Comparison of Hematopoietic Stem Cell Activity in Normal Bone Marrow, in vivo G-CSF Stimulated Bone Marrow, and G-CSF-Mobilized Peripheral Blood / 대한수혈학회지

BACKGROUND: Classically, bone marrow (BM) has been the sole source of hematopoietic stem cell transplantation, but limitations of conventional bone marrow transplantation have stimulated a search for alternative sources of stem cells. METHODS: We compared hematopoietic stem cell activity of normal bone marrow (BM), in vivo G-CSF-stimulated bone marrow (G-CSF BM), and G-CSF-mobilized peripheral blood (G-CSF PB) by immunophenotyping, clonogeneicity, and long-term culture-initiating cell (LTC-IC) analysis. RESLUTS: The average numbers of CD34+/HLA-DR- cells after CD34+ cells isolation from each stem cell source were 59.64 +/- 8.70%, 91.39 +/- 1.98%, and 95.75 +/- 2.08% in normal BM, G-CSF BM, and G-CSF PB, respectively (normal BM vs. G-CSF BM, normal BM vs. G-CSF PB, p<0.0001). And the average numbers of CD34+/CD38- cells were 66.23 +/- 9.33%, 95.08+/- 2.09%, and 91.76 +/- 4.59% in normal BM, G-CSF BM, and G-CSF PB, respectively (normal BM vs. G-CSF BM, normal BM vs. G-CSF PB, p<0.0001). The numbers of CFU-GM was significantly higher in G-CSF PB (53.2 +/- 4.05) and G-CSF BM (52.5 +/- 3.63) than that of normal BM (31.3+/- 5.50) (p<0.0001). Also the numbers of CFU-GEMM and CFU-Mk were also significantly higher in G-CSF PB (110.3 +/- 8.79 and 13.3 +/- 1.49) and G-CSF BM (109.7 +/- 10.78 and 11.2 +/- 1.69) than that of normal BM (48.8 +/- 1.48 and 8.5 +/- 1.72) (p<0.05). Comparison of LTC-IC in the three sources of stem cells showed that G-CSF PB and G-CSF BM were superior to normal BM at five weeks of culture (p<0.05). CONCLUSIONS: These data suggest that the amount of both early progenitor cells and late progenitor cells in G-CSF PB and G-CSF BM are higher than that of normal BM. And our results further support that the higher stem cell transplantation using G-CSF-mobilized PB and in vivo G-CSF-stimulated BM can lead to more rapid and sustained engraftment even in cases of high risk of rejection.

Expression of Multidrug Resistant Genes in Bone Marrow Mononuclear Cells of Patients with Myeloid Leukemia / 대한암학회지

PURPOSE: Multidrug resistance mediated by several drug resistant genes impedes the successful outcome of anti-cancer chemotherapy. In this study, we investigated the expressions of drug resistant genes encoding multidrug resistance (MDR1), multidrug resistance-associated protein (MRP), topoisomerase I (Topo I), topoisomerase II g (Topo II a) in narmal volunteers (n=12) in and patients with myeloid leukemia (n=34). Material and Method: We compared the levels of their transcripts in bone matrow mononuclear cells by semiquantitative RT-PCR. The amount of specific transcripts was represented as the optical density ratio of PCR product of target gene to that of B2- microglobulin (MG). Twenty patients of acute myelogenous leukemia (eight in remission state, twelve in refractory) and fourteen patients of chronic myelogenous leukemia (nine in chronic phase and five in blastic crisis) were examined. Twelve normal healthy persons were compared with leukemic patients. RESULTS: The expression levels of all resistant genes in normal volunteers were relatively high as those of AML patients. Regardless of the disease status including remission status of AML (complete remission versus refractory) and the phase of CML (chronic phase versus blastic phase), the expression levels of all resistant genes in patients with CML were significantly lower than in the patients with AML (p < 0.05). Of interest, the patients with refractary AML did not show any statistical difference in comparison with normal controls and even the patients with AML in complete remission. Among the four drug resistant genes, the optical density ratio of MDRl was significantly lower than that of any other genes (p<0.05). Using HL-60 cell line, we compared the changes of various resistant gene expressions before and after differentiation induced by dimethylsulfoxide. The expressions of resistant genes declined in paralle1 with granulocytic differentiation, suggesting that the induction of cell differentiation might make leukemic cells susceptible to chemotherapeutic agents. CONCLUSION: It is impossibble to explain the mechanism of drug resistance by comparing the level of drug resistant gene expression between nonnal subjects and patients with myeloid leukemias. Therefore, we suppose that longitudinal study of drug resistant gene expression is necessary to demonstrate the development of drug resistant during chemotherapy.