RESUMEN
Repetitive transcranial magnetic stimulation (rTMS), a noninvasive neuroregulatory technique used to treat neurodegenerative diseases, holds promise for spinocerebellar ataxia type 3 (SCA3) treatment, although its efficacy and mechanisms remain unclear. This study aims to observe the short-term impact of cerebellar rTMS on motor function in SCA3 patients and utilize resting-state functional magnetic resonance imaging (RS-fMRI) to assess potential therapeutic mechanisms. Twenty-two SCA3 patients were randomly assigned to receive actual rTMS (AC group, n = 11, three men and eight women; age 32-55 years) or sham rTMS (SH group, n = 11, three men and eight women; age 26-58 years). Both groups underwent cerebellar rTMS or sham rTMS daily for 15 days. The primary outcome measured was the ICARS scores and parameters for regional brain activity. Compared to baseline, ICARS scores decreased more significantly in the AC group than in the SH group after the 15-day intervention. Imaging indicators revealed increased Amplitude of Low Frequency Fluctuation (ALFF) values in the posterior cerebellar lobe and cerebellar tonsil following AC stimulation. This study suggests that rTMS enhances motor functions in SCA3 patients by modulating the excitability of specific brain regions and associated pathways, reinforcing the potential clinical utility of rTMS in SCA3 treatment. The Chinese Clinical Trial Registry identifier is ChiCTR1800020133.
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Enfermedad de Machado-Joseph , Imagen por Resonancia Magnética , Estimulación Magnética Transcraneal , Humanos , Masculino , Femenino , Persona de Mediana Edad , Estimulación Magnética Transcraneal/métodos , Adulto , Enfermedad de Machado-Joseph/terapia , Enfermedad de Machado-Joseph/fisiopatología , Enfermedad de Machado-Joseph/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Resultado del TratamientoRESUMEN
BACKGROUND AND PURPOSE: White matter (WM) damage is the main target of hereditary spastic paraplegia (HSP), but mounting evidence indicates that genotype-specific grey matter (GM) damage is not uncommon. Our aim was to identify and compare brain GM and WM damage patterns in HSP subtypes and investigate how gene expression contributes to these patterns, and explore the relationship between GM and WM damage. METHODS: In this prospective single-centre cohort study from 2019 to 2022, HSP patients and controls underwent magnetic resonance imaging evaluations. The alterations of GM and WM patterns were compared between groups by applying a source-based morphometry approach. Spearman rank correlation was used to explore the associations between gene expression and GM atrophy patterns in HSP subtypes. Mediation analysis was conducted to investigate the interplay between GM and WM damage. RESULTS: Twenty-one spastic paraplegia type 4 (SPG4) patients (mean age 50.7 years ± 12.0 SD, 15 men), 21 spastic paraplegia type 5 (SPG5) patients (mean age 29.1 years ± 12.8 SD, 14 men) and 42 controls (sex- and age-matched) were evaluated. Compared to controls, SPG4 and SPG5 showed similar WM damage but different GM atrophy patterns. GM atrophy patterns in SPG4 and SPG5 were correlated with corresponding gene expression (ρ = 0.30, p = 0.008, ρ = 0.40, p < 0.001, respectively). Mediation analysis indicated that GM atrophy patterns were mediated by WM damage in HSP. CONCLUSIONS: Grey matter atrophy patterns were distinct between SPG4 and SPG5 and were not only secondary to WM damage but also associated with disease-related gene expression. CLINICAL TRIAL REGISTRATION NO: NCT04006418.
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Atrofia , Sustancia Gris , Imagen por Resonancia Magnética , Paraplejía Espástica Hereditaria , Sustancia Blanca , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Atrofia/patología , Estudios de Cohortes , Sustancia Gris/patología , Sustancia Gris/diagnóstico por imagen , Paraplejía , Estudios Prospectivos , Paraplejía Espástica Hereditaria/genética , Paraplejía Espástica Hereditaria/patología , Paraplejía Espástica Hereditaria/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patologíaRESUMEN
The bHLH transcription factors are important plant regulators against abiotic stress and involved in plant growth and development. In this study, SlALC, a gene coding for a prototypical DNA-binding protein in the bHLH family, was isolated, and SlALC-overexpression tomato (SlALC-OE) plants were generated by Agrobacterium-mediated genetic transformation. SlALC transgenic lines manifested higher osmotic stress tolerance than the wild-type plants, estimated by higher relative water content and lower water loss rate, higher chlorophyll, reducing sugar, starch, proline, soluble protein contents, antioxidant enzyme activities, and lower MDA and reactive oxygen species contents in the leaves. In SlALC-OE lines, there were more significant alterations in the expression of genes associated with stress. Furthermore, SlALC-OE fruits were more vulnerable to dehiscence, with higher water content, reduced lignin content, SOD/POD/PAL enzyme activity, and lower phenolic compound concentrations, all of which corresponded to decreased expression of lignin biosynthetic genes. Moreover, the dual luciferase reporter test revealed that SlTAGL1 inhibits SlALC expression. This study revealed that SlALC may play a role in controlling plant tolerance to drought and salt stress, as well as fruit lignification, which influences fruit dehiscence. The findings of this study have established a foundation for tomato tolerance breeding and fruit quality improvement.
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Sequías , Frutas , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Plantas Modificadas Genéticamente , Tolerancia a la Sal , Solanum lycopersicum , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Tolerancia a la Sal/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Frutas/genética , Frutas/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Estrés FisiológicoRESUMEN
BACKGROUND: Mutational inactivation of the SETDB1 histone methyltransferase is found in a subset of mesothelioma, particularly in cases with near-haploidy and TP53 mutations. However, the tumourigenic consequences of SETDB1 inactivation are poorly understood. METHODS: In this study, we investigated SETDB1 tumour suppressor functions in mesothelioma and explored biologic relationships between SETDB1 and TP53. RESULTS: Immunoblotting of early passage cultures showed that SETDB1 was undetectable in 7 of 8 near-haploid mesotheliomas whereas SETDB1 expression was retained in each of 13 near-diploid mesotheliomas. TP53 aberrations were present in 5 of 8 near-haploid mesotheliomas compared to 2 of 13 near-diploid mesotheliomas, and BAP1 inactivation was demonstrated only in near-diploid mesotheliomas, indicating that near-haploid and near-diploid mesothelioma have distinct molecular and biologic profiles. Lentiviral SETDB1 restoration in near-haploid mesotheliomas (MESO257 and MESO542) reduced cell viability, colony formation, reactive oxygen species levels, proliferative marker cyclin A expression, and inhibited growth of MESO542 xenografts. The combination of SETDB1 restoration with pemetrexed and/or cisplatin treatment additively inhibited tumour growth in vitro and in vivo. Furthermore, SETDB1 restoration upregulated TP53 expression in MESO542 and MESO257, whereas SETDB1 knockdown inhibited mutant TP53 expression in JMN1B near-haploid mesothelioma cells. Likewise, TP53 knockdown inhibited SETDB1 expression. Similarly, immunoblotting evaluations of ten near-diploid mesothelioma biopsies and analysis of TCGA expression profiles showed that SETDB1 expression levels paralleled TP53 expression. CONCLUSION: These findings demonstrate that SETDB1 inactivation in near-haploid mesothelioma is generally associated with complete loss of SETDB1 protein expression and dysregulates TP53 expression. Targeting SETDB1 pathways could be an effective therapeutic strategy in these often untreatable tumours.
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Productos Biológicos , Mesotelioma Maligno , Mesotelioma , Humanos , Haploidia , Mesotelioma Maligno/genética , Mesotelioma/genética , Mesotelioma/patología , Genes Supresores de Tumor , Aberraciones Cromosómicas , Proteína p53 Supresora de Tumor/genética , N-Metiltransferasa de Histona-Lisina/genéticaRESUMEN
The analysis of structural covariance has emerged as a powerful tool to explore the morphometric correlations among broadly distributed brain regions. However, little is known about the interactions between the damaged primary motor cortex (M1) and other brain regions in stroke patients with motor deficits. This study is aimed at investigating the structural covariance pattern of the ipsilesional M1 in chronic subcortical stroke patients with motor deficits. High-resolution T1-weighted brain images were acquired from 58 chronic subcortical stroke patients with motor deficits (29 with left-sided lesions and 29 with right-sided lesions) and 50 healthy controls. Structural covariance patterns were identified by a seed-based structural covariance method based on gray matter (GM) volume. Group comparisons between stroke patients (left-sided or right-sided groups) and healthy controls were determined by a permutation test. The association between alterations in the regional GM volume and motor recovery after stroke was investigated by a multivariate regression approach. Structural covariance analysis revealed an extensive increase in the structural interactions between the ipsilesional M1 and other brain regions in stroke patients, involving not only motor-related brain regions but also non-motor-related brain regions. We also identified a slightly different pattern of structural covariance between the left-sided stroke group and the right-sided stroke group, thus indicating a lesion-side effect of cortical reorganization after stroke. Moreover, alterations in the GM volume of structural covariance brain regions were significantly correlated to the motor function scores in stroke patients. These findings indicated that the structural covariance patterns of the ipsilesional M1 in chronic subcortical stroke patients were induced by motor-related plasticity. Our findings may help us to better understand the neurobiological mechanisms of motor impairment and recovery in patients with subcortical stroke from different perspectives.
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Corteza Motora , Accidente Cerebrovascular , Encéfalo , Humanos , Imagen por Resonancia Magnética/métodosRESUMEN
Epstein-Barr virus (EBV) and cytomegalovirus (CMV) reactivations are common complications after allogeneic hematopoietic cell transplantation (allo-HCT), but data focusing on non-Hodgkin lymphoma (NHL) are limited. We retrospectively analyzed the prevalence of EBV and CMV reactivation post-allo-HCT and the impacts on transplant outcomes in 160 NHL patients. The 1-year incidences of EBV and CMV reactivation were 22.58% and 25.55%, respectively. Independent impactors for EBV reactivation were more than 6 lines of chemotherapy (P = 0.030), use of rituximab (P = 0.004), and neutrophil recovery within 30 days post-HCT (P = 0.022). For T-cell lymphoblastic lymphoma patients, the International Prognostic Index (IPI) (P = 0.015) and chronic GVHD (P = 0.001) increased the risk of CMV reactivation. CMV reactivation was independently related to a lower risk of relapse (P = 0.027) but higher transplant-related mortality (TRM) (P = 0.038). Although viral reactivation had no significant impact on overall survival (OS) in the whole cohort, it led to an inferior 2-year OS (67.6% versus 92.5%, P = 0.005) and TRM (20.1% versus 4.7%, P = 0.020) in recipients surviving for more than 180 days. We concluded that EBV and CMV reactivation post-allotransplant still deserved concern particularly in NHL patients with high-risk factors, since it is generally related to a deteriorated prognosis. Large-scale studies are warranted to validate our findings.
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Infecciones por Citomegalovirus/etiología , Citomegalovirus/fisiología , Infecciones por Virus de Epstein-Barr/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Herpesvirus Humano 4/fisiología , Linfoma no Hodgkin/terapia , Activación Viral , Adulto , Aloinjertos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Terapia Combinada , Infecciones por Citomegalovirus/epidemiología , Infecciones por Virus de Epstein-Barr/epidemiología , Femenino , Enfermedad Injerto contra Huésped/etiología , Humanos , Inmunoterapia Adoptiva , Linfoma no Hodgkin/complicaciones , Linfoma no Hodgkin/tratamiento farmacológico , Masculino , Prevalencia , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Rituximab/efectos adversos , Rituximab/uso terapéutico , Acondicionamiento Pretrasplante/efectos adversos , Resultado del Tratamiento , Irradiación Corporal Total/efectos adversosRESUMEN
Cytomegalovirus (CMV) reactivation increases treatment-related mortality (TRM) after allogeneic hematopoietic cell transplantation (allo-HCT). We analyzed 141 adult acute leukemia (AL) patients suffered allo-HCT between 2017 and 2021, who developed CMV viremia post-HCT and treated with valganciclovir or foscarnet, to evaluate effectiveness and safety of both drugs. Viremia clearance rates (14 and 21 d post treatment) and toxicities were similar in two groups. However, valganciclovir was associated with a lower cumulative incidence of CMV recurrence within 180 days (16.7% vs. 35.7%, p=0.029) post CMV clearance. Finally, 2-year TRM was lower in valganciclovir group (9.7% ± 0.2% vs. 26.2% ± 0.3%, p = 0.026), result a superior 2-year overall survival (OS; 88.1% ± 5.2% vs. 64.4% ± 5.5%, p = 0.005) and leukemia-free survival (LFS; 82.0% ± 5.9% vs. 58.9% ± 5.6%, p = 0.009). Valganciclovir might decrease CMV viremia recurrence and led to better long-term outcome than foscarnet in adult AL patients developed CMV viremia post-HCT. Considering the inherent biases of retrospective study, well-designed trials are warranted to validate our conclusion.
Asunto(s)
Antivirales , Infecciones por Citomegalovirus , Citomegalovirus , Foscarnet , Trasplante de Células Madre Hematopoyéticas , Trasplante Homólogo , Valganciclovir , Viremia , Humanos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Infecciones por Citomegalovirus/etiología , Valganciclovir/uso terapéutico , Masculino , Femenino , Viremia/tratamiento farmacológico , Adulto , Antivirales/uso terapéutico , Foscarnet/uso terapéutico , Persona de Mediana Edad , Citomegalovirus/efectos de los fármacos , Estudios Retrospectivos , Adulto Joven , Anciano , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/complicaciones , Leucemia Mieloide Aguda/mortalidad , Resultado del Tratamiento , Leucemia/terapia , Leucemia/complicaciones , Leucemia/mortalidadRESUMEN
OBJECTIVE: To investigate whether neurite orientation dispersion and density imaging (NODDI) could provide the added value for detecting brain microstructural alterations in the preclinical stage of Machado-Joseph disease/spinocerebellar ataxia type 3 (MJD/SCA3) compared with MRI morphometry and diffusion tensor imaging (DTI). METHODS: Twenty preclinical MJD/SCA3 patients and 21 healthy controls were enrolled. Three b values DWI and 3D T1-weighted images were acquired at 3.0 T. Tract-based spatial statistics (TBSS) approach was used to investigate the white matter (WM) alterations in the DTI metrics and NODDI metrics. Gray matter-based spatial statistics (GBSS) approach was used to investigate the grey matter (GM) alterations in the NODDI metrics. Voxel-based morphometry (VBM) approach was performed on the 3D T1-weighted images. The relationship between the cytosine-adenine-guanine (CAG) repeat length and brain microstructural alterations of preclinical MJD/SCA3 was identified. RESULTS: Compared with healthy controls, the preclinical MJD/SCA3 patients showed decreased FA and NDI as well as increased MD, AD, and RD in the WM of cerebellum and brainstem (corrected P < 0.05), and decreased NDI in the GM of cerebellar vermis (corrected P < 0.05). The CAG repeat length in preclinical MJD/SCA3 patients was negatively correlated with the reduced FA and NDI of the infratentorial WM and the reduced NDI of the cerebellum, and positively with the increased MD and RD of the infratentorial WM. CONCLUSIONS: NOODI can provide novel quantitative microstructural changes in MJD/SCA3 carriers, expanding our understanding of the gray and white matter (axons and dendrites) degeneration in this frequent ataxia syndrome.
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Enfermedad de Machado-Joseph , Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora/métodos , Humanos , Enfermedad de Machado-Joseph/diagnóstico por imagen , Imagen por Resonancia Magnética , NeuritasRESUMEN
OBJECTIVE: To analyze and compare the effects of leukapheresis on hemostatic function in patients with hyperleukocytic leukemia. METHODS: A total of 139 patients with AML, ALL and CML who underwent leukapheresis from June 2009 to February 2020 and did coagulation test before and after operation were included in this study. The clearance efficiency of each group and the difference among three groups were evaluated, as well as hemostatic function including platelet counts, coagulation indicators, CDSS score and incidence of adverse events. The difference of hemostatic function caused by leukapheresis in different leukemia patients were compared. RESULTS: After leukapheresis, the WBC counts were decreased significantly in the three groups of patients (P<0.001), and the clearance efficiency was highest in ALL patients. However, the platelet counts also were decreased significantly (AML:Pï¼0.001, ALL: Pï¼0.001, CML: Pï¼0.01) in the three groups of patients, particularly for acute leukemia patients with a positive correlation with WBC clearance efficiency(r=0.284). After leukapheresis, fibrinogen decreased, PT and APTT prolonged. For acute leukemia patients, higher CDSS score was related to an elevated incidence of bleeding events (P<0.05). CONCLUSION: Leukapheresis is an effective method to decrease the leukemic burden, but it is necessary to monitor the impact on hemostatic function. It is recommended to assess the CDSS socre for acute leukemia patients, in order to identify the predictive value for bleedings.
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Hemostáticos , Leucemia Mieloide Aguda , Enfermedad Aguda , Coagulación Sanguínea , Pruebas de Coagulación Sanguínea , Hemorragia , Humanos , Leucaféresis/métodos , Leucemia Mieloide Aguda/terapiaRESUMEN
Spinocerebellar ataxias type 3 (SCA3) patients are clinically characterized by progressive cerebellar ataxia combined with degeneration of the cerebellum. Previous neuroimaging studies have indicated ataxia severity associated with cerebellar atrophy using univariate methods. However, whether cerebellar atrophy patterns can be used to quantitatively predict ataxia severity in SCA3 patients at the individual level remains largely unexplored. In this study, a group of 66 SCA3 patients and 58 healthy controls were included. Disease duration and ataxia assessment, including the Scale for the Assessment and Rating of Ataxia (SARA) and the International Cooperative Ataxia Rating Scale (ICARS), were collected for SCA3 patients. The high-resolution T1-weighted MRI was obtained, and cerebellar grey matter (GM) was extracted using a spatially unbiased infratentorial template toolbox for all participants. We investigated the association between the pattern of cerebellar grey matter (GM) loss and ataxia assessment in SCA3 by using a multivariate machine learning technique. We found that the application of RVR allowed quantitative prediction of both SARA scores (leave-one-subject-out cross-validation: correlation = 0.56, p-value = 0.001; mean squared error (MSE) = 20.51, p-value = 0.001; ten-fold cross-validation: correlation = 0.52, p-value = 0.001; MSE = 21.00, p-value = 0.001) and ICARS score (leave-one-subject-out cross-validation: correlation = 0.59, p-value = 0.001; MSE = 139.69, p-value = 0.001; ten-fold cross-validation: correlation = 0.57, p-value = 0.001; MSE = 145.371, p-value = 0.001) with statistically significant accuracy. These results provide proof-of-concept that ataxia severity in SCA3 patients can be predicted by the alteration pattern of cerebellar GM using multi-voxel pattern analysis.
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Ataxia Cerebelosa , Enfermedad de Machado-Joseph , Ataxia , Ataxia Cerebelosa/diagnóstico por imagen , Cerebelo/diagnóstico por imagen , Sustancia Gris/diagnóstico por imagen , Humanos , Enfermedad de Machado-Joseph/diagnóstico por imagen , Enfermedad de Machado-Joseph/genética , Imagen por Resonancia MagnéticaRESUMEN
Leukapheresis is an effective adjuvant therapy for leukemia patients with hyperleukocytosis, but few studies have reported recent data with modern modalities and comparisons among different leukemia types. We conducted a retrospective study on leukapheresis among 420 patients with AML, ALL and CML in four local centers. WBC counts decreased significantly (p < 0.001) postleukapheresis in all three cohorts. Clearance efficiency was higher in acute leukemia patients than CML patients (p < 0.01). Concomitant leukocytoreduction drugs improved WBC reduction only in AML patients (p < 0.05). Leukocyte, hemoglobin and platelet levels preleukapheresis might affect the clearance efficiency in AML and/or ALL patients. Hematological toxicities were the major concerns, but most of them were mild, and only 11 patients died of all causes within one week postleukapheresis. In conclusion, leukapheresis can safely reduce the leukemic burden, especially for patients with acute leukemias.
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Leucaféresis , Leucemia Mieloide Aguda , Humanos , Estudios Retrospectivos , Leucocitosis/terapia , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/complicaciones , Recuento de Leucocitos , Enfermedad AgudaAsunto(s)
Trasplante de Células Madre de Sangre del Cordón Umbilical , Humanos , Trasplante de Células Madre de Sangre del Cordón Umbilical/métodos , Masculino , Adulto , Femenino , Persona de Mediana Edad , Trasplante Haploidéntico/métodos , Adolescente , Leucemia Mieloide Aguda/terapia , Leucemia/terapia , Anciano , Enfermedad Aguda , AloinjertosRESUMEN
Oncogenic KIT or PDGFRA receptor tyrosine kinase (TK) mutations are compelling therapeutic targets in gastrointestinal stromal tumors (GISTs), and the KIT/PDGFRA kinase inhibitor, imatinib, is the standard of care for patients with metastatic GIST. However, approximately 10% of KIT-positive GIST metastases lose KIT expression at the time of clinical progression during imatinib therapy. In the present report, we performed TK-activation screens, using phosphotyrosine-TK double immunoaffinity purification and mass spectrometry, in GIST in vitro models lacking KIT expression. These studies demonstrated tyrosine-phosphorylated EGFR, AXL, and EPHA2 in four of six KIT-negative GIST lines (GIST62, GIST522, GIST54, GIST226, GIST48B, and GIST430B), and tyrosine-phosphorylated focal adhesion kinase (FAK) in each of the six KIT-negative lines. AXL expression was strong in KIT-negative or -weak clinical GIST samples that were obtained from progressing metastases during imatinib therapy. AXL knockdown inhibited viability in three KIT-negative GIST cell lines (GIST62, GIST54, and GIST522), but not in an AXL-negative, KIT-positive GIST control cell line (GIST430). AXL inhibition by R428, a specific AXL kinase inhibitor, reduced viability in AXL-activated GIST54. AXL knockdown in GIST62, GIST522, and GIST54 was accompanied by an increase in p21, p27, and p53 expression. By contrast, gefitinib-mediated EGFR inhibition, PF562271-mediated FAK inactivation, and shRNA-mediated knockdowns of EPHA2 and FAK had no effect on viability or colony formation of the KIT-negative GISTs. These findings highlight the potential relevance of AXL/p53 signaling as a therapeutic target in a subset of GISTs that have lost KIT oncoprotein expression.
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Proteínas Proto-Oncogénicas c-kit/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Proteína-Tirosina Quinasas de Adhesión Focal/antagonistas & inhibidores , Proteína-Tirosina Quinasas de Adhesión Focal/genética , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Tumores del Estroma Gastrointestinal/metabolismo , Tumores del Estroma Gastrointestinal/patología , Gefitinib/farmacología , Humanos , Mesilato de Imatinib/farmacología , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-kit/genética , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Proteínas Tirosina Quinasas Receptoras/genética , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptor EphA2/antagonistas & inhibidores , Receptor EphA2/genética , Receptor EphA2/metabolismo , Tirosina Quinasa del Receptor AxlRESUMEN
Oncogenic KIT or PDGFRA receptor tyrosine kinase (RTK) mutations are compelling therapeutic targets in gastrointestinal stromal tumors (GIST), and treatment with the KIT/PDGFRA inhibitor imatinib is the standard of care for patients with metastatic GIST. Most GISTs eventually acquire imatinib resistance due to secondary mutations in the KIT kinase domain, but it is unclear whether these genomic resistance mechanisms require other cellular adaptations to create a clinically meaningful imatinib-resistant state. Using phospho-RTK and immunoblot assays, we demonstrate activation of KIT and insulin receptor (IR) in imatinib-resistant GIST cell lines (GIST430 and GIST48) and biopsies with acquisition of KIT secondary mutations, but not in imatinib-sensitive GIST cells (GIST882 and GIST-T1). Treatment with linsitinib, a specific IR inhibitor, inhibited IR and downstream intermediates AKT, MAPK, and S6 in GIST430 and GIST48, but not in GIST882, exerting minimal effect on KIT phosphorylation in these cell lines. Additive effects showing increased apoptosis, antiproliferative effects, cell-cycle arrest, and decreased pAKT and pS6 expression, tumor growth, migration, and invasiveness were observed in imatinib-resistant GIST cells with IR activation after coordinated inhibition of IR and KIT by linsitinib (or IR shRNA) and imatinib, respectively, compared with either intervention alone. IGF2 overexpression was responsible for IR activation in imatinib-resistant GIST cells, whereas IR activation did not result from IR amplification, IR mutation, or KIT phosphorylation. Our findings suggest that combinatorial inhibition of IR and KIT warrants clinical evaluation as a novel therapeutic strategy in imatinib-resistant GISTs. Cancer Res; 77(18); 5107-17. ©2017 AACR.