A study on nude mice models and biological characteristics of yolk sac tumor

Abstract

Objective To establish stable nude mice models from human Yolk Sac tumor (YST)for purpose of experimental research.Methods Fresh YST'S tumor specimen from 2-yr old child was sliced and inoculated hypodermically into the limbs of nude mice with constituted passage.The tumor growth curves of each generation were monitored.The ultra-structural and pathological changes were observed on by electronic and light microscopy.The immunohistochemical staining was applied to observe the expression of AFP,PLAP and CK on tumor tissues.The numbers of chromosome within tumor tissue were analyzed simultaneously.Results During 15-month period of study,7 generations of tumor division were recorded.The oncogenic rate within that of the first 3 generations was 20%,40% and 65%,respectively.After the 4th generation,the oncogenic rate was 100%.The average latency period of tumor in mice was 32 days.The growth curve corresponded to the Gompentz function.The transplanted tumors retained the original histological tumor characteristics.The AFP,PLAP and CK expression were positive by immunocytochemistry staining.The numbers of chromosome of tumor varied between 34～86,with chromosome depletion and breakage,which were different from that of normal nude mice and human(P＜0.01).Conclusions The nude mice models from human YST retained the basic biological characteristics of the primary tumor and it is suitable for the fundamental and clinical researches on YST. Key words: Yolk sac tumor; Disease models,Animal; Neoplasm transplantation; Biology