Objective To establish a flow cytometric measurement of detecting minimal residual disease(MRD) according to the leukemia-associated immunophenotypes in children with acute lymphoblastic leukemia(ALL) and to explore the significance of MRD detection in ALL children for a individualized treatment. Methods A variety of four-color fluorescent antibody combinations were used to investigate the children's normal bone marrow. The normal bone marrow pattern at two-parameter plots was established to identify the residual tumor cells, seventy-five bone marrow samples from newly diagnosed ALL children were analyzed with four-color cytometry to determined the optimal combinations which can clearly distinguish the tumor cells from normal cells. The bone marrow samples were monitored with the combination panel in 60 patients at the end of induction therapy and follow-up treatment. Cytomorphology test, PCR amplification of 29 fusion genes as well as IgG and TCR gene rearrangements were performed simultaneously. Results Sixty-nine cases (92.0%) could be identified for effective antibody combinations to monitor MRD by four-color cytometry. Fusion genes or IgG and T cell receptor (TCR) gene rearrangements can be detected in 21 cases (28.0%) to monitor MRD by PCR. No MRD can be detected in 25 bone marrow samples at the end of induction therapy and follow-up treatment. Four-color cytometry could detect as low as 0.021%-4.130% residual leukemia cells. Conclusion MRD can be monitored by flow cytometry which is faster than PCR, and the sensitivity is superior to morphology method.

PURPOSE: Several signaling pathways have been shown to regulate the lineage commitment and terminal differentiation of bone marrow stromal cells (BMSCs). Bone morphogenetic protein (BMP) signaling has important effects on the process of skeletogenesis. In the present study, we tested the role of bone morphogenetic protein receptor (BMPR) in the osteogenic differentiation of rat bone marrow stromal cells in osteogenic medium (OM) with or without BMP-2. MATERIALS AND METHODS: BMSCs were harvested from rats and cultured in OM containing dexamethasone, beta-glycerophosphate, and ascorbic acid, with or without BMP-2 in order to induce osteogenic differentiation. The alkaline phosphatase (ALP) activity assay and von kossa staining were used to assess the osteogenic differentiation of the BMSCs. BMPR mRNA expression was assessed using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The BMSCs that underwent osteogenic differentiation in OM showed a higher level of ALP activity and matrix mineralization. BMP-2 alone induced a low level of ALP activity and matrix mineralization in BMSCs, but enhanced the osteogenic differentiation of BMSCs when combined with OM. The OM significantly induced the expression of type IA receptor of BMPR (BMPRIA) and type II receptor of BMPR (BMPRII) in BMSCs after three days of stimulation, while BMP-2 significantly induced BMPRIA and BMPRII in BMSCs after nine or six days of stimulation, respectively. CONCLUSION: BMSCs commit to osteoblastic differentiation in OM, which is enhanced by BMP-2. In addition, BMP signaling through BMPRIA and BMPRII regulates the osteogenic differentiation of rat BMSCs in OM with or without BMP-2.
Alkaline Phosphatase/metabolism ; Animals ; Bone Marrow Cells/*cytology/drug effects/*metabolism ; Bone Morphogenetic Protein 2/pharmacology ; Bone Morphogenetic Protein Receptors/genetics/*metabolism ; *Cell Differentiation/drug effects ; Cell Proliferation/drug effects ; Cells, Cultured ; Culture Media/pharmacology ; Male ; Osteogenesis/drug effects/genetics ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Stromal Cells/*cytology/drug effects/*metabolism