RESUMO
Malignant mesothelioma is an aggressive cancer that is resistant to current therapy. The poor prognosis of mesothelioma has been associated with elevated Yes-associated protein (YAP) activity. In this study, we evaluated the effect of targeting YAP in mesothelioma. First, we comprehensively studied YAP activity in five mesothelioma cell lines (211H, H2052, H290, MS-1 and H2452) and one normal mesothelial cell line (LP9). We found decreased phospho-YAP to YAP protein ratio and consistently increased GTIIC reporter activity in 211H, H2052 and H290 compared to LP9. The same three cell lines (IC50 s < 1 µM) were more sensitive than LP9 (IC50 = 3.5 µM) to the YAP/TEAD inhibitor verteporfin. We also found that verteporfin significantly reduced YAP protein level, mRNA levels of YAP downstream genes and GTIIC reporter activity in the same three cell lines, indicating inhibition of YAP signaling by verteporfin. Verteporfin also impaired invasion and tumoursphere formation ability of H2052 and H290. To validate the effect of specific targeting YAP in mesothelioma cells, we down-regulated YAP by siRNA. We found siYAP significantly decreased YAP transcriptional activity and impaired invasion and tumoursphere formation ability of H2052 and H290. Furthermore, forced overexpression of YAP rescued GTIIC reporter activity and cell viability after siYAP targeting 3'UTR of YAP. Finally, we found concurrent immunohistochemistry staining of ROCK2 and YAP (P < 0.05). Inhibition of ROCK2 decreased GTIIC reporter activity in H2052 and 211H suggesting that Rho/ROCK signaling also contributed to YAP activation in mesothelioma cells. Our results indicate that YAP may be a potential therapeutic target in mesothelioma.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Ligação a DNA/genética , Células Epiteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas Nucleares/genética , Fosfoproteínas/genética , RNA Mensageiro/genética , Fatores de Transcrição/genética , Quinases Associadas a rho/genética , Regiões 3' não Traduzidas , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Genes Reporter , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Mesotelioma/genética , Mesotelioma/metabolismo , Mesotelioma/patologia , Mesotelioma Maligno , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/metabolismo , Fosforilação , Porfirinas/farmacologia , Prognóstico , RNA Mensageiro/antagonistas & inibidores , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Verteporfina , Proteínas de Sinalização YAP , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
Orchestrated regulation of neuronal migration and morphogenesis is critical for neuronal development and establishment of functional circuits, but its regulatory mechanism is incompletely defined. We established and analyzed mice with neural-specific knock-out of Trio, a guanine nucleotide exchange factor with multiple guanine nucleotide exchange factor domains. Knock-out mice showed defective cerebella and severe signs of ataxia. Mutant cerebella had no granule cells in the internal granule cell layer due to aberrant granule cell migration as well as abnormal neurite growth. Trio-deficient granule cells showed reduced extension of neurites and highly branched and misguided processes with perturbed stabilization of actin and microtubules. Trio deletion caused down-regulation of the activation of Rac1, RhoA, and Cdc42, and mutant granule cells appeared to be unresponsive to neurite growth-promoting molecules such as Netrin-1 and Semaphorin 6A. These results suggest that Trio may be a key signal module for the orchestrated regulation of neuronal migration and morphogenesis during cerebellar development. Trio may serve as a signal integrator decoding extrinsic signals to Rho GTPases for cytoskeleton organization.
Assuntos
Cerebelo/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Troca do Nucleotídeo Guanina/química , Fosfoproteínas/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Animais , Movimento Celular , Cromossomos Artificiais Bacterianos/metabolismo , Citoesqueleto/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Proteínas de Filamentos Intermediários/metabolismo , Camundongos , Camundongos Knockout , Morfogênese , Proteínas do Tecido Nervoso/metabolismo , Nestina , Neurônios/metabolismo , Fosfoproteínas/genética , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Proteínas rho de Ligação ao GTP/metabolismoRESUMO
Malignant pleural mesothelioma (MPM) is an aggressive cancer for which more effective treatments are needed. In this study, strong to moderate staining of MET and ERK5 was detected in 67.1 and 48% of the analyzed 73 human mesothelioma tumors, and significant correlation of MET and ERK5 expression was identified (P<0.05). We evaluated the doublecortin-like kinase 1 (DCLK1) expression in human mesothelioma tumors. Our results showed that 50.7% of the immunohistochemistry analyzed human mesothelioma tumors have strong to moderate staining of DCLK1, and its expression is significantly correlated with MET or ERK5 expression (P<0.05). Also, the upregulation of DCLK1 is correlated with poor prognosis in MPM patients (P=0.0235). To investigate whether DCLK1 is downstream of MET/ERK5 signaling in human mesothelioma, the effect of DCLK1 expression was analyzed after treatments with either the MET inhibitor XL184 or the ERK5 inhibitor XMD8-92 in human mesothelioma cell lines. Our results showed that the MET inhibitor XL184 reduced the expression of phosphoERK5 and DCLK1 expression in human mesothelioma cell lines. In addition, the ERK5 inhibitor XMD8-92 reduced the expression of phospho-ERK5 and DCLK1 expression in human mesothelioma cell lines. Furthermore, XML184 and XMD8-92 treatment impaired invasion and tumor sphere formation ability of H290 mesothelioma cells. These results suggest that DCLK1 is regulated by MET/ERK5 signaling in human mesothelioma, and the MET/ERK5/DCLK1 signaling cascade could be further developed into a promising therapeutic target against mesothelioma.