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1.
Biochem Biophys Res Commun ; 722: 150161, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-38797153

RESUMO

Melanoma, arising from the malignant transformation of melanocytes, stands as the most lethal type of skin cancer. While significant strides have been made in targeted therapy and immunotherapy, substantially enhancing therapeutic efficacy, the prognosis for melanoma patients remains unoptimistic. SIRT7, a nuclear-localized deacetylase, plays a pivotal role in maintaining cellular homeostasis and adapting to external stressors in melanoma, with its activity closely tied to intracellular nicotinamide adenine dinucleotide (NAD+). However, its involvement in adaptive resistance to targeted therapy remains unclear. Herein, we unveil that up-regulated SIRT7 promotes mitochondrial biogenesis to render the adaptive resistance to MAPK inhibition in melanoma. Initially, we observed a significant increase of SIRT7 expression in publicly available datasets following targeted therapy within a short duration. In consistent, we found elevated SIRT7 expression in melanoma cells subjected to BRAF or MEK inhibitors in vitro. The up-regulation of SIRT7 expression was also confirmed in xenograft tumors in mice after targeted therapy in vivo. Furthermore, we proved that SIRT7 deficiency led to decreased cell viability upon prolonged exposure to BRAF or MEK inhibitors, accompanied by an increase in cell apoptosis. Mechanistically, SIRT7 deficiency restrained the upregulation of genes associated with mitochondrial biogenesis and intracellular ATP levels in response to targeted therapy treatment in melanoma cells. Ultimately, we proved that SIRT7 deficieny could sensitize BRAF-mutant melanoma cells to MAPK inhibition targeted therapy in vivo. In conclusion, our findings underscore the role of SIRT7 in fostering adaptive resistance to targeted therapy through the facilitation of mitochondrial biogenesis. Targeting SIRT7 emerges as a promising strategy to overcome MAPK inhibitor adaptive resistance in melanoma.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Melanoma , Biogênese de Organelas , Inibidores de Proteínas Quinases , Sirtuínas , Melanoma/metabolismo , Melanoma/patologia , Melanoma/genética , Melanoma/tratamento farmacológico , Humanos , Sirtuínas/metabolismo , Sirtuínas/genética , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores de Proteínas Quinases/farmacologia , Camundongos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/tratamento farmacológico , Camundongos Nus , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores
2.
Cell Commun Signal ; 22(1): 83, 2024 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-38291473

RESUMO

BACKGROUND: Tumor cells frequently suffer from endoplasmic reticulum (ER) stress. Previous studies have extensively elucidated the role of tumorous unfolded protein response in melanoma cells, whereas the effect on tumor immunology and the underlying mechanism remain elusive. METHODS: Bioinformatics, biochemical assays and pre-clinical mice model were employed to demonstrate the role of tumorous inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) in anti-tumor immunity and the underlying mechanism. RESULTS: We firstly found that IRE1α signaling activation was positively associated with the feature of tumor-infiltrating lymphocytes. Then, pharmacological ER stress induction by HA15 exerted prominent anti-tumor effect in immunocompetent mice and was highly dependent on CD8+T cells, paralleled with the reshape of immune cells in tumor microenvironment via tumorous IRE1α-XBP1 signal. Subsequently, tumorous IRE1α facilitated the expression and secretion of multiple chemokines and cytokines via XBP1-NF-κB axis, leading to increased infiltration and anti-tumor capacity of CD8+T cells. Ultimately, pharmacological induction of tumorous ER stress by HA15 brought potentiated therapeutic effect along with anti-PD-1 antibody on melanoma in vivo. CONCLUSIONS: Tumorous IRE1α facilitates CD8+T cells-dependent anti-tumor immunity and improves immunotherapy efficacy by regulating chemokines and cytokines via XBP1-NF-κB axis. The combination of ER stress inducer and anti-PD-1 antibody could be promising for increasing the efficacy of melanoma immunotherapy.


Assuntos
Melanoma , Animais , Camundongos , Linfócitos T CD8-Positivos/patologia , Quimiocinas , Citocinas , Endorribonucleases , Melanoma/patologia , NF-kappa B , Proteínas Serina-Treonina Quinases/metabolismo , Linfócitos T/metabolismo , Microambiente Tumoral
3.
Cell Mol Life Sci ; 80(11): 315, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37801083

RESUMO

Melanoma is the most lethal skin cancer originating from the malignant transformation of epidermal melanocyte. The dysregulation of cellular metabolism is a hallmark of cancer, including in melanoma. Aberrant branched-chain amino acids (BCAA) metabolism and related enzymes has been greatly implicated in the progression of multiple types of cancer, whereas remains far from understood in melanoma. Herein, we reported that the critical BCAA metabolism enzyme branched-chain amino acid transaminase 2 (BCAT2) is an oncogenic factor in melanoma by activating lipogenesis via the epigenetic regulation of fatty acid synthase (FASN) and ATP-citrate lyase (ACLY) expressions. Firstly, we found that BCAT2 expression was prominently increased in melanoma, and highly associated with clinical stage. Then, it was proved that the deficiency of BCAT2 led to impaired tumor cell proliferation, invasion and migration in vitro, and tumor growth and metastasis in vivo. Further, RNA sequencing technology and a panel of biochemical assays demonstrated that BCAT2 regulated de novo lipogenesis via the regulation of the expressions of both FASN and ACLY. Mechanistically, the inhibition of BCAT2 suppressed the generation of intracellular acetyl-CoA, mitigating P300-dependent histone acetylation at the promoter of FASN and ACLY, and thereby their transcription. Ultimately, zinc finger E-box binding homeobox 1 (ZEB1) was identified as the upstream transcriptional factor responsible for BCAT2 up-regulation in melanoma. Our results demonstrate that BCAT2 promotes melanoma progression by epigenetically regulating FASN and ACLY expressions via P300-dependent histone acetylation. Targeting BCAT2 could be exploited as a promising strategy to restrain tumor progression in melanoma.


Assuntos
Melanoma , Proteínas da Gravidez , Humanos , Lipogênese/genética , ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Histonas/metabolismo , Epigênese Genética , Melanoma/genética , Transaminases/genética , Proteínas da Gravidez/genética , Proteínas da Gravidez/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Ácido Graxo Sintase Tipo I/genética
4.
Exp Dermatol ; 32(10): 1633-1643, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37377173

RESUMO

The dysregulation of branched-chain amino acid (BCAA) metabolism and related enzymes has been greatly implicated in the progression of multiple types of cancer, whereas remains far from understood in melanoma. Here, we explored the role of the BCAA metabolism enzyme BCKDHA in melanoma pathogenesis and elucidated the underlying mechanisms. In vitro cell biology experiments and in vivo pre-clinical mice model experiments were performed to investigate the role of BCKDHA in melanoma progression. RNA sequencing, immunohistochemical/immunofluorescence staining and bioinformatics analysis were used to examine the underlying mechanism. BCKDHA expression was prominently increased in both melanoma tissues and cell lines. The up-regulation of BCKDHA promoted long-term tumour cell proliferation, invasion and migration in vitro and tumour growth in vivo. Through RNA-sequencing technology, it was found that BCKDHA regulated the expressions of lipogenic fatty acid synthase (FASN) and ATP-citrate lyase (ACLY), which was thereafter proved to mediate the oncogenic role of BCKDHA in melanoma. Our results demonstrate that BCKDHA promotes melanoma progression by regulating FASN and ACLY expressions. Targeting BCKDHA could be exploited as a promising strategy to restrain tumour progression in melanoma.


Assuntos
ATP Citrato (pro-S)-Liase , Melanoma , Animais , Camundongos , ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Linhagem Celular , Proliferação de Células , Lipogênese , Melanoma/genética
5.
Signal Transduct Target Ther ; 8(1): 107, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36918544

RESUMO

Melanoma is the most lethal type of skin cancer, originating from the malignant transformation of melanocyte. While the development of targeted therapy and immunotherapy has gained revolutionary advances in potentiating the therapeutic effect, the prognosis of patients with melanoma is still suboptimal. During tumor progression, melanoma frequently encounters stress from both endogenous and exogenous sources in tumor microenvironment. SIRT7 is a nuclear-localized deacetylase of which the activity is highly dependent on intracellular nicotinamide adenine dinucleotide (NAD+), with versatile biological functions in maintaining cell homeostasis. Nevertheless, whether SIRT7 regulates tumor cell biology and tumor immunology in melanoma under stressful tumor microenvironment remains elusive. Herein, we reported that SIRT7 orchestrates melanoma progression by simultaneously promoting tumor cell survival and immune evasion via the activation of unfolded protein response. We first identified that SIRT7 expression was the most significantly increased one in sirtuins family upon stress. Then, we proved that the deficiency of SIRT7 potentiated tumor cell death under stress in vitro and suppressed melanoma growth in vivo. Mechanistically, SIRT7 selectively activated the IRE1α-XBP1 axis to potentiate the pro-survival ERK signal pathway and the secretion of tumor-promoting cytokines. SIRT7 directly de-acetylated SMAD4 to antagonize the TGF-ß-SMAD4 signal, which relieved the transcriptional repression on IRE1α and induced the activation of the IRE1α-XBP1 axis. Moreover, SIRT7 up-regulation eradicated anti-tumor immunity by promoting PD-L1 expression via the IRE1α-XBP1 axis. Additionally, the synergized therapeutic effect of SIRT7 suppression and anti-PD-1 immune checkpoint blockade was also investigated. Taken together, SIRT7 can be employed as a promising target to restrain tumor growth and increase the effect of melanoma immunotherapy.


Assuntos
Melanoma , Sirtuínas , Humanos , Endorribonucleases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Sobrevivência Celular/genética , Evasão da Resposta Imune , Linhagem Celular Tumoral , Melanoma/genética , Microambiente Tumoral , Sirtuínas/genética
6.
Cells ; 11(22)2022 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-36429010

RESUMO

Melanoma is the most lethal form of skin cancer, resulting from the malignant transformation of epidermal melanocytes. Recent revolutionary progress in targeted therapy and immunotherapy has prominently improved the treatment outcome, but the survival of melanoma patients remains suboptimal. Ferroptosis is greatly involved in cancer pathogenesis and can execute the outcome of immunotherapy. However, the detailed regulatory mechanisms of melanoma cell ferroptosis remain elusive. Herein, we report that Wnt/ß-catenin signaling regulates ferroptosis and melanoma immunotherapy efficacy via the regulation of MITF. First of all, we found that Wnt/ß-catenin signaling was prominently suppressed in melanoma cell ferroptosis. Then, we proved that targeting ß-catenin exacerbated melanoma cell ferroptosis by promoting the generation of lipid peroxidation both in vitro and in vivo. Subsequent mechanistic studies revealed that MITF mediated the effect of Wnt/ß-catenin signaling on melanoma cell ferroptosis, and PGC1α and SCD1 were documented as two main effectors downstream of Wnt/ß-catenin-MITF pathway. Ultimately, pharmacological inhibition of ß-catenin or MITF increased the efficacy of anti-PD-1 immunotherapy in preclinical xenograft tumor model by promoting ferroptosis. Taken together, Wnt/ß-catenin signaling deficiency exacerbates ferroptosis in melanoma via the regulation of MITF. Targeting Wnt/ß-catenin-MITF pathway could be a promising strategy to potentiate ferroptosis and increase the efficacy of anti-PD-1 immunotherapy.


Assuntos
Ferroptose , Melanoma , Humanos , beta Catenina/metabolismo , Proteínas Wnt/metabolismo , Melanoma/patologia , Via de Sinalização Wnt , Imunoterapia , Fator de Transcrição Associado à Microftalmia/metabolismo
7.
Front Immunol ; 13: 909580, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36003368

RESUMO

Melanoma results from the malignant transformation of melanocytes and accounts for the most lethal type of skin cancers. In the pathogenesis of melanoma, disordered metabolism is a hallmark characteristic with multiple metabolic paradigms involved in, e.g., glycolysis, lipid metabolism, amino acid metabolism, oxidative phosphorylation, and autophagy. Under the driving forces of oncogenic mutations, melanoma metabolism is rewired to provide not only building bricks for macromolecule synthesis and sufficient energy for rapid proliferation and metastasis but also various metabolic intermediates for signal pathway transduction. Of note, metabolic alterations in tumor orchestrate tumor immunology by affecting the functions of surrounding immune cells, thereby interfering with their antitumor capacity, in addition to the direct influence on tumor cell intrinsic biological activities. In this review, we first introduced the epidemiology, clinical characteristics, and treatment proceedings of melanoma. Then, the components of the tumor microenvironment, especially different populations of immune cells and their roles in antitumor immunity, were reviewed. Sequentially, how metabolic rewiring contributes to tumor cell malignant behaviors in melanoma pathogenesis was discussed. Following this, the proceedings of metabolism- and metabolic intermediate-regulated tumor immunology were comprehensively dissertated. Finally, we summarized currently available drugs that can be employed to target metabolism to intervene tumor immunology and modulate immunotherapy.


Assuntos
Melanoma , Neoplasias Cutâneas , Glicólise , Humanos , Imunoterapia , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/terapia , Microambiente Tumoral
8.
J Immunother Cancer ; 10(6)2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35738798

RESUMO

BACKGROUND: Although anti-programmed cell death protein 1 (PD-1) immunotherapy is greatly effective in melanoma treatment, low response rate and treatment resistance significantly hinder its efficacy. Tumor cell ferroptosis triggered by interferon (IFN)-γ that is derived from tumor-infiltrating CD8+ T cells greatly contributes to the effect of immunotherapy. However, the molecular mechanism underlying IFN-γ-mediated ferroptosis and related potentially promising therapeutic strategy warrant further clarification. MicroRNAs (miRNAs) participate in ferroptosis execution and can be delivered systemically by multiple carriers, which have manifested obvious therapeutic effects on cancer. METHODS: MiRNAs expression profile in IFN-γ-driven ferroptosis was obtained by RNA sequencing. Biochemical assays were used to clarify the role of miR-21-3p in IFN-γ-driven ferroptosis and the underlying mechanism. MiR-21-3p-loaded gold nanoparticles were constructed and systemically applied to analyze the role of miR-21-3p in anti-PD-1 immunotherapy in preclinical transplanted tumor model. RESULTS: MiRNAs expression profile of melanoma cells in IFN-γ-driven ferroptosis was first obtained. Then, upregulated miR-21-3p was proved to facilitate IFN-γ-mediated ferroptosis by potentiating lipid peroxidation. miR-21-3p increased the ferroptosis sensitivity by directly targeting thioredoxin reductase 1 (TXNRD1) to enhance lipid reactive oxygen species (ROS) generation. Furthermore, miR-21-3p overexpression in tumor synergized with anti-PD-1 antibody by promoting tumor cell ferroptosis. More importantly, miR-21-3p-loaded gold nanoparticles were constructed, and the systemic delivery of them increased the efficacy of anti-PD-1 antibody without prominent side effects in preclinical mice model. Ultimately, ATF3 was found to promote miR-21-3p transcription in IFN-γ-driven ferroptosis. CONCLUSIONS: MiR-21-3 p upregulation contributes to IFN-γ-driven ferroptosis and synergizes with anti-PD-1 antibody. Nanoparticle delivery of miR-21-3 p is a promising therapeutic approach to increase immunotherapy efficacy without obvious systemic side effects.


Assuntos
Ferroptose , Melanoma , Nanopartículas Metálicas , MicroRNAs , Animais , Linfócitos T CD8-Positivos , Linhagem Celular Tumoral , Ouro , Humanos , Imunoterapia , Melanoma/tratamento farmacológico , Melanoma/genética , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo
9.
Dermatol Surg ; 47(11): 1455-1459, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34431819

RESUMO

BACKGROUND: The 2,940 nm erbium-doped yttrium aluminium garnet and 1,064 nm neodymium-doped yttrium aluminium garnet lasers have been widely applied in facial rejuvenation, but no randomized trials exist to evaluate the efficacy of the combination treatment. OBJECTIVE: The efficacy of the combined treatment for facial rejuvenation. MATERIALS AND METHODS: A total of 20 subjects with facial aging were enrolled and randomly assigned into 2 groups: one side of the face was treated with a 2,940 nm or 1,064 nm laser alone and the other side was treated with the combined lasers. The patients were treated by 3 sessions with 1-month intervals. The efficacies were quantitatively accessed by digitalized high-resolution photographs. RESULTS: The 1,064 nm laser alone showed significant improvements on indexes of skin texture, spore, brown spots, elasticity, and melanin as compared with the baseline (p < .05). The 2,940 nm laser alone showed significant improvements on indexes of wrinkle, texture, pore, and elasticity (p < .05). The combined treatments showed significant improvements on the abovementioned indexes as compared with either a 1,064 nm or 2,940 nm laser treatment (p < .05). CONCLUSION: A combination of 1,064 nm and 2,940 nm laser treatment renders significantly better efficacies for facial rejuvenation as compared with a 2,940 nm or 1,064 nm laser alone.


Assuntos
Técnicas Cosméticas , Lasers de Estado Sólido/uso terapêutico , Adulto , Face , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rejuvenescimento , Resultado do Tratamento
10.
J Invest Dermatol ; 141(12): 2932-2943.e12, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34048729

RESUMO

Melanoma cells are relatively resistant to endoplasmic reticulum (ER) stress, which contributes to tumor progression under stressful conditions and renders tolerance to ER stress‒inducing therapeutic agents. Mitochondria are tightly interconnected with ER. However, whether mitochondria play a role in regulating ER stress resistance in melanoma remains elusive. In this study, we reported that the XBP1‒MARCH5‒MFN2 axis conferred ER stress resistance by coordinating mitochondrial fission and mitophagy in melanoma. Our integrative bioinformatics first revealed that the downregulation of mitochondrial genes was highly correlated with unfolded protein response activation in melanoma. Then we proved that mitochondrial fission and mitophagy were prominently induced to contribute to ER stress resistance both in vitro and in vivo by maintaining mitochondrial function. Mechanistically, the activation of IRE1α/ATF6-XBP1 branches of unfolded protein response promoted the transcription of E3 ligase MARCH5 to facilitate the ubiquitination and degradation of MFN2, which thereby triggered mitochondrial fission and mitophagy under ER stress. Together, our findings show a regulatory axis that links mitochondrial fission and mitophagy to the resistance to ER stress. Targeting mitochondrial quality control machinery can be exploited as an approach to reinforce the efficacy of ER stress‒inducing agents against cancer.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , GTP Fosfo-Hidrolases/fisiologia , Melanoma/metabolismo , Proteínas de Membrana/fisiologia , Dinâmica Mitocondrial/fisiologia , Proteínas Mitocondriais/fisiologia , Mitofagia/fisiologia , Ubiquitina-Proteína Ligases/fisiologia , Proteína 1 de Ligação a X-Box/fisiologia , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Resposta a Proteínas não Dobradas
11.
Adv Biosyst ; 4(9): e2000004, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32734694

RESUMO

Age-related human trabecular meshwork (HTM) cell loss is suggested to affect its ability to regulate aqueous humor outflow in the eye. In addition, disease-related HTM cell loss is suggested to lead to elevated intraocular pressure in glaucoma. Induced pluripotent stem cell (iPSC)-derived trabecular meshwork (TM) cells are promising autologous cell sources that can be used to restore the declining TM cell population and function. Previously, an in vitro HTM model is bioengineered for understanding HTM cell biology and screening of pharmacological or biological agents that affect trabecular outflow facility. In this study, it is demonstrated that human iPSC-derived TM cells cultured on SU-8 scaffolds exhibit HTM-like cell morphology, extracellular matrix deposition, and drug responsiveness to dexamethasone treatment. These findings suggest that iPSC-derived TM cells behave like primary HTM cells and can thus serve as reproducible and scalable cell sources when using this in vitro system for glaucoma drug screening and further understanding of outflow pathway physiology, leading to personalized medicine.


Assuntos
Células-Tronco Pluripotentes Induzidas , Modelos Biológicos , Malha Trabecular , Biomimética , Técnicas de Cultura de Células/métodos , Glaucoma/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Malha Trabecular/citologia , Malha Trabecular/metabolismo
12.
Clin Sci (Lond) ; 134(10): 1127-1141, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32400851

RESUMO

Vitiligo is a depigmentation disorder that develops as a result of the progressive disappearance of epidermal melanocytes. The elevated level of amino acid metabolite homocysteine (Hcy) has been identified as circulating marker of oxidative stress and known as a risk factor for vitiligo. However, the mechanism underlying Hcy-regulated melanocytic destruction is currently unknown. The present study aims to elucidate the effect of Hcy on melanocytic destruction and its involvement in the pathogenesis of vitiligo. Our results showed that Hcy level was significantly elevated in the serum of progressive vitiligo patients. Notably, Hcy induced cell apoptosis in melanocytes via activating reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress protein kinase RNA-like ER kinase (PERK)-eukaryotic translation initiation factor 2α (eIF2α)-C/EBP homologous protein (CHOP) pathway. More importantly, folic acid, functioning in the transformation of Hcy, could lower the intracellular Hcy level and further reverse the apoptotic effect of Hcy on melanocytes. Additionally, Hcy disrupted melanogenesis whereas folic acid supplementation could reverse the melanogenesis defect induced by Hcy in melanocytes. Taken together, Hcy is highly increased in vitiligo patients at progressive stage, and our in vitro studies revealed that folic acid could protect melanocytes from Hcy-induced apoptosis and melanin synthesis inhibition, indicating folic acid as a potential benefit agent for patients with progressive vitiligo.


Assuntos
Apoptose , Fator de Iniciação 2 em Eucariotos/metabolismo , Homocisteína/metabolismo , Melanócitos/metabolismo , Melanócitos/patologia , Fator de Transcrição CHOP/metabolismo , Vitiligo/metabolismo , eIF-2 Quinase/metabolismo , Adulto , Apoptose/efeitos dos fármacos , Estudos de Casos e Controles , Proliferação de Células/efeitos dos fármacos , Progressão da Doença , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Feminino , Ácido Fólico/farmacologia , Homocisteína/sangue , Humanos , Masculino , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Modelos Biológicos , Transdução de Sinais/efeitos dos fármacos , Vitiligo/sangue
13.
Med Sci Monit ; 26: e920957, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32273491

RESUMO

Melanoma is an aggressive malignancy of melanocytes and most commonly arises in the skin. In 2002, BRAF gene mutations were identified in melanoma, and this finding resulted in the development of several small-molecule molecular inhibitors that specifically targeted the BRAF V600E mutation. The development of targeted therapies for advanced-stage melanoma, including tyrosine kinase inhibitors (TKIs) of the BRAF (V600E) kinase, vemurafenib and dabrafenib, have been approved for the treatment of advanced melanoma leading to improved clinical outcomes. However, the development of BRAF inhibitor (BRAFi) resistance has significantly reduced the therapeutic efficacy after prolonged treatment. Recent studies have identified the molecular mechanisms for BRAFi resistance. This review aims to describe the impact of BRAFi resistance on the pathogenesis of melanoma, the current status of molecular pathways involved in BRAFi resistance, including intrinsic resistance, adaptive resistance, and acquired resistance. This review will discuss how an understanding of the mechanisms associated with BRAFi resistance may aid the identification of useful strategies for overcoming the resistance to BRAF-targeted therapy in patients with advanced-stage melanoma.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Melanoma/genética , Proteínas Proto-Oncogênicas B-raf/genética , Antineoplásicos/farmacologia , Feminino , Humanos , Imidazóis/farmacologia , Masculino , Melanócitos/metabolismo , Melanoma/metabolismo , Terapia de Alvo Molecular , Mutação , Oximas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/metabolismo , Neoplasias Cutâneas/patologia , Vemurafenib/farmacologia
14.
Acta Biomater ; 105: 203-213, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31982588

RESUMO

Human Schlemm's canal (HSC) cells are critical for understanding outflow physiology and glaucoma etiology. However, primary donor cells frequently used in research are difficult to isolate. HSC cells exhibit both vascular and lymphatic markers. Human adipose-derived stem cells (ADSCs) represent a potential source of HSC due to their capacity to differentiate into both vascular and lymphatic endothelial cells, via VEGF-A and VEGF-C. Shear stress plays a critical role in maintaining HSC integrity, function, and PROX1 expression. Additionally, the human trabecular meshwork (HTM) microenvironment could provide cues for HSC-like differentiation. We hypothesize that subjecting ADSCs to VEGF-A or VEGF-C, shear stress, and co-culture with HTM cells could provide biological, mechanical, and cellular cues necessary for HSC-like differentiation. To test this hypothesis, effects of VEGF-A, VEGF-C, and shear stress on ADSC differentiation were examined and compared to primary HSC cells in terms of cell morphology, and HSC marker expression using qPCR, immunoblotting, and immunocytochemistry analysis. Furthermore, the effect of co-culture with HTM cells on porous scaffolds on ADSC differentiation was studied. Treatment with VEGF-C under shear stress is effective in differentiating ADSCs into PROX1-expressing HSC-like cells. Co-culture with HTM cells on porous scaffolds leads to HTM/ADSC-derived HSC-like constructs that regulate through-flow and respond as expected to dexamethasone. STATEMENT OF SIGNIFICANCE: We successfully generated human Schlemm's canal (HSC) like cells from adipocyte-derived stem cells induced by biochemical and biomechanical cues as well as bioengineered human trabecular meshwork (HTM) on micropatterned, porous SU8 scaffolds. These stem cell-derived HSC-like cells co-cultured with HTM cells on SU8 scaffolds can regulate through-flow, and in particular, are responsive to steroid treatment as expected. These findings show that ADSC-derived HSC-like cells have the potential to recreate the ocular outflow pathway for in vitro glaucoma drug screening. To the best of our knowledge, it is the very first time to demonstrate derivation of Schlemm's canal-like cells from stem cells. It provides an important alternative source to primary Schlemm's canal cells that are very difficult to be isolated and cultured from human donors.


Assuntos
Bioengenharia , Diferenciação Celular , Avaliação Pré-Clínica de Medicamentos , Glaucoma/tratamento farmacológico , Células-Tronco/citologia , Tecido Adiposo/citologia , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Técnicas de Cocultura , Dexametasona/farmacologia , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Glaucoma/patologia , Humanos , Imagem Óptica , Perfusão , Células-Tronco/efeitos dos fármacos , Malha Trabecular/citologia
15.
J Tissue Eng Regen Med ; 13(1): 76-86, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30381899

RESUMO

Retinal pigment epithelial (RPE) cells are highly specialized neural cells that have several functions essential for vision. Progressive deterioration of RPE cells in elderly individuals can result in visual impairment and ultimately the blinding disease age-related macular degeneration. Subretinal transplantation of stem cell-derived RPE cell suspensions is being explored as a strategy to recover the damaged retina and improve vision. This approach may be improved by developing a vehicle that increases postinjection cell viability and distribution and integration of RPE cells. In this study, Food and Drug Administration-approved natural polymers, including alginate, methylcellulose, and hyaluronic acid (HA), were examined for performance as cell vehicles for adult human RPE stem cells (RPESCs). We compared the effect of RPESC storage as a cell suspension in these delivery vehicles for 1-96 hr at different temperatures on subsequent cell performance in a cell culture model. RPESC survival, attachment, distribution, proliferation, and differentiation into RPE cells were monitored by microscopy over the course of 8 weeks. Our in vitro results demonstrate that RPESC suspension in a 0.2% HA solution promotes better initial cell distribution, proliferation, cobblestone formation, and expression of RPE cell markers (microphthalmia-associated transcription factor and orthodenticle homeobox 2) after 96 hr of storage. These data suggest that HA addition to the vehicle can significantly enhance RPESC performance in vitro and is a promising strategy to pursue an improved delivery vehicle supporting in vivo RPE cell transplantation.


Assuntos
Técnicas de Cultura de Células , Diferenciação Celular , Células Imobilizadas/metabolismo , Preservação Biológica , Epitélio Pigmentado da Retina/metabolismo , Células-Tronco/metabolismo , Idoso , Sobrevivência Celular , Células Imobilizadas/citologia , Humanos , Epitélio Pigmentado da Retina/citologia , Transplante de Células-Tronco , Células-Tronco/citologia
17.
Cell Stem Cell ; 22(6): 834-849, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29859174

RESUMO

Ocular regenerative therapies are on track to revolutionize treatment of numerous blinding disorders, including corneal disease, cataract, glaucoma, retinitis pigmentosa, and age-related macular degeneration. A variety of transplantable products, delivered as cell suspensions or as preformed 3D structures combining cells and natural or artificial substrates, are in the pipeline. Here we review the status of clinical and preclinical studies for stem cell-based repair, covering key eye tissues from front to back, from cornea to retina, and including bioengineering approaches that advance cell product manufacturing. While recognizing the challenges, we look forward to a deep portfolio of sight-restoring, stem cell-based medicine. VIDEO ABSTRACT.


Assuntos
Córnea/citologia , Oftalmopatias/terapia , Regeneração , Retina/citologia , Células-Tronco/citologia , Visão Ocular , Animais , Oftalmopatias/cirurgia , Humanos
18.
BMC Cancer ; 17(1): 737, 2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-29121872

RESUMO

BACKGROUND: The diagnostic and prognostic significance of carcinoembryonic antigen (CEA), carbohydrate associated antigen 19-9 (CA19-9), alpha-fetoprotein (AFP) and cancer antigen 125 (CA125) in early gastric cancer have not been investigated yet. Thus, the present study aimed to explore the diagnostic and prognostic significance of the four tumor markers for early gastric cancer. METHODS: From September 2008 to March 2015, 587 early gastric cancer patients were given radical gastrectomy in our center. The clinicopathological characteristics were recorded. The association between levels of CEA and CA19-9 and clinicopathological characteristics and prognosis of patients were analyzed. RESULTS: There were 444 men (75.6%) and 143 women (24.4%). The median age was 57 years (ranged 21-85). The 1-, 3- and 5-year overall survival rate was 99.1%, 96.8% and 93.1%, respectively. The positive rate of CEA, CA19-9, AFP and CA125 was 4.3%, 4.8%, 1.5% and 1.9%, respectively. The positive rate of all markers combined was 10.4%. The associations between the clinicopathological features and levels of CEA and CA19-9 were analyzed. No significant association was found between CEA level and clinicopathological features. However, elevated CA19-9 level was correlated with female gender and presence of lymph node metastasis. Age > 60 years old, presence of lymph node metastasis and elevation of CEA level were independent risk factors for poor prognosis of early gastric cancer. CONCLUSIONS: The positive rates of CEA, CA19-9, APF and CA125 were relatively low for early gastric cancer. Elevation of CA19-9 level was associated with female gender and presence of lymph node metastasis. Elevation of CEA level was an independent risk factor for the poor prognosis of early gastric cancer.


Assuntos
Biomarcadores Tumorais/sangue , Antígeno Ca-125/sangue , Antígeno CA-19-9/sangue , Antígeno Carcinoembrionário/sangue , Neoplasias Gástricas/sangue , alfa-Fetoproteínas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Detecção Precoce de Câncer/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/mortalidade , Taxa de Sobrevida/tendências
19.
Oncotarget ; 8(37): 62622-62629, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-28977974

RESUMO

Data about prognostic value of postoperative fever in gastric cancer was lacking. Thus, the present study aims to investigate the prognostic value of postoperative fever in gastric cancer. From September 2008 to March 2015, 2938 gastric cancer patients were enrolled in the present study. Clinicopathological features were recoded. The association between postoperative fever and prognosis of gastric cancer were analyzed. There were 2294 male (78.1%) and 644 female (21.9%). Seven hundred and fifty-six patients suffered from fever. Among them, the duration of fever less than 48h occurred in 508 cases, and duration of fever over 48h occurred in 248 cases. Univariate and multivariate analysis showed that postoperative fever was an independent risk factor for prognosis of gastric cancer (P < 0.001). For the entire cohort, duration of fever over 48h was significantly associated with decreased survival (P < 0.001). In subgroup analysis, duration of fever over 48h was significantly associated with poor prognosis of stage I and II gastric cancer (both P < 0.001). However, postoperative fever was not associated with the prognosis of stage III gastric cancer (P = 0.334). Considering the type of gastrectomy, postoperative fever was not associated with the prognosis of patients with proximal (P = 0.318) and distal gastrectomy (P = 0.806), but duration of fever over 48h was significantly associated with poor prognosis of patients with total gastrectomy (P = 0.004). In conclusion, postoperative fever was associated with poor prognosis of gastric cancer.

20.
Oncotarget ; 8(17): 28897-28905, 2017 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-28423645

RESUMO

Preoperative pulmonary function assessment is used to select surgical candidates and predict the occurrence of postoperative complications. The present study enrolled 1210 gastric cancer patients (949 males and 261 females). Forced vital capacity (FVC) and maximal voluntary ventilation (MVV) were measured as a percent of predicted values. We then analyzed associations between patient pulmonary function and both prognosis and postoperative complications. Patient 1-, 3- and 5-year overall survival rates were 88.8%, 65.7% and 53.0%, respectively. FVC and MVV optimal cutoff values were 87.0 (P=0.003) and 83.6 (P=0.026), respectively. Low FVC and low MVV were associated with higher rates of postoperative fever (23.8% vs. 13.9%, P<0.001; 17.8% vs. 13.3%, P=0.049, respectively) and poor patient prognosis (5-year overall survival: 43.5% vs. 57.6%, P=0.003; 51.8% vs. 54.3%, P=0.026, respectively). Only low FVC was an independent prognostic predictor for gastric cancer (P=0.012). In subgroup analyses, FVC was not associated with stage I or II gastric cancer patient prognoses (P>0.05), but low FVC was an independent risk factor for poor prognosis in stage III gastric cancer cases (P=0.004). These findings indicate that low FVC is predictive of poorer prognosis and higher risk of postoperative fever in gastric cancer patients.


Assuntos
Febre/etiologia , Pulmão/fisiopatologia , Complicações Pós-Operatórias/epidemiologia , Neoplasias Gástricas/mortalidade , Capacidade Vital , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Febre/epidemiologia , Seguimentos , Gastrectomia/efeitos adversos , Humanos , Masculino , Ventilação Voluntária Máxima , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Complicações Pós-Operatórias/etiologia , Período Pré-Operatório , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Taxa de Sobrevida , Adulto Jovem
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