Microarray RNA/DNA in different stem cell lines.

Stem cells represent the key to tissue genesis, regeneration, and turnover. This notion has spawned the concept of regenerative medicine, or stem cell based therapies to supplement degenerating or damaged tissues. However, stem cells may also represent a preferential target of carcinogens. The unique ability of stem cells to self-renew and to differentiate into multiple phenotypes implies that all stem cells share a common transcriptional signature. A better knowledge of the stem cell transcriptome appears to be fundamental to fully achieve the potential of regenerative medicine, and may lead to new strategies for cancer prevention and treatment. Elucidation of the transcriptional programming and molecular mechanisms which direct stem cell self-renewal, differentiation, and tumorigenesis should provide key insights into deciphering exactly how "stemness" is maintained, as well as the molecular basis of cell plasticity and cancer development. cDNA and oligonucleotide microarrays are the most accessible transcriptome profiling methods to date, providing the unique opportunity to compare global gene expression patterns among different cell populations. Microarray technologies have been applied to three major areas of stem cell research: maintenance of pluripotency, development of uniform and regulated differentiation, and microenvironment analyses. The aim of the present review is to summarize state-of-the-art transcriptional profiling of different stem cell lines, cancer stem cells, and the niches these cells occupy in vivo.