Glioblastoma multiforme (GBM) is the most aggressive form of brain cancer due to its highly invasive nature that impedes the surgical removal of all tumor cells, making relapse inevitable. However, ...the mechanisms used by glioma cells to invade the surrounding tissue are still unclear. In this context, epithelial‐to‐mesenchymal transition (EMT) has emerged as a key regulator of this invasive state and although the real relevance of this program in malignant glioma is still controversial, it has been strongly associated with GBM malignancy. EMT is a very complex process regulated by several families of transcriptional factors through many signaling pathways that form a network that allows cancer cells to acquire invasive properties and penetrate the neighboring stroma, resulting in the formation of an advantageous microenvironment for cancer progression and metastasis. In this systematic review, we focus on the molecular mechanisms of EMT including EMT‐factors, drug resistance, miRNA, and new therapeutic strategies. In addition, we address controversial questions about mesenchymal shift in GBMs with a bioinformatics analysis to show that in terms of epithelial and mesenchymal phenotype, the majority of GBMs samples analyzed have a profile more mesenchymal than epithelial. If induced, this phenotype can be shifted toward an even more mesenchymal phenotype in an EMT‐like process in glioma cells. A better understanding of the molecular regulation of the EMT during tumor spreading will help to provide potential therapeutic interventions to target this program when treating GBM.
For over a year, the coronavirus disease 2019 has been affecting the world population by causing severe tissue injuries and death in infected people. Adenosine triphosphate (ATP) and the nicotinamide ...adenine dinucleotide (NAD +) are two molecules that are released into the extracellular microenvironment after direct virus infection or cell death caused by hyper inflammation and coagulopathy. Also, these molecules are well known to participate in multiple pathways and have a pivotal role in the purinergic signaling pathway. Thus, using public datasets available on the Gene Expression Omnibus (GEO), we analyzed raw proteomics data acquired using mass spectrometry (the gold standard method) and raw genomics data from COVID-19 patient samples obtained by microarray. The data was analyzed using bioinformatics and statistical methods according to our objectives. Here, we compared the purinergic profile of the total leukocyte population and evaluated the levels of these soluble biomolecules in the blood, and their correlation with coagulation components in COVID-19 patients, in comparison to healthy people or non-COVID-19 patients. The blood metabolite analysis showed a stage-dependent inosine increase in COVID-19 patients, while the nucleotides ATP and ADP had positive correlations with fibrinogen and other coagulation proteins. Also, ATP, ADP, inosine, and hypoxanthine had positive and negative correlations with clinical features. Regarding leukocyte gene expression, COVID-19 patients showed an upregulation of the
P2RX1
,
P2RX4
,
P2RX5
,
P2RX7
,
P2RY1
,
P2RY12
,
PANX1
,
ADORA2B
,
NLPR3
, and
F3
genes. Yet, the ectoenzymes of the canonical and non-canonical adenosinergic pathway (
ENTPD1
and
CD38
) are upregulated, suggesting that adenosine is produced by both active adenosinergic pathways. Hence, approaches targeting these biomolecules or their specific purinoreceptors and ectoenzymes may attenuate the high inflammatory state and the coagulopathy seen in COVID-19 patients.
Key messages
Adenosinergic pathways are modulated on leukocytes from COVID-19 patients.
Plasmatic inosine levels are increased in COVID-19 patients.
ATP, ADP, AMP, hypoxanthine, and inosine are correlated with coagulation players.
The nucleotides and nucleosides are correlated with patients’ clinical features.
The P2 receptors and ectoenzymes are correlated with Tissue factor in COVID-19.
Autophagy is a cellular bulk degradation process used as an alternative source of energy and metabolites and implicated in various diseases. Inefficient autophagy in nutrient-deprived cancer cells ...would be beneficial for cancer therapy making its modulation valuable as a therapeutic strategy for cancer treatment, especially in combination with chemotherapy. Dipyridamole (DIP) is a vasodilator and antithrombotic drug. Its major effects involve the block of nucleoside uptake and phosphodiestesase inhibition, leading to increased levels of intracellular cAMP. Here we report that DIP increases autophagic markers due to autophagic flux blockage, resembling autophagosome maturation and/or closure impairment. Treatment with DIP results in an increased number of autophagosomes and autolysosomes and impairs degradation of SQSTM1/p62. As blockage of autophagic flux decreases the recycling of cellular components, DIP reduced the intracellular ATP levels in cancer cells. Autophagic flux blockage was neither through inhibition of lysosome function nor blockage of nucleoside uptake, but could be prevented by treatment with a PKA inhibitor, suggesting that autophagic flux failure mediated by DIP results from increased intracellular levels of cAMP. Treatment with DIP presented antiproliferative effects in vitro alone and in combination with chemotherapy drugs. Collectively, these data demonstrate that DIP can impair autophagic degradation, by preventing the normal autophagosome maturation, and might be useful in combination anticancer therapy.
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•Dipyridamole (DIP) blocks autophagic flux.•DIP leads to the accumulation of double-membrane structures, resembling failure in autophagosome maturation process.•DIP treatment has antiproliferative effects in vitro and sensitizes cancer cells to antineoplastic treatments.
Mesenchymal stem cells (MSCs) have recently been described to home to brain tumors and to integrate into the tumor-associated stroma. Understanding the communication between cancer cells and MSCs has ...become fundamental to determine whether MSC-tumor interactions should be exploited as a vehicle for therapeutic agents or considered a target for intervention. Therefore, we investigated whether conditioned medium from adipose-derived stem cells (ADSCs-CM) modulate glioma tumor cells by analyzing several cell biology processes in vitro. C6 rat glioma cells were treated with ADSCs-CM, and cell proliferation, cell cycle, cell viability, cell morphology, adhesion, migration, and expression of epithelial-mesenchymal transition (EMT)-related surface markers were analyzed. ADSCs-CM did not alter cell viability, cell cycle, and growth rate of C6 glioma cells but increased their migratory capacity. Moreover, C6 cells treated with ADSC-CM showed reduced adhesion and underwent changes in cell morphology. Up-regulation of EMT-associated markers (vimentin, MMP2, and NRAS) was also observed following treatment with ADSC-CM. Our findings demonstrate that the paracrine factors released by ADSCs are able to modulate glioma cell biology. Therefore, ADSC-tumor cell interactions in a tumor microenvironment must be considered in the design of clinical application of stem cell therapy.
Graphical Abstract
Factors released by adipose-derived stem cells (ADSCs) may modulate the biology of C6 glioma cells. When C6 cells are exposed to a conditioned medium from adipose-derived stem cells (ADSCs-CM), some of these cells can undergo an EMT-like process and trans-differentiate into cells with a more mesenchymal phenotype, characterized by enhanced expression of EMT-related surface markers, reduced cell adhesion capacity, increased migratory capacity, as well as changes in cell and nuclei morphology.
A film of chitosan, gelatin and liposome has been designed for dermatological applications. Several adaptations were required throughout development to facilitate in vitro analysis, physicochemical ...characterization and biocompatibility evaluation. The final version of the film was characterized by differential scanning calorimetry, evaluation of swelling and scanning electron microscopy. The biocompatibility of the film was assessed by investigating cellular parameters of three types of human cells by direct contact or through films extracts: I) primary culture of adipose-derived mesenchymal stromal cells (ADCSs) and melanoma cell lines were used to test cell adhesion and morphology by direct cell culture on the material; II) ADSCs and immortalized keratinocytes were used in cell viability assay using different films extracts. The film showed physicochemical characteristics that favored cellular input, being suitable for in vitro analysis, which allowed its biocompatible characteristics such as the absence of toxicity to be verified without causing significant morphological changes in ADSCs and melanoma cell line. Altogether, these results suggest that the material has a potential application for drug delivery and promotion of skin tissue repair and is therefore worthwhile for further investigations using preclinical models to cover dermal lesions.
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•Films of chitosan, gelatin and liposome have been developed.•The films were modified for in vitro analysis in terms of integrity and acidity.•The film is a blend with a homogeneous surface.•Chitosan, gelatin and liposome films showed biocompatible characteristics.
Mesenchymal stem cells (MSCs) play an important role in tissue homeostasis and damage repair through their ability to differentiate into cells of different tissues, trophic support, and ...immunomodulation. These properties made them attractive for clinical applications in regenerative medicine, immune disorders, and cell transplantation. However, despite multiple preclinical and clinical studies demonstrating beneficial effects of MSCs, their native identity and mechanisms of action remain inconclusive. Since its discovery, the CD73/ecto‐5′‐nucleotidase is known as a classic marker for MSCs, but its role goes far beyond a phenotypic characterization antigen. CD73 contributes to adenosine production, therefore, is an essential component of purinergic signaling, a pathway composed of different nucleotides and nucleosides, which concentrations are finely regulated by the ectoenzymes and receptors. Thus, purinergic signaling controls pathophysiological functions such as proliferation, migration, cell fate, and immune responses. Despite the remarkable progress already achieved in considering adenosinergic pathway as a therapeutic target in different pathologies, its role is not fully explored in the context of the therapeutic functions of MSCs. Therefore, in this review, we provide an overview of the role of CD73 and adenosine‐mediated signaling in the functions ascribed to MSCs, such as homing and proliferation, cell differentiation, and immunomodulation. Additionally, we will discuss the pathophysiological role of MSCs, via CD73 and adenosine, in different diseases, as well as in tumor development and progression. A better understanding of the adenosinergic pathway in the regulation of MSCs functions will help to provide improved therapeutic strategies applicable in regenerative medicine.
Purinergic signaling is a necessary mechanism to trigger or even amplify cell communication. Its ligands, notably adenosine triphosphate (ATP) and adenosine, modulate specific membrane‐bound ...receptors in virtually all human cells. Regardless of the stage of the pregnancy, cellular communication between maternal, placental, and fetal cells is the paramount mechanism to sustain its optimal status. In this review, we describe the crucial role of purinergic signaling on the regulation of the maternal‐fetal trophic exchanges, immune control, and endocrine exchanges throughout pregnancy. The nature of the modulation of both ATP and adenosine on the embryo‐maternal interface, going through placental invasion until birth delivery depends on the general maternal‐fetal health state and consequently on the selective activation of their specific receptors. In addition, an increasing number of studies have been demonstrating the pivotal role of ATP and adenosine in modulating deleterious effects of suboptimal conditions of pregnancy. Here, we discuss the role of purinergic signaling on the balance that coordinates the embryo‐maternal exchanges and a promising therapeutic venue in the context of pregnancy disorders.
The mediators of the purinergic signaling are necessary for appropriate pregnancy development. High levels of extracellular ATP are implicated in low placental invasion and pregnancy disorders. Angiogenic properties of the adenosine help in pregnancy functions.
Parkinson's disease (PD) is a disabling and highly costly neurodegenerative condition with worldwide prevalence. Despite advances in treatments that slow progression and minimize locomotor ...impairments, its clinical management is still a challenge. Previous preclinical studies, using mesenchymal stem cell (MSC) transplantation and isolated physical exercise (EX), reported beneficial results for treatment of PD. Therefore, this experimental randomized study aimed to elucidate the therapeutic potential of combined therapy using adipose‐derived human MSCs (ADSCs) grafted into the striatum in conjunction with aerobic treadmill training, specifically in terms of locomotor performance in a unilateral PD rat model induced by 6‐hydroxydopamine (6‐OHDA). Forty‐one male Wistar rats were categorized into five groups in accordance with the type of treatment to which they were subjected (Sham, 6‐OHDA − injury, 6‐OHDA + exercise, 6‐OHDA + cells, and 6‐OHDA + combined). Subsequently, dopaminergic depletion was assessed by the methylphenidate challenge and the specified therapeutic intervention was conducted in each group. The foot fault task was performed at the end of the experiment to serve as an assessment of motor skills. The results showed that despite disturbances in motor balance and coordination, locomotor dysfunction was ameliorated in all treatment categories in comparison to the injury group (sign test, p < 0.001, effect size: 0.71). The exercise alone and combined groups were the categories that exhibited the best recovery in terms of movement performance (p < 0.001). Overall, this study confirms that exercise is a powerful option to improve motor function and a promising adjuvant intervention for stem cell transplantation in the treatment of PD motor symptoms.
Open Practices
This article has been awarded Open Data. All materials and data are publicly accessible at https://figshare.com/s/18a543c101a17a1d5560. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.
Parkinson disease is a complex disorder in which neurodegenerative processes that affect locomotor function are not well known. This study demonstrates that conducting aerobic exercise intervention per se or combined with mesenchymal stem cells induce favorable effects on the motor symptomatology in a male rat model of Parkinson's disease
MEK inhibitors (MEKi) demonstrate anti‐proliferative activity in patients with metastatic uveal melanoma, but responses are short‐lived. In the present study, we evaluated the MEKi trametinib alone ...and in combination with drugs targeting epigenetic regulators, including DOT1L, EZH2, LSD1, DNA methyltransferases, and histone acetyltransferases. The DNA methyltransferase inhibitor (DNMTi) decitabine effectively enhanced the anti‐proliferative activity of trametinib in cell viability, colony formation, and 3D organoid assays. RNA‐Seq analysis showed the MEKi‐DNMTi combination primarily affected the expression of genes involved in G1 and G2/2M checkpoints, cell survival, chromosome segregation and mitotic spindle. The DNMTi‐MEKi combination did not appear to induce a DNA damage response (as measured by γH2AX foci) or senescence (as measured by β‐galactosidase staining) compared to either MEKi or DNMTi alone. Instead, the combination increased expression of the CDK inhibitor p21 and the pro‐apoptotic protein BIM. In vivo, the DNMTi‐MEKi combination was more effective at suppressing growth of MP41 uveal melanoma xenografts than either drug alone. Our studies indicate that DNMTi may enhance the activity of MEKi in uveal melanoma.
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