Normal human marrow stromal cells induce clonal growth of human malignant T-lymphoblasts.

The effect of marrow stromal cells (MSC) on the clonal growth of a human malignant T-lymphoblast (MTL) cell line was investigated in a bilayer culture system. The MSC consistently stimulated clonal growth of MTL, and no stimulatory humoral factor was present in the medium conditioned by the MSC. These observations and other reports suggest that marrow stromal cells may provide a microenvironment in vivo that is not only conducive to the growth of malignant lymphoblasts, but may actually enhance proliferation of malignant T-lymphoblasts in the bone marrow.