AUTOSTIMULATION OF GROWTH BY HUMAN MYELOGENOUS LEUKEMIA-CELLS (HL-60)

Google Scholar
  • 1 January 1981
    • journal article
    • research article
    • Vol. 58  (4) , 803-812
Abstract
The effects of medium conditioned by the human progranulocytic leukemia cell line HL-60 on the subsequent growth of new inocula of HL-60 cells were studied. When HL-60 cells were cultured at high cell density, optimal growth rate occurred in liquid suspension and confluent colony growth was observed in viscous medium without the addition of conditioned medium. When cells were cultured at lower cell density, growth rate was reduced and colony growth was nil unless conditioned medium from HL-60 culture was added. All HL-60 populations studied, including 9, the earliest available passage, elaborated and responded to HL-60 CM. HL-60 CM did not stimulate normal human or mouse granulocyte-monocyte colony-forming cell (CFU-GM) growth. Conditioned media from other human cell lines varied in the ability to stimulate HL-60 cell and CFU-GM proliferation. Some, such as GCT CM, stimulated HL-60 cells and normal CFU-GM, whereas others, like HL-60 CM, stimulated only HL-60 growth. The majority of cell line CM tested did not stimulate either HL-60 or CFU-GM. Chromatography of HL-60 CM on Ultrogel AcA54 showed a single peak of HL-60 stimulating activity of apparent MW 13,000. The ability of HL-60 cells to elaborate this activity provides a possible explanation for their proliferation at higher cell densities. Autostimulation may be important in the high growth potential of other cell populations that undergo unrepressed proliferation.