Erythropoietin increases nuclear DNA binding activity of MTF-1 transcription factor. Electrophoretic mobility shift assay (EMSA) on nuclear extracts from the SK-N-MC Ewing sarcoma cell line, which expresses both PlGF and a functional erythropoietin receptor, using a radiolabeled oligonucleotide probe containing MTF-1 response elements. The blot shows increased nuclear DNA binding of MTF-1 to the probe within 15 minutes (lane 3), with a maximal binding at 30 minutes (lane 4). The response is abrogated with excess cold (nonradiolabeled) oligonucleotide MTF-1 probe (lane 5).