The effect of direct intratumoral injection of the DTA-H19 plasmid on subcutaneous ovarian tumor growth in nude mice. 24 mice were injected with the ES-2 cells. Starting on day 10, 12 mice received 4 injections of 25 μg of DTA-H19 plasmid and the other 12 mice received 4 injections of 25 μg of Luc-H19 plasmid complexed with PEI. Injections were given with two-day intervals. One day after the last treatment, animals were sacrificed. The tumor dimensions were measured in situ prior to the treatment with the plasmid and after sacrifice. The effect of treatments with DTA-H19 or Luc-H19 plasmids on tumor volumes (cm3) over time (days) is indicated (A), while day 0 represents the first treatment given. The mean fold increase of the final volume was compared to the initial volume in the DTA-H19 and Luc-H19 treated tumors (B).