ABSTRACT
Mesenchymal stem cells (MSCs) not only exhibit a marked tropism for tumors,but also exert antitumorigenic activity or as an emerging vectors to express foreign genes continuously and efficiently within the tumor microenvironment,suppress tumor's growth and metastasis.Conversely,MSCs can accelerate tumor development through promoting tumor stroma remodeling and tumor vascular formation,inhibiting tumor local immune and changing tumor phenotype.The reason for this discrepancy may be attributable to different sources of MSCs,the heterogeneity of MSCs,differences in tumor microenviroment,or another factor that is not yet appreciated.
ABSTRACT
Objective:To study the cooperated effect of Human Embryonic Lung Fibroblast(HELF) feeder layer and LIF in the culture of human Embryonic Stem(hES) cells and establish the method of identifying hES cells from Primordial Germ Cells(PGCs).Methods:Embryonic lungs were mechanically disaggregated,then cultured to establish HELF feeder layer.Gonadal ridges and mesenteries of embryos were mechanically disaggeregated,then cultured and passaged in vitro.Comparing the growth characters of hES cells in different conditions.To identify hES cells through their biological characteristics.Results:The coactions of HELF feeder layer and LIF play an important role in proliferation and undifferentiation of hES cells in vitro.High levels of AKP and telomerase activity are associated with hES cells. The cultrued cells have been continuously passaged for more than two months and found to be karyotypically normal and stable.When differentiating,they form embryoid bodies(EBs).Conclusion:To avoid indection of the heterogeneous protein,HELF feeder layer, in the presence of LIF,can be used in culture of hES cells;hES cells from PGCs can be identified through their biological characteristic. [