The Tumor Suppressor SASH1 Interacts With the Signal Adaptor CRKL to Inhibit Epithelial–Mesenchymal Transition and Metastasis in Colorectal Cancer
Identificadores
Identificadores
Visualización o descarga de ficheros
Visualización o descarga de ficheros
Fecha de publicación
2019Título de revista
CELLULAR AND MOLECULAR GASTROENTEROLOGY AND HEPATOLOGY
Tipo de contenido
Artigo
DeCS
proteínas nucleares | fenotipo | dominios de homología src | unión proteica | sistemas CRISPR-Cas | metástasis neoplásica | motivos de aminoácidos | transducción de señales | células HCT116 | proteínas supresoras de tumor | invasividad neoplásica | transición epiteliomesenquimatosa | humanos | neoplasias colorrectales | células HEK293MeSH
CRISPR-Cas Systems | Tumor Suppressor Proteins | src Homology Domains | Neoplasm Invasiveness | Neoplasm Metastasis | HCT116 Cells | Phenotype | Signal Transduction | Epithelial-Mesenchymal Transition | Protein Binding | Nuclear Proteins | HEK293 Cells | Humans | Amino Acid Motifs | Colorectal NeoplasmsResumen
Background & Aims: The tumor-suppressor sterile alpha motif- and Src-homology 3-domain containing 1 (SASH1) has clinical relevance in colorectal carcinoma and is associated specifically with metachronous metastasis. We sought to identify the molecular mechanisms linking decreased SASH1 expression with distant metastasis formation. Methods: SASH1-deficient, SASH1-depleted, or SASH1-overexpressing HCT116 colon cancer cells were generated by the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9-method, RNA interference, and transient plasmid transfection, respectively. Epithelial-mesenchymal transition (EMT) was analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblotting, immunofluorescence microscopy, migration/invasion assays, and 3-dimensional cell culture. Yeast 2-hybrid assays and co-immunoprecipitation/mass-spectrometry showed V-Crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) as a novel interaction partner of SASH1, further confirmed by domain mapping, site-directed mutagenesis, co-immunoprecipitation, and dynamic mass redistribution assays. CRKL-deficient cells were generated in parental or SASH1-deficient cells. Metastatic capacity was analyzed with an orthotopic mouse model. Expression and significance of SASH1 and CRKL for survival and response to chemotherapy was assessed in patient samples from our department and The Cancer Genome Atlas data set. Results: SASH1 expression is down-regulated during cytokine-induced EMT in cell lines from colorectal, pancreatic, or hepatocellular cancer, mediated by the putative SASH1 promoter. Deficiency or knock-down of SASH1 induces EMT, leading to an aggressive, invasive phenotype with increased chemoresistance. SASH1 counteracts EMT through interaction with the oncoprotein CRKL, inhibiting CRKL-mediated activation of SRC kinase, which is crucially required for EMT. SASH1-deficient cells form significantly more metastases in vivo, depending entirely on CRKL. Patient tumor samples show significantly decreased SASH1 and increased CRKL expression, associated with significantly decreased overall survival. Patients with increased CRKL expression show significantly worse response to adjuvant chemotherapy. Conclusions: We propose SASH1 as an inhibitor of CRKL-mediated SRC signaling, introducing a potentially druggable mechanism counteracting chemoresistance and metastasis formation.