Comparison of the tumor cells proliferative activity in donor tissue and samples of xenograft generations.

Abstract

e15619 Background: Esophageal cancer is a common tumor of the mucous layer of the esophagus and the sixth most common cause of cancer deaths worldwide. Studying the mechanisms of its occurrence and development and the search for new approaches to its prevention and treatment are relevant. Such studies require a reliable experimental basis with such an important component as the use of animal models of cancer. In vivo models are an important tool both for testing new drugs and for studying the mechanisms of disease development. The purpose of the study was to create a patient-derived xenograft (PDX) model of esophageal cancer and to evaluate the proliferative activity of cells in the donor tumor and in xenograft samples in a series of successive generations. Methods: A PDX model of esophageal cancer was created by transplanting a tumor fragment from a patient with esophageal squamous cell carcinoma to the distal esophagus of BALB/c Nude athymic mice. The tumor histotype was confirmed histologically (hematoxylin and eosin staining). The proliferative activity of cells was evaluated by immunohistochemistry (IHC) with anti-Ki-67 antibodies. Results: Histological identity of xenograft samples and the donor tumor was confirmed. IHC showed an increase in the proliferative activity index in samples of transplanted tumors compared to the donor material: 12.4% in the primary tumor and 58%, 65.2%, 54.2% and 60.7% in generations 1, 3, 4 and 5, respectively. Conclusions: Histological characteristics of the donor tumor are preserved in all PDX models. The study demonstrated an increase of the proliferative activity in the first PDX generation compared to the primary tumor which persisted in the subsequent models.