Fig. 1.

Cdx2 expression is not sustained in normal EPC-hTERT keratinocytes. Human EPC-hTERT keratinocytes were infected with a retroviral vector to induce Cdx2 expression (MIGR-Cdx2) or the control empty viral vector MIGR1. GFP serves as a marker for viral infection and gene expression. (A) Fluorescent image for GFP⁺ cells overlaid with phase contrast image. At 72 h, nearly equivalent numbers of GFP⁺ cells with both vectors. After 10 days in culture, repeat images demonstrate highly significant reduction in GFP⁺ expression in those cells infected with the MIGR-Cdx2 virus. (B) The number of GFP⁺ cells per total cells in six high power fields (HPFs) was determined on days 2, 3, 5, 7, 8 and 10 post-retroviral infection. Averages and standard deviations were calculated and graphed. Black circle, EPC-hTERT.MIGR. Black square, EPC-hTERT.Cdx2. a, significantly differs from MIGR same day controls using analysis of variance and Tukey Rank Mean testing, P < 0.005. b, significantly differs from day 2 MIGR controls, P < 0.005.