RESUMEN
In glioblastomas, apoptosis inhibitor proteins (IAPs) are involved in apoptotic and nonapoptotic processes. We previously showed that IAP inhibition induced a loss of stemness and glioblastoma stem cells differentiation by activating nuclear factor-κB under normoxic conditions. Hypoxia has been shown to modulate drug efficacy. Here, we investigated how IAPs participate in glioblastoma stem-like cell maintenance and fate under hypoxia. We showed that in a hypoxic environment, IAPs inhibition by GDC-0152, a small-molecule IAPs inhibitor, triggered stem-like cell apoptosis and decreased proliferation in four human glioblastoma cell lines. We set up a three-dimensional glioblastoma spheroid model in which time-of-flight secondary ion mass spectrometry analyses revealed a decrease in oxygen levels between the periphery and core. We observed low proliferative and apoptotic cells located close to the hypoxic core of the spheres and glial fibrillary acidic protein+ cells at their periphery. These oxygen-dependent GDC-0152 antitumoral effects have been confirmed on human glioblastoma explants. Notably, serine-threonine kinase activation analysis revealed that under hypoxic conditions, IAP inhibition activated ataxia telangiectasia and Rad3-related protein signaling. Our findings provide new insights into the dual mechanism of action of IAP inhibitors that depends on oxygen level and are relevant to their therapeutic application in tumors. Stem Cells 2019;37:731-742.
Asunto(s)
Apoptosis/genética , Neoplasias Encefálicas/genética , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Células Madre Neoplásicas/metabolismo , Oxígeno/farmacología , Proteínas Adaptadoras Transductoras de Señales/antagonistas & inhibidores , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adrenomedulina/genética , Adrenomedulina/metabolismo , Apoptosis/efectos de los fármacos , Proteína 3 que Contiene Repeticiones IAP de Baculovirus/antagonistas & inhibidores , Proteína 3 que Contiene Repeticiones IAP de Baculovirus/genética , Proteína 3 que Contiene Repeticiones IAP de Baculovirus/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Anhidrasa Carbónica IX/genética , Anhidrasa Carbónica IX/metabolismo , Diferenciación Celular/efectos de los fármacos , Hipoxia de la Célula/genética , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ciclohexanos/farmacología , Inhibidores Enzimáticos/farmacología , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Proteínas Inhibidoras de la Apoptosis/antagonistas & inhibidores , Proteínas Inhibidoras de la Apoptosis/genética , Proteínas Inhibidoras de la Apoptosis/metabolismo , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Oxígeno/metabolismo , Pirroles/farmacología , Transducción de Señal , Esferoides Celulares/efectos de los fármacos , Esferoides Celulares/metabolismo , Esferoides Celulares/patología , Técnicas de Cultivo de Tejidos , Proteína Inhibidora de la Apoptosis Ligada a X/antagonistas & inhibidores , Proteína Inhibidora de la Apoptosis Ligada a X/genética , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismoRESUMEN
BACKGROUND: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technology (MALDI-TOF MS) is an innovative tool that has been shown to be effective for the identification of numerous arthropod groups including mosquitoes. A critical step in the implementation of MALDI-TOF MS identification is the creation of spectra databases (DB) for the species of interest. Mosquito legs were the body part most frequently used to create identification DB. However, legs are one of the most fragile mosquito compartments, which can put identification at risk. Here, we assessed whether mosquito thoraxes could also be used as a relevant body part for mosquito species identification using a MALDI-TOF MS biotyping strategy; we propose a double DB query strategy to reinforce identification success. METHODS: Thoraxes and legs from 91 mosquito specimens belonging to seven mosquito species collected in six localities from Guadeloupe, and two laboratory strains, Aedes aegypti BORA and Aedes albopictus Marseille, were dissected and analyzed by MALDI-TOF MS. Molecular identification using cox1 gene sequencing was also conducted on representative specimens to confirm their identification. RESULTS: MS profiles obtained with both thoraxes and legs were highly compartment-specific, species-specific and species-reproducible, allowing high identification scores (log-score values, LSVs) when queried against the in-house MS reference spectra DB (thorax LSVs range: 2.260-2.783, leg LSVs range: 2.132-2.753). CONCLUSIONS: Both thoraxes and legs could be used for a double DB query in order to reinforce the success and accuracy of MALDI-TOF MS identification.
Asunto(s)
Aedes/anatomía & histología , Aedes/química , Culicidae/clasificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Aedes/clasificación , Aedes/genética , Animales , Culicidae/anatomía & histología , Culicidae/química , Extremidades , Tórax/químicaRESUMEN
Sea anemones are a remarkable source of active principles due to a decentralized venom system. New blood vessel growth or angiogenesis is a very promising target against cancer, but the few available antiangiogenic compounds have limited efficacy. In this study, a protein fraction, purified from tentacles of Anemonia viridis, was able to limit endothelial cells proliferation and angiogenesis at low concentration (14 nM). Protein sequences were determined with Edman degradation and mass spectrometry in source decay and revealed homologies with Blood Depressing Substance (BDS) sea anemones. The presence of a two-turn alpha helix observed with circular dichroism and a trypsin activity inhibition suggested that the active principle could be a Kunitz-type inhibitor, which may interact with an integrin due to an Arginine Glycin Aspartate (RGD) motif. Molecular modeling showed that this RGD motif was well exposed to solvent. This active principle could improve antiangiogenic therapy from existing antiangiogenic compounds binding on the Vascular Endothelial Growth Factor (VEGF).