Establishment of Mouse Teratocarcinomas Stem Cells Line and Screening Genes Responsible for Malignancy

Tao Liu,Xinrong Peng,Qijun Qian,Mengchao Wu,Huajun Jin,Jingbo Cheng,Ying Wang,Liqing Zhang,Fazlul H Sarkar

doi:10.1371/journal.pone.0043955

Abstract

The sequential transplantation of embryonal carcinoma cells in vivo can accelerate the growth and malignancy of teratocarcinomas. However, the possible molecular mechanisms in this process that reflect cancer formation in the early stage are largely unknown and. To identify which genes are associated with the changes of malignancy of teratocarcinomas, we established a tumorigenesis model in which teratocarcinoma were induced via injecting embryonic stem cells into immuno-deficiency mice, isolating teratocarcinoma stem cell from a teratocarcinoma in serum-free culture medium and injecting teratocarcinoma stem cells into immune-deficient mice continuously. By using high-throughput deep sequence technology, we identified 26 differentially expressed genes related to the changes of characteristics of teratocarcinoma stem cell in which 18 out of 26 genes were down-regulated and 8 genes were up-regulated. Among these genes, several tumor-related genes such as Gata3, Arnt and Tdgf1, epigenetic associated genes such as PHC1 and Uty were identified. Pathway enrichment analysis result revealed that Wnt signaling pathway, primary immunodeficiency pathway, antigen processing and presentation pathway and allograft rejection pathway were involved in the teratocarcinoma tumorigenesis (corrected p value<0.05). In summary, our study established a tumorigenesis model and proposed some candidate genes and signaling pathways that may play a key role in the early stage of cancer occurrence.

Highlights

Teratomas are benign germ cell tumors with somatic tissue or organ components of all three embryonic germ layers
Based on the hypothesis that tumor originated in the early stage of remaining embryonic pluripotent cells and the fact that embryonal carcinoma cells (ECCs) sequential transplantation in vivo could accelerate the growth and malignancy of teratocarcinomas [11], we obtained teratocarcinoma via injecting ICM origin pluripotent stem cells subcutaneously into immune-deficient mice, and isolated teratocarcinoma stem cells and used sequential transplantation to simulate early stage of tumor development and progression
We performed microarray analysis to identify candidate genes which may play a key role in the changes of malignancy of teratocarcinoma stem cell

Summary

Introduction

Teratomas are benign germ cell tumors with somatic tissue or organ components of all three embryonic germ layers. A teratocarcinomas model was established via extrauterine transplantation of pregastrulation stage embryos [3,4], and Evans et al achieved the establishment of in vitro culture methods of mouse ECCs by cocultured with fibroblasts [5]. On this basis, isolating mouse embryonic stem cells (ESCs) from blastocysts was achieved [5,6]. We performed highthroughput deep sequence technology to identify some malignancy-related genes via comparing the gene expression level between ESCs and series of ECCs which may play a key role in the early stage of cancer occurrence

Materials and Methods

Results

Findings

Discussion