Purging murine leukemic marrow with alkyl-lysophospholipids

Area of Science:

• Hematology
• Oncology
• Pharmacology

Background:

• Autologous bone marrow transplantation (BMT) offers a potential cure for acute leukemia.
• Eliminating residual leukemic cells from bone marrow before BMT is crucial for treatment success.

Purpose of the Study:

• To evaluate the efficacy of a synthetic alkyl-lysophospholipid (ALP), ET-18-OCH3, in purging leukemic cells from bone marrow.
• To assess the impact of ALP treatment on the survival and hematologic reconstitution of mice undergoing BMT.

Main Methods:

• In vitro treatment of simulated remission bone marrow containing 2% leukemic cells (WEHI-3B myelomonocytic leukemia) with varying concentrations of ET-18-OCH3.
• Transplantation of treated bone marrow into lethally irradiated BALB/c mice.
• Survival analysis and post-mortem examination of transplanted recipients.
• Spleen colony assay to evaluate the effect of ALP on normal hematopoietic stem cells.

Main Results:

• In vitro treatment with 20 and 100 micrograms/mL of ET-18-OCH3 significantly prolonged the survival of transplanted mice.
• At 100 micrograms/mL, 88% of mice survived for approximately five months.
• Microscopic examination revealed leukemia in 25% of the survivors.
• A spleen colony assay indicated that ALP exhibits some cytotoxicity towards normal hematopoietic stem cells.

Conclusions:

• In vitro treatment with ET-18-OCH3 can effectively eliminate leukemic blasts from bone marrow.
• The treatment spares sufficient normal hematopoietic stem cells to enable hematologic reconstitution post-transplantation.
• While effective against leukemia, ET-18-OCH3 lacks complete selectivity, impacting normal stem cells to some extent.