RESUMO
Breast cancer resistance protein (BCRP/ABCG2) is a critical drug efflux transporters by limiting drugs' transplacental transfer rates. More investigations on the regulation of placental BCRP offer great promise for enabling pronounced progress in individualized and safe pharmacotherapy during pregnancy. Histone deacetylases (HDACs) play an important role in epigenetic regulation of placental genes. It was reported recently by us that HDAC1 was involved in placental BCRP regulation in vitro. The aim of this study was to further explore the effect of HDAC1 on placental BCRP expression and functionality in animals. Randomly assigned C57BL pregnant dams received intraperitoneal injections of a negative control siRNA or Hdac1 siRNA from embryonic day 7.5 (E7.5) to E15.5, respectively. At E16.5, glyburide (GLB), a probe for evaluating placental BCRP efflux functionality, was injected via the tail vein. Animals were sacrificed through cervical dislocation at various times (5-180 min) after drug administration. The maternal blood, placentas, and fetal-units were collected. GLB concentrations were determined by a validated high-performance liquid chromatography/mass spectrometry (HPLC-MS) assay. Real-time quantitative PCR (qRT-PCR), Western blot, and immunohistochemical (IHC) analysis were employed to identify mRNA/protein levels and localization of gene expressions, respectively. It was noted that Hdac1 inhibition significantly decreased placental Bcrp expression, with markedly increases of GLB concentrations and area under the concentration-time curve (AUC) in fetal-units. Particularly, the ratios of fetal-unit/maternal plasma GLB concentrations were also significantly elevated following Hdac1 repression. Taken together, these findings suggested that HDAC1 was involved in positive regulation of placental BCRP expression and functionality in vivo.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Histona Desacetilase 1/biossíntese , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/metabolismo , Placenta/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Feminino , Inativação Gênica/efeitos dos fármacos , Inativação Gênica/fisiologia , Glibureto/administração & dosagem , Glibureto/metabolismo , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/genética , Camundongos , Camundongos Endogâmicos C57BL , Placenta/efeitos dos fármacos , Gravidez , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/metabolismoRESUMO
Scleroderma, or systemic sclerosis, is a multi-organ connective tissue disease resulting in fibrosis of the skin, heart, and lungs with no effective treatment. Endocannabinoids acting via cannabinoid-1 receptors (CB1R) and increased activity of inducible NO synthase (iNOS) promote tissue fibrosis including skin fibrosis, and joint targeting of these pathways may improve therapeutic efficacy. Recently, we showed that in mouse models of liver, lung and kidney fibrosis, treatment with a peripherally restricted hybrid CB1R/iNOS inhibitor (MRI-1867) yields greater anti-fibrotic efficacy than inhibiting either target alone. Here, we evaluated the therapeutic efficacy of MRI-1867 in bleomycin-induced skin fibrosis. Skin fibrosis was induced in C57BL/6J (B6) and Mdr1a/b-Bcrp triple knock-out (KO) mice by daily subcutaneous injections of bleomycin (2 IU/100 µL) for 28 days. Starting on day 15, mice were treated for 2 weeks with daily oral gavage of vehicle or MRI-1867. Skin levels of MRI-1867 and endocannabinoids were measured by mass spectrometry to assess target exposure and engagement by MRI-1867. Fibrosis was characterized histologically by dermal thickening and biochemically by hydroxyproline content. We also evaluated the potential increase of drug-efflux associated ABC transporters by bleomycin in skin fibrosis, which could affect target exposure to test compounds, as reported in bleomycin-induced lung fibrosis. Bleomycin-induced skin fibrosis was comparable in B6 and Mdr1a/b-Bcrp KO mice. However, the skin level of MRI-1867, an MDR1 substrate, was dramatically lower in B6 mice (0.023 µM) than in Mdr1a/b-Bcrp KO mice (8.8 µM) due to a bleomycin-induced increase in efflux activity of MDR1 in fibrotic skin. Furthermore, the endocannabinoids anandamide and 2-arachidonylglycerol were elevated 2-4-fold in the fibrotic vs. control skin in both mouse strains. MRI-1867 treatment attenuated bleomycin-induced established skin fibrosis and the associated increase in endocannabinoids in Mdr1a/b-Bcrp KO mice but not in B6 mice. We conclude that combined inhibition of CB1R and iNOS is an effective anti-fibrotic strategy for scleroderma. As bleomycin induces an artifact in testing antifibrotic drug candidates that are substrates of drug-efflux transporters, using Mdr1a/b-Bcrp KO mice for preclinical testing of such compounds avoids this pitfall.
Assuntos
Antifibróticos , Fibrose , Óxido Nítrico Sintase Tipo II , Receptor CB1 de Canabinoide , Dermatopatias , Animais , Humanos , Masculino , Camundongos , Antibióticos Antineoplásicos , Antifibróticos/uso terapêutico , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Bleomicina , Endocanabinoides/metabolismo , Fibrose/induzido quimicamente , Fibrose/tratamento farmacológico , Fibrose/patologia , Hidroxiprolina/metabolismo , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Receptor CB1 de Canabinoide/antagonistas & inibidores , Pele/patologia , Dermatopatias/induzido quimicamente , Dermatopatias/tratamento farmacológico , Dermatopatias/patologiaRESUMO
Cyclin-dependent kinase 7 (CDK7) is a master regulatory kinase that drives cell cycle progression and stimulates expression of oncogenes in a myriad of cancers. Inhibitors of CDK7 (CDK7i) are currently in clinical trials; however, as with many cancer therapies, patients will most likely experience recurrent disease due to acquired resistance. Identifying targets underlying CDK7i resistance will facilitate prospective development of new therapies that can circumvent such resistance. Here we utilized triple-negative breast cancer as a model to discern mechanisms of resistance as it has been previously shown to be highly responsive to CDK7 inhibitors. After generating cell lines with acquired resistance, high-throughput RNA sequencing revealed significant upregulation of genes associated with efflux pumps and transforming growth factor-beta (TGF-ß) signaling pathways. Genetic silencing or pharmacological inhibition of ABCG2, an efflux pump associated with multidrug resistance, resensitized resistant cells to CDK7i, indicating a reliance on these transporters. Expression of activin A (INHBA), a member of the TGF-ß family of ligands, was also induced, whereas its intrinsic inhibitor, follistatin (FST), was repressed. In resistant cells, increased phosphorylation of SMAD3, a downstream mediator, confirmed an increase in activin signaling, and phosphorylated SMAD3 directly bound the ABCG2 promoter regulatory region. Finally, pharmacological inhibition of TGF-ß/activin receptors or genetic silencing of SMAD4, a transcriptional partner of SMAD3, reversed the upregulation of ABCG2 in resistant cells and phenocopied ABCG2 inhibition. This study reveals that inhibiting the TGF-ß/Activin-ABCG2 pathway is a potential avenue for preventing or overcoming resistance to CDK7 inhibitors.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Quinases Ciclina-Dependentes/antagonistas & inibidores , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Subunidades beta de Inibinas/metabolismo , Proteínas de Neoplasias/biossíntese , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Regulação para Cima/efeitos dos fármacos , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Linhagem Celular Tumoral , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Subunidades beta de Inibinas/genética , Proteínas de Neoplasias/genética , Transdução de Sinais/genética , Fator de Crescimento Transformador beta/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Quinase Ativadora de Quinase Dependente de CiclinaRESUMO
The expression of transporters on the apical and basal membranes of renal proximal tubular cells are down- or upregulated to various extents under cisplatin (CDDP)-induced acute kidney injury (AKI). However, little is known about the changes in transporters in tissues other than the kidney under CDDP-induced AKI. This study aimed to investigate the modulation of the expression/function of intestinal efflux transporters, P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp), in CDDP-induced AKI rats. On day 3 after the intraperitoneal administration of CDDP (5 mg/kg) to rats, the expression levels of P-gp and Bcrp were compared with those of normal rats. Further, the absorption of three P-gp substrates (6α-methylprednisolone, rhodamine 123, and gatifloxacin) was evaluated in both groups using conventional loop techniques. In the CDDP-induced AKI rats, P-gp expression in the ileum was markedly decreased to approximately 38% of that in the normal rats. However, no significant changes in Bcrp expression were observed in the AKI rats. In contrast with the reduction in P-gp expression in the AKI rats, the absorption of the three P-gp substrates remained almost the same or decreased in the AKI group. The addition of verapamil (a potent P-gp inhibitor) increased the absorption of the three P-gp substrates to the values obtained from the normal rats. In conclusion, our results suggested that P-gp expression is downregulated in rats with CDDP-induced AKI but that P-gp maintains its potency as a "gatekeeper" against the absorption of xenobiotics by amplifying its individual transport capacity under these conditions.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/metabolismo , Cisplatino/toxicidade , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Injúria Renal Aguda/genética , Animais , Antineoplásicos/toxicidade , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Expressão Gênica , Masculino , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-DawleyRESUMO
Overexpression of breast cancer resistance protein (BCRP) plays a crucial role in the acquired multidrug resistance (MDR) in breast cancer. The elucidation of molecular events that confer BCRP-mediated MDR is of major therapeutic importance in breast cancer. Epithelial cell adhesion molecule (EpCAM) has been implicated in tumor progression and drug resistance in various types of cancers, including breast cancer. However, the role of EpCAM in BCRP-mediated MDR in breast cancer remains unknown. In the present study, we revealed that EpCAM expression was upregulated in BCRP-overexpressing breast cancer MCF-7/MX cells, and EpCAM knockdown using siRNA reduced BCRP expression and increased the sensitivity of MCF-7/MX cells to mitoxantrone (MX). The epithelial-mesenchymal transition (EMT) promoted BCRP-mediated MDR in breast cancer cells, and EpCAM knockdown partially suppressed EMT progression in MCF-7/MX cells. In addition, Wnt/ß-catenin signaling was activated in MCF-7/MX cells, and the inhibition of this signaling attenuated EpCAM and BCRP expression and partially reversed EMT. Together, this study illustrates that EpCAM upregulation by Wnt/ß-catenin signaling induces partial EMT to promote BCRP-mediated MDR resistance in breast cancer cells. EpCAM may be a potential therapeutic target for overcoming BCRP-mediated resistance in human breast cancer.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Neoplasias da Mama/metabolismo , Resistência a Múltiplos Medicamentos/fisiologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Molécula de Adesão da Célula Epitelial/biossíntese , Transição Epitelial-Mesenquimal/fisiologia , Proteínas de Neoplasias/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Molécula de Adesão da Célula Epitelial/antagonistas & inibidores , Molécula de Adesão da Célula Epitelial/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Humanos , Células MCF-7 , Mitoxantrona/farmacologia , Proteínas de Neoplasias/genética , RNA Interferente Pequeno/administração & dosagemRESUMO
Breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp) are co-located at blood-brain barrier (BBB) cells, preventing their substrates from entering brain. Accumulating evidence demonstrates that liver failure impairs P-gp and BCRP expression and function in the brain. In the current study, we investigated how liver failure influenced the expression and function of brain BCRP and P-gp in rats subjected to bile duct ligation (BDL). The function of BCRP, P-gp and BBB integrity was assessed using distribution of prazosin, rhodamine 123 and fluorescein, respectively. We showed that BDL significantly decreased BCRP function, but increased P-gp function without affecting BBB integrity. Furthermore, we found that BDL significantly downregulated the expression of membrane BCRP and upregulated the expression of membrane P-gp protein in the cortex and hippocampus. In human cerebral microvascular endothelial cells, NH4Cl plus unconjugated bilirubin significantly decreased BCRP function and expression of membrane BCRP protein, but upregulated P-gp function and expression of membrane P-gp protein. The decreased expression of membrane BCRP protein was linked to the decreased expression of membrane radixin protein, while the increased expression of membrane P-gp protein was related to the increased location of membrane ezrin protein. Silencing ezrin impaired membrane location of P-gp, whereas silencing radixin impaired membrane location of BCRP protein. BDL rats showed the increased expression of membrane ezrin protein and decreased expression of membrane radixin protein in the brain. We conclude that BDL causes opposite effects on the expression and function of brain BCRP and P-gp, attributing to the altered expression of membrane radixin and ezrin protein, respectively, due to hyperbilirubinemia and hyperammonemia.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Ductos Biliares/metabolismo , Encéfalo/metabolismo , Proteínas do Citoesqueleto/biossíntese , Proteínas de Membrana/biossíntese , Proteínas dos Microfilamentos/biossíntese , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Membrana Celular/metabolismo , Proteínas do Citoesqueleto/genética , Expressão Gênica , Ligadura/efeitos adversos , Masculino , Proteínas de Membrana/genética , Proteínas dos Microfilamentos/genética , RNA Interferente Pequeno/administração & dosagem , Ratos , Ratos Sprague-DawleyRESUMO
ATPbinding cassette subfamily G member 2 (ABCG2), a member of the ABC transporter superfamily, has been implicated in the development of chemotherapeutic drug resistance in cancer cells. However, the regulators of ABCG2 expression and their roles in anticancer drug resistance have not been fully characterized, especially in the context of pancreatic cancer. The aim of the present study was to investigate whether ABCG2 contributed to drug resistance in pancreatic cancer and to elucidate its regulatory molecular pathways. Using immunohistochemical analysis of pancreatic ductal adenocarcinoma and adjacent healthy tissue samples, the present study identified a positive correlation between ABCG2 and Wnt5a, a member of the Wnt family of secreted proteins. It was also determined that treatment with recombinant human Wnt5a protein could upregulate the expression of ABCG2 in the Capan2 human pancreatic cancer cell line and enhance its resistance to gemcitabine. The upregulation of ABCG2 by Wnt5a was inhibited by small interfering RNA silencing of Frizzled class receptor 7 (FZD7) or by FZD7 inhibitors. Moreover, both FZD7 silencing or inhibition of its function attenuated gemcitabine resistance induced by Wnt5a in Capan2 cells. Therefore, the present findings suggested that Wnt5a and FZD7 acted as upstream regulators of ABCG2 expression and that FZD7 may be an essential factor for Wnt5ainduced gemcitabine resistance in pancreatic cancer cells.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Carcinoma Ductal Pancreático/genética , Receptores Frizzled/metabolismo , Proteínas de Neoplasias/biossíntese , Neoplasias Pancreáticas/genética , Proteína Wnt-5a/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Correlação de Dados , Bases de Dados Genéticas , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Regulação para Cima , Via de Sinalização Wnt , GencitabinaRESUMO
BACKGROUND/AIMS: Obstructive sleep apnea (OSA) is characterized by repeated episodes of complete or partial obstruction of the upper airways, leading to chronic intermittent hypoxia (IH). OSA patients are considered at high cerebrovascular risk and may also present cognitive impairment. One hypothesis explored is that disturbances may be linked to blood-brain barrier (BBB) dysfunction. The BBB is a protective barrier separating the brain from blood flow. The BBB limits the paracellular pathway through tight and adherens junctions, and the transcellular passage by efflux pumps (ABC transporters). The aims of this study were to evaluate the impact of IH and sustained hypoxia (SH) on a validated in vitro BBB model and to investigate the factors expressed under both conditions. METHODS: Exposure of endothelial cells (HBEC-5i) in our in vitro model of BBB to hypoxia was performed using IH cycles: 1% O2-35 min/18% O2-25 min for 6 cycles or 6 h of SH at 1% O2. After exposure, we studied the cytotoxicity and the level of ROS in our cells. We measured the apparent BBB permeability using sodium fluorescein, FITC-dextran and TEER measurement. Whole cell ELISA were performed to evaluate the expression of tight junctions, ABC transporters, HIF-1α and Nrf2. The functionality of ABC transporters was evaluated with accumulation studies. Immunofluorescence assays were also conducted to illustrate the whole cell ELISAs. RESULTS: Our study showed that 6 h of IH or SH induced a BBB disruption marked by a significant decrease in junction protein expressions (claudin-5, VE-cadherin, ZO-1) and an increase in permeability. We also observed an upregulation in P-gp protein expression and functionality and a downregulation in BCRP. Hypoxia induced production of ROS, Nrf2 and HIF-1α. They were expressed in both sustained and intermittent conditions, but the expression and the activity of P-gp and BCRP were different. CONCLUSION: Understanding these mechanisms seems essential in order to propose new therapeutic strategies for patients with OSA.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Barreira Hematoencefálica/metabolismo , Regulação da Expressão Gênica , Hipóxia Encefálica/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Modelos Cardiovasculares , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas de Neoplasias/biossíntese , Subfamília B de Transportador de Cassetes de Ligação de ATP/biossíntese , Barreira Hematoencefálica/patologia , Linhagem Celular , Humanos , Hipóxia Encefálica/patologiaRESUMO
Acquired resistance to doxorubicin is a major hurdle in triple-negative breast cancer (TNBC) therapy, emphasizing the need to identify improved strategies. Apigenin and other structurally related dietary flavones are emerging as potential chemo-sensitizers, but their effect on three-dimensional TNBC spheroid models has not been investigated. We previously showed that apigenin associates with heterogeneous ribonuclear protein A2/B1 (hnRNPA2), an RNA-binding protein involved in mRNA and co-transcriptional regulation. However, the role of hnRNPA2 in apigenin chemo-sensitizing activity has not been investigated. Here, we show that apigenin induced apoptosis in TNBC spheroids more effectively than apigenin-glycoside, owing to higher cellular uptake. Moreover, apigenin inhibited the growth of TNBC patient-derived organoids at an in vivo achievable concentration. Apigenin sensitized spheroids to doxorubicin-induced DNA damage, triggering caspase-9-mediated intrinsic apoptotic pathway and caspase-3 activity. Silencing of hnRNPA2 decreased apigenin-induced sensitization to doxorubicin in spheroids by diminishing apoptosis and partly abrogated apigenin-mediated reduction of ABCC4 and ABCG2 efflux transporters. Together these findings provide novel insights into the critical role of hnRNPA2 in mediating apigenin-induced sensitization of TNBC spheroids to doxorubicin by increasing the expression of efflux transporters and apoptosis, underscoring the relevance of using dietary compounds as a chemotherapeutic adjuvant.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Apigenina/metabolismo , Doxorrubicina/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/deficiência , Proteínas Associadas à Resistência a Múltiplos Medicamentos/biossíntese , Proteínas de Neoplasias/biossíntese , Neoplasias de Mama Triplo Negativas/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/metabolismo , Apigenina/administração & dosagem , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Feminino , Regulação Neoplásica da Expressão Gênica , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/genética , Humanos , Camundongos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas de Neoplasias/genética , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Increasing evidence shows that the intestinal tract plays an important role in maintaining urate homeostasis and might be a potential therapeutic target for hyperuricaemia. However, uric acid-lowering drugs available in the clinic do not target intestinal excretion as a therapeutic strategy. We previously reported that mangiferin had potent hypouricaemic effects in hyperuricaemic animals. However, the underlying mechanisms are not completely clear. Here, we investigated the effects of mangiferin on the intestinal excretion of urate and its underlying mechanisms. The data revealed that mangiferin concentration-dependently promoted the intestinal secretion of endogenous urate in in situ intestinal closed loops in normal and hyperuricaemic mice, as well as inhibited the absorption of exogenous uric acid perfused into the intestinal loops in rats. Administration of mangiferin not only decreased the serum urate levels in the hyperuricaemic mice but also increased the protein expression of ATP-binding cassette transporter, subfamily G, member 2 (ABCG2) and inhibited the protein expression of glucose transporter 9 (GLUT 9) in the intestine. These findings suggested that intestinal ABCG2 and GLUT9 might be pivotal and possible action sites for the observed hypouricaemic effects. Moreover, no significant changes in intestinal xanthine oxidoreductase activities were observed, suggesting that mangiferin did not affect intestinal uric acid generation in the hyperuricaemic mice. Overall, promoting intestinal elimination of urate by upregulating ABCG2 expression and downregulating GLUT9 expression might be an important mechanism underlying mangiferin lowering serum uric acid levels. Mangiferin supplementation might be beneficial for the prevention and treatment of hyperuricaemia.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Eliminação Intestinal/efeitos dos fármacos , Proteínas de Transporte de Monossacarídeos/biossíntese , Ácido Úrico/metabolismo , Xantonas/farmacologia , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/agonistas , Animais , Hiperuricemia/tratamento farmacológico , Hiperuricemia/metabolismo , Eliminação Intestinal/fisiologia , Masculino , Camundongos , Proteínas de Transporte de Monossacarídeos/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Xantonas/uso terapêuticoRESUMO
In hepatocellular carcinoma (HCC), the presence of cancer stem cells (CSCs) have been linked to drug resistance, epithelial-mesenchymal transition (EMT), and cancer relapse. This study investigates the expression profile of ZEB1, ZEB2, ABCG2 in HCC-CSCs, and the role of EMT promoter ZEB2 in cells treated with resveratrol. The expression of ZEB1, ZEB2 and ABCG2 transcripts were analyzed in CD133^(+)/CD44^(+) cells isolated from the PLC/PRF/5 cell line. ZEB2-dependent ABCG2 gene expression and the effects of resveratrol on proliferation, cell cycle and apoptosis were explored in SNU398 cell clones. An inverse correlation between ZEB1/ZEB2 and ABCG2 levels were observed both in CSCs and in ZEB2-knock-down cells. The resveratrol treatment significantly decreased cell viability, while promoting cell cycle arrest in ZEB2-independent manner. Interestingly, resveratrol-treated cells with low levels of ZEB2 were resistant to apoptosis. The interplay of expression levels of ABCG2 and ZEB family EMT transcription factors may play a role in establishing CSC-like phenotype in HCC cells resistant to resveratrol.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Carcinoma Hepatocelular/patologia , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Hepáticas/patologia , Proteínas de Neoplasias/biossíntese , Resveratrol/farmacologia , Homeobox 2 de Ligação a E-box com Dedos de Zinco/metabolismo , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Regulação para Cima/efeitos dos fármacos , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismoRESUMO
The ATP-binding cassette (ABC) superfamily G member 2 (ABCG2) transmembrane protein transporter is known for conferring resistance to treatment in cancers. Photodynamic therapy (PDT) is a promising anti-cancer method involving the use of light-activated photosensitisers to precisely induce oxidative stress and cell death in cancers. ABCG2 can efflux photosensitisers from out of cells, reducing the capacity of PDT and limiting the efficacy of treatment. Many studies have attempted to elucidate the relationship between the expression of ABCG2 in cancers, its effect on the cellular retention of photosensitisers and its impact on PDT. This review looks at the studies which investigate the effect of ABCG2 on a range of different photosensitisers in different pre-clinical models of cancer. This work also evaluates the approaches that are being investigated to address the role of ABCG2 in PDT with an outlook on potential clinical validation.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Resistencia a Medicamentos Antineoplásicos/fisiologia , Neoplasias/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacocinética , Fármacos Fotossensibilizantes/uso terapêutico , Animais , Linhagem Celular Tumoral , Humanos , Fármacos Fotossensibilizantes/antagonistas & inibidoresRESUMO
Multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP) protect the brain by restricting the passage of chemicals across the blood-brain barrier. Prior studies have demonstrated the epigenetic regulation of MDR1 and BCRP in cancer cells treated with histone deacetylase (HDAC) inhibitors that enhance histone acetylation and gene transcription. In the present study, we tested the in vivo effects of two HDAC inhibitors, valproic acid (VPA; 400 mg/kg) and apicidin (5 mg/kg), on Mdr1 and Bcrp transporter expression in brain regions of adult male mice injected intraperitoneally daily for 7 days. VPA increased Mdr1 protein expression in the striatum (70%) and Bcrp protein in the midbrain (30%). Apicidin enhanced striatal Mdr1 protein (30%) and hippocampal Bcrp protein (20%). Transporter induction correlated with increased histone H3 acetylation in discrete brain regions. In conclusion, HDAC inhibitors upregulate transporter proteins in vivo, which may be important in regulating regional xenobiotic disposition within the brain.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Encéfalo/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Histonas/metabolismo , Peptídeos Cíclicos/farmacologia , Ácido Valproico/farmacologia , Acetilação/efeitos dos fármacos , Animais , Histona Desacetilases/metabolismo , Masculino , CamundongosRESUMO
BACKGROUND: Recently, 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX fluorescence was reported to be a useful tool during total surgical resection of high-grade gliomas. However, the labeling efficacy of protoporphyrin IX fluorescence is lower in metastatic brain tumors compared to that in high-grade gliomas, and the mechanism underlying protoporphyrin IX fluorescence in metastatic brain tumors remains unclear. Lung cancer, particularly non-small cell lung cancer (NSCLC), is the most common origin for metastatic brain tumor. Therefore, we investigated the mechanism of protoporphyrin IX fluorescence in NSCLC and associated metastatic brain tumors. METHODS: Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) was employed to evaluate the protein and mRNA levels of five transporters and enzymes involved in the porphyrin biosynthesis pathway: peptide transporter 1 (PEPT1), hydroxymethylbilane synthase (HMBS), ferrochelatase (FECH), ATP-binding cassette 2 (ABCG2), and heme oxygenase 1 (HO-1). The correlation between protein, mRNA, and protoporphyrin IX levels in NSCLC cells were evaluated in vitro. Immunohistochemistry was used to determine proteins that played a key role in intraoperative protoporphyrin IX fluorescence in clinical samples from patients with NSCLC and pathologically confirmed metastatic brain tumors. RESULTS: A significant correlation between PEPT1 expression and protoporphyrin IX accumulation in vitro was identified by western blotting (P = 0.003) and qRT-PCR (P = 0.04). Immunohistochemistry results indicated that there was a significant difference in PEPT1 between the intraoperative protoporphyrin IX fluorescence-positive and protoporphyrin IX fluorescence-negative groups (P = 0.009). CONCLUSION: Expression of PEPT1 was found to be positively correlated with 5-ALA-induced protoporphyrin IX accumulation detected by photodynamic reaction in metastatic brain tumors originating from NSCLC.
Assuntos
Ácido Aminolevulínico/farmacologia , Transportador 1 de Peptídeos/biossíntese , Fotoquimioterapia/métodos , Protoporfirinas/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Western Blotting , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Ferroquelatase/biossíntese , Heme Oxigenase-1/biossíntese , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Metástase Neoplásica , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Fluorescência , Uroporfirinogênios/biossínteseRESUMO
Overexpression of ATP-binding cassette (ABC) transporters is one of the most important mechanisms responsible for the development of multidrug resistance (MDR). Selonsertib, a serine/threonine kinase inhibitor, targets apoptosis signal-regulating kinase 1 (ASK1) and is now in phase III clinical trial for the treatment of non-alcoholic steatohepatitis (NASH). In this study, we investigated whether selonsertib could reverse MDR-mediated by ABC transporters, including ABCB1, ABCG2, ABCC1 and ABCC10. The results showed that selonsertib significantly reversed ABCB1- and ABCG2-mediated MDR, but not MDR-mediated by ABCC1 or ABCC10. Mechanism studies indicated that the reversal effect of selonsertib was related to the attenuation of the efflux activity of ABCB1 and ABCG2 transporters, without the protein level decrease or change in the subcellular localization of ABCB1 or ABCG2. Selonsertib stimulated the ATPase activity of ABCB1 and ABCG2 in a concentration-dependent manner, and in silico docking study showed selonsertib could interact with the substrate-binding sites of both ABCB1 and ABCG2. This study provides a clue into a novel treatment strategy, which includes a combination of selonsertib with antineoplastic drugs to attenuate MDR-mediated by ABCB1 or ABCG2 in cancer cells overexpressing these transporters.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Anticorpos Monoclonais Humanizados/farmacologia , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/biossíntese , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Adenosina Trifosfatases/metabolismo , Antineoplásicos/farmacocinética , Antineoplásicos Fitogênicos/farmacocinética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Células HEK293 , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , MAP Quinase Quinase Quinase 5/antagonistas & inibidores , MAP Quinase Quinase Quinase 5/metabolismo , Mitoxantrona/farmacocinética , Modelos Moleculares , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Paclitaxel/farmacocinética , Inibidores de Proteínas Quinases/farmacologiaRESUMO
ATP-binding cassette sub-family G member 2 (ABCG2) confers to the major phenotypes of side population (SP) cells, the cancer stem-like cells. In this study, the SP cells displayed a distinctly higher ABCG2 expression level, sphere formation efficiency (SFE) and growth rate even under hypoxia condition. CXCR4 overexpression by pcDNA-CXCR4 transfection robustly increased ABCG2 expression, and promoted SFE and growth of hypoxic SP cells, while CXCR4 inhibitor AMD3100 could suppress the promotion. Additionally, we found that CXCR4 promoted the expression of c-Jun, a major gene in the oncogenic JNK/c-Jun pathway. Our data on electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays both showed that c-Jun directly bound with the ABCG2 promoter sequence. Moreover, overexpression of JNK/c-Jun promoted ABCG2 expression, SFE, and growth of hypoxic SP cells and the promotion could be rescued by c-Jun inhibitor SP600125. In conclusion, CXCR4 increases the growth and SFE of breast cancer SP cells under hypoxia through c-Jun-mediated transcriptional activation of ABCG2.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Receptores CXCR4/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Hipóxia Celular , Proliferação de Células , Quimiocina CXCL12/metabolismo , Feminino , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Células MCF-7 , Proteínas de Neoplasias/biossíntese , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-jun/fisiologia , Transdução de Sinais , Esferoides Celulares , Ativação TranscricionalRESUMO
The present study investigated the correlation between the abnormal expression of adenosine triphosphate (ATP)-binding cassette transporter G2 (ABCG2) in esophageal cancer and the drug resistance of esophageal cancer, the reversal effect in drug resistance of artesunate (Art), and the mechanism underlying esophageal cancer using nude mice with subcutaneous xenograft as an animal model. The gene and protein expression of ABCG2 was detected in 80 cases of esophageal cancer, atypical dysplasia, and normal mucosa. A subcutaneous xenograft tumor mouse model was established by subcutaneous inoculation of esophageal cancer cell line Eca109/ABCG2 into BALB/c nu/nu nude mice. The reversal of drug resistance by Art in esophageal cancer was studied in vivo. The mice model was injected intraperitoneally with Art and/or doxorubicin (ADM). The animals were divided into six groups: high dose Art (50 mg/kg), low dose Art (25 mg/kg), ADM (1 mg/kg), ADM and high-dose Art, ADM and low-dose Art, and physiological saline as a control. ABCG2 protein expression and cellular ADM concentration were detected by flow cytometry. The mRNA and protein expressions of ABCG2 in esophageal cancer were significantly higher than that in the normal esophagus (P < 0.01). The volume and mass of the subcutaneously implanted tumors in the ADM+Art high- and low-dose groups were significantly decreased than that in the control group (P < 0.05), while the apoptosis rate of tumor cells and the cellular concentration of ADM were increased significantly (P < 0.05), and the ABCG2 protein expression in the tumor cells decreased significantly (P < 0.05). Abnormally high expression of ABCG2 in esophageal cancer tissues is involved in the multidrug resistance of esophageal cancer. In vivo studies showed that Art could reverse the esophageal cancer drug resistance by regulating the ABCG2 expression in tumor cells.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Antineoplásicos/farmacologia , Artemisininas/farmacologia , Carcinoma de Células Escamosas/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Esofágicas/patologia , Proteínas de Neoplasias/biossíntese , Adulto , Idoso , Animais , Artesunato , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/genética , Resistencia a Medicamentos Antineoplásicos/genética , Carcinoma de Células Escamosas do Esôfago , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Ricolinostat is the first orally available, selective inhibitor of histone deacetylase 6 (HDAC6), currently under evaluation in clinical trials in patients with various malignancies. It is likely that the inevitable emergence of resistance to ricolinostat is likely to reduce its clinical effectiveness in cancer patients. In this study, we investigated the potential impact of multidrug resistance-linked ATP-binding cassette (ABC) transporters ABCB1 and ABCG2 on the efficacy of ricolinostat, which may present a major hurdle to its development as an anticancer drug in the future. We demonstrated that the overexpression of ABCB1 or ABCG2 reduces the intracellular accumulation of ricolinostat, resulting in reduced efficacy of ricolinostat to inhibit the activity of HDAC6 in cancer cells. Moreover, the efficacy of ricolinostat can be fully restored by inhibiting the drug efflux function of ABCB1 and ABCG2 in drug-resistant cancer cells. In conclusion, our results provide some insights into the basis for the development of resistance to ricolinostat and suggest that co-administration of ricolinostat with a modulator of ABCB1 or ABCG2 could overcome ricolinostat resistance in human cancer cells, which may be relevant to its use in the clinic.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Desacetilase 6 de Histona/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Proteínas de Neoplasias/biossíntese , Pirimidinas/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/biossíntese , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/fisiologia , Células HEK293 , Desacetilase 6 de Histona/metabolismo , Humanos , Células MCF-7RESUMO
The ATP-binding cassette (ABC) transporter family is a large class of ATP energy-dependent transmembrane proteins, and its primary function is to use the energy produced by ATP hydrolysis to transfer the substrate bound to the plasma membrane. This family is also closely related to multidrug resistance (MDR) in various diseases. Among the ABC transporter proteins, P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP) and breast cancer resistance protein (BCRP) are the main members associated with MDR. At present, the roles of these transporters in therapeutic failures have been extensively studied and reviewed in cancer; however, they have rarely been described in autoimmune diseases (AIDs). AID is a group of chronic inflammatory diseases of unknown aetiology. AID's basic feature is the production of a large number of autoantibodies, which leads to extensive damage to multiple systems and multiple organs. Disease-modifying anti-rheumatic drugs (DMARDs) are commonly used in the treatment of AID, but a considerable number of patients have no response or develop resistance to these drugs over time. This phenomenon may be related to the abnormal expression of the ABC transporter, which leads to a decrease in the amount of drug entering cells that produce MDR. This article reviews the effects of DMARDs on the expression and function of P-gp, MRPs, and BCRP and the related molecular mechanism in the treatment of AID.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Antirreumáticos/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/biossíntese , Proteínas de Neoplasias/biossíntese , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Antirreumáticos/farmacologia , Doenças Autoimunes/metabolismo , Resistência a Múltiplos Medicamentos/fisiologia , Expressão Gênica , Humanos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Resultado do TratamentoRESUMO
Osteosarcoma is the most common type of malignant bone tumors. Insulin Growth Factor 1 receptor (IGFR1) has been known as a prognostic factor for metastasis of osteosarcoma. ABC subfamily G member2 (ABCG2) is related to resistance to anti-cancer drug, and CD44 has a role in tumor growth and metastasis. The purpose of this study is to investigate the relationship among expression patterns of IGF1R, ABCG2, and CD44 in osteosarcoma. The expression levels of IGF1R, ABCG2, and CD44 proteins were determined in tissue arrays containing osteosarcoma tissues from 59 osteosarcoma patients. The expression pattern of IGF1R was highly correlated with the expression pattern of ABCG2 (r = 0.88) in overall osteosarcoma patients. According to pathological types, the expression pattern of IGF1R showed the higher correlation with ABGC2 (r = 0.90) and CD44 (r = 0.61) in osteoblatic type than in chondroblastic type. According to gender with pathologic type, the correlation between the expression patterns of IGF1R and CD44 was higher in male with osteoblatic type than in female with osteoblatic type. Among different age groups, the 1-10 years age group showed higher correlation in IGF1R versus CD44 (r = 0.90) and ABCG2 versus CD44 (0.80) than in other age groups. These results showed that the expression of IGF1R appears to be highly correlated with the expression of ABCG2 in osteosarcoma and with the expression of CD44 in osteosarcoma patients under age of 10, which suggests that ABCG2 and CD44 can be used as prognostic factors with IGF1R for specific prognosis and efficient treatment of osteosarcoma.