RESUMO
An immortalized mouse fetal liver stromal cell line, named KM3, has demonstrated the potential to support the growth and maintenance of human embryonic stem cells (hESCs). In this study, the characteristics of KM3 cells were examined following cryopreservation at -70°C and in liquid nitrogen for 15, 30 and 60 days following treatment with 10 µg/ml mitomycin C. In addition, whether the KM3 cells were suitable for use as feeder cells to support the growth of hESCs was evaluated. The inhibition of mitosis without cell death was observed when the KM3 cells were treated with 10 µg/ml mitomycin C for 2 h. The morphology of the KM3 cells cryopreserved in liquid nitrogen for 60 days was not markedly changed, and the cell survival rate was 84.60±1.14%. By contrast, the survival rate of the KM3 cells was 66.40±2.88% following cryopreservation at -70°C for 60 days; the cells readily detached, were maintained for a shorter time, and had a reduced expression level of basic fibroblast growth factor. hESCs cultured on KM3 cells cryopreserved in liquid nitrogen for 60 days showed the typical bird's nest structure, with clear boundaries and a differentiation rate of 16.33±2.08%. The differentiation rate of hESCs cultured on KM3 cells cryopreserved at -70°C for 60 days was 37.67±3.51%. These results indicate that the cryopreserved KM3 cells treated with mitomycin C may be directly used in the subculture of hESCs, and the effect is relatively good with -70°C short-term or liquid nitrogen cryopreservation.
RESUMO
Mesenchymal stem cells (MSCs) or MSC-like cells have now been isolated from various sites, including different types of tumor tissues. Whether MSCs or MSC-like cells in different tumor tissues possess differentiated biological characteristics remains unclear, and the correlation between MSCs or MSC-like cells and tumors has been a controversial topic. In the present study, we isolated MSC-like cells from human esophageal carcinoma (hEC-MSCs) and adjacent non-cancerous tissues (hECN-MSCs). Although the two types of MSC-like cells were in different microenvironments and had certain differences, they possessed similar morphological properties and surface antigens, including CD13, CD29, CD44 and CD105. Our results indicated that hEC-MSCs and hECN-MSCs are similar in a number of ways. This may have implications for further research on the esophageal carcinoma microenvironment and its pathological mechanism.
RESUMO
Human embryonic stem cells (hESCs) are usually maintained in an undifferentiated state by co-culture with feeder cells. The feeder cells are important for the growth of hESCs. A novel spontaneously immortalizated mouse fetal liver stromal cell line, named KM3, was isolated from a 13.5day mouse fetal liver. In this study, we examined whether KM3 cells could be used as feeders to support the growth of hESCs. hESCs cultured on KM3 cells showed a similar proliferation rate and characteristics to mouse embryonic fibroblasts (MEFs) after prolonged culture, including morphology, unlimited and undifferentiated proliferative ability, maintenance of normal karyotypes, formation of embryoid bodies in vitro and typically immature teratomas in vivo. Our results indicate that the immortalized KM3 cell line has the potential to support the growth and maintenance of hESCs. The cell line may be used for the large-scale expansion of hESCs in a low-cost and less labor-intensive manner.