Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
BMC Cancer ; 22(1): 908, 2022 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-35986318

RESUMEN

BACKGROUND: Less than 20 % of patients with resectable oesophageal adenocarcinoma obtain a pathological response following neoadjuvant chemotherapy. Studies using oesophageal cancer cell lines have shown that drug sensitive tumour cells undergo apoptosis in response to drug treatment, whereas resistant cells induce autophagy and can recover following withdrawal of drug. In this study, we evaluated markers of apoptosis (active/cleaved caspase-3) and autophagy (LC3B) to establish whether these markers are useful prognostic indicators following neoadjuvant therapy. METHODS: Oesophageal adenocarcinoma tumour tissue from the Northern Ireland Biobank at Queens University Belfast was examined retrospectively. Tumours from 144 patients treated with platinum-based neoadjuvant chemotherapy followed by surgical resection were assembled into tissue microarrays prior to immunohistochemical analysis. Kaplan-Meier survival curves and log-rank tests were used to assess the impact of cleaved caspase-3 and LC3B expression on survival. Cox regression was used to examine association with clinical risk factors. RESULTS: High levels of cleaved caspase-3 were found in 14.6 % of patients and this correlated with a significantly better overall survival (p = 0.03). 38.9 % of patients had high cytoplasmic LC3B expression, which correlated with poor overall survival (p = 0.041). In addition, a distinct globular pattern of LC3B expression was identified in 40.3 % of patients and was also predictive of overall survival (p < 0.001). LC3B globular structures are also associated with tumour recurrence (p = 0.014). When these markers were assessed in combination, it was found that patients who showed low/negative cleaved caspase-3 staining and high/positive staining for both patterns of LC3B had the worst overall survival (p < 0.001). Multi-variate analysis also indicated that this marker combination was an independent predictor of poor prognosis (p = 0.008; HR = 0.046, 95% CI = (0.005-0.443). CONCLUSIONS: The expression of cleaved caspase-3 and specific LC3B staining patterns are associated with overall survival following neoadjuvant treatment. The combination of these markers is an independent indicator of outcome in neoadjuvant chemotherapy treated oesophageal adenocarcinoma.


Asunto(s)
Adenocarcinoma , Neoplasias Esofágicas , Adenocarcinoma/patología , Apoptosis , Autofagia , Biomarcadores de Tumor/metabolismo , Caspasa 3 , Humanos , Terapia Neoadyuvante , Pronóstico , Estudios Retrospectivos
2.
Eur J Haematol ; 104(3): 236-250, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31811682

RESUMEN

OBJECTIVE: In acute promyelocytic leukemia (APL), normal retinoid signaling is disrupted by an abnormal PML-RARα fusion oncoprotein, leading to a block in cell differentiation. Therapeutic concentrations of all-trans-retinoic acid (ATRA) can restore retinoid-induced transcription and promote degradation of the PML-RARα protein. Autophagy is a catabolic pathway that utilizes lysosomal machinery to degrade intracellular material and facilitate cellular re-modeling. Recent studies have identified autophagy as an integral component of ATRA-induced myeloid differentiation. METHODS: As the molecular communication between retinoid signaling and the autophagy pathway is not defined, we performed RNA sequencing of NB4 APL cells treated with ATRA and examined autophagy-related transcripts. RESULTS: ATRA altered the expression of >80 known autophagy-related transcripts, including the key transcriptional regulator of autophagy and lysosomal biogenesis, TFEB (11.5-fold increase). Induction of TFEB and its transcriptional target, sequestosome 1 (SQSTM1, p62), is reduced in ATRA-resistant NB4R cells compared to NB4 cells. TFEB knockdown in NB4 cells alters the expression of transcriptional targets of TFEB and reduces CD11b transcript levels in response to ATRA. CONCLUSIONS: We show for the first time that TFEB plays an important role in ATRA-induced autophagy during myeloid differentiation and that autophagy induction potentiates leukemic cell differentiation (Note: this study includes data obtained from NCT00195156, https://clinicaltrials.gov/show/NCT00195156).


Asunto(s)
Antineoplásicos/farmacología , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Diferenciación Celular/efectos de los fármacos , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patología , Tretinoina/farmacología , Antineoplásicos/uso terapéutico , Autofagia/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Biopsia , Médula Ósea/patología , Línea Celular Tumoral , Técnicas de Silenciamiento del Gen , Humanos , Leucemia Promielocítica Aguda/tratamiento farmacológico , Leucemia Promielocítica Aguda/metabolismo , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/genética , Transducción de Señal/efectos de los fármacos , Tretinoina/uso terapéutico
3.
BMC Cancer ; 19(1): 1177, 2019 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-31795977

RESUMEN

Following publication of the original article [1], the authors reported an omission in the affiliations.

4.
J Pediatr Gastroenterol Nutr ; 69(2): 171-175, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30964821

RESUMEN

INTRODUCTION AND OBJECTIVES: The endoscopy Global Rating Scale (GRS) is a web-based self-assessment quality improvement (QI) tool that provides a framework for service improvement. Widespread use of the GRS in adult endoscopy services in the United Kingdom (UK) has led to a demonstrable improvement in quality. The adult GRS is not directly applicable to paediatric endoscopy services. The objective of this study is to develop and pilot a paediatric endoscopy Global Rating Scale (P-GRS) as a QI tool. METHODS: Members of the British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) Endoscopy Working Group collaborated with the Joint Advisory Group on Gastrointestinal Endoscopy (JAG) to develop the P-GRS. After a period of consultation, this was piloted nationally at 9 centres and data were collected prospectively at 2 census points, May and December 2016. RESULTS: The P-GRS mirrors the adult GRS by dividing care into 4 domains and includes 19 standards with several measures that underpin the standards. Eight services completed the online P-GRS return in May 2016 and 6 in December 2016. All pilot sites identified areas that needed improvement and post-pilot reflected on the key challenges and developments. Several positive developments were reported by the pilot sites. CONCLUSIONS: The national pilot helped ensure that the P-GRS developed was relevant to the paediatric endoscopy services. The pilot demonstrated that even in the first year of engaging with this QI tool, services were starting to identify areas that needed improvement, share best practice documents, put in place QI plans, and support greater patient involvement in services.


Asunto(s)
Benchmarking , Servicios de Salud del Niño/normas , Endoscopía Gastrointestinal/normas , Niño , Humanos , Proyectos Piloto , Mejoramiento de la Calidad , Medicina Estatal , Reino Unido
5.
Biochim Biophys Acta ; 1866(1): 87-105, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27373814

RESUMEN

Increased glycolysis is the main source of energy supply in cancer cells that use this metabolic pathway for ATP generation. Altered energy metabolism is a biochemical fingerprint of cancer cells that represents one of the "hallmarks of cancer". The immune system can prevent tumour growth by eliminating cancer cells but this editing process ultimately results in poorly immunogenic cells remaining allowing for unchallenged tumour growth. In this review we look at the glycolysis pathway as a target for cancer treatments. We also examine the interplay between the glycolysis modulation and the immune response as an anti-cancer therapy.


Asunto(s)
Glucólisis/efectos de los fármacos , Inmunidad Celular/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Adenosina Trifosfato/metabolismo , Metabolismo Energético/efectos de los fármacos , Humanos , Redes y Vías Metabólicas/efectos de los fármacos , Terapia Molecular Dirigida , Neoplasias/metabolismo , Neoplasias/patología
6.
Mol Pharm ; 14(3): 940-952, 2017 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-28146632

RESUMEN

Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults and is associated with high relapse rates. It is known that leukemia stem cells (LSCs), a very small subpopulation of the total number of leukemic cells, maintain the leukemia phenotype (∼80-90% of AML remain the same as at first diagnosis), display chemotherapy resistance, and contribute to disease regeneration. Therefore, targeting LSCs could control the relapse of AML. Small interfering RNA (siRNA), an effector of the RNA interference (RNAi) pathway, can selectively downregulate any gene implicated in the pathology of disease, presenting great potential for treatment of AML. In this study an antibody targeted cyclodextrin-based nanoparticle (NP) (CD.DSPE-PEG-Fab) was developed for siRNA delivery specifically to AML LSCs. The targeted CD.siRNA.DSPE-PEG-Fab formulation, where Fab specifically targets the IL-3 receptor α-chain (IL-3Rα, also known as CD123, a cell surface antigen for human AML LSCs), achieved antigen-mediated cellular uptake in KG1 cells (an AML leukemia stem and progenitor cell line). Efficient delivery of bromodomain-containing protein 4 (BRD4) siRNA using the targeted formulation resulted in downregulation of the corresponding mRNA and protein in KG1 cells and in ex vivo primary AML patient derived samples. The resulting silencing of BRD4 induced myeloid differentiation and triggered leukemia apoptosis. In addition, a synergistic therapeutic effect was detected when administered in combination with the chemotherapeutic, cytarabine (Ara-C). These results indicate the clinical potential of the antibody-tagged cyclodextrin NP for targeted delivery of therapeutic siRNA in the treatment of AML.


Asunto(s)
Anticuerpos/administración & dosificación , Ciclodextrinas/administración & dosificación , Leucemia Mieloide Aguda/tratamiento farmacológico , Nanopartículas/administración & dosificación , ARN Interferente Pequeño/administración & dosificación , Apoptosis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Citarabina/farmacología , Regulación hacia Abajo/efectos de los fármacos , Humanos , Células K562 , Leucemia Mieloide Aguda/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Receptores de Interleucina-3/metabolismo , Factores de Transcripción/metabolismo
7.
BMC Cancer ; 16: 101, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26878873

RESUMEN

BACKGROUND: Successful treatment of oesophageal cancer is hampered by recurrent drug resistant disease. We have previously demonstrated the importance of apoptosis and autophagy for the recovery of oesophageal cancer cells following drug treatment. When apoptosis (with autophagy) is induced, these cells are chemosensitive and will not recover following chemotherapy treatment. In contrast, when cancer cells exhibit only autophagy and limited Type II cell death, they are chemoresistant and recover following drug withdrawal. METHODS: MicroRNA (miRNA) expression profiling of an oesophageal cancer cell line panel was used to identify miRNAs that were important in the regulation of apoptosis and autophagy. The effects of miRNA overexpression on cell death mechanisms and recovery were assessed in the chemoresistant (autophagy inducing) KYSE450 oesophageal cancer cells. RESULTS: MiR-193b was the most differentially expressed miRNA between the chemosensitive and chemoresistant cell lines with higher expression in chemosensitive apoptosis inducing cell lines. Colony formation assays showed that overexpression of miR-193b significantly impedes the ability of KYSE450 cells to recover following 5-fluorouracil (5-FU) treatment. The critical mRNA targets of miR-193b are unknown but target prediction and siRNA data analysis suggest that it may mediate some of its effects through stathmin 1 regulation. Apoptosis was not involved in the enhanced cytotoxicity. Overexpression of miR-193b in these cells induced autophagic flux and non-apoptotic cell death. CONCLUSION: These results highlight the importance of miR-193b in determining oesophageal cancer cell viability and demonstrate an enhancement of chemotoxicity that is independent of apoptosis induction.


Asunto(s)
Apoptosis/genética , Autofagia/genética , Resistencia a Antineoplásicos/genética , Neoplasias Esofágicas/metabolismo , MicroARNs/metabolismo , Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Neoplasias Esofágicas/genética , Fluorouracilo/farmacología , Humanos , MicroARNs/genética
8.
BMC Cancer ; 15: 582, 2015 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-26265176

RESUMEN

BACKGROUND: Esophageal adenocarcinoma has the fastest growing incidence of any solid tumor in the Western world. Prognosis remains poor with overall five-year survival rates under 25 %. Only a limited number of patients benefit from chemotherapy and there are no biomarkers that can predict outcome. Previous studies have indicated that induction of autophagy can influence various aspects of tumor cell biology, including chemosensitivity. The objective of this study was to assess whether expression of the autophagy marker (LC3B) correlated with patient outcome. METHODS: Esophageal adenocarcinoma tumor tissue from two independent sites, was examined retrospectively. Tumors from 104 neoadjuvant naïve patients and 48 patients post neoadjuvant therapy were assembled into tissue microarrays prior to immunohistochemical analysis. Kaplan-Meier survival curves and log-rank tests were used to assess impact of LC3B expression on survival. Cox regression was used to examine association with clinical risk factors. RESULTS: A distinct globular pattern of LC3B expression was found to be predictive of outcome in both patient groups, irrespective of treatment (p < 0.001). Multivariate analysis found that this was a strong independent predictor of poor prognosis (p < 0.001). CONCLUSIONS: This distinctive staining pattern of LC3B represents a novel prognostic marker for resectable esophageal adenocarcinoma.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patología , Proteínas Asociadas a Microtúbulos/metabolismo , Autofagia , Línea Celular Tumoral , Neoplasias Esofágicas/tratamiento farmacológico , Humanos , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia
9.
MMWR Morb Mortal Wkly Rep ; 64(47): 1312-4, 2015 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-26633233

RESUMEN

Skin cancer is the most common cancer in the United States, and most cases are preventable. Persons with certain genetic risk factors, including having a lighter natural skin color; blue or green eyes; red or blonde hair; dysplastic nevi or a large number of common moles; and skin that burns, freckles, or reddens easily or becomes painful after time in the sun, have increased risk for skin cancer. Persons with a family or personal history of skin cancer, especially melanoma, are also at increased risk. Although these genetic factors contribute to individual risk, most skin cancers are also strongly associated with ultraviolet (UV) radiation exposure. Most UV exposure comes from the sun, although some persons use UV-emitting indoor tanning devices (e.g., beds, booths, and lamps).


Asunto(s)
Neoplasias Cutáneas/prevención & control , Adolescente , Adulto , Centers for Disease Control and Prevention, U.S. , Práctica Clínica Basada en la Evidencia , Femenino , Predicción , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Cutáneas/epidemiología , Estados Unidos/epidemiología , Adulto Joven
10.
Exp Cell Res ; 324(1): 1-12, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24694321

RESUMEN

Retinoids are a family of signaling molecules derived from vitamin A with well established roles in cellular differentiation. Physiologically active retinoids mediate transcriptional effects on cells through interactions with retinoic acid (RARs) and retinoid-X (RXR) receptors. Chromosomal translocations involving the RARα gene, which lead to impaired retinoid signaling, are implicated in acute promyelocytic leukemia (APL). All-trans-retinoic acid (ATRA), alone and in combination with arsenic trioxide (ATO), restores differentiation in APL cells and promotes degradation of the abnormal oncogenic fusion protein through several proteolytic mechanisms. RARα fusion-protein elimination is emerging as critical to obtaining sustained remission and long-term cure in APL. Autophagy is a degradative cellular pathway involved in protein turnover. Both ATRA and ATO also induce autophagy in APL cells. Enhancing autophagy may therefore be of therapeutic benefit in resistant APL and could broaden the application of differentiation therapy to other cancers. Here we discuss retinoid signaling in hematopoiesis, leukemogenesis, and APL treatment. We highlight autophagy as a potential important regulator in anti-leukemic strategies.


Asunto(s)
Autofagia/genética , Leucemia Promielocítica Aguda , Receptores de Ácido Retinoico/fisiología , Animales , Diferenciación Celular/genética , Hematopoyesis/fisiología , Humanos , Leucemia Promielocítica Aguda/tratamiento farmacológico , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patología , Retinoides/uso terapéutico , Transducción de Señal/fisiología
11.
Contemp Clin Trials Commun ; 39: 101290, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38595771

RESUMEN

Background: Current health behavior recommendations for skin cancer prevention, treatment, and survivorship are the same for survivors of other cancers; they include eating a healthy diet, being physically active, maintaining a healthy weight, and minimizing ultraviolet (U.V.) exposure. Few interventions exist to support health behaviors beyond U.V. exposure. We adapted Harvest for Health, a home-based mentored gardening intervention for cancer survivors, for implementation in Arizona as a community-based intervention. Methods: Stakeholder-informed adaptations for Harvest for Health Together Arizona (H4H2-AZ) included updating intervention materials to be relevant to the arid desert environment, emphasizing the importance of sun safety in cancer survivorship, and shifting from a home-based to a community-based delivery model. Participants will be enrolled in cohorts aligned with growing seasons (e.g., spring, monsoon, fall) and matched to an individual 30 ft2 community garden plot for two growing seasons (6 months). Original intervention components retained are: 1) Master Gardeners deliver the intervention providing one-to-one mentorship and 2) gardening materials and supplies provided. This pilot six-month single-arm intervention will determine feasibility, acceptability, and appropriateness of an evidence-based adapted mentored community gardening intervention for survivors of skin cancer as primary outcomes. Secondary outcomes are to explore the effects on cancer preventive health behaviors and health-related quality of life. Discussion: This pilot single-arm intervention will determine feasibility, acceptability, and appropriateness of an evidence-based adapted mentored community gardening intervention for survivors of skin cancer. If successful, the intervention could be widely implemented throughout existing Master Gardener programs and community garden networks for survivors of other cancers. Trial registration: ClinicalTrials.gov identifier: NCT05648604. Trial registered on December 13, 2022.

12.
Am J Hematol ; 88(6): 455-62, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23440701

RESUMEN

Chronic Myeloid Leukemia (CML) is a disease of hematopoietic stem cells which harbor the chimeric gene Bcr-Abl. Expression levels of this constitutively active tyrosine kinase are critical for response to tyrosine kinase inhibitor treatment and also disease progression, yet the regulation of protein stability is poorly understood. We have previously demonstrated that imatinib can induce autophagy in Bcr-Abl expressing cells. Autophagy has been associated with the clearance of large macromolecular signaling complexes and abnormal proteins, however, the contribution of autophagy to the turnover of Bcr-Abl protein in imatinib treated cells is unknown. In this study, we show that following imatinib treatment, Bcr-Abl is sequestered into vesicular structures that co-localize with the autophagy marker LC3 or GABARAP. This association is inhibited by siRNA mediated knockdown of autophagy regulators (Beclin 1/ATG7). Pharmacological inhibition of autophagy also reduced Bcr-Abl/LC3 co-localization in both K562 and CML patient cells. Bcr-Abl protein expression was reduced with imatinib treatment. Inhibition of both autophagy and proteasome activity in imatinib treated cells was required to restore Bcr-Abl protein levels to those of untreated cells. This ability to down-regulate Bcr-Abl protein levels through the induction of autophagy may be an additional and important feature of the activity of imatinib.


Asunto(s)
Autofagia/efectos de los fármacos , Benzamidas/farmacología , Proteínas de Fusión bcr-abl/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Piperazinas/farmacología , Pirimidinas/farmacología , Adenina/análogos & derivados , Adenina/farmacología , Animales , Proteínas Reguladoras de la Apoptosis/deficiencia , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Beclina-1 , Línea Celular Tumoral , Regulación hacia Abajo/efectos de los fármacos , Proteínas de Fusión bcr-abl/biosíntesis , Proteínas de Fusión bcr-abl/genética , Técnicas de Silenciamiento del Gen , Humanos , Mesilato de Imatinib , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/enzimología , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Fagosomas/efectos de los fármacos , Fagosomas/enzimología , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , ARN Interferente Pequeño/administración & dosificación , ARN Interferente Pequeño/genética , Transducción de Señal , Transfección
13.
Apoptosis ; 17(9): 950-63, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22696202

RESUMEN

Chronic myeloid leukemia (CML) is a disorder of hematopoietic stem cells caused by the expression of BCR-ABL. Loss of p53 has not been implicated as important for the development of CML. Mutations in p53 protein are infrequent, however they correlate with the disease progression. The absence of p53 mutations does not exclude the possibility that other dysfunctions play an important role in CML pathology. Acetylation represents a very potent posttranslational mechanism regulating p53 stability, transcriptional activity and localization. In this study we have investigated whether the expression of BCR-ABL could influence the acetylation of p53, specifically at lysine 317/320 (K317/K320), which has been shown to regulate nuclear export and transcription-independent apoptotic activity of p53. We found that BCR-ABL expression increases K317 acetylation of p53 and is able to prevent a drop in acetylation observed upon DNA damage, followed by translocation of p53 to the cytoplasm and by Bax activation. We have shown that this site plays a crucial role in the regulation of p53 localization and p53-dependent, Bax-mediated apoptosis. Our study presents a novel BCR-ABL-dependent mechanism protecting from DNA-damage-induced cell death. It can, in addition to already known mechanisms, explain the resistance to p53-dependent apoptosis observed in CML cells expressing wt p53. We propose that the acetyltransferases regulating the p53 acetylation could be an interesting and potent target for therapeutic intervention.


Asunto(s)
Apoptosis , Daño del ADN , Proteínas de Fusión bcr-abl/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Acetilación , Animales , Línea Celular , Supervivencia Celular , Citoplasma/metabolismo , Activación Enzimática , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Ratones , Mitocondrias/metabolismo , Transporte de Proteínas , Interferencia de ARN , ARN Interferente Pequeño , Proteína X Asociada a bcl-2/metabolismo , Factores de Transcripción p300-CBP/genética , Factores de Transcripción p300-CBP/metabolismo
14.
Front Oncol ; 12: 848517, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35280824

RESUMEN

Acute myeloid leukemia (AML) is an aggressive blood cancer with an overall survival of 30%. One form of AML, acute promyelocytic leukemia (APL) has become more than 90% curable with differentiation therapy, consisting of all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO). Application of differentiation therapy to other AML subtypes would be a major treatment advance. Recent studies have indicated that autophagy plays a key role in the differentiation of ATRA-responsive APL cells. In this study, we have investigated whether differentiation could be enhanced in ATRA resistant cells by promoting autophagy induction with valproic acid (VPA). ATRA sensitive (NB4) and resistant leukemia cells (NB4R and THP-1) were co-treated with ATRA and valproic acid, followed by assessment of autophagy and differentiation. The combination of VPA and ATRA induced autophagic flux and promoted differentiation in ATRA-sensitive and -resistant cell lines. shRNA knockdown of ATG7 and TFEB autophagy regulators impaired both autophagy and differentiation, demonstrating the importance of autophagy in the combination treatment. These data suggest that ATRA combined with valproic acid can promote differentiation in myeloid leukemia cells by mechanism involving autophagy.

15.
Am J Hematol ; 86(1): 38-47, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21132731

RESUMEN

Although Imatinib has transformed the treatment of chronic myeloid leukemia (CML), it is not curative due to the persistence of resistant cells that can regenerate the disease. We have examined how Bcr-Abl-expressing cells respond to two mechanistically different therapeutic agents, etoposide and Imatinib. We also examined Bcr-Abl expression at low and high levels as elevated expression has been associated with treatment failure. Cells expressing low levels of Bcr-Abl undergo apoptosis in response to the DNA-targeting agent (etoposide), whereas high-Bcr-Abl-expressing cells primarily induce autophagy. Autophagic populations engage a delayed nonapoptotic death; however, sufficient cells evade this and repopulate following the withdrawal of the drug. Non-Bcr-Abl-expressing 32D or Ba/F3 cells induce both apoptosis and autophagy in response to etoposide and can recover. Imatinib treatment induces both apoptosis and autophagy in all Bcr-Abl-expressing cells and populations rapidly recover. Inhibition of autophagy with ATG7 and Beclin1 siRNA significantly reduced the recovery of Imatinib-treated K562 cells, indicating the importance of autophagy for the recovery of treated cells. Combination regimes incorporating agents that disrupt Imatinib-induced autophagy would remain primarily targeted and may improve response to the treatment in CML.


Asunto(s)
Autofagia/efectos de los fármacos , Doxorrubicina/farmacología , Etopósido/farmacología , Proteínas de Fusión bcr-abl/biosíntesis , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Piperazinas/farmacología , Pirimidinas/farmacología , Animales , Autofagia/genética , Benzamidas , Línea Celular Tumoral , Daño del ADN , Proteínas de Fusión bcr-abl/genética , Técnicas de Silenciamiento del Gen , Humanos , Mesilato de Imatinib , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Ratones , Terapia Molecular Dirigida/métodos , ARN Interferente Pequeño/administración & dosificación , ARN Interferente Pequeño/genética , Transfección
16.
J Am Acad Dermatol ; 65(5 Suppl 1): S104-13, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22018059

RESUMEN

BACKGROUND: Primary school-based educational strategies are proven interventions to raise children's awareness and knowledge about sun safety. OBJECTIVE: We highlight barriers and facilitators to implementing interventions across multiple populations in 3 state comprehensive cancer control programs/partnerships that implemented primary school-based sun-safety educational programs. METHODS: Using a case study approach, we collected semistructured program information and evaluation results from New Mexico's Raising Awareness in Youth about Sun Safety Project, the Sun Protection in Florida Project, and the Arizona SunWise Program. RESULTS: Each program used different strategies for implementing school-based educational programs in their respective state based on local needs, funding constraints, and unique characteristics of their populations. Barriers to implementation included difficulties reaching schools and school administrators and changes in staff workload. Facilitators to implementation included using innovative recruitment approaches (mini grants, school assemblies), having community partners, reaching out to educators in various settings, and having program advocates within schools. Each program placed emphasis on supplementing educational programs with sun-safety policies. LIMITATIONS: We only present a case study from 3 comprehensive cancer control programs/partnerships. Rigorous evaluation methods are needed to test the effectiveness of the various strategies that were used to implement these programs on a population-based level. CONCLUSION: Partnerships and program advocates are important for successfully implementing and sustaining sun-safety programs. Innovative strategies for reaching school administrators are likely needed to effectively implement sun-safety programs and policies. School policy and environmental change are important and valued components of sun-safety programs.


Asunto(s)
Educación en Salud , Política de Salud , Melanoma/prevención & control , Neoplasias Cutáneas/prevención & control , Luz Solar/efectos adversos , Arizona , Niño , Preescolar , Femenino , Florida , Humanos , Masculino , New Mexico , Evaluación de Programas y Proyectos de Salud , Servicios de Salud Escolar , Protectores Solares/uso terapéutico
17.
Leukemia ; 35(10): 2759-2770, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34462526

RESUMEN

Lysosomes, since their discovery, have been primarily known for degrading cellular macromolecules. However, in recent studies, they have begun to emerge as crucial regulators of cell homeostasis. They are at the crossroads of catabolic and anabolic pathways and are intricately involved in cellular trafficking, nutrient signaling, energy metabolism, and immune regulation. Their involvement in such essential cellular functions has renewed clinical interest in targeting the lysosome as a novel way to treat disease, particularly cancer. Acute myeloid leukemia (AML) is an aggressive blood cancer with a low survival probability, particularly in older patients. The genomic landscape of AML has been extensively characterized but few targeted therapies (with the exception of differentiation therapy) can achieve a long-term cure. Therefore, there is an unmet need for less intensive and more tolerable therapeutic interventions. In this review, we will give an overview on the myriad of functions performed by lysosomes and their importance in malignant disease. Furthermore, we will discuss their relevance in hematopoietic cells and different ways to potentially target them in AML.


Asunto(s)
Leucemia Mieloide Aguda/patología , Lisosomas/patología , Animales , Humanos , Terapia Molecular Dirigida/métodos , Transducción de Señal/fisiología
18.
Cell Death Differ ; 28(8): 2465-2481, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33742137

RESUMEN

Fatty acid synthase (FASN) is the only human lipogenic enzyme available for de novo fatty acid synthesis and is often highly expressed in cancer cells. We found that FASN mRNA levels were significantly higher in acute myeloid leukemia (AML) patients than in healthy granulocytes or CD34+ hematopoietic progenitors. Accordingly, FASN levels decreased during all-trans retinoic acid (ATRA)-mediated granulocytic differentiation of acute promyelocytic leukemia (APL) cells, partially via autophagic degradation. Furthermore, our data suggest that inhibition of FASN expression levels using RNAi or (-)-epigallocatechin-3-gallate (EGCG) accelerated the differentiation of APL cell lines and significantly re-sensitized ATRA refractory non-APL AML cells. FASN reduction promoted translocation of transcription factor EB (TFEB) to the nucleus, paralleled by activation of CLEAR network genes and lysosomal biogenesis. Together, our data demonstrate that inhibition of FASN expression in combination with ATRA treatment facilitates granulocytic differentiation of APL cells and may extend differentiation therapy to non-APL AML cells.


Asunto(s)
Acido Graso Sintasa Tipo I/metabolismo , Leucemia Mieloide Aguda/genética , Oncogenes/genética , Diferenciación Celular , Humanos , Leucemia Mieloide Aguda/patología
19.
Explor Target Antitumor Ther ; 2(6): 543-575, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-36046118

RESUMEN

Aim: To investigate alterations in transcription of genes, encoding Ca2+ toolkit proteins, in oesophageal adenocarcinoma (OAC) and to assess associations between gene expression, tumor grade, nodal-metastatic stage, and patient survival. Methods: The expression of 275 transcripts, encoding components of the Ca2+ toolkit, was analyzed in two OAC datasets: the Cancer Genome Atlas [via the University of Alabama Cancer (UALCAN) portal] and the oesophageal-cancer, clinical, and molecular stratification [Oesophageal Cancer Clinical and Molecular Stratification (OCCAMS)] dataset. Effects of differential expression of these genes on patient survival were determined using Kaplan-Meier log-rank tests. OAC grade- and metastatic-stage status was investigated for a subset of genes. Adjustment for the multiplicity of testing was made throughout. Results: Of the 275 Ca2+-toolkit genes analyzed, 75 displayed consistent changes in expression between OAC and normal tissue in both datasets. The channel-encoding genes, N-methyl-D-aspartate receptor 2D (GRIN2D), transient receptor potential (TRP) ion channel classical or canonical 4 (TRPC4), and TRP ion channel melastatin 2 (TRPM2) demonstrated the greatest increase in expression in OAC in both datasets. Nine genes were consistently upregulated in both datasets and were also associated with improved survival outcomes. The 6 top-ranking genes for the weighted significance of altered expression and survival outcomes were selected for further analysis: voltage-gated Ca2+ channel subunit α 1D (CACNA1D), voltage-gated Ca2+ channel auxiliary subunit α2 δ4 (CACNA2D4), junctophilin 1 (JPH1), acid-sensing ion channel 4 (ACCN4), TRPM5, and secretory pathway Ca2+ ATPase 2 (ATP2C2). CACNA1D, JPH1, and ATP2C2 were also upregulated in advanced OAC tumor grades and nodal-metastatic stages in both datasets. Conclusions: This study has unveiled alterations of the Ca2+ toolkit in OAC, compared to normal tissue. Such Ca2+ signalling findings are consistent with those from studies on other cancers. Genes that were consistently upregulated in both datasets might represent useful markers for patient diagnosis. Genes that were consistently upregulated, and which were associated with improved survival, might be useful markers for patient outcome. These survival-associated genes may also represent targets for the development of novel chemotherapeutic agents.

20.
Oncotarget ; 11(2): 212, 2020 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-32010432

RESUMEN

[This corrects the article DOI: 10.18632/oncotarget.15182.].

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA