RESUMEN
EGFR amplification and mutations are the most common oncogenic events in GBM. EGFR overexpression correlates with GBM invasion, but the underlying mechanisms are poorly understood. In a previous study, we showed that AJAP1 is involved in regulating F-actin to inhibit the invasive ability of GBM. In addition, in a GBM cell line, the AJAP1 promoter was highly bound by H3K27me3 and, through bioinformatics analysis, we found that AJAP1 expression was negatively correlated with EGFR. In this study, we found that the pathway downstream of EGFR had a higher activation level in GBM cell lines, which led to excessive tumor suppressor silencing. Therefore, we deduced that in glioma cells, the pathway downstream of EGFR remodels the cytoskeleton via AJAP1 epigenetic silencing to enhance invasion. Furthermore, MK2206 reversed AJAP1 downregulation by inhibiting the EGFR pathway. In vivo, MK2206 also inhibited the proliferation and local invasion of 87-EGFRvIII. These data suggest that activation of the EGFR signal transduction pathway genetically silences anti-oncogenes to enhance GBM malignancy. MK2206 might be a promising therapeutic for EGFR/EGFRvIII-positive GBMs.
Asunto(s)
Citoesqueleto de Actina/metabolismo , Neoplasias Encefálicas/metabolismo , Moléculas de Adhesión Celular/metabolismo , Movimiento Celular , Metilación de ADN , Epigénesis Genética , Receptores ErbB/metabolismo , Animales , Antineoplásicos/farmacología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Moléculas de Adhesión Celular/genética , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Biología Computacional , Bases de Datos Genéticas , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Receptores ErbB/genética , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Compuestos Heterocíclicos con 3 Anillos/farmacología , Humanos , Ratones Endogámicos BALB C , Ratones Desnudos , Invasividad Neoplásica , Fosfatidilinositol 3-Quinasa/metabolismo , Regiones Promotoras Genéticas , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Interferencia de ARN , Transducción de Señal , Transfección , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Worldwide, glioblastoma (GBM) is the most lethal and frequent intracranial tumor. Despite decades of study, the overall survival of GBM patients remains unchanged. epidermal growth factor receptor (EGFR) amplification and gene mutation are thought to be negatively correlated with prognosis. In this study, we used proteomics to determine that UBXN1 is a negative downstream regulator of the EGFR mutation vIII (EGFRvIII). Via bioinformatics analysis, we found that UBXN1 is a factor that can improve glioma patients' overall survival time. We also determined that the down-regulation of UBXN1 is mediated by the upregulation of H3K27me3 in the presence of EGFRvIII. Because NF-κB can be negatively regulated by UBXN1, we believe that EGFRwt/vIII activates NF-κB by suppressing UBXN1 expression. Importantly, we used the latest genomic editing tool, CRISPR/Cas9, to knockout EGFRwt/vIII on exon 17 and further proved that UBXN1 is negatively regulated by EGFRwt/vIII. Furthermore, knockout of EGFR/EGFRvIII could benefit GBM in vitro and in vivo, indicating that CRISPR/Cas9 is a promising therapeutic strategy for both EGFR amplification and EGFR mutation-bearing patients.