AGTI staff assist NIEHS team to characterize adult stem cells in mouse skin and their potential roles in tumor formation. (December 2007)

Skin and hair undergo constant growth and renewal. A niche population of adult stem cells in the skin, which are dormant during normal skin renewal, are mobilized to repair and regenerate the skin upon wounding, e.g. from abrasion of the skin. These stem cells are believed to be the origin of some skin cancers when inappropriately activated through exposure to carcinogens.

Scientists from the Cancer Biology Group at the National Institute for Environmental health Sciences (NIEHS) have used a cell surface marker to isolate the adult stem cells from mouse skin, and studied their distinct characteristics and the mechanism of tumorigenesis, using a variety of techniques, including high-throughput DNA microarrays. Dr. Hong Dang, senior bioinformatician at Alpha-Gamma Technologies, Inc. played a key role in the efforts, through genomic consultation and bioinformatic data analysis, particularly on microarray data. In a December, 2007 publication in the Journal of Investigative Dermatology (http://www.nature.com/jid/journal/vaop/ncurrent/abs/5700917a.html), we reported the most comprehensive gene expression profiles to date, of the skin adult stem cells using DNA microarrays that contain ~22,000 mouse genes. These data yielded ~2,000 genes differentially modulated in the stem cells compared to the surrounding skin. Bioinformatics analyses of the ~2,000 genes confirmed our prior knowledge about the adult skin stem cells, highlighted the unique characteristics compared to other stem cells, suggested potential mechanism of tumor formation, and raised many new questions and novel gene expression patterns.

We are conducting further studies to follow up on the leads generated by the microarray data analysis to further understand the critical roles played by these stem cells in tumor formation, which could yield targets for novel cancer therapy in the future.