RESUMEN
Permanent magnet synchronous machine (PMSM) has proven to be a more economical traction drive system for electric vehicle (EV) applications owing to increased efficiency and high-power density. However, the drive system requires more efficient control schemes to deliver better dynamic performance irrespective of dynamic changes in the motor speed, machine parameters and disturbances. Hence, to tackle the dynamic changes, to enhance the wider operating speed, to achieve precise speed tracking capability, and improved efficiency, a novel control algorithm for the PMSM based EV is proposed in this paper. The control algorithm is implemented by adopting the merits of conventional proportional resonance (PR) and proportional integral (PI) controller. The proposed control strategy is designed with an outer PI speed regulator and the inner enhanced PR (EPR) current regulator. The uniqueness of the proposed EPR controller is that the controller is designed to damp the torsional mode oscillation owing to dynamic changes such as speed and torque regulation evading the additional control loop. The effectiveness of the control scheme is tested in MATLAB Simulink and hardware-in-loop (HIL) real time simulator RT5700. To validate the effectiveness of the proposed control scheme the results are compared with the conventional control schemes. The results presented show that the proposed control technique successfully enhances the static and dynamic performance, and resilience of the EV system. Also, the proposed scheme significantly reduces the flux ripples, torque ripples, current jitter, peak overshoot, undershoot compared to the conventional current controllers.
RESUMEN
Trio exome sequencing was performed on a fetus with bilateral mesomelia of the lower limbs with significant angulation of the tibial bones, micrognathia and hypertelorism detected on ultrasound scan at 19 + 0 weeks gestation. The couple is consanguineous. A homozygous pathogenic frameshift variant in the SMOC1 gene (c.339_340del p.(Phe114Cysfs*40)) was detected and both parents were shown to be heterozygous. Pathogenic variants in the SMOC1 gene are associated with microphthalmia with limb anomalies which multidisciplinary team discussion determined to be causal of the scan anomalies detected. The fetus was also a compound heterozygote for CYP21A2 pathogenic variants, confirming a second diagnosis of non-classical congenital adrenal hyperplasia, which was felt incidental to the scan findings. The risk that this couple's next pregnancy would be affected by either of these disorders is 1 in 4 (25%) and demonstrates the importance of genetic diagnoses for the family and implications for future pregnancies.
Asunto(s)
Hiperplasia Suprarrenal Congénita , Enfermedades Fetales , Hipertelorismo , Micrognatismo , Embarazo , Femenino , Humanos , Hiperplasia Suprarrenal Congénita/genética , Micrognatismo/diagnóstico por imagen , Micrognatismo/genética , Hallazgos Incidentales , Enfermedades Fetales/genética , Feto , Extremidad Inferior , Mutación , Osteonectina/genética , Esteroide 21-Hidroxilasa/genéticaRESUMEN
Duo exome testing was performed on a fetus conceived via in vitro fertilization with an egg donor. The fetus presented with non-immune hydrops fetalis (NIHF) at 20 + 0 weeks gestation. Two variants were detected in the GUSB gene. Biallelic pathogenic variants cause mucopolysaccharidosis type VII (MPS-VII), which can present with NIHF prenatally. At the time of analysis and initial report, one variant was classified as likely pathogenic and the other as of uncertain clinical significance. Biochemical testing of the amniotic fluid supernatant showed elevated glycosaminoglycans and low ß-glucuronidase activity consistent with the diagnosis of MPS-VII. This evidence allowed the upgrade of the pathogenicity for both variants, confirming the diagnosis of MPS-VII. The infant was born at 36 + 5 weeks and enzyme replacement therapy (ERT) using vestronidase was initiated at 20 days with planning for hematopoietic stem cell transplant ongoing. The ERT therapy has been well tolerated, with decreasing quantitative urine glycosaminoglycans. Long-term follow up is required to determine whether treatment has been successful. This case demonstrates the utility of alternative testing methods to clarify the pathogenicity of variants and the clinical utility of obtaining a diagnosis antenatally in facilitating treatment in the neonatal period, and specifically highlights MPS-VII as a treatable cause of NIHF.
Asunto(s)
Mucopolisacaridosis VII , Recién Nacido , Embarazo , Femenino , Humanos , Mucopolisacaridosis VII/diagnóstico , Mucopolisacaridosis VII/genética , Mucopolisacaridosis VII/terapia , Glucuronidasa/genética , Glucuronidasa/uso terapéutico , Hidropesía Fetal/diagnóstico , Hidropesía Fetal/genética , Hidropesía Fetal/terapia , Diagnóstico Prenatal , Líquido Amniótico , GlicosaminoglicanosRESUMEN
BACKGROUND: Prenatal exome sequencing (ES) for monogenic disorders in fetuses with structural anomalies increases diagnostic yield. In England there is a national trio ES service delivered from two laboratories. To minimise incidental findings and reduce the number of variants investigated, analysis uses a panel of 1205 genes where pathogenic variants may cause abnormalities presenting prenatally. Here we review our laboratory's early experience developing and delivering ES to identify challenges in interpretation and reporting and inform service development. METHODS: A retrospective laboratory records review from 01.04.2020 to 31.05.2021. RESULTS: Twenty-four of 116 completed cases were identified as challenging including 13 resulting in difficulties in analysis and reporting, nine where trio inheritance filtering would have missed the diagnosis, and two with no prenatal diagnosis; one due to inadequate pipeline sensitivity, the other because the gene was not on the panel. Two cases with copy number variants identified were not detectable by microarray. CONCLUSIONS: Variant interpretation requires close communication between referring clinicians, with occasional additional examination of the fetus or parents and communication of evolving phenotypes. Inheritance filtering misses â¼5% of diagnoses. Panel analysis reduces but does not exclude incidental findings. Regular review of published literature is required to identify new reports that may aid classification.
Asunto(s)
Exoma , Ultrasonografía Prenatal , Femenino , Feto/diagnóstico por imagen , Humanos , Embarazo , Diagnóstico Prenatal/métodos , Estudios Retrospectivos , Secuenciación del Exoma/métodosAsunto(s)
Interleucina-6 , Melanoma , Biomarcadores , Biomarcadores de Tumor , Humanos , Inmunoterapia , Melanoma/tratamiento farmacológico , PronósticoAsunto(s)
Países en Desarrollo/economía , Combustibles Fósiles/economía , Combustibles Fósiles/provisión & distribución , Pobreza/economía , Pobreza/tendencias , Energía Renovable/economía , Energía Renovable/legislación & jurisprudencia , África , Dióxido de Carbono/metabolismo , Países Desarrollados/economía , Humanos , Desarrollo Sostenible/economía , Desarrollo Sostenible/legislación & jurisprudenciaRESUMEN
BACKGROUND: MUC18 is a glycoprotein highly expressed on the surface of melanoma and other cancers which promotes tumor progression and metastasis. However, its mechanism of action and suitability as a therapeutic target are unknown. METHODS: A monoclonal antibody (mAb) (JM1-24-3) was generated from metastatic melanoma tumor live cell immunization, and high-throughput screening identified MUC18 as the target. RESULTS: Analysis of molecular interactions between MUC18 and JM1-24-3 revealed that the downstream signaling events depended on binding of the mAb to a conformational epitope on the extracellular domain of MUC18. JM1-24-3 inhibited melanoma cell proliferation, migration and invasion in vitro and reduced tumor growth and metastasis in vivo. CONCLUSION: These results confirm that MUC18 is mechanistically important in melanoma growth and metastasis, suggest that the MUC18 epitope identified is a promising therapeutic target, and that the JM1-24-3 mAb may serve as the basis for a potential therapeutic agent.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Melanoma/terapia , Animales , Anticuerpos Monoclonales/inmunología , Antígeno CD146/inmunología , Línea Celular Tumoral , Humanos , Masculino , Melanoma/inmunología , Ratones , Ratones Endogámicos A , Ratones Desnudos , Distribución Aleatoria , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Pathogenic variants in ZMYND11, which acts as a transcriptional repressor, have been associated with intellectual disability, behavioral abnormalities, and seizures. Only 11 affected individuals have been reported to date, and the phenotype associated with pathogenic variants in this gene have not been fully defined. Here, we present 16 additional patients with predicted pathogenic heterozygous variants in including four individuals from the same family, to further delineate and expand the genotypic and phenotypic spectrum of ZMYND11-related syndromic intellectual disability. The associated phenotype includes developmental delay, particularly affecting speech, mild-moderate intellectual disability, significant behavioral abnormalities, seizures, and hypotonia. There are subtle shared dysmorphic features, including prominent eyelashes and eyebrows, a depressed nasal bridge with bulbous nasal tip, anteverted nares, thin vermilion of the upper lip, and wide mouth. Novel features include brachydactyly and tooth enamel hypoplasia. Most identified variants are likely to result in premature truncation and/or nonsense-mediated decay. Two ZMYND11 variants located in the final exon-p.(Gln586*) (likely escaping nonsense-mediated decay) and p.(Cys574Arg)-are predicted to disrupt the MYND-type zinc-finger motif and likely interfere with binding to its interaction partners. Hence, the homogeneous phenotype likely results from a common mechanism of loss-of-function.
Asunto(s)
Proteínas de Ciclo Celular/genética , Proteínas Co-Represoras/genética , Proteínas de Unión al ADN/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Alelos , Niño , Preescolar , Facies , Femenino , Estudios de Asociación Genética/métodos , Genotipo , Haploinsuficiencia , Humanos , Masculino , Mutación , Degradación de ARNm Mediada por Codón sin Sentido , Fenotipo , Síndrome , Dedos de ZincRESUMEN
BACKGROUND: Osteocraniostenosis (OCS) is a rare genetic disorder characterised by premature closure of cranial sutures, gracile bones and perinatal lethality. Previously, diagnosis has only been possible postnatally on clinical and radiological features. This study describes the first prenatal diagnosis of OCS. CASE PRESENTATION: In this case prenatal ultrasound images were suggestive of a serious but non-lethal skeletal dysplasia. Due to the uncertain prognosis the parents were offered Whole Exome Sequencing (WES), which identified a specific gene mutation in the FAMIIIa gene. This mutation had previously been detected in two cases and was lethal in both perinatally. This established the diagnosis, a clear prognosis and allowed informed parental choice regarding ongoing pregnancy management. CONCLUSIONS: This case report supports the use of targeted WES prenatally to confirm the underlying cause and prognosis of sonographically suspected abnormalities.
Asunto(s)
Enfermedades del Desarrollo Óseo/diagnóstico , Anomalías Craneofaciales/diagnóstico , Citocinas/genética , Secuenciación del Exoma , Diagnóstico Prenatal , Adulto , Enfermedades del Desarrollo Óseo/diagnóstico por imagen , Enfermedades del Desarrollo Óseo/genética , Enfermedades del Desarrollo Óseo/patología , Anomalías Craneofaciales/diagnóstico por imagen , Anomalías Craneofaciales/genética , Anomalías Craneofaciales/patología , Femenino , Humanos , Recién Nacido , Padres , EmbarazoAsunto(s)
Política Ambiental/legislación & jurisprudencia , Agricultores , Explotaciones Pesqueras , Centrales Eléctricas/legislación & jurisprudencia , Decisiones de la Corte Suprema , Poblaciones Vulnerables/legislación & jurisprudencia , Política Ambiental/economía , Explotaciones Pesqueras/economía , India , Centrales Eléctricas/economía , Estados UnidosRESUMEN
Autosomal Dominant Polycystic Kidney Disease (ADPKD) accounts for 2.6% of the patients with chronic kidney disease in India. ADPKD is caused by pathogenic variants in either PKD1 or PKD2 gene. There is no comprehensive genetic data from Indian subcontinent. We aimed to identify the pathogenic variants in the heterogeneous Indian population. PKD1 and PKD2 variants were identified by direct gene sequencing and/or multiplex ligation-dependent probe amplification (MLPA) in 125 unrelated patients of ADPKD. The pathogenic potential of the variants was evaluated computationally and were classified according to ACMG guidelines. Overall 300 variants were observed in PKD1 and PKD2 genes, of which 141 (47%) have been reported previously as benign. The remaining 159 variants were categorized into different classes based on their pathogenicity. Pathogenic variants were observed in 105 (84%) of 125 patients, of which 99 (94.3%) were linked to PKD1 gene and 6 (6.1%) to PKD2 gene. Of 159 variants, 97 were novel variants, of which 43 (44.33%) were pathogenic, and 10 (10.31%) were of uncertain significance. Our data demonstrate the diverse genotypic makeup of single gene disorders in India as compared to the West. These data would be valuable in counseling and further identification of probable donors among the relatives of patients with ADPKD.
Asunto(s)
Ligamiento Genético , Variación Genética , Riñón Poliquístico Autosómico Dominante/genética , Canales Catiónicos TRPP/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , India , Masculino , Persona de Mediana EdadRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, and it is unclear whether its stromal infiltrate contributes to its aggressiveness. Here, we demonstrate that Dickkopf-3 (DKK3) is produced by pancreatic stellate cells and is present in most human PDAC. DKK3 stimulates PDAC growth, metastasis, and resistance to chemotherapy with both paracrine and autocrine mechanisms through NF-κB activation. Genetic ablation of DKK3 in an autochthonous model of PDAC inhibited tumor growth, induced a peritumoral infiltration of CD8+ T cells, and more than doubled survival. Treatment with a DKK3-blocking monoclonal antibody inhibited PDAC progression and chemoresistance and prolonged survival. The combination of DKK3 inhibition with immune checkpoint inhibition was more effective in reducing tumor growth than either treatment alone and resulted in a durable improvement in survival, suggesting that DKK3 neutralization may be effective as a single targeted agent or in combination with chemotherapy or immunotherapy for PDAC.
Asunto(s)
Carcinoma Ductal Pancreático/patología , Progresión de la Enfermedad , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Anticuerpos Neutralizantes/farmacología , Anticuerpos Neutralizantes/uso terapéutico , Comunicación Autocrina/efectos de los fármacos , Carcinoma Ductal Pancreático/tratamiento farmacológico , Línea Celular Tumoral , Quimiocinas , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Desoxicitidina/uso terapéutico , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos/efectos de los fármacos , Silenciador del Gen , Humanos , Inmunoterapia , Ratones Endogámicos C57BL , Ratones Desnudos , FN-kappa B/metabolismo , Pruebas de Neutralización , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/patología , Células Estrelladas Pancreáticas/efectos de los fármacos , Células Estrelladas Pancreáticas/metabolismo , Células Estrelladas Pancreáticas/patología , Comunicación Paracrina/efectos de los fármacos , Análisis de Supervivencia , Gemcitabina , Neoplasias PancreáticasRESUMEN
Pelizaeus-Merzbacher disease (PMD) is a rare, X-linked disorder characterized by hypomyelination of the Central Nervous System due to mutations in the PLP1 gene. Certain mutations of the PLP1 gene correlate with specific clinical phenotypes and neuroimaging findings. We herein report a novel mutation of the PLP1 gene in two siblings with PMD associated with a rare and protean neuroimaging finding of optic nerve enlargement. To the best of our knowledge this is the first time that this novel mutation H133P of PLP1 gene is identified and clinically associated with optic nerve enlargement in PMD patients.
Asunto(s)
Imagen por Resonancia Magnética , Mutación/genética , Proteína Proteolipídica de la Mielina/genética , Nervio Óptico/patología , Enfermedad de Pelizaeus-Merzbacher/genética , Niño , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Enfermedad de Pelizaeus-Merzbacher/diagnóstico , Fenotipo , HermanosRESUMEN
Autosomal dominant polycystic kidney disease (ADPKD) is characterized by a significant phenotypic variability in progression of the disease. Vascular endothelial growth factor (VEGF) has been reported to play a major role in renal pathophysiology. The aim of the present case-control study was to evaluate the association of two promoter polymorphisms (-2578C>A and-1154G>A) of VEGF gene and ADPKD. Genotyping was carried out in 123 ADPKD patients and 100 healthy controls, using a polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP). The genotype, allele and haplotype frequencies of these two polymorphisms in ADPKD patients were compared with those in controls, as well as in patients with early and advanced chronic kidney disease (CKD) stages, using Chi-square (χ2) test. The distribution frequency of CC, CA and AA genotypes of -2578C>A polymorphism differed significantly between patients and controls (0.31, 0.63 and 0.06 vs 0.37, 0.44 and 0.19, respectively (P=0.003)), but no significantly different genotype distribution was observed for the-1154G>A polymorphism. The A allele of -2578C>A and G allele of -1154G>A, were significantly more present in the controls as compared to the patients, and may provide protection for CKD under recessive (OR, 3.73; 95% CI, 1.45-9.62; P=0.0042), and dominant (OR, 0.55; 95%CI, 0.31-0.98; P=0.041) models. The [A;G] haplotype was more frequently present in controls (18%) than in cases (8%), (OR 0.398; 95% CI 0.22-0.71; P=0.002). These results suggest that the two promoter polymorphisms of VEGF may modify the disease risk in ADPKD patients from North India.
RESUMEN
BACKGROUND/AIMS: The cell surface protein transmembrane 4 L6 family member 1 (TM4SF1) has been detected in various tumors and plays a major role in the development of cancer. We aimed to investigate the effects of TM4SF1 on the migration and invasion of pancreatic cancer in vitro and in vivo and explore its related molecular mechanisms. METHODS: qRT-PCR and immunohistochemical analyses were used to measure the expression of TM4SF1 in pancreatic cancer tissues and adjacent tissues. TM4SF1 was silenced using siRNA and shRNA to investigate the role of this protein in the proliferation and metastasis of pancreatic cancer cells. MTS and Transwell assays were used to examine the effect of TM4SF1 on pancreatic cancer cell lines. The expression and activity of MMP-2 and MMP-9 were determined by qRT-PCR, western blots and gelatin zymography. In vivo, orthotopic pancreatic tumor models were used to examine the formation of metastasis. RESULTS: qRT-PCR and immunohistochemical analyses showed that TM4SF1 was highly expressed in pancreatic cancer tissues compared with the adjacent tissues. In in vitro experiments the silencing of TM4SF1 reduced cell migration and invasion and down-regulated the expression and activity of MMP-2 and MMP-9. However, no significant difference in cell proliferation was detected after silencing TM4SF1. Additionally, knocking down TM4SF1 decreased the formation of lung and liver metastases in orthotopic pancreatic tumor models. CONCLUSION: Our results demonstrate that the expression of TM4SF1 is higher in pancreatic cancer tissues and pancreatic cancer cell lines than controls. Knockdown of TM4SF1 inhibited the migration and invasion of pancreatic cancer cells by regulating the expression and activity of MMP-2 and MMP-9, which suggests that TM4SF1 may play a significant role in metastasis in pancreatic cancer.
Asunto(s)
Antígenos de Superficie/genética , Movimiento Celular/genética , Regulación Neoplásica de la Expresión Génica , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/genética , Animales , Antígenos de Superficie/metabolismo , Línea Celular Tumoral , Humanos , Inmunohistoquímica , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones Desnudos , Invasividad Neoplásica , Metástasis de la Neoplasia , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/terapia , Interferencia de ARN , Tratamiento con ARN de Interferencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: TM4SF1 is overexpressed in pancreatic ductal adenocarcinoma (PDAC) and affects the development of this cancer. Also, multidrug resistance (MDR) is generally associated with tumor chemoresistance in pancreatic cancer. However, the correlation between TM4SF1 and MDR remains unknown. This research aims to investigate the effect of TM4SF1 on gemcitabine resistance in PDAC and explore the possible molecular mechanism between TM4SF1 and MDR. METHODS: The expression of TM4SF1 was evaluated in pancreatic cancer cell lines and human pancreatic duct epithelial (HPDE) cell lines by quantitative RT-PCR. TM4SF1 siRNA transfection was carried out using Hiperfect transfection reagent to knock down TM4SF1. The transcripts were analyzed by quantitative RT-PCR, RT-PCR and western blotting for further study. The cell proliferation and apoptosis were obtained to investigate the sensitivity to gemcitabine of pancreatic cancer cells after silencing TM4SF1 in vitro. We demonstrated that cell signaling of TM4SF1 mediated chemoresistance in cancer cells by assessing the expression of multidrug resistance (MDR) genes using quantitative RT-PCR. In vivo, we used orthotopic pancreatic tumor models to investigate the effect of proliferation after silencing TM4SF1 by a lentivirus-mediated shRNA in MIA PaCa-2 cell lines. RESULTS: The mRNA expression of TM4SF1 was higher in seven pancreatic cancer cell lines than in HPDE cell lines. In three gemcitabine-sensitive cell lines (L3.6pl, BxPC-3, SU86.86), the expression of TM4SF1 was lower than that in four gemcitabine-resistant cell lines (MIA PaCa-2, PANC-1, Hs766T, AsPC-1). We evaluated that TM4SF1 was a putative target for gemcitabine resistance in pancreatic cancer cells. Using AsPC-1, MIA PaCa-2 and PANC-1, we investigated that TM4SF1 silencing affected cell proliferation and increased the percentages of cell apoptosis mediated by treatment with gemcitabine compared with cells which were treated with negative control. This resistance was associated with the expression of multidrug resistance genes including ABCB1 and ABCC1. In vivo, silencing of TM4SF1 in MIA PaCa-2 cell lines increased the effectiveness of gemcitabine-based treatment in orthotopic pancreatic tumor models evaluated using noninvasive bioluminescent imaging. CONCLUSION: These findings suggest that TM4SF1 is a surface membrane antigen that is highly expressed in pancreatic cancer cells and increases the chemoresistance to gemcitabine. Thus, TM4SF1 may be a promising target to overcome the chemoresistance of pancreatic cancer.
Asunto(s)
Antígenos de Superficie/genética , Carcinoma Ductal Pancreático/genética , Desoxicitidina/análogos & derivados , Resistencia a Múltiples Medicamentos/genética , Resistencia a Antineoplásicos/genética , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/tratamiento farmacológico , Subfamilia B de Transportador de Casetes de Unión a ATP/biosíntesis , Animales , Apoptosis/efectos de los fármacos , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Desoxicitidina/farmacología , Humanos , Masculino , Ratones , Ratones Desnudos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/biosíntesis , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Interferencia de ARN , ARN Mensajero/biosíntesis , ARN Interferente Pequeño/genética , Transducción de Señal/genética , GemcitabinaRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is relatively rare but extremely lethal. Standard cytotoxic therapeutics provide little benefit. To date, newer targeted therapeutics have also not been highly successful. Often novel therapeutics that have appeared to perform well in preclinical models have failed in the clinic. Many factors contribute to these failures, but the one most often attributed is the shortcomings of the preclinical models. A plethora of animal models now exist for PDAC, including cell line xenografts, patient-derived xenografts, a wide variety of genetic mouse models, and syngeneic xenografts. These models have generated a tremendous amount of information useful for the understanding of PDAC. Yet none seems to well predict clinical outcomes of new treatments. This review will discuss how genetic instability and cellular heterogeneity make this disease so difficult to model accurately. We will also discuss the strengths and weaknesses of many of the popular models. Ultimately we will argue that there is no perfect model and that the best approach to understanding clinical performance is the use of multiple preclinical models with an understanding of their salient features.
Asunto(s)
Carcinoma Ductal Pancreático/patología , Neoplasias Pancreáticas/patología , Ensayos Antitumor por Modelo de Xenoinjerto/métodos , Animales , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/fisiopatología , Carcinoma Ductal Pancreático/terapia , Evaluación Preclínica de Medicamentos/métodos , Humanos , Ratones , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/fisiopatología , Neoplasias Pancreáticas/terapia , Especificidad de la EspecieRESUMEN
Anterior gradient 2 (AGR2) promotes cancer growth, metastasis, and resistance to therapy via unknown mechanisms. We investigated the effects of extracellular AGR2 signaling through the orphan glycosylphosphatidylinositol-linked receptor C4.4A in pancreatic ductal adenocarcinoma (PDAC). Proliferation, migration, invasion, and apoptosis were measured using colorimetric, Boyden chamber, and FACS analyses. We developed blocking mAbs against AGR2 and C4.4A and tested their effects, along with siRNAs, on cancer cell functions and on orthotopic tumors in nude mice. Extracellular AGR2 stimulated proliferation, migration, invasion, and chemoresistance of PDAC cell lines. AGR2 interacted with C4.4A in cell lysates and mixtures of recombinant proteins. Knockdown of C4.4A reduced migration and resistance to gemcitabine. PDAC tissues, but not adjacent healthy pancreatic tissues, expressed high levels of AGR2 and C4.4A. AGR2 signaling through C4.4A required laminins 1 or 5 and integrin ß1. Administration of antibodies against AGR2 and C4.4A reduced growth and metastasis and caused regression of aggressive xenograft tumors, leading to increased survival of mice. These data support a model in which AGR2 binds and signals via C4.4A in an autocrine loop and promotes the growth of pancreas tumors in mice. Blocking mAbs against AGR2 and C4.4A may have therapeutic potential against PDAC.
Asunto(s)
Anticuerpos Bloqueadores/farmacología , Anticuerpos Monoclonales/farmacología , Antineoplásicos/farmacología , Moléculas de Adhesión Celular/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Moléculas de Adhesión Celular/genética , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos , Espacio Extracelular/metabolismo , Femenino , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/metabolismo , Expresión Génica , Humanos , Cadenas beta de Integrinas/metabolismo , Laminina/metabolismo , Ratones , Mucoproteínas , Proteínas Oncogénicas , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Unión Proteica , Proteínas/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Kalinina , Neoplasias PancreáticasRESUMEN
The mechanisms that allow cancer cells to adapt to the typical tumor microenvironment of low oxygen and glucose and high lactate are not well understood. GPR81 is a lactate receptor recently identified in adipose and muscle cells that has not been investigated in cancer. In the current study, we examined GPR81 expression and function in cancer cells. We found that GPR81 was present in colon, breast, lung, hepatocellular, salivary gland, cervical, and pancreatic carcinoma cell lines. Examination of tumors resected from patients with pancreatic cancer indicated that 94% (148 of 158) expressed high levels of GPR81. Functionally, we observed that the reduction of GPR81 levels using shRNA-mediated silencing had little effect on pancreatic cancer cells cultured in high glucose, but led to the rapid death of cancer cells cultured in conditions of low glucose supplemented with lactate. We also observed that lactate addition to culture media induced the expression of genes involved in lactate metabolism, including monocarboxylase transporters in control, but not in GPR81-silenced cells. In vivo, GPR81 expression levels correlated with the rate of pancreatic cancer tumor growth and metastasis. Cells in which GPR81 was silenced showed a dramatic decrease in growth and metastasis. Implantation of cancer cells in vivo was also observed to lead to greatly elevated levels of GPR81. These data support that GPR81 is important for cancer cell regulation of lactate transport mechanisms. Furthermore, lactate transport is important for the survival of cancer cells in the tumor microenvironment. Cancer Res; 74(18); 5301-10. ©2014 AACR.