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1.
Stem Cells ; 42(3): 200-215, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38167958

RESUMO

Leukemogenesis is a complex process that involves multiple stages of mutation in either hematopoietic stem or progenitor cells, leading to cancer development over time. Acute myeloid leukemia (AML) is an aggressive malignancy that affects myeloid cells. The major disease burden is caused by immature blast cells, which are eliminated using conventional chemotherapies. Unfortunately, relapse is a leading cause of death in AML patients, with 30%-80% experiencing it within 2 years of initial treatment. The dominant cause of relapse in leukemia is the presence of therapy-resistant leukemic stem cells (LSCs). These cells express genes related to stemness that are frequently difficult to eradicate and tend to survive standard treatments. Studies have demonstrated that by targeting the metabolic pathways of LSCs, it is possible to improve outcomes and extend the survival of those afflicted by leukemia. The overwhelming evidence suggests that lipid metabolism is reprogrammed in LSCs, leading to an increase in fatty acid uptake and de novo lipogenesis. Genes regulating this process also play a crucial role in therapy evasion. In this concise review, we summarize the lipid metabolism in normal hematopoietic cells, AML blast cells, and AML LSCs. We also compare the lipid metabolic signatures in de novo versus therapy-resistant AML blast and LSCs. We further discuss the metabolic switches, cellular crosstalk, potential targets, and inhibitors of lipid metabolism that could alleviate treatment resistance and relapse.


Assuntos
Leucemia Mieloide Aguda , Células-Tronco Neoplásicas , Humanos , Células-Tronco Neoplásicas/metabolismo , Leucemia Mieloide Aguda/patologia , Carcinogênese/patologia , Recidiva , Lipídeos/uso terapêutico
2.
J Cell Biochem ; 125(1): 3-21, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37997702

RESUMO

Reactive oxygen species (ROS) and its related signaling pathways and regulating molecules play a major role in the growth and development of cancer stem cells. The concept of ROS and cancer stem cells (CSCs) has been gaining much attention since the past decade and the evidence show that these CSCs possess robust self-renewal and tumorigenic potential and are resistant to conventional chemo- and radiotherapy and believed to be responsible for tumor progression, metastasis, and recurrence. It seems reasonable to say that cancer can be cured only if the CSCs are eradicated. ROS are Janus-faced molecules that can regulate cellular physiology as well as induce cytotoxicity, depending on the magnitude, duration, and site of generation. Unlike normal cancer cells, CSCs expel ROS efficiently by upregulating ROS scavengers. This unique redox regulation in CSCs protects them from ROS-mediated cell death and nullifies the effect of radiation, leading to chemoresistance and radioresistance. However, how these CSCs control ROS production by scavenging free radicals and how they maintain low levels of ROS is a challenging to understand and these attributes make CSCs as prime therapeutic targets. Here, we summarize the mechanisms of redox regulation in CSCs, with a focus on therapy resistance, its various pathways and microRNAs regulation, and the potential therapeutic implications of manipulating the ROS levels to eradicate CSCs. A better understanding of these molecules, their interactions in the CSCs may help us to adopt proper control and treatment measures.


Assuntos
MicroRNAs , Neoplasias , Humanos , Espécies Reativas de Oxigênio/metabolismo , Neoplasias/metabolismo , MicroRNAs/metabolismo , Oxirredução , Células-Tronco Neoplásicas/metabolismo
3.
Drug Dev Res ; 84(7): 1496-1512, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37571798

RESUMO

A reliable and efficient in vitro model is needed to screen drugs for Alzheimer's disease (AD), as many drugs are currently in the developmental stage. To address this, we developed an in vitro model using amniotic membrane-derived mesenchymal stem cells (AM-MSCs) to screen novel drugs for AD. We differentiated AM-MSCs into neurons and degenerated them using beta amyloid1-42 (Aß). We then tested AD drugs, which are commercially available such as donepezil, rivastigmine, memantine, citicoline, and two novel drugs, that is, probucol, an anti-hyperlipidaemic drug, and NMJ-2, a cinnamic acid analogue for their potential to protect the cells against neurodegeneration. We used gene expression and immunofluorescence staining to assess the neuroprotective ability of these drugs. We also measured the ability of these drugs to reduce lactate dehydrogenase, reactive oxygen species, and nitric oxide levels, as well as their ability to stabilize the mitochondrial membrane potential and increase acetylcholine (ACh) levels. The AD drugs and novel drugs reduced cytotoxicity and oxidative stress, stabilized mitochondrial membrane potential, and restored ACh levels. Furthermore, they reduced BACE1 expression, with a concomitant increase in the expression of cholinergic markers. This AM-MSCs-based AD-like model has immense potential to be an accurate human model and an alternative to animal models for testing a large number of lead compounds in a short time. Our results also suggest that the novel drugs probucol and NMJ-2 may protect against Aß-induced neurodegeneration.


Assuntos
Doença de Alzheimer , Células-Tronco Mesenquimais , Animais , Humanos , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide , Probucol/metabolismo , Avaliação Pré-Clínica de Medicamentos , Ácido Aspártico Endopeptidases , Células-Tronco Mesenquimais/metabolismo
4.
Exp Cell Res ; 409(2): 112912, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34762897

RESUMO

Rapid proliferation, high stemness potential, high invasiveness and apoptotic evasion are the distinctive hallmarks of glioma malignancy. The dysregulation of the Wnt/ß-catenin pathway is the key factor regulating glioma malignancy. Wnt antagonist, secreted frizzled-related protein 4 (sFRP4), which has a prominent pro-apoptotic role in glioma stem cells, has two functional domains, the netrin-like domain (NLD), and cysteine-rich domain (CRD) both of which contribute to apoptotic properties of the whole protein. However, there are no reports elucidating the specific effects of individual domains of sFRP4 in inhibiting the invasive properties of glioma. This study explores the efficacy of the domains of sFRP4 in inhibiting the key hallmarks of glioblastoma such as invasion, metastasis, and stemness. We overexpressed sFRP4 and its domains in the glioblastoma cell line, U87MG cells and observed that both CRD and NLD domains played prominent roles in attenuating cancer stem cell properties. Significantly, we could demonstrate for the first time that both NLD and CRD domains negatively impacted the key driver of metastasis and migration, the matrix metalloproteinase-2 (MMP-2). Mechanistically, compared to CRD, NLD domain suppressed MMP-2 mediated invasion more effectively in glioma cells as observed in matrigel invasion assay and a function-blocking antibody assay. Fluorescent matrix degradation assay further revealed that NLD reduces matrix degradation. NLD also significantly disrupted fibronectin assembly and decreased cell adhesion in another glioma cell line LN229. In conclusion, the NLD peptide of sFRP4 could be a potent short peptide therapeutic candidate for targeting MMP-2-mediated invasion in the highly malignant glioblastoma multiforme.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/tratamento farmacológico , Metaloproteinase 2 da Matriz/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/antagonistas & inibidores , Apoptose , Ciclo Celular , Movimento Celular , Proliferação de Células , Glioma/genética , Glioma/metabolismo , Glioma/patologia , Humanos , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Invasividade Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Células Tumorais Cultivadas , beta Catenina/genética , beta Catenina/metabolismo
5.
Int J Mol Sci ; 23(24)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36555293

RESUMO

Pigment epithelium-derived factor (PEDF) protein regulates normal bone, with anti-tumour roles in bone and breast cancer (BC). Pre- and post-menopausal oestrogen levels may regulate PEDF expression and function in BC, though the mechanisms behind this remain unknown. In this study, in vitro models simulating pre- and post-menopausal bone microenvironments were used to evaluate if PEDF regulates pro-metastatic biomarker expression and downstream functional effects on BC cells. PEDF treatment reduced phosphorylated-nuclear factor-κB p65 subunit (p-NFκB-p65), tumour necrosis factor-α (TNFα), C-X-C chemokine receptor type-4 (CXCR4), and urokinase plasminogen activator receptor (uPAR) in oestrogen receptor (ER)+/human epidermal growth factor receptor-2 (HER2)- BC cells under post-menopausal oestrogen conditions. In triple negative BC (TNBC) cells, PEDF treatment reduced pNFκB-p65 and uPAR expression under pre-menopausal oestrogen conditions. A potential reciprocal regulatory axis between p-NFκB-65 and PEDF in BC was identified, which was BC subtype-specific and differentially regulated by menopausal oestrogen conditions. The effects of PEDF treatment and NFκB inhibition on BC cell function under menopausal conditions were also compared. PEDF treatment exhibited superior anti-viability effects, while combined PEDF and NFκB-p65 inhibitor treatment was superior in reducing BC cell colony formation in a subtype-specific manner. Lastly, immunohistochemical evaluation of p-NFκB-p65 and PEDF expression in human BC and bone metastases specimens revealed an inverse correlation between nuclear PEDF and NFκB expression in bone metastases. We propose that menopausal status is associated with a PEDF/NFκB reciprocal regulatory axis, which drives PEDF expression and anti-metastatic function in a subtype-specific manner. Altogether, our findings identify pre-menopausal TNBC and post-menopausal ER+/HER2- BC patients as target populations for future PEDF research.


Assuntos
Neoplasias da Mama , Serpinas , Neoplasias de Mama Triplo Negativas , Humanos , Feminino , Neoplasias da Mama/genética , NF-kappa B/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Pós-Menopausa , Estrogênios , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Serpinas/genética , Serpinas/metabolismo , Receptores de Estrogênio/genética , Microambiente Tumoral
6.
Stem Cells ; 38(1): 6-14, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31648395

RESUMO

Emerging evidence in cancer metabolomics has identified reprogrammed metabolic pathways to be a major hallmark of cancer, among which deregulated lipid metabolism is a prominent field receiving increasing attention. Cancer stem cells (CSCs) comprise <0.1% of the tumor bulk and possess high self-renewal, tumor-initiating properties, and are responsible for therapeutic resistance, disease recurrence, and tumor metastasis. Hence, it is imperative to understand the metabolic rewiring occurring in CSCs, especially their lipid metabolism, on which there have been recent reports. CSCs rely highly upon lipid metabolism for maintaining their stemness properties and fulfilling their biomass and energy demands, ultimately leading to cancer growth and invasion. Hence, in this review we will shed light on the aberrant lipid metabolism that CSCs exploit to boost their survival, which comprises upregulation in de novo lipogenesis, lipid droplet synthesis, lipid desaturation, and ß-oxidation. Furthermore, the metabolic regulators involved in the process, such as key lipogenic enzymes, are also highlighted. Finally, we also summarize the therapeutic strategies targeting the key regulators involved in CSCs' lipid metabolism, which thereby demonstrates the potential to develop powerful and novel therapeutics against the CSC lipid metabolome.


Assuntos
Metabolismo dos Lipídeos/fisiologia , Células-Tronco Neoplásicas/metabolismo , Humanos
7.
Exp Cell Res ; 389(2): 111891, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32035134

RESUMO

Pigment epithelium-derived factor (PEDF) is an endogenous human glycoprotein first identified as a neurotrophic factor in retinal pigmented epithelium cells. PEDF has since been shown to play a central role in mediating cellular protection against oxidative stress, by promoting cell survival, reducing inflammation, and inhibiting pathological angiogenesis in a range of cell types and tissues. PEDF is a well-established neurotrophic factor which supports neurogenesis and provides neuroprotection in response to cellular stress, with numerous studies demonstrating the ability of PEDF to promote neuronal survival and growth following injury. PEDF is an essential component of the stem cell microenvironment and bone extracellular matrix, where it regulates the differentiation of osteoblast precursor cells to promote normal bone development. Accumulating evidence indicates that PEDF maintains stem cell populations and promotes neuronal growth and bone formation by directing cell fate and regulating cell cycle progression. The ability of PEDF to promote neurogenesis, osteogenesis, and stemness indicates therapeutic potential in diseases characterised by tissue degeneration. In this review, we provide a current summary of the role of PEDF in regulating cellular survival and differentiation in bone, the central nervous system, and other stem cell niches, and highlight the emerging potential of PEDF as a regenerative therapeutic agent.


Assuntos
Diferenciação Celular , Proteínas do Olho/metabolismo , Fatores de Crescimento Neural/metabolismo , Neurônios/citologia , Medicina Regenerativa , Serpinas/metabolismo , Células-Tronco/citologia , Animais , Morte Celular , Humanos , Neurônios/metabolismo , Células-Tronco/metabolismo
8.
Acta Virol ; 65(2): 160-172, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34130467

RESUMO

The deadly disease-causing novel coronavirus has recently swept across the world and endangered many human lives. Although, various research on therapeutic measures to solve this pandemic crisis has been published; no favourable results have been achieved. We propose the use of potential FDA-approved dual inhibitors which can inhibit two targets (either on entry-level or the main protease) for the effective treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We screened 12 FDA-approved antiviral inhibitors listed in Drug bank and analysed the ADMET properties of each drug of interest to study the bioavailability, safety and toxicity. Two potential targets, the spike protein and the main protease of SARS-CoV-2 obtained from PDB have been used for molecular docking. All the selected drugs were docked with both targets and demonstrated strong hydrogen bond (HB) interactions in multiple active sites. Amongst these, the range of binding energy was from 3-7 kcal/mol for spike protein and 2-8 kcal/mol for the main protease. Upon comparison of all the processed drugs ganciclovir and zanamivir displayed significant binding energy with HB interactions with both, spike (-9.2 and -9 kcal/mol respectively) and the main protease (-9 kcal/mol). Ribavirin and tenofovir showed significant binding energy above -8 kcal/mol with seven HB interactions with the main protease and also spike protein. The novel findings regarding the antiviral properties of these dual inhibitors using a computational approach will be a good starting point for the efficacy determination of these drugs for pre-clinical and clinical studies aimed at developing active antivirals to target SARS-CoV-2. Keywords: SARS-CoV-2; FDA-approved drugs; viral inhibitors; in-silico analysis; molecular docking.


Assuntos
COVID-19 , Glicoproteína da Espícula de Coronavírus , Antivirais/farmacologia , Humanos , Simulação de Acoplamento Molecular , Peptídeo Hidrolases , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética
9.
J Biol Chem ; 292(27): 11218-11229, 2017 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-28533339

RESUMO

Wnt signaling pathways are of significant interest in development and oncogenesis. The first step in these pathways typically involves the binding of a Wnt protein to the cysteine-rich domain (CRD) of a Frizzled receptor. Wnt-Frizzled interactions can be antagonized by secreted Frizzled-related proteins (SFRPs), which also contain a Frizzled-like CRD. The large number of Wnts, Frizzleds, and SFRPs, as well as the hydrophobic nature of Wnt, poses challenges to laboratory-based investigations of interactions involving Wnt. Here, utilizing structural knowledge of a representative Wnt-Frizzled CRD interaction, as well as experimentally determined binding affinities for a selection of Wnt-Frizzled CRD interactions, we generated homology models of Wnt-Frizzled CRD interactions and developed a quantitative structure-activity relationship for predicting their binding affinities. The derived model incorporates a small selection of terms derived from scoring functions used in protein-protein docking, as well as an energetic term considering the contribution made by the lipid of Wnt to the Wnt-Frizzled binding affinity. Validation with an external test set suggests that the model can accurately predict binding affinity for 75% of cases and that the error associated with the predictions is comparable with the experimental error. The model was applied to predict the binding affinities of the full range of mouse and human Wnt-Frizzled and Wnt-SFRP interactions, indicating trends in Wnt binding affinity for Frizzled and SFRP CRDs. The comprehensive predictions made in this study provide the basis for laboratory-based studies of previously unexplored Wnt-Frizzled and Wnt-SFRP interactions, which, in turn, may reveal further Wnt signaling pathways.


Assuntos
Receptores Frizzled , Simulação de Acoplamento Molecular , Proteínas Wnt , Via de Sinalização Wnt/fisiologia , Animais , Receptores Frizzled/genética , Receptores Frizzled/metabolismo , Humanos , Ligação Proteica , Domínios Proteicos , Proteínas Wnt/química , Proteínas Wnt/genética , Proteínas Wnt/metabolismo
10.
Mol Cell Biochem ; 443(1-2): 205-213, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29185158

RESUMO

In malignant mesothelioma (MM) cells, secreted frizzled-related protein 4 (SFRP4) expression is downregulated by promoter methylation. In this study, we evaluated the effect of encapsulated chitosan-dextran (CS-DS) nanoparticle formulations of SFRP4 and its cysteine-rich domain (CRD) and netrin-like domain (NLD) as means of SFRP4-GFP protein delivery and their effects in JU77 and ONE58 MM cell lines. CS-DS formulations of SFRP4, CRD, and NLD nanoparticles were prepared by a complex coacervation technique, and particle size ranged from 300 nm for empty particles to 337 nm for particles containing the proteins. Measurement of the zeta potential showed that all preparations were around 25 mV or above, suggesting stable formulation and good affinity for the DNA molecules. The CS-DS nanoparticle formulation maintained high integrity and entrapment efficiency. Gene delivery of SFRP4 and its domains showed enhanced biological effects in both JU77 and ONE58 cell lines when compared to the non-liposomal FUGENE® HD transfection reagent. In comparison to the CRD nanoparticles, both the SFRP4 and NLD nanoparticles significantly reduced the viability of MM cells, with the NLD showing the greatest effect. The CS-DS nanoparticle effects were observed at an earlier time point and with lower DNA concentrations. Morphological changes in MM cells were characterized by the formation of membrane-associated vesicles and green fluorescent protein expression specific to SFRP4 and the NLD. The findings from our proof-of-concept study provide a stepping stone for further investigations using in vivo models.


Assuntos
Quitosana , Sulfato de Dextrana , Expressão Gênica , Técnicas de Transferência de Genes , Mesotelioma/metabolismo , Nanopartículas , Proteínas Proto-Oncogênicas/biossíntese , Linhagem Celular Tumoral , Quitosana/química , Quitosana/farmacologia , Sulfato de Dextrana/química , Sulfato de Dextrana/farmacologia , Humanos , Mesotelioma/genética , Mesotelioma/patologia , Mesotelioma/terapia , Nanopartículas/química , Nanopartículas/uso terapêutico , Proteínas Proto-Oncogênicas/genética
11.
Nitric Oxide ; 66: 30-42, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28267592

RESUMO

Nitric oxide (NO) plays a critical role in endothelial functions such as cellular migration, vascular permeability and angiogenesis. Angiogenesis, the formation of new blood vessels from "pre-existing" ones is a carefully regulated process and essential during reproduction, development and wound healing. Previously our lab group reported that Secreted Frizzled-Related Protein 4 (sFRP4) could inhibit angiogenesis in both in vitro and in vivo conditions. sFRP4 belongs to a family of secreted glycoproteins that function as antagonists of the canonical Wnt signalling pathway. Although the pro-apoptotic role of sFRP4 is well discussed in literature, little is known in regards to its anti-angiogenic property. The objective of this study was to elucidate sFRP4 implications in NO biology of the endothelium. Results demonstrate that sFRP4 causes endothelial dysfunction by suppressing NO-cGMP signaling and elevating corresponding ROS levels. The imbalance between NO and ROS levels results in apoptosis and subsequent leakiness of endothelium as confirmed in vivo (Texas red/Annxin - CAM assay) and in vitro (Monolayer permeability assay) conditions. Furthermore utilizing peptides synthesized from the CRD domain of sFRP4, our results showed that while these peptides were able to cause endothelial dysfunctions, they did not cause apoptosis of the endothelial cells. Thereby confirming that sFRP4 can mediate its anti-angiogenic effect independent of its pro-apoptotic property. In conclusion, the current study reports that sFRP4-mediated anti-angiogenesis occurs as a result of impaired NO-cGMP signaling which in turn allow for elevation of redox levels and promotion of apoptosis of endothelial cells.


Assuntos
Apoptose/fisiologia , Permeabilidade da Membrana Celular/fisiologia , GMP Cíclico/metabolismo , Endotélio/metabolismo , Óxido Nítrico/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Linhagem Celular , Células Endoteliais/metabolismo , Humanos , Neovascularização Patológica/metabolismo , Espécies Reativas de Oxigênio , Transdução de Sinais/fisiologia
12.
Exp Cell Res ; 341(2): 218-24, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26868304

RESUMO

Malignant mesothelioma (MM) is an aggressive cancer, characterized by rapid progression, along with late metastasis and poor patient prognosis. It is resistant to many forms of standard anti-cancer treatment. In this study, we determined the effect of secreted frizzled-related protein 4 (sFRP4), a Wnt pathway inhibitor, on cancer cell proliferation and metabolism using the JU77 mesothelioma cell line. Treatment with sFRP4 (250 pg/ml) resulted in a significant reduction of cell proliferation. The addition of the Wnt activator Wnt3a (250 pg/ml) or sFRP4 had no significant effect on ATP production and glucose utilisation in JU77 cells at both the 24 and 48 h time points examined. We also examined their effect on Akt and Glycogen synthase kinase-3 beta (GSK3ß) phosphorylation, which are both important components of Wnt signalling and glucose metabolism. We found that protein phosphorylation of Akt and GSK3ß varied over the 24h and 48 h time points, with constitutive phosphorylation of Akt at serine 473 (pAkt) decreasing to its most significant level when treated with Wnt3a+sFRP4 at the 24h time point. A significant reduction in the level of Cytochrome c oxidase was observed at the 48 h time point, when sFRP4 and Wnt3a were added in combination. We conclude that sFRP4 may function, in part, to reduce/alter cancer cell metabolism, which may lead to sensitisation of cancer cells to chemotherapeutics, or even cell death.


Assuntos
Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Via de Sinalização Wnt/fisiologia , Apoptose/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Mesotelioma/tratamento farmacológico , Mesotelioma/patologia , Mesotelioma Maligno , Fosforilação , Proteínas Proto-Oncogênicas/antagonistas & inibidores
13.
Mol Cancer ; 15(1): 69, 2016 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-27825361

RESUMO

Cancer Stem cells (CSCs) are a unipotent cell population present within the tumour cell mass. CSCs are known to be highly chemo-resistant, and in recent years, they have gained intense interest as key tumour initiating cells that may also play an integral role in tumour recurrence following chemotherapy. Cancer cells have the ability to alter their metabolism in order to fulfil bio-energetic and biosynthetic requirements. They are largely dependent on aerobic glycolysis for their energy production and also are associated with increased fatty acid synthesis and increased rates of glutamine utilisation. Emerging evidence has shown that therapeutic resistance to cancer treatment may arise due to dysregulation in glucose metabolism, fatty acid synthesis, and glutaminolysis. To propagate their lethal effects and maintain survival, tumour cells alter their metabolic requirements to ensure optimal nutrient use for their survival, evasion from host immune attack, and proliferation. It is now evident that cancer cells metabolise glutamine to grow rapidly because it provides the metabolic stimulus for required energy and precursors for synthesis of proteins, lipids, and nucleic acids. It can also regulate the activities of some of the signalling pathways that control the proliferation of cancer cells.This review describes the key metabolic pathways required by CSCs to maintain a survival advantage and highlights how a combined approach of targeting cellular metabolism in conjunction with the use of chemotherapeutic drugs may provide a promising strategy to overcome therapeutic resistance and therefore aid in cancer therapy.


Assuntos
Metabolismo Energético , Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Animais , Antimetabólitos Antineoplásicos/farmacologia , Antimetabólitos Antineoplásicos/uso terapêutico , Respiração Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Metabolismo Energético/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Glicólise/genética , Humanos , Proteínas de Membrana Transportadoras/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos
14.
Reprod Fertil Dev ; 28(5): 525-44, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25190280

RESUMO

The integration of a complex network of signalling molecules promotes implantation of the blastocyst and development of the placenta. These processes are crucial for a successful pregnancy and fetal growth and development. The signalling network involves both cell-cell and cell-extracellular matrix communication. The family of secreted glycoprotein ligands, the Wnts, plays a major role in regulating a wide range of biological processes, including embryonic development, cell fate, proliferation, migration, stem cell maintenance, tumour suppression, oncogenesis and tissue homeostasis. Recent studies have provided evidence that Wnt signalling pathways play an important role in reproductive tissues and in early pregnancy events. The focus of this review is to summarise our present knowledge of expression, regulation and function of the Wnt signalling pathways in early pregnancy events of human and other model systems, and its association with pathological conditions. Despite our recent progress, much remains to be learned about Wnt signalling in human reproduction. The advancement of knowledge in this area has applications in the reduction of infertility and the incidence and morbidity of gestational diseases.


Assuntos
Blastocisto/metabolismo , Implantação do Embrião , Placenta/metabolismo , Placentação , Útero/metabolismo , Proteínas Wnt/metabolismo , Via de Sinalização Wnt , Animais , Comunicação Celular , Feminino , Doenças dos Genitais Femininos/metabolismo , Doenças dos Genitais Femininos/patologia , Doenças dos Genitais Femininos/fisiopatologia , Humanos , Infertilidade Feminina/metabolismo , Infertilidade Feminina/patologia , Infertilidade Feminina/fisiopatologia , Placenta/patologia , Placenta/fisiopatologia , Doenças Placentárias/metabolismo , Doenças Placentárias/patologia , Doenças Placentárias/fisiopatologia , Gravidez , Útero/patologia , Útero/fisiopatologia
15.
Biochim Biophys Acta ; 1845(1): 53-65, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24316024

RESUMO

The Wnt (wingless-type) signaling pathway plays an important role in embryonic development, tissue homeostasis, and tumor progression becaluse of its effect on cell proliferation, migration, and differentiation. Secreted frizzled-related proteins (SFRPs) are extracellular inhibitors of Wnt signaling that act by binding directly to Wnt ligands or to Frizzled receptors. In recent years, aberrant expression of SFRPs has been reported to be associated with numerous cancers. As gene expression of SFRP members is often lost through promoter hypermethylation, inhibition of methylation through the use of epigenetic modifying agents could renew the expression of SFRP members and further antagonize deleterious Wnt signaling. Several reports have described epigenetic silencing of these Wnt signaling antagonists in various human cancers, suggesting their possible role as tumor suppressors. SFRP family members thus come across as potential tools in combating Wnt-driven tumorigenesis. However, little is known about SFRP family members and their role in different cancers. This review comprehensively covers all the available information on the role of SFRP molecules in various human cancers.


Assuntos
Glicoproteínas/fisiologia , Neoplasias/etiologia , Proteínas Wnt/antagonistas & inibidores , Animais , Glicoproteínas/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/fisiologia , Via de Sinalização Wnt
16.
Reproduction ; 150(2): 151-63, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25948249

RESUMO

The aim of the present study was to determine the direct cause of the mutation-induced, increased ovulation rate in Booroola Merino (BB) sheep. Granulosa cells were removed from antral follicles before ovulation and post-ovulation from BB (n=5) and WT (n=12) Merino ewes. Direct immunofluorescence measurement of mature cell surface receptors using flow cytometry demonstrated a significant up-regulation of FSH receptor (FSHR), transforming growth factor beta type 1, bone morphogenetic protein receptor (BMPR1B), and LH receptor (LHR) in BB sheep. The increased density of FSHR and LHR provide novel evidence of a mechanism for increasing the number of follicles that are recruited during dominant follicle selection. The compounding increase in receptors with increasing follicle size maintained the multiple follicles and reduced the apoptosis, which contributed to a high ovulation rate in BB sheep. In addition, we report a mutation-independent mechanism of down-regulation to reduce receptor density of the leading dominant follicle in sheep. The suppression of receptor density coincides with the cessation of mitogenic growth and steroidogenic differentiation as part of the luteinization of the follicle. The BB mutation-induced attenuation of BMPR1B signaling led to an increased density of the FSHR and LHR and a concurrent reduction in apoptosis to increase the ovulation rate. The role of BMPs in receptor modulation is implicated in the development of multiple ovulations.


Assuntos
Apoptose/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/genética , Células da Granulosa/efeitos dos fármacos , Ovulação/genética , Receptores do FSH/genética , Receptores do LH/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/antagonistas & inibidores , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/metabolismo , Feminino , Citometria de Fluxo , Mutação/genética , Mutação/fisiologia , Folículo Ovariano/anatomia & histologia , Folículo Ovariano/fisiologia , Ovulação/efeitos dos fármacos , Ovulação/fisiologia , Gravidez , Receptores do FSH/antagonistas & inibidores , Receptores do FSH/metabolismo , Receptores do LH/antagonistas & inibidores , Receptores do LH/metabolismo , Carneiro Doméstico , Esteroides/biossíntese
17.
Tumour Biol ; 36(1): 143-52, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25501511

RESUMO

Secreted frizzled-related protein 4 (SFRP4) is a glycoprotein that acts as an antagonist of Wnt ligands, causing inhibition of the canonical Wnt signalling pathway. First noticed due to high expression levels during times of increased apoptosis, SFRP4 has been implicated in cell proliferation and differentiation and plays an important role in carcinogenesis. Many tumours such as endometrial, cervical, ovarian, prostate, bladder, colorectal, mesothelioma, pancreatic, renal, and oesophageal tumours are characterised by aberrant promoter hypermethylation, which causes variations in the expression level of SFRP4 when compared to normal cells. Combined experimental data appear to confirm the suggested role of SFRP4 as a local initiator of apoptosis; however, increased SFRP4 expression may not always correlate with an increase in apoptosis, possibly due to the complex interactions between different signalling pathways. SFRP4 can be explored for its use in novel therapeutic modalities as well as being a potential diagnostic biomarker.


Assuntos
Apoptose , Neoplasias/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Humanos , Neoplasias/patologia , Proteínas Proto-Oncogênicas/fisiologia
18.
Cancer Cell Int ; 14(1): 110, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25400509

RESUMO

BACKGROUND: Prostate cancer is associated with a poor survival rate. The ability of cancer cells to evade apoptosis and exhibit limitless replication potential allows for progression of cancer from a benign to a metastatic phenotype. The aim of this study was to investigate in vitro the effect of the isoflavone phenoxodiol on the expression of cell cycle genes. METHODS: Three prostate cancer cell lines-LNCaP, DU145, and PC3 were cultured in vitro, and then treated with phenoxodiol (10 µM and 30 µM) for 24 and 48 h. The expression of cell cycle genes p21(WAF1), c-Myc, Cyclin-D1, and Ki-67 was investigated by Real Time PCR. RESULTS: Here we report that phenoxodiol induces cell cycle arrest in the G1/S phase of the cell cycle, with the resultant arrest due to the upregulation of p21(WAF1) in all the cell lines in response to treatment, indicating that activation of p21(WAF1) and subsequent cell arrest was occurring via a p53 independent manner, with induction of cytotoxicity independent of caspase activation. We found that c-Myc and Cyclin-D1 expression was not consistently altered across all cell lines but Ki-67 signalling expression was decreased in line with the cell cycle arrest. CONCLUSIONS: Phenoxodiol demonstrates an ability in prostate cancer cells to induce significant cytotoxicity in cells by interacting with p21(WAF1) and inducing cell cycle arrest irrespective of p53 status or caspase pathway interactions. These data indicate that phenoxodiol would be effective as a potential future treatment modality for both hormone sensitive and hormone refractory prostate cancer.

19.
Cancers (Basel) ; 16(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38473318

RESUMO

Carcinogenesis is a complex process characterized by intricate changes in organ histology, biochemistry, epigenetics, and genetics. Within this intricate landscape, cancer stem cells (CSCs) have emerged as distinct cell types possessing unique attributes that significantly contribute to the pathogenesis of cancer. The WNT signaling pathway plays a critical role in maintaining somatic stem cell pluripotency. However, in cancer, overexpression of WNT mediators enhances the activity of ß-catenin, resulting in phenomena such as recurrence and unfavorable survival outcomes. Notably, CSCs exhibit heightened WNT signaling compared to bulk cancer cells, providing intriguing insights into their functional characteristics. MicroRNAs (miRNAs), as post-transcriptional gene expression regulators, modulate various physiological processes in numerous diseases including cancer. Upregulation or downregulation of miRNAs can affect the production of pro-oncogenic or anti-oncogenic proteins, influencing cellular processes that maintain tissue homeostasis and promote either apoptosis or differentiation, even in cancer cells. In order to understand the dysregulation of miRNAs, it is essential to examine miRNA biogenesis and any possible alterations at each step. The potential of a miRNA as a biomarker in prognosis, diagnosis, and detection is being assessed using technologies such as next-generation sequencing. Extensive research has explored miRNA expression profiles in cancer, leading to their utilization as diagnostic tools and the development of personalized and targeted cancer therapies. This review delves into the role of miRNAs in carcinogenesis in relation to the WNT signaling pathway along with their potential as druggable compounds.

20.
Mol Neurobiol ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38421469

RESUMO

Spinal cord injury (SCI) is a complex neurodegenerative pathology that consistently harbours a poor prognostic outcome. At present, there are few therapeutic strategies that can halt neuronal cell death and facilitate functional motor recovery. However, recent studies have highlighted the Wnt pathway as a key promoter of axon regeneration following central nervous system (CNS) injuries. Emerging evidence also suggests that the temporal dysregulation of Wnt may drive cell death post-SCI. A major challenge in SCI treatment resides in developing therapeutics that can effectively target inflammation and facilitate glial scar repair. Before Wnt signalling is exploited for SCI therapy, further research is needed to clarify the implications of Wnt on neuroinflammation during chronic stages of injury. In this review, an attempt is made to dissect the impact of canonical and non-canonical Wnt pathways in relation to individual aspects of glial and fibrotic scar formation. Furthermore, it is also highlighted how modulating Wnt activity at chronic time points may aid in limiting lesion expansion and promoting axonal repair.

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