THE EFFECT OF FIBRONECTIN ON HEMATOPOIESI S IN LONG-TERM CULTURES OF BONE-MARROW FROM PATIENTS WITH ACUTE MYELOID-LEUKEMIA IN REMISSION

Hemopoietic effects in bone marrow long-term cultures (BMLTC) of healt hy subjects and patients with acute myeloid leukemia (AML) in remissio n were studied due to fibronectin (FN) and glycoprotein of extracellul ar matrix of stromal microenvironment. Twelve AML patients and 6 healt hy donors of allogenic transplant were examined. Blood formation in th e BMLTC was assessed by weekly production of cells in nonadhesive BMLT C fraction and the content of granulocytic-macrophagal colony-forming cells in it. The response of hemopoietic stroma on FN sublayer was eva luated by weekly measurements of BMLTC adhesive layer cellularity. FN is demonstrated to stimulate the growth of BMLTC adhesive cell sublaye r, the cellularity increase being the same in the above groups. FN sub layer had no influence on cellularity of the nonadhesive fraction and on the number of granulocytic-macrophagal colony-forming cells in heal thy subjects, whereas it increased these values in AML patients in rem ission. This rise, however, was not significant. BMLTC is capable of d efining a favorable effect of FN sublayer on hemopoiesis in AML patien ts in remission. This effect may arise from higher quality of the subl ayer and survival of cells-precursors at initial stages of the cultiva tion.