Background & AimsThe tumor-suppressor sterile α 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.MethodsSASH1-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.ResultsSASH1 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.ConclusionsWe propose SASH1 as an inhibitor of CRKL-mediated SRC signaling, introducing a potentially druggable mechanism counteracting chemoresistance and metastasis formation.

Nutritional management of patients with intestinal failure often includes the use of oligomeric formulas. Implementing the use of oligomeric formulas in surgical patients with maldigestion or malabsorption could be a nutritional strategy to be included in clinical protocols. We aim to generate knowledge from a survey focused on the effectiveness of nutritional therapy with oligomeric formulas with Delphi methodology. Each statement that reached an agreement consensus among participants was defined as a median consensus score ≥7 and as an interquartile range ≤3. The use of oligomeric formulas in surgical patients, starting enteral nutrition in the post-operative phase in short bowel syndrome and in nonspecific diarrhea after surgical procedures, could improve nutritional therapy implementation. Stakeholders agreed that early jejunal enteral nutrition with oligomeric formula is more effective compared to intravenous fluid therapy and it is useful in patients undergoing upper gastro-intestinal tract major surgery when malabsorption or maldigestion is suspected. Finally, oligomeric formulas may be useful when a feeding tube is placed distally to the duodenum. This study shows a practical approach to the use of oligomeric formulas in surgical patients with intestinal disorders and malabsorption, and it helps clinicians in the decision-making process.