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Ectophosphatases catalyse the hydrolysis of phosphorylated molecules, such as phospho-amino acids, in the extracellular environment. Nevertheless, the hydrolysis of nucleotides in the extracellular environment is typically catalysed by ectonucleotidases. Studies have shown that acid ectophosphatase, or transmembrane-prostatic acid phosphatase (TM-PAP), a membrane-bound splice variant of prostatic acid phosphatase, has ecto-5'-nucleotidase activity. Furthermore, it was demonstrated that ectophosphatase cannot hydrolyse ATP, ADP, or AMP in triple-negative breast cancer cells. In contrast to previous findings in MDA-MB-231 cells, the ectophosphatase studied in the present work displayed a remarkable capacity to hydrolyse AMP in luminal A breast cancer cells (MCF-7). We showed that AMP dose-dependently inhibited p-nitrophenylphosphate (p-NPP) hydrolysis. The p-NPP and AMP hydrolysis showed similar biochemical behaviours, such as increased hydrolysis under acidic conditions and comparable inhibition by NiCl2, ammonium molybdate, and sodium orthovanadate. In addition, this ectophosphatase with ectonucleotidase activity was essential for the release of adenosine and inorganic phosphate from phosphorylated molecules available in the extracellular microenvironment. This is the first study to show that prostatic acid phosphatase on the membrane surface of breast cancer cells (MCF-7) is correlated with cell adhesion and migration.
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Fosfatasa Ácida , Neoplasias de la Mama , Humanos , Células MCF-7 , Femenino , Hidrólisis , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/enzimología , Fosfatasa Ácida/metabolismo , 5'-Nucleotidasa/metabolismo , Adenosina Monofosfato/metabolismo , Proteínas Tirosina Fosfatasas/metabolismo , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Nitrofenoles/farmacología , Nitrofenoles/metabolismo , Línea Celular Tumoral , Compuestos OrganofosforadosRESUMEN
The chemistry of pure cerium oxide (CeO2-x) nanoparticles has been widely studied since the 1970s, especially for chemical catalysis. CeO2-x nanoparticles have been included in an important class of industrial metal oxide nanoparticles and have been attributed a range of wide applications, such as ultraviolet absorbers, gas sensors, polishing agents, cosmetics, consumer products, high-tech devices and fuel cell conductors. Despite these early applications in the field of chemistry, the biological effects of CeO2-x nanoparticles were only explored in the 2000s. Since then, CeO2-x nanoparticles have gained a spot in research related to various diseases, especially the ones in which oxidative stress plays a part. Due to an innate oxidation state variation on their surface, CeO2-x nanoparticles have exhibited redox activities in diseases, such as cancer, acting either as an oxidizing agent, or as an antioxidant. In biological models, CeO2-x nanoparticles have been shown to modulate cancer cell viability and, more recently, cell death pathways. However, a deeper understanding on how the chemical structure of CeO2-x nanoparticles (including nanoparticle size, shape, suspension, agglomeration in the medium used, pH of the medium, type of synthesis and crystallite size) influences the cellular effects observed remains to be elucidated. In the present review, the chemistry of CeO2-x nanoparticles and their impact on biological models and modulation of cell signalling, particularly focusing on oxidative and cell death pathways, were investigated. The deeper understanding of the chemical activity of CeO2-x nanoparticles may provide the rationale for further biomedical applications towards disease treatment and drug delivery purposes.
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OBJECTIVES: Lymphomas represent around 10% of head and neck neoplasms, among which the diffuse large B-cell lymphoma (DLBCL) is the most common histologic subtype. In the present study, we characterized demographic parameters, anatomical sites, and survival rates of patients in a Brazilian cancer center. MATERIALS AND METHODS: Single-center retrospective epidemiological study of 243 head and neck DLBCL patients. Demographic characteristics, tumor localization, HIV status, lactate dehydrogenase (LDH) activity, and treatment modality were obtained from electronic medical records. RESULTS: The most common primary head and neck tumor location in patients with DLBCL was Waldeyer's ring. Interestingly, age above 80 years, male gender, high LDH levels, and HIV positivity were significantly associated with shorter overall survival (OS) rates and increased risk of death. We further demonstrated that treatment had a protective effect, improving OS, and reducing risk of death. Notably, we found no benefit of combination of chemotherapy and radiotherapy versus isolated treatment modalities. CONCLUSION: The study showed that primary head and neck DLBCL is more incident in middle age and elderly patients with a small male patients' majority in a Brazilian population. Moreover, we observed a 3-year OS rate of almost 60% and multivariate analysis showed that treatment was the only protective factor.
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Seropositividad para VIH , Neoplasias de Cabeza y Cuello , Linfoma de Células B Grandes Difuso , Persona de Mediana Edad , Humanos , Masculino , Anciano , Anciano de 80 o más Años , Pronóstico , Estudios Retrospectivos , Brasil/epidemiología , Linfoma de Células B Grandes Difuso/terapia , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/epidemiología , Neoplasias de Cabeza y Cuello/terapiaRESUMEN
Acute myeloid leukemia (AML) is a complex hematological disorder characterized by blockage of differentiation and high proliferation rates of myeloid progenitors. Anthracycline and cytarabinebased therapy has remained the standard treatment for AML over the last four decades. Although this treatment strategy has increased survival rates, patients often develop resistance to these drugs. Despite efforts to understand the mechanisms underlying cytarabine resistance, there have been few advances in the field. The present study developed an in vitro AML cell line model resistant to cytarabine (HL60R), and identified chromosomal aberrations by karyotype evaluation and potential molecular mechanisms underlying chemoresistance. Cytarabine decreased cell viability, as determined by MTT assay, and induced cell death and cell cycle arrest in the parental HL60 cell line, as revealed by Annexin V/propidium iodide (PI) staining and PI DNA incorporation, respectively, whereas no change was observed in the HL60R cell line. In addition, the HL60R cell line exhibited a higher tumorigenic capacity in vivo compared with the parental cell line. Notably, no reduction in tumor volume was detected in mice treated with cytarabine and inoculated with HL60R cells. In addition, western blotting revealed that the protein expression levels of Bcl2, Xlinked inhibitor of apoptosis protein (XIAP) and cMyc were upregulated in HL60R cells compared with those in HL60 cells, along with predominant nuclear localization of the p50 and p65 subunits of NFκB in HL60R cells. Furthermore, the antitumor effect of LQB118 pterocarpanquinone was investigated; this compound induced apoptosis, a reduction in cell viability and a decrease in XIAP expression in cytarabineresistant cells. Taken together, these data indicated that acquired cytarabine resistance in AML was a multifactorial process, involving chromosomal aberrations, and differential expression of apoptosis and cell proliferation signaling pathways. Furthermore, LQB118 could be a potential alternative therapeutic approach to treat cytarabineresistant leukemia cells.
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Aberraciones Cromosómicas , Leucemia Mieloide Aguda/tratamiento farmacológico , Naftoquinonas/farmacología , Pterocarpanos/farmacología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Citarabina/uso terapéutico , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HL-60 , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Masculino , Ratones , Naftoquinonas/uso terapéutico , Pterocarpanos/uso terapéutico , Proteína Inhibidora de la Apoptosis Ligada a X/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Osteopontin (OPN) is upregulated in several types of tumor and has been associated with chemoresistance. However, the contribution of OPN splicing isoforms (OPNSIs) to chemoresistance requires further investigation. The present study aimed to evaluate the expression patterns of each tested OPNSI in cisplatin (CDDP)resistant ovarian carcinoma cell lines, focusing on the role of the OPNc isoform (OPNc) in drug resistance. ACRP ovarian cancer cells resistant to CDDP, as well as their parental cell line A2780, were used. Analyses of the transcriptional expression of OPNSIs, epithelialmesenchymal transition (EMT) markers and EMTrelated cytokines were performed using reverse transcriptionquantitative PCR. OPNc was silenced in ACRP cells using antiOPNc DNA oligomers and stably overexpressed by transfecting A2780 cells with a mammalian expression vector containing the full length OPNc cDNA. Functional assays were performed to determine cell proliferation, viability and colony formation. The results demonstrated that among the three tested OPNSIs, OPNc was the most upregulated transcript in the ACRP cells compared with the parental A2780 cells. In addition, the expression levels of Pglycoprotein multidrug transporter were upregulated in CDDPresistant ACRP cells compared with those in A2780 cells. OPNc knockdown sensitized ACRP cells to CDDP treatment and downregulated Pgp expression levels compared with those in the negative control group. Additionally, silencing of OPNc impaired cell proliferative and colony formation abilities, as well as reversed the expression levels of EMT markers and EMTrelated cytokines compared with those in the negative control cells. Notably, although stable OPNc overexpression resulted in increased A2780 cell proliferation, it notably increased CDDP sensitivity compared with that in the cells transfected with a control vector. These results suggested that OPNc silencing may represent a putative approach to sensitize resistant ovarian cancer cells to chemotherapeutic agents.
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Cisplatino/farmacología , Resistencia a Antineoplásicos/genética , Osteopontina/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Empalme Alternativo , Línea Celular Tumoral , Plasticidad de la Célula/efectos de los fármacos , Plasticidad de la Célula/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Cisplatino/uso terapéutico , Transición Epitelial-Mesenquimal/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Osteopontina/genética , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismoRESUMEN
Evasion from apoptosis is one of the hallmarks of cancer. X-linked inhibitor of apoptosis protein (XIAP) is known to modulate apoptosis by inhibiting caspases and ubiquitinating target proteins. XIAP is mainly found at the cytoplasm, but recent data link nuclear XIAP to poor prognosis in breast cancer. Here, we generated a mutant form of XIAP with a nuclear localization signal (XIAPNLS-C-term) and investigated the oncogenic mechanisms associated with nuclear XIAP in breast cancer. Our results show that cells overexpressing XIAPΔRING (RING deletion) and XIAPNLS-C-term exhibited XIAP nuclear localization more abundantly than XIAPwild-type. Remarkably, overexpression of XIAPNLS-C-term, but not XIAPΔRING, conferred resistance to doxorubicin and increased cellular proliferative capacity. Interestingly, Survivin and c-IAP1 expression were not associated with XIAP oncogenic effects. However, NFκB expression and ubiquitination of K63, but not K48 chains, were increased following XIAPNLS-C-term overexpression, pointing to nuclear signaling transduction. Consistently, multivariate analysis revealed nuclear, but not cytoplasmic XIAP, as an independent prognostic factor in hormone receptor-negative breast cancer patients. Altogether, our findings suggest that nuclear XIAP confers poor outcome and RING-associated breast cancer growth and chemoresistance.
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Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Núcleo Celular/metabolismo , Resistencia a Antineoplásicos , Regulación Neoplásica de la Expresión Génica , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Apoptosis/efectos de los fármacos , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patología , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Doxorrubicina/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HEK293 , Humanos , Lisina/metabolismo , Análisis Multivariante , Proteínas Mutantes/metabolismo , Mutación/genética , FN-kappa B/metabolismo , Poliubiquitina/metabolismo , Pronóstico , Dominios Proteicos , Receptores de Superficie Celular/metabolismo , Análisis de Supervivencia , Ubiquitinación/efectos de los fármacos , Proteína Inhibidora de la Apoptosis Ligada a X/químicaRESUMEN
Neglected tropical diseases, such as Chagas disease caused by the protozoa Trypanosoma cruzi, affect millions of people worldwide but lack effective treatments that are accessible to the entire population, especially patients with the debilitating chronic phase. The recognition of host cells, invasion and its intracellular replicative success are essential stages for progression of the parasite life cycle and the development of Chagas disease. It is predicted that programmed cell death pathways (apoptosis) would be activated in infected cells, either via autocrine secretion or mediated by cytotoxic immune cells. This process should play a key role in resolving infections by hindering the evolutionary success of the parasite. In this research, we performed assays to investigate the role of the lectin galectin-3 (Gal3) in parasite-host signaling pathways. Using cells with endogenous levels of Gal3 compared to Gal3-deficient cells (induced by RNA interference), we demonstrated that T. cruzi mediated the survival pathways and the subverted apoptosis through Gal3 promoting a pro-survival state in infected cells. Infected Gal3-depleted cells showed increased activation of caspase 3 and pro-apoptotic targets, such as poly (ADP-ribose) polymerase (PARP), and lower accumulation of anti-apoptotic proteins, such as c-IAP1, survivin and XIAP. During the early stages of infection, Gal3 translocates from the cytoplasm to the nucleus and must act in survival pathways. In a murine model of experimental infection, Gal3 knockout macrophages showed lower infectivity and viability. In vivo infection revealed a lower parasitemia and longer survival and an increased spleen cellularity in Gal3 knockout mice with consequences on the percentage of T lymphocytes (CD4+ CD11b+) and macrophages. In addition, cytokines such as IL-2, IL-4, IL-6 and TNF-α are increased in Gal3 knockout mice when compared to wild type genotype. These data demonstrate a Gal3-mediated complex interplay in the host cell, keeping infected cells alive long enough for infection and intracellular proliferation of new parasites. However, a continuous knowledge of these signaling pathways should contribute to a better understanding the mechanisms of cell death subversion that are promoted by protozoans in the pathophysiology of neglected diseases such as Chagas disease.
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Apoptosis/fisiología , Enfermedad de Chagas/parasitología , Galectina 3/fisiología , Trypanosoma cruzi/fisiología , Análisis de Varianza , Animales , Western Blotting , Caspasa 3/análisis , Supervivencia Celular , Enfermedad de Chagas/mortalidad , Chlorocebus aethiops , Colorimetría , Citocinas/sangre , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Galectina 3/análisis , Galectina 3/genética , Células HeLa , Humanos , Inmunofenotipificación , Macrófagos Peritoneales/parasitología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Parasitemia/mortalidad , Parasitemia/parasitología , Fenotipo , Bazo/patología , Células VeroRESUMEN
Drug resistance represents a major issue in treating breast cancer, despite the identification of novel therapeutic strategies, biomarkers, and subgroups. We have previously identified the LQB-223, 11a-N-Tosyl-5-deoxi-pterocarpan, as a promising compound in sensitizing doxorubicin-resistant breast cancer cells, with little toxicity to non-neoplastic cells. Here, we investigated the mechanisms underlying LQB-223 antitumor effects in 2D and 3D models of breast cancer. MCF-7 and MDA-MB-231 cells had migration and motility profile assessed by wound-healing and phagokinetic track motility assays, respectively. Cytotoxicity in 3D conformation was evaluated by measuring spheroid size and performing acid phosphatase and gelatin migration assays. Protein expression was analyzed by immunoblotting. Our results show that LQB-223, but not doxorubicin treatment, suppressed the migratory and motility capacity of breast cancer cells. In 3D conformation, LQB-223 remarkably decreased cell viability, as well as reduced 3D culture size and migration. Mechanistically, LQB-223-mediated anticancer effects involved decreased proteins levels of XIAP, c-IAP1, and Mcl-1 chemoresistance-related proteins, but not survivin. Survivin knockdown partially potentiated LQB-223-induced cytotoxicity. Additionally, cell treatment with LQB-223 resulted in changes in the mRNA levels of epithelial-mesenchymal transition markers, suggesting that it might modulate cell plasticity. Our data demonstrate that LQB-223 impairs 3D culture growth and migration in 2D and 3D models of breast cancer exhibiting different phenotypes.
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Antineoplásicos/farmacología , Apoptosis , Neoplasias de la Mama/metabolismo , Resistencia a Antineoplásicos , Pterocarpanos/farmacología , Antineoplásicos/toxicidad , Movimiento Celular , Proliferación Celular , Femenino , Humanos , Proteínas Inhibidoras de la Apoptosis/metabolismo , Células MCF-7 , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Pterocarpanos/toxicidad , Esferoides Celulares/efectos de los fármacos , Survivin/genética , Survivin/metabolismo , Células Tumorales Cultivadas , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismoRESUMEN
Subsequent to the publication of the above article, the authors have realized that there were errors associated with Figs. 1c and 2b. In Fig. 1c, the authors noted that the same data were incorrectly presented for the 'Untreated cells" and 'DMSO' dotblot experiments. After having reexamined their source data, the authors were able to confirm that the data correctly shown for the 'Untreated cells' experiment had inadvertently been included in the Figure as the data for the 'DMSO' experiment. Additionally, in Fig. 2b, the authors noticed that the percentage of untreated cells with active caspase3 was missing (the label for the 'No antibody' experiment). Corrected versions of Figs. 1 (including the correct data for the 'DMSO' dot blot) and 2 (with the label now incorporated) are shown opposite. Note that these changes do not affect the results or the conclusions reported in this paper, and all the authors agree to this correction. The authors apologize to the Editor and to the readership of the Journal for any inconvenience caused. [the original article was published in International Journal of Oncology 45: 19491958, 2014; DOI: 10.3892/ijo.2014.2615].
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Forkhead box (FOX) transcription factors compose a large family of regulators of key biological processes within a cell. FOXK2 is a member of FOX family, whose biological functions remain relatively unexplored, despite its description in the early nineties. More recently, growing evidence has been pointing towards a role of FOXK2 in cancer, which is likely to be context-dependent and tumour-specific. Here, we provide an overview of important aspects concerning the mechanisms of regulation of FOXK2 expression and function, as well as its complex interactions at the chromatin level, which orchestrate how it differentially regulates the expression of gene targets in pathophysiology. Particularly, we explore the emerging functions of FOXK2 as a regulator of a broad range of cancer features, such as cell proliferation and survival, DNA damage, metabolism, migration, invasion and metastasis. Finally, we discuss the prognostic value of assessing FOXK2 expression in cancer patients and how it can be potentially targeted for future anticancer interventions.
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Chronic myeloid leukemia (CML) is a rare disease in children. Different from that in adults, childhood CML involves transformative events occurring over a short time period. CML transformation to lymphoid blast phase (BP) is associated with copy number abnormalities, characteristic of BCR-ABL1 positive acute lymphoblastic leukemia, but not of CML in the chronic phase. Here, we present an unusual case of CML progressing to BP in a 1.6-year-old child, harboring IKZF1, PAX5, CDKN2A, and ETV6 deletions at diagnosis. It remains to be addressed whether distinct mechanisms might account for CML pathogenesis in early childhood.
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Crisis Blástica/genética , Eliminación de Gen , Factor de Transcripción Ikaros/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Proteínas de Neoplasias/genética , Crisis Blástica/patología , Femenino , Humanos , Lactante , Leucemia Mielógena Crónica BCR-ABL Positiva/patologíaRESUMEN
Osteopontin (OPN) is a matricellular phosphoglycoprotein overexpressed in several tumor types and can activate several aspects of cancer progression in solid and nonsolid tumors. In the present review, the roles of OPN in mediating resistance to chemotherapy and radiotherapy and their main associated signaling pathways were summarized and discussed. Furthermore, it was detailed how OPN expression may be able to modulate resistance to these therapies by controlling epithelial cell plasticity, stemness potential and cell survival. Based on these data, the use of OPN and associated signaling was then proposed as potential molecular targets in order to sensitize resistant cells to main current therapeutic approaches. Finally, based on experimental evidence obtained by our group, the importance of investigating the specific roles OPN splicing isoforms have and how their properties may specifically control resistance to therapy was highlighted. These data elucidate a better understanding of how total OPN and their splicing isoforms, as well as their associated signaling, may contribute to main aspects of chemoresistance and radioresistance, such as those controlling cell survival, apoptosis, autophagy, stemness, epithelial cell plasticity and associated cell receptors.
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Neoplasias/tratamiento farmacológico , Neoplasias/radioterapia , Osteopontina/genética , Isoformas de Proteínas/genética , Apoptosis/genética , Autofagia/genética , Resistencia a Antineoplásicos/genética , Humanos , Neoplasias/genética , Empalme del ARN/genética , Tolerancia a Radiación/genética , Transducción de SeñalRESUMEN
UNLABELLED: Multidrug resistance is the major obstacle for successful treatment of breast cancer, prompting the investigation of novel anticancer compounds. PURPOSE: In this study, we tested whether LQB-223, an 11a-N-Tosyl-5-deoxi-pterocarpan newly synthesized compound, could be effective toward breast cancer cells. METHODS: Human breast cell lines MCF-7, MDA-MB-231, HB4a and MCF-7 Dox(R) were used as models for this study. Cell culture, MTT and clonogenic assay, flow cytometry and Western blotting were performed. RESULTS: The LQB-223 decreased cell viability, inhibited colony formation and induced an expressive G2/M arrest in breast cancer cells. There was an induction in p53 and p21(Cip1) protein levels following treatment of wild-type p53 MCF-7 cells, which was not observed in the mutant p53 MDA-MB-231 cell line, providing evidence that the compound might act to modulate the cell cycle regardless of p53 status. In addition, LQB-223 resulted in decreased procaspase levels and increased annexin V staining, suggesting that the apoptotic cascade is also triggered. Importantly, LQB-223 treatment was shown to be less cytotoxic to non-neoplastic breast cells than docetaxel and doxorubicin. Strikingly, exposure of doxorubicin-resistant MCF-7-Dox(R) cells to LQB-223 resulted in suppression of cell viability and proliferation in levels comparable to MCF-7. Of note, MCF-7-Dox(R) cells have an elevated expression of the P-glycoprotein efflux pump when compared to MCF-7. CONCLUSION: Together, these results show that LQB-223 mediates cytotoxic effects in sensitive and resistant breast cancer cells, while presenting low toxicity to non-neoplastic cells. The new compound might represent a potential strategy to induce toxicity in breast cancer cells, especially chemoresistant cells.
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Neoplasias de la Mama/tratamiento farmacológico , Carcinoma Ductal de Mama/tratamiento farmacológico , Pterocarpanos/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/biosíntesis , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/metabolismo , División Celular/efectos de los fármacos , Línea Celular Tumoral , Docetaxel , Doxorrubicina/efectos adversos , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Femenino , Fase G2/efectos de los fármacos , Humanos , Células MCF-7 , Fenotipo , Pterocarpanos/efectos adversos , Taxoides/efectos adversos , Taxoides/farmacologíaRESUMEN
Acute myeloid leukemia (AML) patients' outcome is usually poor, mainly because of drug resistance phenotype. The identification of new drugs able to overcome mechanisms of chemoresistance is essential. The pterocarpanquinone LQB-118 compound has been shown to have a potent cytotoxic activity in myeloid leukemia cell lines and patient cells. Our aim was to investigate if LQB-118 is able to target FoxO3a and FoxM1 signaling pathways while sensitizing AML cell lines. LQB-118 induced apoptosis in both AML cell lines HL60 (M3 FAB subtype) and U937 (M4/M5 FAB subtype). Cell death occurred independently of alterations in cell cycle distribution. In vivo administration revealed that LQB-118 was not cytotoxic to normal bone marrow-derived cells isolated from mice. LQB-118 induced FoxO3a nuclear translocation and upregulation of its direct transcriptional target Bim, in HL60 cells. However, LQB-118 induced FoxO3a nuclear exclusion, followed by Bim downregulation, in U937 cells. Concomitantly, LQB-118 exposure reduced FoxM1 and Survivin expression in U937 cells, but this effect was more subtle in HL60 cells. Taken together, our data suggest that LQB-118 has a selective and potent antitumor activity against AML cells with distinct molecular subtypes, and it involves differential modulation of the signaling pathways associated with FoxO3a and FoxM1 transcription factors.
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Factores de Transcripción Forkhead/biosíntesis , Leucemia Mieloide Aguda/tratamiento farmacológico , Naftoquinonas/administración & dosificación , Pterocarpanos/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proteína Forkhead Box M1 , Proteína Forkhead Box O3 , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Células HL-60 , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , RatonesRESUMEN
ABCB1/P-glycoprotein (Pgp) and ABCG2/BCRP overexpression have been described as related to imatinib resistance in chronic myeloid leukemia (CML). We showed in CML cells from 55 patients that Pgp activity was more frequently detected than BCRP activity (p=0.0074). Imatinib-induced Crkl phosphorylated protein (pCrkl) reduction was more pronounced in K562 (Pgp-negative) than in K562-Lucena (Pgp-positive) CML cell line. Expressive pCrkl reduction levels after in vitro imatinib treatment was observed in samples from patients exhibiting lower Pgp activity levels compared with patients exhibiting higher Pgp activity levels (p=0.0045). Pgp activity in association with pCrkl reduction levels might help to distinguish between imatinib-resistant and imatinib-sensitive CML cells.
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Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Proteínas Proto-Oncogénicas c-crk/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Benzamidas/uso terapéutico , Biomarcadores de Tumor/metabolismo , Niño , Preescolar , Resistencia a Antineoplásicos , Femenino , Humanos , Mesilato de Imatinib , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Células MCF-7 , Masculino , Persona de Mediana Edad , Fosforilación , Piperazinas/uso terapéutico , Proteínas Quinasas/metabolismo , Pirimidinas/uso terapéutico , Adulto JovenRESUMEN
Breast cancer is the leading cause of deaths in women around the world. Resistance to therapy is the main cause of treatment failure and still little is known about predictive biomarkers for response to systemic therapy. Increasing evidence show that Survivin and XIAP overexpression is closely associated with chemoresistance and poor prognosis in breast cancer. However, their impact on resistance to doxorubicin (dox), a chemotherapeutic agent widely used to treat breast cancer, is poorly understood. Here, we demonstrated that dox inhibited cell viability and induced DNA fragmentation and activation of caspases-3, -7 and -9 in the breast cancer-derived cell lines MCF7 and MDA-MB-231, regardless of different p53 status. Dox exposure resulted in reduction of Survivin and XIAP mRNA and protein levels. However, when we transfected cells with a Survivin-encoding plasmid, we did not observe a cell death-resistant phenotype. XIAP and Survivin silencing, either alone or in combination, had no effect on breast cancer cells sensitivity towards dox. Altogether, we demonstrated that breast cancer cells are sensitive to the chemotherapeutic agent dox irrespective of Survivin and XIAP expression levels. Also, our findings suggest that dox-mediated modulation of Survivin and XIAP might sensitize cells to taxanes when used in a sequential regimen.
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Antibióticos Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Muerte Celular/efectos de los fármacos , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Proteínas Inhibidoras de la Apoptosis/metabolismo , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Antibióticos Antineoplásicos/uso terapéutico , Apoptosis , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Muerte Celular/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Doxorrubicina/uso terapéutico , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Silenciador del Gen , Humanos , Proteínas Inhibidoras de la Apoptosis/genética , Células MCF-7 , ARN Mensajero/metabolismo , ARN Interferente Pequeño/genética , Survivin , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteína Inhibidora de la Apoptosis Ligada a X/genéticaRESUMEN
P-glycoprotein (Pgp) and XIAP co-expression has been discussed in the process of the acquisition of multidrug resistance (MDR) in cancer. Here, we evaluated XIAP and Pgp expression in chronic myeloid leukemia (CML) samples, showing a positive correlation between them. Furthermore, we evaluated the effects of imatinib in XIAP and Pgp expression using CML cell lines K562 (Pgp(-)) and K562-Lucena (Pgp(+)). Imatinib increased XIAP and Pgp expression in K562-Lucena cells, while in K562 cells a downregulation of these proteins was observed, suggesting that imatinib induces an increment of MDR phenotype of CML cells that previously exhibit high levels of Pgp/XIAP co-expression.
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Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Antineoplásicos/farmacología , Benzamidas/farmacología , Resistencia a Antineoplásicos/genética , Expresión Génica , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Piperazinas/farmacología , Pirimidinas/farmacología , Proteína Inhibidora de la Apoptosis Ligada a X/genética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Apoptosis/efectos de los fármacos , Apoptosis/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Niño , Femenino , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Humanos , Mesilato de Imatinib , Proteínas Inhibidoras de la Apoptosis/genética , Proteínas Inhibidoras de la Apoptosis/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Masculino , Persona de Mediana Edad , Inhibidores de Proteínas Quinasas/farmacología , Interferencia de ARN , Survivin , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Adulto JovenRESUMEN
Chronic myeloid leukemia (CML) is a clonal hematopoietic disorder characterized by the presence of the Philadelphia chromosome which resulted from the reciprocal translocation between chromosomes 9 and 22. The pathogenesis of CML involves the constitutive activation of the BCR-ABL tyrosine kinase, which governs malignant disease by activating multiple signal transduction pathways. The BCR-ABL kinase inhibitor, imatinib, is the front-line treatment for CML, but the emergence of imatinib resistance and other tyrosine kinase inhibitors (TKIs) has called attention for additional resistance mechanisms and has led to the search for alternative drug treatments. In this paper, we discuss our current understanding of mechanisms, related or unrelated to BCR-ABL, which have been shown to account for chemoresistance and treatment failure. We focus on the potential role of the influx and efflux transporters, the inhibitor of apoptosis proteins, and transcription factor-mediated signals as feasible molecular targets to overcome the development of TKIs resistance in CML.
RESUMEN
Overexpression of P-glycoprotein (Pgp/ABCB1) in tumor cells is associated with a classic phenotype of multidrug resistance (MDR). Moreover, some members of the inhibitor of apoptosis protein (IAP) family, such as survivin, contribute to an apoptosis-resistant phenotype, by inhibiting chemotherapy-induced cell death and promoting MDR. By using Western blotting, qRT-PCR, Annexin V and immunofluorescence assays we have demonstrated a relationship between Pgp and survivin in a prior sensitive chronic myeloid leukemia (CML) cell line (K562). A high dose of vincristine induced a concomitant overexpression of Pgp and survivin, which was associated with a low apoptotic index in the K562 cell line. In addition, we observed a cytoplasmic co-localization of Pgp and survivin, suggesting a functional association between these two proteins in apoptosis control by a common mechanism. In summary, our data suggest that Pgp and survivin should be analyzed in aggregate because they may have significant impact on drug resistance in CML cells.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proteínas Inhibidoras de la Apoptosis/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Vincristina/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , División Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Fase G2/efectos de los fármacos , Humanos , Proteínas Inhibidoras de la Apoptosis/genética , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Survivin , Proteína Inhibidora de la Apoptosis Ligada a X/genéticaRESUMEN
Cell death by apoptosis triggers the engagement of a conserved intracellular machinery of execution, involving mainly the activation of the caspase family of cysteine proteases. Caspase-3 is a common effector of most of the apoptotic pathways and is able to cleave several target proteins whose degradation will contribute to the execution phase of the cell demise program. Here we present a modification of the Western blot protocol to improve sensitivity of caspase-3 detection, providing a valuable tool to access its activation in biological specimens.