Stem cell-ness and stem cell differentiation: expression profiling of genes involved in the control of pluripotency using cDNA microarray

초록

Stem cells are unique cell populations with the ability to undergo both self-renewal and differentiation simultaneously. A wide variety of adult mammalian tissues harbors stem cells, yet "adult" stem cells may be capable of reconstituting only a limited number of cell types. In contrast, embryonic stem (ES) cells, derived from blastocyst-stage of early mammalian embryos, are capable of differentiating into any fully differentiated somatic as well as germ cell lineages (namely pluripotency) when conjoined with blastomeres of early mouse embryos. To our surprise, adult stem cells have recently reported to have potential to trans-differentiate into other tissue stem cells under specific internal environments (namely stem cell plasticity). Yet, neither the detailed molecular mechanisms underlying nor fate signaling genes involved in stem cell-ness and plasticity are not known. To identify genes implicated in the control of pluripotency as well as characteristics of each stem cells, we analyzed expression profiles of genes derived from mouse morulas, blastocysts, ES cells, mesenchymal stem cells, and uterus tissues using cDNA microarray. Comparative analyses of their expression profiles identified putative clones implicated in the control of pluripotency (stem cell-ness) as well as characteristics of each stem cell. The expression patterns of these candidate clones were analyzed using RT-PCR and non-radioactive in situ hybridizaion. Functional annotation of these clones on pluripotency and stem cell plasticity is in an underway. These studies may further our understanding on the nature of the stem cells and molecular mechanisms underlying many facets of mammalian development and differentiation.