ST antigen mRNA level increases significantly following UV radiation.

<p><b>A</b>, Relative quantification of small t antigen (STA) and interleukin 6 (IL6) transcripts by RT-QPCR after a pre-amplification step, using total RNA from patient P18 skin samples, after 2J and 4 J/cm² SSR <i>in vivo</i> irradiation, and in control samples. Each histogram bar represents the mean value obtained from six independent QPCR reactions. The Y-axis represents the absolute value of the “delta-delta-Ct” (threshold cycle). Data were normalized relative to <i>HPRT</i> mRNA levels. The p-value was calculated using student test. <b>B</b>, Relative luciferase activity in HaCaT cells transfected either with control pGL3-basic vector or with pGL3-Mrkl-prom plasmid, and irradiated with 50 mJ/cm² UVB or not. Each histogram bar represents the mean value obtained from two independent experiments and six replicates for each condition. Raw data of luciferase assays were normalized relative to the samples protein amounts. The p-value was calculated using student test.