Objective: To investigate the significance of the adhesion of CD(34)(+) stem/progenitor cells to fibronectin in the pathogenesis of chronic myelogenous leukemia (CML).
Methods: (1) Integrin beta(1) chain (CD(29)) and alpha(4) chain (CD(49d)) expressions on CD(34)(+) cells were measured by flow cytometry in 30 untreated CML patients in chronic phase (CML-CP) and 10 healthy donors. (2) The adhesion function of immunomagnetic beads selected CD(34)(+) cells to fibronectin was detected by crystal violet staining in 5 untreated CML-CP patients and 5 healthy donors. (3) The effect of fibronectin on CFU-GM colony formation of bone marrow cells in 3 CML patients and 3 healthy donors was observed by limited dilution liquid microculture.
Results: (1) There was no significant difference in CD(29) and CD(49d) expressions on CD(34)(+) bone marrow cells between CML patients and healthy donors. (2) The adhesion of CD(34)(+) bone marrow cells to fibronectin decreased significantly in CML patients as compared with that in healthy donors (P < 0.01). (3) The CFU-GM colony formation was significantly inhibited by fibronectin in healthy donors (P < 0.01), but not in CML patients.
Conclusion: The adhesion function abnormality of CML CD(34)(+) bone marrow cells to fibronectin may underlie the abnormal proliferation of CML progenitors.