| Abstrakt: |
Numerous human embryonic stem cell lines with different genetic background are widely used as cell models for fundamental, biomedical and pharmacological research. New hES cell lines SC5, SC6, SC7, and SC3a are derived from the blastocysts and maintained on mitotically inactivated human feeder cells. All derived hES cell lines passed through more than 120 cell population doublings, retained normal diploid karyotype and ability of in vitro differentiation in the derivates of three germ layers. These lines express the markers of undifferentiated hES cells: Oct-4, Nanog, SSEA-4, TRA-1-60, and alkaline phosphatase. Moreover, undifferentiated cells of SC5, SC6, and SC7 lines expressed germ line specific genes DPPA3/STELLA and DAZL and did not express somatic lineages specific genes. In contrast, undifferentiated cells of SC3a line did not express DPPA3/STELLA and DAZL but expressed extra embryonic endoderm cell markers GATA4 and AFP. Double staining of SC5 and SC3a colonies by antibodies against transcription factors Oct-4 and GATA4 has demonstrated that most SC3a cells in colonies were positive for both factors. Furthermore, the cells of SC5, SC6, SC7 lines but not of SC3a line formed teratomas containing the derivates of the three germ layers. These results indicate that, in contrast to the other cell lines, the cells in the SC3a colonies represent an early committed cell population. Moreover, expression of the multidrug resistance transporter gene ABCG2 was detected in undifferentiated cells and differentiating embryonic bodies during 10 days of all lines by immunofluorescent and RT-PCR analyses, whereas RT-PCR analysis has revealed up-regulation of the ABCB1 transporter gene expression in differentiating embryoid bodies of SC5, SC6, and SC7 cells only. Thus, these findings demonstrate different characteristics and differentiation potential of SC5, SC6, SC7, and SC3a hES cell lines which were derived in different conditions. |
