Dr. J. Christopher States, Director of the NIEHS Environmental Health Sciences Core Center at the University of Louisville will present "miRNA Dysegulation and Chromosomal Instability in Arsenic-Induced Skin Cancer" during our March Zoominar. Chronic arsenic exposure, mostly via contaminated drinking water is a worldwide health problem affecting more than 200 million people. It causes a variety of chronic diseases, including cardiovascular disease, diabetes and cancer. Skin is the major target organ and arsenic exposure is the second leading cause of skin cancer.

Arsenic does not cause point mutations like most chemical carcinogens, but is clastogenic causing DNA breaks and chromosomal instability. miRNAs are small regulatory RNAs that play a major role in post-transcriptional modulation of protein expression.

The laboratory has shown differential miRNA profiles in arsenic-induced squamous and basal cell carcinomas and premalignant hyperkeratosis. hsa-miR-186 is overexpressed in some squamous cell carcinomas relative to premalignant hyperkeratoses, and is known to target regulators of mitosis. The linkage between overexpression of hsa-miR-186 and chromosomal instability will be discussed.