osteocalcina/biosíntesis , Ácido Valproico/farmacología , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Pulpa Dental/citología , Pulpa Dental/enzimología , Pulpa Dental/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Histona Desacetilasa 1/antagonistas & inhibidores , Histona Desacetilasa 2/antagonistas & inhibidores , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/enzimología , Células Madre Mesenquimatosas/metabolismo , Osteoblastos/citología , Osteoblastos/enzimología , Osteoblastos/metabolismo , Osteocalcina/genética , Osteopontina/metabolismo , TransfecciónRESUMEN
Primary tumors are responsible for 10% of cancer deaths. In most cases, the main cause of mortality is the formation of metastases. Accumulating evidence suggests that a subpopulation of tumor cells with distinct stem-like properties is responsible for tumor initiation, invasive growth, and metastasis formation. This population is defined as cancer stem cells (CSCs). Existing therapies have enhanced the length of survival after diagnosis of cancer but have completely failed in terms of recovery. CSCs appear to be resistant to chemotherapy, may remain quiescent for extended periods, and have affinity for hypoxic environments. The CSCs can be identified and isolated by different methodologies, including isolation by CSC-specific cell surface marker expression, detection of side population phenotype by Hoechst 33342 exclusion, assessment of their ability to grow as floating spheres, and aldehyde dehydrogenase (ALDH) activity assay. None of the methods mentioned are exclusively used to isolate the solid tumor CSCs, highlighting the imperative to delineate more specific markers or to use combinatorial markers and methodologies. This review provides an overview of the main characteristics and approaches used to identify, isolate, and characterize CSCs from solid tumors.
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Neoplasias/patología , Células Madre Neoplásicas/patología , Separación Celular , HumanosRESUMEN
Over the past 20 years, there has been a lot of interest in the study and investigation of cancer stem cells (CSCs) or tumor-initiating cells (TICs). CSCs are rare, dormant cells and able to self-renew and maintain tumor development and heterogeneity. A new age of basic and clinical cancer research, reclassification of human tumors, and the development of novel therapeutic approaches will undoubtedly result from a better knowledge of CSCs. In order to develop effective and therapeutic strategies to treat cancer, it is crucial to understand the basic characteristics of CSCs, their importance to cancer therapy, and methodologies to isolate, detect, and characterize them. Here, we outline the main methods and protocols to identify, isolate, and culture CSCs from primary tumors.
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Neoplasias , Humanos , Neoplasias/patología , Células Madre Neoplásicas/patologíaRESUMEN
Cancer stem cells (CSCs) are a small tumor cell subpopulation, driving cancer initiation, progression, multidrug resistance, and metastasis. Several methods are used to detect and isolate CSCs by flow cytometry. Among these, measurement of aldehyde dehydrogenase (ALDH) activity within the cell is an assay widely used to identify and isolate CSCs from different types of solid tumors. The aldehyde dehydrogenase (ALDH) is a polymorphic enzyme responsible for the oxidation of aldehydes to carboxylic acids, overexpressed both in normal and cancer stem cells. In this chapter, it is described how CSCs are detected and isolated by using ALDH activity assay.
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Neoplasias , Células Madre Neoplásicas , Línea Celular Tumoral , Células Madre Neoplásicas/metabolismo , Aldehído Deshidrogenasa/metabolismo , Citometría de Flujo , Neoplasias/patologíaRESUMEN
It is now recognized that sphingolipids are involved in the regulation and pathophysiology of several cellular processes such as proliferation, migration, and survival. Growing evidence also implicates them in regulating the behaviour of stem cells, the use of which is increasingly finding application in regenerative medicine. A shotgun lipidomic study was undertaken to determine whether sphingolipid biomarkers exist that can regulate the proliferation and osteogenic differentiation of human Dental Pulp Stem Cells (hDPSCs). Sphingolipids were extracted and identified by direct infusion into an electrospray mass spectrometer. By using cells cultured in osteogenic medium and in medium free of osteogenic stimuli, as a control, we analyzed and compared the SPLs profiles. Both cellular systems were treated at different times (72â¯hours, 7 days, and 14 days) to highlight any changes in the sphingolipidomic profiles in the subsequent phases of the differentiation process. Signals from sphingolipid species demonstrating clear differences were selected, their relative abundance was determined, and statistical differences were analyzed. Thus, our work suggests a connection between sphingolipid metabolism and hDPSC osteogenic differentiation and provides new biomarkers for improving hDPSC-based orthopaedic regenerative medicine.
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Diferenciación Celular , Pulpa Dental , Osteogénesis , Esfingolípidos , Células Madre , Pulpa Dental/citología , Pulpa Dental/metabolismo , Humanos , Esfingolípidos/metabolismo , Células Madre/citología , Células Madre/metabolismo , Células Cultivadas , LipidómicaRESUMEN
The tumor microenvironment (TME) significantly influences cancer progression, and mesenchymal stem cells (MSCs) play a crucial role in interacting with tumor cells via paracrine signaling, affecting behaviors such as proliferation, migration, and epithelial-mesenchymal transition. While conventional 2D culture models have provided valuable insights, they cannot fully replicate the complexity and diversity of the TME. Therefore, developing 3D culture systems that better mimic in vivo conditions is essential. This review delves into the heterogeneous nature of the TME, spotlighting MSC-tumor cellular signaling and advancements in 3D culture technologies. Utilizing MSCs in cancer therapy presents opportunities to enhance treatment effectiveness and overcome resistance mechanisms. Understanding MSC interactions within the TME and leveraging 3D culture models can advance novel cancer therapies and improve clinical outcomes. Additionally, this review underscores the therapeutic potential of engineered MSCs, emphasizing their role in targeted anti-cancer treatments.
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Adipose-derived stem cells (ASCs) significantly influence tumor progression within the tumor microenvironment (TME). This review examines the pro-tumorigenic roles of ASCs, focusing on paracrine signaling, direct cell-cell interactions, and immunomodulation. ASC-mediated mitochondrial transfer through tunneling nanotubes (TNTs) and gap junctions (GJs) plays a significant role in enhancing cancer cell survival and metabolism. Cancer cells with dysfunctional mitochondria acquire mitochondria from ASCs to meet their metabolic needs and thrive in the TME. Targeting mitochondrial transfer, modulating ASC function, and influencing metabolic pathways are potential therapeutic strategies. However, challenges like TME complexity, specificity, safety concerns, and resistance mechanisms must be addressed. Disrupting the ASC-cancer cell-mitochondria axis offers a promising approach to cancer therapy.
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BACKGROUND: Breast cancer (BC) is a complex disease, showing heterogeneity in the genetic background, molecular subtype, and treatment algorithm. Historically, treatment strategies have been directed towards cancer cells, but these are not the unique components of the tumor bulk, where a key role is played by the tumor microenvironment (TME), whose better understanding could be crucial to obtain better outcomes. METHODS: We evaluated mitochondrial transfer (MT) by co-culturing Adipose stem cells with different Breast cancer cells (BCCs), through MitoTracker assay, Mitoception, confocal and immunofluorescence analyses. MT inhibitors were used to confirm the MT by Tunneling Nano Tubes (TNTs). MT effect on multi-drug resistance (MDR) was assessed using Doxorubicin assay and ABC transporter evaluation. In addition, ATP production was measured by Oxygen Consumption rates (OCR) and Immunoblot analysis. RESULTS: We found that MT occurs via Tunneling Nano Tubes (TNTs) and can be blocked by actin polymerization inhibitors. Furthermore, in hybrid co-cultures between ASCs and patient-derived organoids we found a massive MT. Breast Cancer cells (BCCs) with ASCs derived mitochondria (ADM) showed a reduced HIF-1α expression in hypoxic conditions, with an increased ATP production driving ABC transporters-mediated multi-drug resistance (MDR), linked to oxidative phosphorylation metabolism rewiring. CONCLUSIONS: We provide a proof-of-concept of the occurrence of Mitochondrial Transfer (MT) from Adipose Stem Cells (ASCs) to BC models. Blocking MT from ASCs to BCCs could be a new effective therapeutic strategy for BC treatment.
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Neoplasias de la Mama , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Mitocondrias , Humanos , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Mitocondrias/metabolismo , Células Madre/metabolismo , Tejido Adiposo/citología , Tejido Adiposo/metabolismo , Línea Celular Tumoral , Microambiente TumoralRESUMEN
Gastro-esophageal tumors constitute a big health problem. Treatment options still mainly rely on chemotherapy, and apart from human epidermal growth factor receptor 2 positive and microsatellite instable/Epstein-Barr Virus disease, there are no molecularly guided options. Therefore, despite the large number of identified molecular alterations, precision medicine is still far from the clinic. In this context, the recently developed technology of patient-derived organoids (PDOs) could offer the chance to accelerate drug development and biomarker discovery. Indeed, PDOs are 3D primary cultures that were shown to reproduce patient's tumor characteristics. Moreover, several reports indicated that PDOs can replicate patient's response to a given drug; therefore, they are one of the most promising tools for functional precision medicine.
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Infecciones por Virus de Epstein-Barr , Neoplasias Esofágicas , Humanos , Medicina de Precisión , Infecciones por Virus de Epstein-Barr/metabolismo , Infecciones por Virus de Epstein-Barr/patología , Herpesvirus Humano 4 , Neoplasias Esofágicas/patología , Organoides/metabolismoRESUMEN
Type 1 diabetes (T1D) is an autoimmune disease with immune cells' islet infiltration (called "insulitis"), which leads to beta cell loss. Despite being the critical element of T1D occurrence and pathogenesis, insulitis is often present in a limited percentage of islets, also at diagnosis. Therefore, it is needed to define reproducible methods to detect insulitis and beta-cell decline, to allow accurate and early diagnosis and to monitor therapy. However, this goal is still far due to the morphological aspect of islet microvasculature, which is rather dense and rich, and is considerably rearranged during insulitis. More studies on microvasculature are required to understand if contrast-enhanced ultrasound sonography measurements of pancreatic blood-flow dynamics may provide a clinically deployable predictive marker to predict disease progression and therapeutic reversal in pre-symptomatic T1D patients. Therefore, it is needed to clarify the relation between insulitis and the dynamics of ß cell loss and with coexisting mechanisms of dysfunction, according to clinical stage, as well as the micro vessels' dynamics and microvasculature reorganization. Moreover, the ideal cell-based therapy of T1D should start from an early diagnosis allowing a sufficient isolation of specific Procr+ progenitors, followed by the generation and expansion of islet organoids, which could be transplanted coupled to an immune-regulatory therapy which will permit the maintenance of pancreatic islets and an effective and long-lasting insulitis reversal.
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Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Islotes Pancreáticos , Enfermedades Pancreáticas , Humanos , Diabetes Mellitus Tipo 1/metabolismo , Páncreas/patología , Islotes Pancreáticos/metabolismo , Células Secretoras de Insulina/metabolismo , Células Madre/metabolismoRESUMEN
In the field of biology and medicine, one hears often about stem cells and their potential. The dental implant new surfaces, subjected to specific treatments, perform better and allow for quicker healing times and better clinical performance. The purpose of this study is to evaluate from a biological point of view the interaction and cytotoxicity between stem cells derived from dental pulp (DPSCs) and titanium surfaces. Through the creation of complex cells/implant, this study is aimed at analyzing the cytotoxicity of dental implant surfaces (Myth (Maipek Manufacturer Industrial Care, Naples, Italy)) and the adhesion capacity of cells on them and at considering the essential factors for implant healing such as osteoinduction and vasculogenesis. These parameters are pointed out through histology (3D cell culture), immunofluorescence, proliferation assays, scanning electron microscopy, and PCR investigations. The results of the dental implant surface and its interaction with the DPSCs are encouraging, obtaining results increasing the mineralization of the tissues. The knowledge of this type of interaction, highlighting its chemical and biological features, is certainly also an excellent starting point for the development of even more performing surfaces for having better healing in the oral surgical procedures related to dental implant positioning.
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Implantes Dentales , Pulpa Dental/citología , Células Madre/citología , Matriz Ósea/efectos de los fármacos , Matriz Ósea/metabolismo , Adhesión Celular/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Medios de Cultivo Condicionados/farmacología , Humanos , Neovascularización Fisiológica/efectos de los fármacos , Oseointegración/efectos de los fármacos , Osteocalcina/metabolismo , Células Madre/efectos de los fármacos , Células Madre/ultraestructura , Propiedades de Superficie , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Gelatin hydrogels by microbial-transglutaminase crosslinking are being increasingly exploited for tissue engineering, and proved high potential in bone regeneration. This study aimed to evaluate, for the first time, the combination of enzymatically crosslinked gelatin with hyaluronan and the newly developed biotechnological chondroitin in enhancing osteogenic potential. Gelatin enzymatic crosslinking was carried out in the presence of hyaluronan or of a hyaluronan-chondroitin mixture, obtaining semi-interpenetrating gels. The latter proved lower swelling extent and improved stiffness compared to the gelatin matrix alone, whilst maintaining high stability. The heteropolysaccharides were retained for 30 days in the hydrogels, thus influencing cell response over this period. To evaluate the effect of hydrogel composition on bone regeneration, materials were seeded with human dental pulp stem cells and osteogenic differentiation was assessed. The expression of osteocalcin (OC) and osteopontin (OPN), both at gene and protein level, was evaluated at 7, 15 and 30 days of culture. Scanning electron microscopy (SEM) and two-photon microscope observations were performed to assess bone-like extracellular matrix (ECM) deposition and to observe the cell penetration depth. In the presence of the heteropolysaccharides, OC and OPN expression was upregulated and a higher degree of calcified matrix formation was observed. Combination with hyaluronan and chondroitin improved both the biophysical properties and the biological response of enzymatically crosslinked gelatin, fastening bone deposition.
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In oral implantology, the success and persistence of dental implants over time are guaranteed by the bone formation around the implant fixture and by the integrity of the peri-implant mucosa seal, which adheres to the abutment and becomes a barrier that hinders bacterial penetration and colonization close to the outer parts of the implant. Research is constantly engaged in looking for substances to coat the titanium surface that guarantees the formation and persistence of the peri-implant bone, as well as the integrity of the mucous perimeter surrounding the implant crown. The present study aimed to evaluate in vitro the effects of a titanium surface coated with polylysine homopolymers on the cell growth of dental pulp stem cells and keratinocytes to establish the potential clinical application. The results reported an increase in cell growth for both cellular types cultured with polylysine-coated titanium compared to cultures without titanium and those without coating. These preliminary data suggest the usefulness of polylysine coating not only for enhancing osteoinduction but also to speed the post-surgery mucosal healings, guarantee appropriate peri-implant epithelial seals, and protect the fixture against bacterial penetration, which is responsible for compromising the implant survival.
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BACKGROUND: Hyaluronans exist in different forms, accordingly with molecular weight and degree of crosslinking. Here, we tested the capability to induce osteogenic differentiation in hDPSCs (human dental pulp stem cells) of three hyaluronans forms: linear pharmaceutical-grade hyaluronans at high and (HHA) low molecular weight (LHA) and hybrid cooperative complexes (HCC), containing both sizes. METHODS: hDPSCs were treated with HHA, LHA, HCC for 7, 14 and 21 days. The effects of hyaluronans on osteogenic differentiation were evaluated by qRT-PCR and WB of osteogenic markers and by Alizarin Red S staining. To identify the involved pathway, CD44 was analyzed by immunofluorescence, and YAP/TAZ expression was measured by qRT-PCR. Moreover, YAP/TAZ inhibitor-1 was used, and the loss of function of YAP/TAZ was evaluated by qRT-PCR, WB and immunofluorescence. RESULTS: We showed that all hyaluronans improves osteogenesis. Among these, HCC is the main inducer of osteogenesis, along with overexpression of bone related markers and upregulating CD44. We also found that this biological process is subordinate to the activation of YAP/TAZ pathway. CONCLUSIONS: We found that HA's molecular weight can have a relevant impact on HA performance for bone regeneration, and we unveil a new molecular mechanism by which HA acts on stem cells.
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Huesos/citología , Diferenciación Celular , Pulpa Dental/citología , Ácido Hialurónico/farmacología , Transducción de Señal , Células Madre/citología , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ/metabolismo , Proteínas Señalizadoras YAP/metabolismo , Biomarcadores/metabolismo , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Separación Celular , Células Cultivadas , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Receptores de Hialuranos/metabolismo , Sialoproteína de Unión a Integrina/genética , Sialoproteína de Unión a Integrina/metabolismo , Osteocalcina/genética , Osteocalcina/metabolismo , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Osteopontina/genética , Osteopontina/metabolismo , Células Madre/efectos de los fármacos , Células Madre/metabolismoRESUMEN
Autophagy is a self-degradative cellular process, involved in stress response such as starvation, hypoxia, and oxidative stress. This mechanism balances macro-molecule recycling to regulate cell homeostasis. In cancer, autophagy play a role in the development and progression, while several studies describe it as one of the key processes in drug resistance. In the last years, in addition to standard anti-cancer treatments such as chemotherapies and irradiation, targeted therapy became one of the most adopted strategies in clinical practices, mainly due to high specificity and reduced side effects. However, similar to standard treatments, drug resistance is the main challenge in most patients. Here, we summarize recent studies that investigated the role of autophagy in drug resistance after targeted therapy in different types of cancers. We highlight positive results and limitations of pre-clinical and clinical studies in which autophagy inhibitors are used in combination with targeted therapies.
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Resistencia a Antineoplásicos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Animales , Anticuerpos Monoclonales/farmacología , Antineoplásicos Inmunológicos/farmacología , Autofagia/efectos de los fármacos , Autofagia/fisiología , Humanos , Inmunotoxinas/farmacología , Terapia Molecular Dirigida , Neoplasias/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Bibliotecas de Moléculas Pequeñas/farmacologíaRESUMEN
The ß2-Adrenergic receptor (ß2-AR) is a G protein-coupled receptor (GPCR), involved in the development of many cancers, among which HNSCC. In this contest, ß2-AR signaling interacts with different pathways, such as PI3K and MAPK, commonly activated by TK receptors. For this reason, TK blockade is one of the most adopted therapeutic strategies in HNSCC patients. In our study we investigated the effects of the ß2-AR blocking in HNSCC cell lines, using the selective inhibitor ICI118,551 (ICI), in combination with the MAPK inhibitor U0126. We found that ICI leads to the blocking of p38 and NF-kB oncogenic pathways, strongly affecting also the ERK and PI3K pathways. Cotreatment with U0126 displays a synergic effect on cell viability and pathway alteration. Interestingly, we found that the ß2-AR blockade affects Nrf2-Keap1 stability and its nuclear translocation leading to a drastic ROS increase and oxidative stress. Our results are confirmed by a TCGA dataset analysis, showing that NFE2L2 gene is commonly overexpressed in HNSC, and correlated with a lower survival rate. In our system, the PI3K pathway inhibition culminated in the blocking of pro-survival autophagy, a mechanism normally adopted by cancer cells to became less responsive to the therapies. The mTOR expression, commonly upregulated in HNSC, was reduced in patients with disease-recurrence. It is well known that mTOR has a strong autophagy inhibition effect, therefore its downregulation promoted pro-survival autophagy, with a related increase recurrence rate. Our findings highlight for the first time the key role of ß2-AR and related pathway in HNSCC cell proliferation and drug resistance, proposing it as a valuable therapeutic molecular target.
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Antagonistas de Receptores Adrenérgicos beta 2/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Factor 2 Relacionado con NF-E2/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Receptores Adrenérgicos beta 2/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Antagonistas de Receptores Adrenérgicos beta 2/administración & dosificación , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/patología , Humanos , MAP Quinasa Quinasa 1/antagonistas & inhibidores , MAP Quinasa Quinasa 2/antagonistas & inhibidores , Propanolaminas/administración & dosificación , Propanolaminas/farmacología , Inhibidores de Proteínas Quinasas/administración & dosificación , Transducción de Señal , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/patologíaRESUMEN
Epigenetic regulation has been considered an important mechanism for influencing stem cell differentiation. In particular, histone deacetylases (HDACs) have been shown to play a role in the osteoblast differentiation of mesenchymal stem cells (MSCs). In this study, the effect of the HDAC inhibitor, valproic acid (VPA), on bone formation in vivo by MSCs was determined. Surprisingly, VPA treatment, unlike other HDAC inhibitors, produced a well-organized lamellar bone tissue when MSCsâ»collagen sponge constructs were implanted subcutaneously into nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice, although a decrease of osteocalcin (OC) expression was observed. Consequently, we decided to investigate the molecular mechanisms by which VPA exerts such effects on MSCs. We identified the glucocorticoid receptor (GR) as being responsible for that downregulation, and suggested a correlation between GR and HDAC2 inhibition after VPA treatment, as evidenced by HDAC2 knockdown. Furthermore, using co-immunoprecipitation analysis, we showed for the first time in the cytoplasm, binding between GR and HDAC2. Additionally, chromatin immunoprecipitation (ChIP) assays confirmed the role of GR in OC downregulation, showing recruitment of GR to the nGRE element in the OC promoter. In conclusion, our results highlight the existence of a cross-talk between GR and HDAC2, providing a mechanistic explanation for the influence of the HDAC inhibitor (namely VPA) on osteogenic differentiation in MSCs. Our findings open new directions in targeted therapies, and offer new insights into the regulation of MSC fate determination.
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Citoplasma/metabolismo , Histona Desacetilasa 2/metabolismo , Células Madre Mesenquimatosas/metabolismo , Osteocalcina/metabolismo , Receptores de Glucocorticoides/metabolismo , Ácido Valproico/farmacología , Adulto , Biomarcadores/metabolismo , Citoplasma/efectos de los fármacos , Pulpa Dental/citología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Masculino , Células Madre Mesenquimatosas/efectos de los fármacos , Mifepristona/farmacología , Osteocalcina/genética , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Implantación de Prótesis , Unión Proteica/efectos de los fármacos , Elementos de Respuesta/genética , Adulto JovenRESUMEN
BACKGROUND: Glucose-6-phospate dehydrogenase (G6PD) is the limiting enzyme of the pentose phosphate pathway (PPP) correlated to cancer progression and drug resistance. We previously showed that G6PD inhibition leads to Endoplasmic Reticulum (ER) stress often associated to autophagy deregulation. The latter can be induced by target-based agents such as Lapatinib, an anti-HER2 tyrosine kinase inhibitor (TKI) largely used in breast cancer treatment. METHODS: Here we investigate whether G6PD inhibition causes autophagy alteration, which can potentiate Lapatinib effect on cancer cells. Immunofluorescence and flow cytometry for LC3B and lysosomes tracker were used to study autophagy in cells treated with lapatinib and/or G6PD inhibitors (polydatin). Immunoblots for LC3B and p62 were performed to confirm autophagy flux analyses together with puncta and colocalization studies. We generated a cell line overexpressing G6PD and performed synergism studies on cell growth inhibition induced by Lapatinib and Polydatin using the median effect by Chou-Talay. Synergism studies were additionally validated with apoptosis analysis by annexin V/PI staining in the presence or absence of autophagy blockers. RESULTS: We found that the inhibition of G6PD induced endoplasmic reticulum stress, which was responsible for the deregulation of autophagy flux. Indeed, G6PD blockade caused a consistent increase of autophagosomes formation independently from mTOR status. Cells engineered to overexpress G6PD became resilient to autophagy and resistant to lapatinib. On the other hand, G6PD inhibition synergistically increased lapatinib-induced cytotoxic effect on cancer cells, while autophagy blockade abolished this effect. Finally, in silico studies showed a significant correlation between G6PD expression and tumour relapse/resistance in patients. CONCLUSIONS: These results point out that autophagy and PPP are crucial players in TKI resistance, and highlight a peculiar vulnerability of breast cancer cells, where impairment of metabolic pathways and autophagy could be used to reinforce TKI efficacy in cancer treatment.