RESUMEN
A comprehensive understanding of the dynamic activation and crosstalk between different cellular stress response pathways that drive cell adversity is crucial in chemical safety assessment. Various chemicals have electrophilic properties that drive cell injury responses in particular oxidative stress signaling and inflammatory signaling. Here we used bacterial artificial chromosome-based GFP cellular stress reporters with live cell confocal imaging, to systematically monitor the differential modulation of the dynamics of stress pathway activation by six different soft electrophiles: sulforaphane, andrographolide, diethyl maleate, CDDO-Me, ethacrynic acid and tert-butyl hydroquinone. The various soft electrophiles showed differential potency and dynamics of Nrf2 activation and nuclear translocation. These differences in Nrf2 dynamics correlated with distinct activation pattern of Nrf2 downstream targets SRNX1 and HMOX1. All soft electrophiles caused a strong dose dependent suppression of a cytokine-induced NFĸB response represented by suppression of NFĸB nuclear oscillation and inhibition of the downstream target gene activation A20 and ICAM1, which followed the potency of Nrf2 modulation but occurred at higher concentration close to saturation of Nrf2 activation. RNAi-based depletion of RelA resulted in a prolonged presence of Nrf2 in the nucleus after soft electrophile treatment; depletion of Nrf2 caused the induction of NFĸB signaling and activation of its downstream targets A20 and ICAM1. A systematic transcriptome analysis confirmed these effects by soft electrophiles on Nrf2 and NFκB signaling crosstalk in human induced-pluripotent stem cell-derived hepatocyte-like cells. Altogether our data indicate that modulation of Nrf2 by soft electrophiles may have consequences for efficient inflammatory signaling.
Asunto(s)
Antioxidantes , Factor 2 Relacionado con NF-E2 , Antioxidantes/farmacología , Hepatocitos , Humanos , Hígado/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Ácido Oleanólico/análogos & derivados , Estrés OxidativoRESUMEN
Ttriple-negative breast cancer (TNBC) is an aggressive and highly metastatic breast cancer subtype. Enhanced TNBC cell motility is a prerequisite of TNBC cell dissemination. Here, we apply an imaging-based RNAi phenotypic cell migration screen using two highly motile TNBC cell lines (Hs578T and MDA-MB-231) to provide a repository of signaling determinants that functionally drive TNBC cell motility. We have screened ~4,200 target genes individually and discovered 133 and 113 migratory modulators of Hs578T and MDA-MB-231, respectively, which are linked to signaling networks predictive for breast cancer progression. The splicing factors PRPF4B and BUD31 and the transcription factor BPTF are essential for cancer cell migration, amplified in human primary breast tumors and associated with metastasis-free survival. Depletion of PRPF4B, BUD31 and BPTF causes primarily down regulation of genes involved in focal adhesion and ECM-interaction pathways. PRPF4B is essential for TNBC metastasis formation in vivo, making PRPF4B a candidate for further drug development.
Asunto(s)
Movimiento Celular/genética , Regulación Neoplásica de la Expresión Génica , Proteínas Serina-Treonina Quinasas/metabolismo , Ribonucleoproteína Nuclear Pequeña U4-U6/metabolismo , Neoplasias de la Mama Triple Negativas/patología , Antígenos Nucleares/genética , Antígenos Nucleares/metabolismo , Línea Celular Tumoral , Estudios de Cohortes , Conjuntos de Datos como Asunto , Supervivencia sin Enfermedad , Matriz Extracelular/metabolismo , Femenino , Adhesiones Focales/genética , Humanos , Microscopía Intravital , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Interferencia de ARN , Empalme del ARN/genética , ARN Interferente Pequeño/metabolismo , Ribonucleoproteína Nuclear Pequeña U4-U6/genética , Transducción de Señal/genética , Análisis de Supervivencia , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/mortalidadRESUMEN
Drug-induced liver injury remains a concern during drug treatment and development. There is an urgent need for improved mechanistic understanding and prediction of DILI liabilities using in vitro approaches. We have established and characterized a panel of liver cell models containing mechanism-based fluorescent protein toxicity pathway reporters to quantitatively assess the dynamics of cellular stress response pathway activation at the single cell level using automated live cell imaging. We have systematically evaluated the application of four key adaptive stress pathway reporters for the prediction of DILI liability: SRXN1-GFP (oxidative stress), CHOP-GFP (ER stress/UPR response), p21 (p53-mediated DNA damage-related response) and ICAM1 (NF-κB-mediated inflammatory signaling). 118 FDA-labeled drugs in five human exposure relevant concentrations were evaluated for reporter activation using live cell confocal imaging. Quantitative data analysis revealed activation of single or multiple reporters by most drugs in a concentration and time dependent manner. Hierarchical clustering of time course dynamics and refined single cell analysis allowed the allusion of key events in DILI liability. Concentration response modeling was performed to calculate benchmark concentrations (BMCs). Extracted temporal dynamic parameters and BMCs were used to assess the predictive power of sub-lethal adaptive stress pathway activation. Although cellular adaptive responses were activated by non-DILI and severe-DILI compounds alike, dynamic behavior and lower BMCs of pathway activation were sufficiently distinct between these compound classes. The high-level detailed temporal- and concentration-dependent evaluation of the dynamics of adaptive stress pathway activation adds to the overall understanding and prediction of drug-induced liver liabilities.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Modelos Biológicos , Estrés Fisiológico/fisiología , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Relación Dosis-Respuesta a Droga , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células Hep G2 , Humanos , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/genética , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/metabolismo , Análisis de la Célula Individual , Estrés Fisiológico/efectos de los fármacos , Máquina de Vectores de Soporte , Factor de Transcripción CHOP/genética , Factor de Transcripción CHOP/metabolismoRESUMEN
A quantitative dynamics pathway map of the Nrf2-mediated oxidative stress response and p53-related DNA damage response pathways as well as the cross-talk between these pathways has not systematically been defined. To allow the dynamic single cell evaluation of these pathways, we have used BAC-GFP recombineering to tag for each pathway's three key components: for the oxidative stress response, Keap1-GFP, Nrf2-GFP, and Srxn1-GFP; for the DNA damage response, 53bp1-GFP, p53-GFP, and p21-GFP. The dynamic activation of these individual components was assessed using quantitative high throughput confocal microscopy after treatment with a broad concentration range of diethyl maleate (DEM; to induce oxidative stress) and etoposide (to induce DNA damage). DEM caused a rapid activation of Nrf2, which returned to baseline levels at low concentrations but remained sustained at high concentrations. Srxn1-GFP induction and Keap1-GFP translocation to autophagosomes followed later, with upper boundaries reached at high concentrations, close to the onset of cell death. Etoposide caused rapid accumulation of 53bp1-GFP in DNA damage foci, which was later followed by the concentration dependent nuclear accumulation of p53-GFP and subsequent induction of p21-GFP. While etoposide caused activation of Srxn1-GFP, a modest activation of DNA damage reporters was observed for DEM at high concentrations. Interestingly, Nrf2 knockdown caused an inhibition of the DNA damage response at high concentrations of etoposide, while Keap1 knockdown caused an enhancement of the DNA damage response already at low concentrations of etoposide. Knockdown of p53 did not affect the oxidative stress response. Altogether, the current stress response landscapes provide insight in the time course responses of and cross-talk between oxidative stress and DNA-damage and defines the tipping points where cell injury may switch from adaptation to injury.
Asunto(s)
Daño del ADN/efectos de los fármacos , Etopósido/toxicidad , Maleatos/toxicidad , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Genes Reporteros , Células Hep G2 , Humanos , Proteína 1 Asociada A ECH Tipo Kelch/antagonistas & inhibidores , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/antagonistas & inhibidores , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/genética , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Cancer cells migrate from the primary tumour into surrounding tissue in order to form metastasis. Cell migration is a highly complex process, which requires continuous remodelling and re-organization of the cytoskeleton and cell-matrix adhesions. Here, we aimed to identify genes controlling aspects of tumour cell migration, including the dynamic organization of cell-matrix adhesions and cellular traction forces. In a siRNA screen targeting most cell adhesion-related genes we identified 200+ genes that regulate size and/or dynamics of cell-matrix adhesions in MCF7 breast cancer cells. In a subsequent secondary screen, the 64 most effective genes were evaluated for growth factor-induced cell migration and validated by tertiary RNAi pool deconvolution experiments. Four validated hits showed significantly enlarged adhesions accompanied by reduced cell migration upon siRNA-mediated knockdown. Furthermore, loss of PPP1R12B, HIPK3 or RAC2 caused cells to exert higher traction forces, as determined by traction force microscopy with elastomeric micropillar post arrays, and led to considerably reduced force turnover. Altogether, we identified genes that co-regulate cell-matrix adhesion dynamics and traction force turnover, thereby modulating overall motility behaviour.