Elimination of leukemic cells by laser photodynamic therapy.
We studied the effects of 514-nm laser light-induced merocyanine 540 (MC540)-mediated toxicity on both leukemic and normal bone marrow (BM) cells. Acute promyelocytic leukemia (HL-60) cells were incubated with MC540 (20 micrograms/ml) and exposed to 93.6 J/cm2 irradiation at a 514-nm wavelength. Normal bone marrow cells were treated under similar conditions. At this dose, 99.9999% of the leukemic cells were killed while 55% of the BM cell survived. Of the granulocyte-macrophage colony-forming cells (CFU-GM), 27% also survived this treatment. Photosensitization of a mixture of irradiated BM cells mixed with an equal number of nonirradiated HL-60 cell did not interfere with the killing of HL-60 cells. There was no significant reduction in the viability of cells when exposed to the laser light alone. In summary, laser light-induced photosensitization with MC540 has a selective cytotoxicity to leukemic cells; therefore, this procedure may be useful for purging neoplastic cells from autologous BM.
Gulliya
K S
KS
Baylor Research Foundation, Baylor University Medical Center, Dallas, TX 75246.
Fay
J W
JW
Dowben
R M
RM
Berkholder
S
S
Matthews
J L
JL
D001853:Bone Marrow / Q000187:drug effects / Q000528:radiation effects; D001854:Bone Marrow Cells; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003114:Colony-Forming Units Assay; D004307:Dose-Response Relationship, Radiation; D006098:Granulocytes / Q000166:cytology; D006801:Humans; D053685:Laser Therapy; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy*; D008264:Macrophages / Q000166:cytology; D010778:Photochemotherapy / Q000379:methods*; D011744:Pyrimidinones / Q000627:therapeutic use; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use; D013234:Stem Cells / Q000187:drug effects / Q000528:radiation effects; D014407:Tumor Cells, Cultured
D011744:Pyrimidinones; D011838:Radiation-Sensitizing Agents; C003954:merocyanine dye