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BACKGROUND: Triple negative breast cancer is more aggressive than other breast cancer subtypes and constitutes a public health problem worldwide since it has high morbidity and mortality due to the lack of defined therapeutic targets. Resistance to chemotherapy complicates the course of patients' treatment. Several authors have highlighted the participation of nicotinic acetylcholine receptors (nAChR) in the modulation of conventional chemotherapy treatment in cancers of the airways. However, in breast cancer, less is known about the effect of nAChR activation by nicotine on chemotherapy treatment in smoking patients. AIM: To investigate the effect of nicotine on paclitaxel treatment and the signaling pathways involved in human breast MDA-MB-231 tumor cells. METHODS: Cells were treated with paclitaxel alone or in combination with nicotine, administered for one or three 48-h cycles. The effect of the addition of nicotine (at a concentration similar to that found in passive smokers' blood) on the treatment with paclitaxel (at a therapeutic concentration) was determined using the 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The signaling mediators involved in this effect were determined using selective inhibitors. We also investigated nAChR expression, and ATP "binding cassette" G2 drug transporter (ABCG2) expression and its modulation by the different treatments with Western blot. The effect of the treatments on apoptosis induction was determined by flow cytometry using annexin-V and 7AAD markers. RESULTS: Our results confirmed that treatment with paclitaxel reduced MDA-MB-231 cell viability in a concentration-dependent manner and that the presence of nicotine reversed the cytotoxic effect induced by paclitaxel by involving the expression of functional α7 and α9 nAChRs in these cells. The action of nicotine on paclitaxel treatment was linked to modulation of the protein kinase C, mitogen-activated protein kinase, extracellular signal-regulated kinase, and NF-κB signaling pathways, and to an up-regulation of ABCG2 protein expression. We also detected that nicotine significantly reduced the increase in cell apoptosis induced by paclitaxel treatment. Moreover, the presence of nicotine reduced the efficacy of paclitaxel treatment administered in three cycles to MDA-MB-231 tumor cells. CONCLUSION: Our findings point to nAChRs as responsible for the decrease in the chemotherapeutic effect of paclitaxel in triple negative tumors. Thus, nAChRs should be considered as targets in smoking patients.
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Objective: In the last two years progress was made in molecular, physio pathological understanding and the form of transmission of COVID-19, and different therapeutic strategies have been explored to deal with the situation of the pandemic. However, the evaluation of certain genes that participate in the metabolism and transport of these drugs has not been fully explored. A lack of response to treatment and a lower survival have been observed that may be due to the presence of the ABCB1 drug resistance gene. Our research group analyzed whether the expression levels of the ABCB1 gene are associated with comorbidities, treatments, overall survival and risk of death in patients with severe COVID-19. Methods: The expression levels of the ABCB1 gene were analyzed by RT-qPCR in 61 patients diagnosed with COVID-19. The association between the levels of expression, the risk variables and different treatments were determined by the Chi-Square test and the Fisher's exact test. Global Survival (GS) was determined by the Kaplan-Meier method. The impact of high levels of expression and the risk of death was performed by odds ratio. Results: The different risk variables showed that patients with either high or absent levels of ABCB1 gene expression presented a greater risk of death (OR 3.08, 95%, CI 1.02-9.26) as well as need for ventilatory support (OR 2.8, 95%, CI 0.98 -8.5). Patients with diabetes and COVID-19, treated with metformin, were associated with a lower risk of death (OR 1.11, 95%, CI 0.38-3.22). OS with respect to high or absent levels of expression of the ABCB1 gene was lower. Conclusion: High levels or null expression of the ABCB1 gene are associated with a higher risk of death or progression of the disease, the use of metformin in patients with COVID-19 confers a lower risk of death.
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Acute myeloid leukemia (AML) is one of the most common hematological neoplasia causing death worldwide. The long-term overall survival is unsatisfactory due to many factors including older age, genetic heterogeneity and molecular characteristics comprising additional mutations, and resistance to chemotherapeutic drugs. The expression of ABCB1/P-glycoprotein, ABCC1/MRP1, ABCG2/BCRP and LRP transporter proteins is considered the major reason for multidrug resistance (MDR) in AML, however conflicting data have been reported. Here, we review the main issues about drug transporter proteins in AML clinical scenario, and highlight the clinicopathological significance of MDR phenotype associated with ABCB1 polymorphisms and FLT3 mutation.
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Leucemia Mieloide Aguda , Preparações Farmacêuticas , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP , Idoso , Resistencia a Medicamentos Antineoplásicos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismoRESUMO
The immunosuppressant mycophenolic acid (MPA), derived from the prodrug mycophenolate mofetil (MMF), is a drug used widely by kidney transplant recipients. This drug selectively inhibits inosine monophosphate dehydrogenase that controls the proliferation of lymphocytes, aiding in the prevention of rejection of the transplanted organ. Polymorphisms in key genes involved in MMF metabolism may alter the function of the enzymes encoded by them and contribute to interindividual variability in the response to the drug and its efficacy. The aim of this study was to investigate the association of nine polymorphic variants of eight genes involved in MMF pharmacokinetics, with rejection and adverse effects exhibited by kidney transplant recipients who use this drug. Our sample comprised 145 kidney transplant recipients undergoing post-transplant treatment whose immunosuppressive therapy consisted of MMF and corticosteroid combined or not with a calcineurin inhibitor or mTOR inhibitor. The average age of the patients was 46.9⯱â¯12.5 years, and they underwent transplantation 7⯱â¯5.71 years ago. The combination of the T/C and C/C genotypes of the polymorphism rs11706052 (IMPDH2) was associated with a 4.2-fold protection, and the combination of the genotypes A/G and G/G of the polymorphism rs7438135 (UGT2B7) showed a 2.4-fold protection, against rejection. The association of T/C and C/C genotypes in the SNP rs11706052 (IMPDH2) with the occurrence of rejection episodes considering only patients who received immunosuppressive drug MMF associated with cyclosporine or tacrolimus and corticoids, demonstrated association with a protection against rejection 15.6-fold. The T/T genotype of the polymorphism rs2241409 (CES2) was associated with a 7.2-fold increased risk of rejection. Therefore, these polymorphisms that showed a strong association with rejection episodes should be considered in future studies on new prognostic markers for rejection in patients treated with MMF.
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Carboxilesterase/genética , Glucuronosiltransferase/genética , Rejeição de Enxerto/etiologia , IMP Desidrogenase/genética , Transplante de Rim/efeitos adversos , Ácido Micofenólico/efeitos adversos , Polimorfismo Genético , Antibióticos Antineoplásicos/efeitos adversos , Feminino , Genótipo , Rejeição de Enxerto/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
In patients with CKD, not only renal but also, nonrenal clearance of drugs is altered. Uremic toxins could modify the expression and/or activity of drug transporters in the liver. We tested whether the uremic toxin indoxyl sulfate (IS), an endogenous ligand of the transcription factor aryl hydrocarbon receptor, could change the expression of the following liver transporters involved in drug clearance: SLC10A1, SLC22A1, SLC22A7, SLC47A1, SLCO1B1, SLCO1B3, SLCO2B1, ABCB1, ABCB11, ABCC2, ABCC3, ABCC4, ABCC6, and ABCG2 We showed that IS increases the expression and activity of the efflux transporter P-glycoprotein (P-gp) encoded by ABCB1 in human hepatoma cells (HepG2) without modifying the expression of the other transporters. This effect depended on the aryl hydrocarbon receptor pathway. Presence of human albumin at physiologic concentration in the culture medium did not abolish the effect of IS. In two mouse models of CKD, the decline in renal function associated with the accumulation of IS in serum and the specific upregulation of Abcb1a in the liver. Additionally, among 109 heart or kidney transplant recipients with CKD, those with higher serum levels of IS needed higher doses of cyclosporin, a P-gp substrate, to obtain the cyclosporin target blood concentration. This need associated with serum levels of IS independent of renal function. These findings suggest that increased activity of P-gp could be responsible for increased hepatic cyclosporin clearance. Altogether, these results suggest that uremic toxins, such as IS, through effects on drug transporters, may modify the nonrenal clearance of drugs in patients with CKD.
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Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Indicã/sangue , Receptores de Hidrocarboneto Arílico/metabolismo , Insuficiência Renal Crônica/sangue , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Albuminas/farmacologia , Animais , Ciclosporina/sangue , Ciclosporina/farmacocinética , Modelos Animais de Doenças , Feminino , Expressão Gênica/efeitos dos fármacos , Transplante de Coração , Células Hep G2 , Humanos , Imunossupressores/sangue , Imunossupressores/farmacocinética , Indicã/farmacologia , Transplante de Rim , Fígado/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Proteína 2 Associada à Farmacorresistência Múltipla , RNA Mensageiro/metabolismo , Insuficiência Renal Crônica/fisiopatologia , Transdução de Sinais , Regulação para CimaRESUMO
The present study aimed to investigate whether MBZ down-regulates drug transporter expression (ABCB1, ABCC1, SLC47A1). mRNA expression level of ABCB1, ABCC1 and SLC47A1 was evaluated by qPCR and protein expression levels MDR-1 was performed by western blotting in malignant ascites cells (AGP-01) treated with MBZ for 24h. The mRNA expression level of ABCB1 and ABCC1 significantly decreased at a 1.0µM of MBZ compared to negative control, while SLC47A1 extremely decreased at all tested concentrations of MBZ. Protein expression levels MDR-1 significantly decreased at a 1.0µM of MBZ compared to negative control. Therefore, our results showed MBZ may play an important role in inhibiting MDR gene expression in malignant ascites cells.
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Antiparasitários/farmacologia , Mebendazol/farmacologia , Proteínas de Membrana Transportadoras/metabolismo , Neoplasias Peritoneais/metabolismo , Neoplasias Gástricas/metabolismo , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Humanos , Proteínas de Membrana Transportadoras/genética , RNA Mensageiro/metabolismoRESUMO
Previously, we have demonstrated that 17α-ethynylestradiol (EE) induces rat multidrug-resistance associated protein 3 (Mrp3, Abcc3) expression transcriptionally through estrogen receptor-α (ER-α) activation. We explored the effect of EE on MRP3 expression of human origin. HepG2 cells were transfected with ER-α and incubated with EE (1-10-50 µM) for 48 h. MRP3 protein and mRNA levels were measured by Western blotting and Real time PCR, respectively. EE up-regulated MRP3 protein and mRNA at 50 µM only in ER-α(+)-HepG2 cells. The in silico analysis of mrp3 promoter region demonstrated absence of estrogen response elements, but showed several Ap-1 binding sites. We further evaluated the potential involvement of the transcription factors c-JUN and c-FOS (members of Ap-1) in MRP3 up-regulation. ER-α(+) HepG2 cells were incubated with EE and c-FOS and c-JUN levels measured by Western blotting in nuclear extracts. EE up-regulated only c-JUN. Experiments of overexpression and knock-down of c-JUN by siRNA further demonstrated that this transcription factor is indeed implicated in MRP3 upregulation by EE. Co-immunoprecipitation assay demonstrated that EE induces c-JUN/ER-α interaction, and chromatin immunoprecipitation assay showed that this complex is recruited to the AP-1 binding consensus element present at the position (-1300/-1078 bp) of human mrp3 promoter. We conclude that EE induces MRP3 expression through ER-α, with recruitment of ER-α in complex with c-JUN to the human mrp3 promoter.