Preferential suppression of low molecular weight natural tumor suppressor of human fetal liver origin on the growth of leukemic cells in vitro.

A natural tumor suppressor of human fetal liver origin with low molecular weight (LMW-NTS) was studied. The methanol extract of human fetal liver supernatant (FLS-MeOH), a crude preparation of LMW-NTS, showed preferential suppression on the growth of leukemic cell lines HL-60, L833, WEHI-3, and L1210, but less effect on the growth of normal bone marrow granulocyte-macrophage colony-forming units (CFU-GM) in vitro. Preliminary experiments showed that FLS-MeOH also exhibited preferential suppression on the growth of leukemic colony-forming units (L-CFU) from six patients suffering from acute myeloid leukemia (AML). In combination with a long-term in vitro liquid culture system, FLS-MeOH could be adopted as an effective purging agent in the autologous bone marrow transplantation treatment of myeloid leukemia.