Introduction of exogeneous STAT1 increases RT resistance in RCC cells lacking endogeneous STAT1 expression.

<p><i>A,</i> Exogenous STAT1 expression after transfection with a vector carrying GFP or eGFP-fused full-length STAT1 cDNA in Caki-1 cells. Cells efficiently expressed exogenous STAT1 at 48 h after transfection. <i>B,</i> introduction of exogenous STAT1 increases RT resistance in Caki-1 cells. Cells transfected with vectors carrying GFP or eGFP-STAT1 cDNA were irradiated at indicated doses 48 h after transfection. Fourteen days after plating the cells, plating efficiency (upper panel) and survival fraction (lower panel) were calculated by means of clonogenic cell survival assay. Data represent mean ± SD from two independent experiments.