Ts1Rhr mice demonstrate increased proliferation and TPA-induced hyperkeratosis <i>in vivo</i> and <i>in vitro</i>.

<p>(A) The average tumor size (mm) ± S.E. was plotted versus time in WT and Ts groups. * T-test, p<0.05. (B) Tumors showed increased relative growth rate in Ts compared to WT (*p<0.028). (C) H&E stain of WT and Ts skin without TPA treatment (WT-NT and Ts-NT). H&E stain of TPA-treated skin (WT-TPA and Ts-TPA). (D) There is no difference in thickness of the epidermis between WT (n = 12) and Ts (n = 14) without TPA treatment (NT group). The epidermis of Ts (n = 14) is significantly thicker than that of WT (n = 16) (*P = 0.023, T-test). (E) EdU staining of keratinocytes +/- TPA treatment. (F) Quantitation of cells in (2E) showed significantly more EdU positive cells in Ts cultures following TPA treatment (*p = 0.043, T-test). NT, no TPA treatment; TPA, treatment with TPA (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0146570#sec002" target="_blank">Methods</a>).