Flt3 RECEPTOR EXPRESSION ON THE SURFACE OF MALIGNANT HEMATOPOIETIC CELLS AND RESPONSES TO Flt3 LIGAND STIMULATION
Abstract
Objective: To investigate the Flt3 receptor expression on the surface of malignant hematopoietic cells, the effect of TNFa and dexamethasone (DXM) on its expression and the responses of those cells to recombinant human Flt3 ligand (rhFL).
Methods: Eighteen malignant hematopoietic cell lines were determined for the Fit3 receptor expression by flow cytometric analysis. The effect of rhFL on the proliferation of malignant hematopoietic cells in vitro was measured using MTT assay.
Results: The expressions of Flt3 receptor on the surface of Raji, Daudi, HL-60, 8266 and XG-6 cells were detected by flow cytometric analysis. Following incubation with 20 ng/ml TNFa for 24h, the number of Flt3 receptor positive cells decreased in Raji and 8266, increased in HL-60 and XG-6, and no difference in Daudi cells. After incubation with 10 .6 mol/L DXM for 24h, the number of Flt3 receptor positive cells decreased in all the 5 Flt3 receptor positive cell lines, rhFL stimulated the proliferation of HL-60 and Raji cells.
Conclusion: For most of the malignant hematopoietic cells, there was neither the expression of Flt3 receptor nor the response to rhFL. DXM may be useful to reduce the effect of FL on the proliferation of some Flt3 receptor positive malignant hematopoietic cells in vitro and in vivo.
Methods: Eighteen malignant hematopoietic cell lines were determined for the Fit3 receptor expression by flow cytometric analysis. The effect of rhFL on the proliferation of malignant hematopoietic cells in vitro was measured using MTT assay.
Results: The expressions of Flt3 receptor on the surface of Raji, Daudi, HL-60, 8266 and XG-6 cells were detected by flow cytometric analysis. Following incubation with 20 ng/ml TNFa for 24h, the number of Flt3 receptor positive cells decreased in Raji and 8266, increased in HL-60 and XG-6, and no difference in Daudi cells. After incubation with 10 .6 mol/L DXM for 24h, the number of Flt3 receptor positive cells decreased in all the 5 Flt3 receptor positive cell lines, rhFL stimulated the proliferation of HL-60 and Raji cells.
Conclusion: For most of the malignant hematopoietic cells, there was neither the expression of Flt3 receptor nor the response to rhFL. DXM may be useful to reduce the effect of FL on the proliferation of some Flt3 receptor positive malignant hematopoietic cells in vitro and in vivo.