Long-term proliferation of human leukemia cells induced by mouse stroma.

Acute lymphocytic leukemias (ALL) of infants and children were found to preferentially survive in coculture with a cloned cell line of endothelial adipose cells (14F1.1) from mouse bone marrow. One of these ALLs expressed a phenotype compatible with an early stage of differentiation (HLA-DR+, CD19+, and CD34+) and exhibited extensive growth in the presence of the mouse stromal cells during a period greater than 25 weeks following seeding.