HEPATOCYTE GROWTH-FACTOR LEVELS IN BONE-MARROW PLASMA OF PATIENTS WITH LEUKEMIA AND ITS GENE-EXPRESSION IN LEUKEMIC BLAST CELLS

Hepatocyte growth factor (HGF) has been known as a multiple function f actor, which also stimulates early haematopoiesis. In this study, we f ound that HGF was expressed at both the RNA and protein levels in acut e myeloid leukaemia (AML) and chronic myeloid leukaemia (CML). In pati ents with AML (n = 20) and CML (n = 5), bone marrow plasma HGF concent rations were 20.44 +/- 6.26 (mean +/- s.e.) ng ml(-1) and 7.17 +/- 0.5 3 ng ml-(1) respectively. These were significantly higher (P<0.01) tha n the value for normal subjects (n = 26): mean 0.92 +/- 0.09 ng ml(-1) . Constitutive HGF production was observed in freshly prepared leukaem ic blast cells from three patients with high HGF levels of bone marrow plasma. Expression of HGF mRNA was correlated with bone marrow plasma HGF levels. After complete remission was obtained in six patients, bo ne marrow plasma HGF levels were significantly decreased. In contrast, the HGF mRNA was less abundantly expressed in acute lymphoid leukaemi a (ALL). In patients with ALL (n = 5), bone marrow plasma HGF concentr ation (0.69 +/- 0.14 ng ml(-1)) remained low within the value for norm al subjects. These results suggest that some populations of myeloid li neage cells have the ability to produce HGF.