ABSTRACT
BACKGROUND: There still is rarely report about the effect of glycosylphosphatidilinoditol-specific phospholipase D (GPI-PLD) on the adhesion function of leukemic cells through screening Medline and CNKI databases.OBJECTIVE: To observe the effect of GPI-PLD on the adhesion function of bone marrow mononuclear cells separated from myeloid leukemia patients, and to investigate the related mechanism. DESIGN, TIME AND SETTING: This study addressing cytology in vitro was conducted at the Hematological Laboratory of Xiangya Hospital from January to June 2004.MATERIALS: Bone marrow was collected from myeloid leukemia patients at the Department of Hematology, Xiangya Hospital, China.METHODS: The GPI-PLD activity of bone marrow mononuclear cells separated from myeloid leukemia patients was measured by using GPI-anchored placental alkaline phosphatase as substrate and Triton-X114 partition. By use of 1,10-phenanthroline, the activity of GPI-PLD was inhibited, the experiment was divided into 2 groups: treatment group adding phenanthroline to achieve a final concentration of 1 mmol/L, while control group adding the same amount of phosphate buffered saline. The adhesion rate to the fibronectin and CD24 expression of these cells were measured by MTT and immunohistochemical method, respectively.MAIN OUTCOME MEASURES: GPI-PLD activity of myeloid leukemic cells, cell adhesion rate, CD24 expression were all measured. RESULTS: The GPI-PLD activity of bone marrow mononuclear cells separated from myeloid leukemia patients was inhibited significantly after these cells were treated by 1 mmol/L 1,10-phenanthroline for 5 hours compared with control groups [(5.40±2.96)%, (42.08±7.21)%, P < 0.01]. At the same time, the adhesion rate of these cells were increased after the GPI-PLD activity was inhibited [(61.19±29.14)%, (49.78±26.73)%, P < 0.01], and the CD24 expression was also up-regulated [(18.5±11.14)%, (16.02±9.68), P < 0.01].CONCLUSION: The adhesion rate of bone marrow mononuclear cells separated from myeloid leukemia patients can be promoted by inhibiting GPI-PLD activity. At the same time, the CD24 expression of GPI-anchored proteins on bone marrow mononuclear cells is improved.
ABSTRACT
BACKGROUND: The correlation of gycosylphosphatidilinoditol-specific phospholipase D (GPI-PLD) activity, mRNA expression to leukemia type, hepatosplenomegaly and/or lymphadenopathy has been rarely reported. OBJECTIVE: To explore the correlation of GPI-PLD expression to leukemia type and hepatosplenomegaly and/or lymphadenopathy of acute myeloid leukemia (AML) patients. METHODS: Fresh bone marrow specimens were obtained from 43 newly diagnosed AML patients, 28 acute lymphocytic leukemia (ALL) patients, and 21 normal persons. Bone marrow mononuclear cells were harvested by density gradient centrifugation. GPI-anchored human placent alkaline phosphatase was used as substrate. GPI-PLD activity was determined bytriton-X114 phase partitioning procedure. GPI-PLD mRNA expression was detected by semi-quantitative RT-PCR. The relationship of GPI-PLD activity, mRNA expression and leukemia type, hepatosplenomegaly and/or lymphadenopathy was analyzed. RESULTS AND CONCLUSION: Compared with control group, GPI-PLD activity and mRNA expression in bone marrow mononuclear cells were significantly higher in AML group (P < 0.01), while they were significantly lower in the ALL group (P < 0.01). Of 43 patients with AML patients, 13 patients had hepatosplenomegaly and/or lymphadenopathy. The GPI-PLD activity (%) and mRNA expression were significantly higher in AML patients without hepatosplenomegaly and lymphadenopathy than those patients with hepatosplenomegaly and/or lymphadenopathy (P < 0.05). These results demonstrated that GPI-PLD activity alteration is consistent with GPI-PLD mRNA expression in AML patients, and the expression levels correlate to leukemia type and hepatosplenomegaly and/or lymphadenopathy of AML patients.
ABSTRACT
ly reduces the expression of αⅡbβ3 complex on the membrane. This mutation may interfere the formation of αⅡbβ3 complex or impair the proper conformation of αⅡb subunit.