Photochemotherapy of myelogenous and non-myelogenous tumor cells Available to Purchase

Dye mediated laser photoradiation therapy was tested in an in vitro model for its efficacy to eliminate occult tumor cells for ex vivo autologous bone marrow purging. Merocyanine 540 was mixed with leukemia, lymphoma, small cell lung carcinoma, and multiple myeloma cells supplemented with 0.25% human albumin. This cell-dye mixture was exposed to 514 nm laser light. Results show that >5 log reduction in the clonogenic tumor stem cells was obtained with this procedure. Under identical conditions, 80% of the normal bone marrow cells and 41% of the granulocyte-macrophage colony forming cells were preserved. At least 25% of the stromal cells also survived. The nonspecific cytotoxicity of laser light to normal cells was <10%. These survival rates of normal cells coupled with >5 log killing of tumor cells have not been reported by existing chemotherapy treatment. Therefore, laser photoradiation therapy could be a method of choice for the elimination of contaminating tumor cells from autologous marrow grafts.