INTERACTION BETWEEN A MURINE MYELOMA CELL-LINE AND BONE-MARROW STROMAL CELLS

Intravenous transplantation of an in vitro maintained murine myeloma c ell line, 5T33, results in progressive growth in the bone marrow of C5 7Bl/KaLwRiJ mice. Concurrent with the growth of the tumor in vivo, the bone marrow stromal cells are inhibited, as assayed by their ability to form stromal cell foci and long-term monolayers in vitro. Inhibitio n of normal mouse marrow stromal cell growth also occurs when 5T33 cel ls are added to the marrow cells in vitro, and contact between the mar row and 5T33 cells is not necessary to achieve inhibition, indicating secretion of one or more diffusible inhibitory factors.