RESUMO
The primary inflammatory process in atherosclerosis, a major contributor to cardiovascular disease, begins with monocyte adhering to vascular endothelial cells. Actinidia arguta (kiwiberry) is an edible fruit that contains various bioactive components. While A. arguta extract (AAE) has been recognized for its anti-inflammatory characteristics, its specific inhibitory effect on early atherogenic events has not been clarified. We used tumor necrosis factor-α (TNF-α)-stimulated human umbilical vein endothelial cells (HUVECs) for an in vitro model. AAE effectively hindered the attachment of THP-1 monocytes and reduced the expression of vascular cell adhesion molecule-1 (VCAM-1) in HUVECs. Transcriptome analysis revealed that AAE treatment upregulated phosphatase and tensin homolog (PTEN), subsequently inhibiting phosphorylation of AKT and glycogen synthase kinase 3ß (GSK3ß) in HUVECs. AAE further hindered phosphorylation of AKT downstream of the nuclear factor kappa B (NF-κB) signaling pathway, leading to suppression of target gene expression. Oral administration of AAE suppressed TNF-α-stimulated VCAM-1 expression, monocyte-derived macrophage infiltration, and proinflammatory cytokine expression in C57BL/6 mouse aortas. Myo-inositol, identified as the major compound in AAE, played a key role in suppressing THP-1 monocyte adhesion in HUVECs. These findings suggest that AAE could serve as a nutraceutical for preventing atherosclerosis by inhibiting its initial pathogenesis.
Assuntos
Actinidia , Adesão Celular , Glicogênio Sintase Quinase 3 beta , Células Endoteliais da Veia Umbilical Humana , Inositol , Monócitos , NF-kappa B , PTEN Fosfo-Hidrolase , Extratos Vegetais , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Fator de Necrose Tumoral alfa , Molécula 1 de Adesão de Célula Vascular , Molécula 1 de Adesão de Célula Vascular/metabolismo , Molécula 1 de Adesão de Célula Vascular/genética , Humanos , NF-kappa B/metabolismo , NF-kappa B/genética , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , PTEN Fosfo-Hidrolase/metabolismo , PTEN Fosfo-Hidrolase/genética , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética , Actinidia/química , Animais , Extratos Vegetais/farmacologia , Transdução de Sinais/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/genética , Adesão Celular/efeitos dos fármacos , Camundongos , Inositol/farmacologia , Inositol/análogos & derivados , Camundongos Endogâmicos C57BL , Aterosclerose/metabolismo , Aterosclerose/tratamento farmacológico , MasculinoRESUMO
Schisandra chinensis extract (SCE) protects against hypocholesterolemia by inhibiting proprotein convertase subtilisin/kexin 9 (PCSK9) protein stabilization. We hypothesized that the hypocholesterolemic activity of SCE can be attributable to upregulation of the PCSK9 inhibition-associated low-density lipoprotein receptor (LDLR). Male mice were fed a low-fat diet or a Western diet (WD) containing SCE at 1% for 12 weeks. WD increased final body weight and blood LDL cholesterol levels as well as alanine transaminase and aspartate aminotransferase expression. However, SCE supplementation significantly attenuated the increase in blood markers caused by WD. SCE also attenuated WD-mediated increases in hepatic LDLR protein expression in the obese mice. In addition, SCE increased LDLR protein expression and attenuated cellular PCSK9 levels in HepG2 cells supplemented with delipidated serum (DLPS). Non-toxic concentrations of schisandrin A (SA), one of the active components of SCE, significantly increased LDLR expression and tended to decrease PCSK9 protein levels in DLPS-treated HepG2 cells. High levels of SA-mediated PCSK9 attenuation was not attributable to reduced PCSK9 gene expression, but was associated with free PCSK9 protein degradation in this cell model. Our findings show that PCSK9 secretion can be significantly reduced by SA treatment, contributing to reductions in free cholesterol levels.
Assuntos
Ciclo-Octanos , Fígado Gorduroso , Lignanas , Compostos Policíclicos , Schisandra , Masculino , Camundongos , Animais , Humanos , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Schisandra/metabolismo , Serina Endopeptidases/genética , Subtilisina , Pró-Proteína Convertases/genética , Pró-Proteína Convertases/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Células Hep G2RESUMO
Doxorubicin (DOX), an effective chemotherapeutic drug, causes cardiotoxicity in a cumulative and dose-dependent manner. The aim of this study is to investigate the effects of hot-water extract of Capsella bursa-pastoris (CBW) on DOX-induced cardiotoxicity (DICT). We utilized H9c2 rat cardiomyocytes and MDA-MB-231 human breast cancer cells to evaluate the effects of CBW on DOX-induced cell death. Superoxide dismutase (SOD) levels, reactive oxygen species (ROS) production, and oxygen consumption rate were measured in H9c2 cells. C57BL/6 mice were treated with DOX and CBW to assess their impact on various cardiac parameters. Human-induced pluripotent stem-cell-derived cardiomyocytes were also used to investigate DOX-induced electrophysiological changes and the potential ameliorative effects of CBW. UPLC-TQ/MS analysis identified seven flavonoids in CBW, with luteolin-7-O-glucoside and isoorientin as the major compounds. CBW inhibited DOX-induced death of H9c2 rat cardiomyocytes but did not affect DOX-induced death of MDA-MB-231 human breast cancer cells. CBW increased SOD levels in a dose-dependent manner, reducing ROS production and increasing the oxygen consumption rate in H9c2 cells. The heart rate, RR interval, QT, and ST prolongation remarkably recovered in C57BL/6 mice treated with the combination of DOX and CBW compared to those in mice treated with DOX alone. Administration of CBW with DOX effectively alleviated collagen accumulation, cell death in mouse heart tissues, and reduced the levels of creatinine kinase (CK) and lactate dehydrogenase (LDH) in serum. Furthermore, DOX-induced pathological electrophysiological features in human-induced pluripotent stem-cell-derived cardiomyocytes were ameliorated by CBW. CBW may prevent DICT by stabilizing SOD and scavenging ROS. The presence of flavonoids, particularly luteolin-7-O-glucoside and isoorientin, in CBW may contribute to its protective effects. These results suggest the potential of CBW as a traditional therapeutic option to mitigate DOX-induced cardiotoxicity.
Assuntos
Neoplasias da Mama , Capsella , Ratos , Camundongos , Animais , Humanos , Feminino , Antioxidantes/metabolismo , Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/etiologia , Cardiotoxicidade/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Capsella/metabolismo , Estresse Oxidativo , Camundongos Endogâmicos C57BL , Doxorrubicina/toxicidade , Doxorrubicina/metabolismo , Miócitos Cardíacos/metabolismo , Flavonoides/farmacologia , Superóxido Dismutase/metabolismo , Neoplasias da Mama/metabolismo , ApoptoseRESUMO
Patulin (PAT) is a natural mycotoxin found in decaying pome fruits. Although some toxicological studies have been conducted on PAT, recent research has highlighted its anticancer and antifungal effects. However, studies have yet to examine the effects and molecular mechanisms of PAT in other metabolic diseases. Obesity is a chronic disease caused by excessive food intake and abnormal lifestyle, leading to low-grade inflammation. Therefore, this study aimed to elucidate the effect of PAT on obesity at the cellular level. PAT treatment reduced lipid accumulation, suppressed glucose and LDL uptake, inhibited lipid deposition and triglyceride synthesis, upregulated fatty acid oxidation-related genes (Pgc1α), and downregulated adipogenic/lipogenic genes (Pparγ and C/ebpα) in hypertrophied 3T3-L1 adipocytes. Additionally, PAT treatment enhanced mitochondrial respiration and mass in differentiated adipocytes and alleviated inflammatory response in activated RAW 264.7 macrophages. Moreover, PAT treatment downregulated pro-inflammatory genes (il-6, Tnf-α, Cox-2, and inos), suppressed lipopolysaccharide (LPS)-induced increase in inflammatory mediators (IL-6, TNF-α, and NO), and restored mitochondrial oxidative function in LPS-stimulated macrophages by improving oxygen consumption and mitochondrial integrity and suppressing ROS generation. Overall, these findings suggest a potential for PAT in the prevention of lipid accumulation and inflammation-related disorders.
RESUMO
AIMS: The aim of this study is to evaluate the effects of patulin on hepatic lipid metabolism and mitochondrial oxidative function and elucidate the underlying molecular mechanisms. MAIN METHODS: The effects of patulin on hepatic lipid accumulation were evaluated in free fatty acid-treated AML12 or HepG2 cells through oil red O staining, triglyceride assay, real-time polymerase chain reaction, and western blotting. Alteration of mitochondrial oxidative capacity by patulin treatment was determined using Seahorse analysis to measure the oxygen consumption rate. KEY FINDINGS: The increased amounts of lipid droplets induced by free fatty acids were significantly reduced by patulin treatment. Patulin markedly activated the CaMKII/AMP-activated protein kinase (AMPK)/proliferator-activated receptor-γ coactivator (PGC)-1α signaling pathway in hepatocytes, reduced the expression of sterol regulatory element binding protein 1c (SREBP-1c) and lipogenic genes, and increased the expression of genes related to mitochondrial fatty acid oxidation. In addition, patulin treatment enhanced the mitochondrial consumption rate and increased the expression of mitochondrial oxidative phosphorylation proteins in HepG2 hepatocytes. The effects of patulin on anti-lipid accumulation; SREBP-1c, PGC-1α, and carnitine palmitoyltransferase 1 expression; and mitochondrial oxidative capacity were significantly prevented by compound C, an AMPK inhibitor. SIGNIFICANCE: Patulin is a potent inducer of the AMPK pathway, and AMPK-mediated mitochondrial activation is required for the efficacy of patulin to inhibit hepatic lipid accumulation. This study is the first to report that patulin is a promising bioactive compound that prevents the development and worsening of fatty liver diseases, including non-alcoholic fatty liver disease, by improving mitochondrial quality and lipid metabolism.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Patulina , Humanos , Lipogênese , Patulina/farmacologia , Patulina/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Metabolismo dos Lipídeos , Células Hep G2 , Ácidos Graxos não Esterificados/metabolismo , RespiraçãoRESUMO
Mitochondria are subcellular organelles that are a hub for key biological processes, such as bioenergetic, biosynthetic, and signaling functions. Mitochondria are implicated in all oncogenic processes, from malignant transformation to metastasis and resistance to chemotherapeutics. The harsh tumor environment constantly exposes cancer cells to cytotoxic stressors, such as nutrient starvation, low oxygen, and oxidative stress. Excessive or prolonged exposure to these stressors can cause irreversible mitochondrial damage, leading to cell death. To survive hostile microenvironments that perturb mitochondrial function, cancer cells activate a stress response to maintain mitochondrial protein and genome integrity. This adaptive mechanism, which is closely linked to mitochondrial function, enables rapid adjustment and survival in harsh environmental conditions encountered during tumor dissemination, thereby promoting cancer progression. In this review, we describe how the mitochondria stress response contributes to the acquisition of typical malignant traits and highlight the potential of targeting the mitochondrial stress response as an anti-cancer therapeutic strategy.
Assuntos
Fenômenos Biológicos , Neoplasias , Humanos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Neoplasias/metabolismo , Estresse Oxidativo , Microambiente TumoralRESUMO
As essential phospholipid signaling regulators, phospholipase C (PLC)s are activated by various extracellular ligands and mediate intracellular signal transduction. PLCγ1 is involved in regulating various cancer cell functions. However, the precise in vivo link between PLCγ1 and cancer behavior remains undefined. To investigate the role of PLCγ1 in colorectal carcinogenesis, we generated an intestinal tissue-specific Plcg1 knock out (KO) in adenomatous polyposis coli (Apc) Min/+ mice. Plcg1 deficiency in ApcMin/+ mice showed earlier death, with a higher colorectal tumor incidence in both number and size than in wild-type mice. Mechanistically, inhibition of PLCγ1 increased the levels of its substrate phosphoinositol 4,5-bisphosphate (PIP2) at the plasma membrane and promoted the activation of Wnt receptor low-density lipoprotein receptor-related protein 6 (LRP6) by glycogen synthase kinase 3ß (GSK3ß) to enhance ß-catenin signaling. Enhanced cell proliferation and Wnt/ß-catenin signaling were observed in colon tumors from Plcg1 KO mice. Furthermore, low PLCγ1 expression was associated with a poor prognosis of colon cancer patients. Collectively, we demonstrated the role of PLCγ1 in vivo as a tumor suppressor relationship between the regulation of the PIP2 level and Wnt/ß-catenin-dependent intestinal tumor formation.
Assuntos
Proliferação de Células/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Fosfolipase C gama/genética , Via de Sinalização Wnt/genética , beta Catenina/genética , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/patologia , Progressão da Doença , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Intestinos/enzimologia , Intestinos/patologia , Estimativa de Kaplan-Meier , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfolipase C gama/deficiência , beta Catenina/metabolismoRESUMO
A metabolic imbalance between lipid synthesis and degradation can lead to hepatic lipid accumulation, a characteristic of patients with non-alcoholic fatty liver disease (NAFLD). Here, we report that high-fat-diet-induced sterol regulatory element-binding protein (SREBP)-1c, a key transcription factor that regulates lipid biosynthesis, impairs autophagic lipid catabolism via altered H2S signaling. SREBP-1c reduced cystathionine gamma-lyase (CSE) via miR-216a, which in turn decreased hepatic H2S levels and sulfhydration-dependent activation of Unc-51-like autophagy-activating kinase 1 (ULK1). Furthermore, Cys951Ser mutation of ULK1 decreased autolysosome formation and promoted hepatic lipid accumulation in mice, suggesting that the loss of ULK1 sulfhydration was directly associated with the pathogenesis of NAFLD. Moreover, silencing of CSE in SREBP-1c knockout mice increased liver triglycerides, confirming the connection between CSE, autophagy, and SREBP-1c. Overall, our results uncover a 2-fold mechanism for SREBP-1c-driven hepatic lipid accumulation through reciprocal activation and inhibition of hepatic lipid biosynthesis and degradation, respectively.
Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Fígado Gorduroso/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Animais , Autofagia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/fisiologia , Linhagem Celular Tumoral , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/fisiopatologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipídeos/fisiologia , Lipogênese , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/metabolismo , Transdução de Sinais/fisiologia , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/fisiologia , Triglicerídeos/metabolismoRESUMO
Mitochondrial proteases are key components in mitochondrial stress responses that maintain proteostasis and mitochondrial integrity in harsh environmental conditions, which leads to the acquisition of aggressive phenotypes, including chemoresistance and metastasis. However, the molecular mechanisms and exact role of mitochondrial proteases in cancer remain largely unexplored. Here, we identified functional crosstalk between LONP1 and ClpP, which are two mitochondrial matrix proteases that cooperate to attenuate proteotoxic stress and protect mitochondrial functions for cancer cell survival. LONP1 and ClpP genes closely localized on chromosome 19 and were co-expressed at high levels in most human cancers. Depletion of both genes synergistically attenuated cancer cell growth and induced cell death due to impaired mitochondrial functions and increased oxidative stress. Using mitochondrial matrix proteomic analysis with an engineered peroxidase (APEX)-mediated proximity biotinylation method, we identified the specific target substrates of these proteases, which were crucial components of mitochondrial functions, including oxidative phosphorylation, the TCA cycle, and amino acid and lipid metabolism. Furthermore, we found that LONP1 and ClpP shared many substrates, including serine hydroxymethyltransferase 2 (SHMT2). Inhibition of both LONP1 and ClpP additively increased the amount of unfolded SHMT2 protein and enhanced sensitivity to SHMT2 inhibitor, resulting in significantly reduced cell growth and increased cell death under metabolic stress. Additionally, prostate cancer patients with higher LONP1 and ClpP expression exhibited poorer survival. These results suggest that interventions targeting the mitochondrial proteostasis network via LONP1 and ClpP could be potential therapeutic strategies for cancer.
RESUMO
Since conventional chemotherapy (gemcitabine and cisplatin) has marginal survival benefit in patients with advanced cholangiocarcinoma (CCA), an effective targeted therapeutic agent is urgently required. Activation of the PI3K/Akt/mTOR signaling pathway is frequently observed in CCA, and thus, PI3K and mTOR are promising therapeutic targets in CCA. Recently a new dual PI3K/mTOR inhibitor GDC-0980 (apitolisib) was introduced. This study was undertaken to examine the activity of apitolisib against CCA cells in vitro and in vivo. Apitolisib treatment strongly reduced Akt and mTOR active phosphorylation levels and attenuated cell growth in two different CCA cell lines (SNU478 and SNU1196). In addition, the cytotoxic activity of apitolisib enhanced the effects of gemcitabine or cisplatin in vitro and increased PARP cleavage. Moreover, we observed these co-treatments significantly reduced colony formation by SNU478 and SNU1196 cells and potently inhibited tumor growth in a mouse xenograft model. The results of the present study show that apitolisib effectively reduces CCA cell growth by suppressing the PI3K/Akt/mTOR pathway. In addition, co-treatments with apitolisib and gemcitabine or cisplatin synergistically enhanced apitolisib activity, which suggests a means of improving the chemotherapeutic sensitivity of CCA.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/patologia , Cisplatino/uso terapêutico , Desoxicitidina/análogos & derivados , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirimidinas/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colangiocarcinoma/metabolismo , Cisplatino/farmacologia , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Sinergismo Farmacológico , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pirimidinas/farmacologia , Transdução de Sinais , Ensaios Antitumorais Modelo de Xenoenxerto , GencitabinaRESUMO
Hepatocellular carcinoma (HCC) accounts for approximately 90% of all cases of primary liver cancer; it is the third most frequent cause of cancer-related death worldwide. In early-stage disease, surgical resection and liver transplantation are considered curative treatments. However, the majority of HCC patients present with advanced-stage disease that is treated using palliative systemic therapy. Since HCC is heterogeneous owing to its multiple etiologies, various risk factors, and inherent resistance to chemotherapy, the development of an effective systemic treatment strategy for HCC remains a considerable challenge. Autophagy is a lysosome-dependent catabolic degradation pathway that is essential for maintaining cellular energy homeostasis. Autophagy dysfunction is closely linked with the pathogenesis of various cancers; therefore, the discovery of small molecules that can modulate autophagy has attracted considerable interest in the development of a systemic treatment strategy for advanced HCC. Here, we reviewed the roles of autophagy in HCC and the recent advances regarding small molecules that target autophagy regulatory mechanisms.
Assuntos
Antineoplásicos/uso terapêutico , Autofagia/efeitos dos fármacos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Lisossomos , Transdução de Sinais/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Lisossomos/metabolismo , Lisossomos/patologiaRESUMO
Androgen receptor (AR) signaling plays a central role in metabolic reprogramming for prostate cancer (PCa) growth and progression. Mitochondria are metabolic powerhouses of the cell and support several hallmarks of cancer. However, the molecular links between AR signaling and the mitochondria that support the metabolic demands of PCa cells are poorly understood. Here, we demonstrate increased levels of dynamin-related protein 1 (DRP1), a mitochondrial fission mediator, in androgen-sensitive and castration-resistant AR-driven PCa. AR signaling upregulates DRP1 to form the VDAC-MPC2 complex, increases pyruvate transport into mitochondria, and supports mitochondrial metabolism, including oxidative phosphorylation and lipogenesis. DRP1 inhibition activates the cellular metabolic stress response, which involves AMPK phosphorylation, induction of autophagy, and the ER unfolded protein response, and attenuates androgen-induced proliferation. Additionally, DRP1 expression facilitates PCa cell survival under diverse metabolic stress conditions, including hypoxia and oxidative stress. Moreover, we found that increased DRP1 expression was indicative of poor prognosis in patients with castration-resistant PCa. Collectively, our findings link androgen signaling-mediated mitochondrial dynamics to metabolic reprogramming; moreover, they have important implications for understanding PCa progression.
Assuntos
Androgênios/metabolismo , Dinaminas/biossíntese , Mitocôndrias/metabolismo , Neoplasias de Próstata Resistentes à Castração/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Ciclo do Ácido Cítrico , Di-Hidrotestosterona/farmacologia , Dinaminas/antagonistas & inibidores , Dinaminas/genética , Dinaminas/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Masculino , Dinâmica Mitocondrial , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Fosforilação Oxidativa , Células PC-3 , Neoplasias de Próstata Resistentes à Castração/patologia , Piruvatos/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais , Regulação para Cima , Canais de Ânion Dependentes de Voltagem/metabolismoRESUMO
The regulators of mitochondrial cell death in cancer have remained elusive, hampering the development of new therapies. Here, we showed that protein isoforms of mitochondrial fission factor (MFF1 and MFF2), a molecule that controls mitochondrial size and shape, that is, mitochondrial dynamics, were overexpressed in patients with non-small cell lung cancer and formed homo- and heterodimeric complexes with the voltage-dependent anion channel-1 (VDAC1), a key regulator of mitochondrial outer membrane permeability. MFF inserted into the interior hole of the VDAC1 ring using Arg225, Arg236, and Gln241 as key contact sites. A cell-permeable MFF Ser223-Leu243 d-enantiomeric peptidomimetic disrupted the MFF-VDAC1 complex, acutely depolarized mitochondria, and triggered cell death in heterogeneous tumor types, including drug-resistant melanoma, but had no effect on normal cells. In preclinical models, treatment with the MFF peptidomimetic was well-tolerated and demonstrated anticancer activity in patient-derived xenografts, primary breast and lung adenocarcinoma 3D organoids, and glioblastoma neurospheres. These data identify the MFF-VDAC1 complex as a novel regulator of mitochondrial cell death and an actionable therapeutic target in cancer. SIGNIFICANCE: These findings describe mitochondrial fission regulation using a peptidomimetic agent that disturbs the MFF-VDAC complex and displays anticancer activity in multiple tumor models.See related commentary by Rao, p. 6074.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Proteínas de Membrana/metabolismo , Mitocôndrias/patologia , Dinâmica Mitocondrial/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Animais , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Proteínas de Membrana/antagonistas & inibidores , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/patologia , Proteínas Mitocondriais/antagonistas & inibidores , Permeabilidade/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Canal de Ânion 1 Dependente de Voltagem/antagonistas & inibidores , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Mitochondrial functions are exploited in cancer and provide a validated therapeutic target. However, how this process is regulated has remained mostly elusive and the identification of new pathways that control mitochondrial integrity in cancer is an urgent priority. METHODS: We studied clinically-annotated patient series of primary and metastatic prostate cancer, representative cases of multiple myeloma (MM) and publicly available genetic databases. Gene regulation studies involved chromatin immunoprecipitation, PCR amplification and Western blotting of conditional Myc-expressing cell lines. Transient or stable gene silencing was used to quantify mitochondrial functions in bioenergetics, outer membrane permeability, Ca2+ homeostasis, redox balance and cell death. Tumorigenicity was assessed by cell proliferation, colony formation and xenograft tumour growth. FINDINGS: We identified Mitochondrial Fission Factor (MFF) as a novel transcriptional target of oncogenic Myc overexpressed in primary and metastatic cancer, compared to normal tissues. Biochemically, MFF isoforms, MFF1 and MFF2 associate with the Voltage-Dependent Anion Channel-1 (VDAC1) at the mitochondrial outer membrane, in vivo. Disruption of this complex by MFF silencing induces general collapse of mitochondrial functions with increased outer membrane permeability, loss of inner membrane potential, Ca2+ unbalance, bioenergetics defects and activation of cell death pathways. In turn, this inhibits tumour cell proliferation, suppresses colony formation and reduces xenograft tumour growth in mice. INTERPRETATION: An MFF-VDAC1 complex is a novel regulator of mitochondrial integrity and actionable therapeutic target in cancer.
Assuntos
Mitocôndrias/genética , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/genética , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Proliferação de Células , Humanos , Potencial da Membrana Mitocondrial/genética , Proteínas Mitocondriais/genética , PermeabilidadeRESUMO
The natural, phenolic lipid urushiol exhibits both antioxidant and anticancer activities; however, its biological activity on hepatocellular carcinoma (HCC) has not been previously investigated. Here, we demonstrate that an urushiol derivative, 3-decylcatechol (DC), induces human HCC Huh7 cell death by induction of autophagy. DC initiates the autophagic process by activation of the mammalian target of rapamycin signaling pathway via Unc-51-like autophagy activating kinase 1, leading to autophagosome formation. The autophagy inhibitor, chloroquine, suppressed autolysosome formation and cell death induction by DC, indicating an autophagic cell death. Interestingly, DC also activated the endoplasmic reticulum (ER) stress response that promotes autophagy via p62 transcriptional activation involving the inositol-requiring enzyme 1α/c-Jun N-terminal kinase/c-jun pathway. We also show that cytosolic calcium mobilization is necessary for the ER stress response and autophagy induction by DC. These findings reveal a novel mechanism by which this urushiol derivative induces autophagic cell death in HCC.
RESUMO
Despite the critical role of melanin in the protection of skin against UV radiation, excess production of melanin can lead to hyperpigmentation and skin cancer. Pear fruits are often used in traditional medicine for the treatment of melasma; therefore, we investigated the effects of pear extract (PE) and its component, protocatechuic acid (PCA), on melanogenesis in mouse melanoma cells. We found that PE and PCA significantly suppressed melanin content and cellular tyrosinase activity through a decrease in the expression of melanogenic enzymes and microphthalmia-associated transcription factor (Mitf) in α-melanocyte stimulating hormone-stimulated mouse melanoma cells. Moreover, PCA decreased cyclic adenosine monophosphate (cAMP) levels and cAMP-responsive element-binding protein phosphorylation, which downregulated Mitf promoter activation and subsequently mediated the inhibition of melanogenesis. These results suggested that pear may be an effective skin lightening agent that targets either a tyrosinase activity or a melanogenic pathway.