Knock-down of PRAME and increased sensitivity for retinoic acid.

<p>A) Expression of PRAME was analyzed in HL cell line L-428 by qRT-PCR. The control cells were transfected with the empty vector, whereas the other cells were transfected with a vector allowing suppression of PRAME by RNA interference. Presented are means and standard errors from six/eleven determinations. For comparative analysis, the mean of L-428 cells with the empty vector was set as 1. B) Cells of the HL cell line L-428 with empty vector, L-428 cells after knock-down of PRAME, and the HL cell line L-540 were incubated with 2.5×10⁻⁴ M ATRA or DMSO. After four days the viability was assessed by propidium iodide staining. The number of living cells in the samples with DMSO was set as 100%. Presented are means and standard errors from triplicate determinations. Asterisks indicate significance (p<0.05; Students t test).