Correlation of SOX-2 and NOTCH1 copy numbers with vimentin expression in orthotopic patient-derived xenografts of cardioesophageal cancer in immunodeficient mice.

Abstract

e15034 Background: Cardioesophageal cancer is one of the most common tumors affecting the mucosa of the cardiac stomach and distal esophagus. Despite the variety of treatment strategies and chemotherapy agents, the prognosis for the patients remains poor. The purpose of the study was to analyze the relative copy numbers of SOX-2 and NOTCH1 and vimentin expression in orthotopic patient-derived xenografts of cardioesophageal cancer. Methods: The model of cardioesophageal cancer was created in Balb/c Nude mice with surgical bioptates of moderately differentiated adenocarcinoma obtained from a donor with infiltrative ulcerative cancer of the lower third of the esophagus with a transition to the cardiac stomach into the distal esophagus of Balb/c Nude mice. The index of proliferative activity in the bioptates was assessed by IHC. The relative copy numbers of SOX-2 and NOTCH1 and vimentin expression were determined by Real-Time qPCR. Results: Expression of vimentin was absent in tissues of the donor tumor. The levels of vimentin expression statistically significantly increased in xenografts (1+ and 3+). The SOX-2 and NOTCH1 relative copy numbers were statistically significantly increased in tissues of the donor tumor (0.9 and 0.7), compared to xenografts (1.5±0.03 and 1.7±0.03). Molecular genetic analysis demonstrated an association between an increased vimentin expression and changes in the relative copy numbers of SOX-2 and NOTCH1 (p = 0.013 and p = 0.0001). Conclusions: The relative copy numbers of SOX-2 and NOTCH1 genetic loci was associated with increased expression of the epithelial-mesenchymal transition marker vimentin in tumor tissue samples and changed with each new generation of orthotopic xenografts.