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BioMed Research International
Volume 2013 (2013), Article ID 908797, 3 pages
http://dx.doi.org/10.1155/2013/908797
Research Article

Role of Melanin in Melanocyte Dysregulation of Reactive Oxygen Species

1Oncological Sciences, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA
2Department of Dermatology, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA
3Department of Dermatology, Huntsman Cancer Institute, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA

Received 3 December 2012; Accepted 25 January 2013

Academic Editor: Norma Possa Marroni

Copyright © 2013 Noah C. Jenkins and Douglas Grossman. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We have recently reported a potential alternative tumor suppressor function for p16 relating to its capacity to regulate oxidative stress and observed that oxidative dysregulation in p16-depleted cells was most profound in melanocytes, compared to keratinocytes or fibroblasts. Moreover, in the absence of p16 depletion or exogenous oxidative insult, melanocytes exhibited significantly higher basal levels of reactive oxygen species (ROS) than these other epidermal cell types. Given the role of oxidative stress in melanoma development, we speculated that this increased susceptibility of melanocytes to oxidative stress (and greater reliance on p16 for suppression of ROS) may explain why genetic compromise of p16 is more commonly associated with predisposition to melanoma rather than other cancers. Here we show that the presence of melanin accounts for this differential oxidative stress in normal and p16-depleted melanocytes. Thus the presence of melanin in the skin appears to be a double-edged sword: it protects melanocytes as well as neighboring keratinocytes in the skin through its capacity to absorb UV radiation, but its synthesis in melanocytes results in higher levels of intracellular ROS that may increase melanoma susceptibility.