title: Newer options for treating drug-resistant (MDR+) cancer cells using photoradiation therapy.
abstract: Emergence of drug resistance with conventional cytotoxic therapy is a major challenge towards the curability of many cancers, especially in patients undergoing autologous BMT with ex-vivo purged hematopoietic support. We have explored the potential role of photoradiation therapy in purging hematopoietic stem cells of various hematological malignancies. Benzoporphyrin derivative, monoacid ring A (BPD-MA), dihematoporphyrin ether (DHE), and MC-540 were evaluated for the "ex-vivo" purging of residual tumor cells from autologous bone marrow (BM) grafts. BPD-MA and DHE photosensitizing activity was tested against two human large cell lymphoma cell lines and colony forming-unit leukemia (CFU-L) derived from patients with acute myelogenous leukemia (AML). In mixing experiments four log elimination of tumor cell lines was observed after 1 hr of incubation with BPD-MA or DHE followed by white light exposure. By comparison, using the same concentration of BPD-MA or DHE, the mean recovery of normal BM progenitors was 4-5.2% for granulocyte-macrophage colony forming unit (CFU-GM) and 5-9.8% for burst forming unit erythroid (BFU-E). The T lymphoblastic leukemia cell line CEM and its vinblastine (VBL)-resistant subline CEM/VBL100, along with the acute promyelocyte leukemia cell line HL-60 and its vincristine (VCR)-resistant subline HL-60/VCR, were also tested. Our results demonstrated the preferential cytotoxicity of BPD-MA and DHE toward neoplastic cell lines and CFU-L from AML patients. In addition, DHE was slightly more effective in purging tumor cells expressing the p-170 glycoprotein.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine-MSKCC, New York, New York 10021.
authors.forename: S C
authors.initials: SC
authors.lastname: Gulati
authors.forename: R M
authors.initials: RM
authors.lastname: Lemoli
authors.forename: T
authors.initials: T
authors.lastname: Igarashi
authors.forename: J
authors.initials: J
authors.lastname: Atzpodien
mesh_terms: D016465:Bone Marrow Purging; D016026:Bone Marrow Transplantation; D004351:Drug Resistance; D006412:Hematopoietic Stem Cells; D006801:Humans; D007938:Leukemia / Q000628:therapy*; D008223:Lymphoma / Q000628:therapy*; D010789:Phototherapy; D014407:Tumor Cells, Cultured