ELIMINATION OF ADULT T-CELL LEUKEMIA-CELLS BY ULTRASOUND IN THE PRESENCE OF PORFIMER SODIUM

Sonodynamic effects using porfimer sodium (Photofrin(R); Pf) on leukem ic and normal cells were evaluated. The purpose of this experiment was to compare cell survival among MT-2 cells, normal peripheral mononucl ear cells (PMNCs) and adult T cell leukemia (ATL) patients' PMNCs afte r sonodynamic treatment. Cells were exposed to 450 kHz ultrasound at a n intensity of 500 mW/cm(2). The survival rate of MT-2 cells exposed t o ultrasound alone for 80 s was 20.1 +/- 4.8%, whereas survival rates exposed to ultrasound in combination with 25, 50 and 100 mu g/ml of Pf resulted in 11.5 +/- 2.9, 3.2 +/- 1.6 and 1.6 +/- 1.4%, respectively. There was a significant difference of cell survival between the group exposed to ultrasound alone and the Pf-combined groups (n = 6, p < 0. 05). On the other hand, in the normal human PMNCs, no significant diff erences of cell survival rates were found between ultrasound-treated g roups with and without Pf. We similarly examined the survival rate of PMNCs in the peripheral blood of five acute-type ATL patients (n = 5) after ultrasound (60s, 300 mW/cm(2)) exposure with or without 100 mu g /ml of Pf. Comparison of cell survival rate between ultrasound alone a nd ultrasound plus Pf showed significant differences (69.4 +/- 22.5 an d 30.0 +/- 23.0%, respectively). There were no significant cytotoxicit ies in all Pf alone treated groups of the MT-2 cells, the normal PMNCs and the ATL patients' PMNCs (p < 0.05). It was suggested from this st udy that there was a specific selectivity of sonodynamic effects to MT -2 cell lines and ATL patients' PMNCs. It is anticipated that this new method of treatment, i.e. sonodynamic therapy, could be used for extr acorporeal blood treatment of acute-type ATL patients.