Effect and mechanism of glycosylphosphatidilinoditol- specific phospholipase D on the adhesion function of bone marrow mononuclear cells separated from myeloid leukemia patients

Guangfen XIAO; Fangping CHEN; Bin FU; Guangping WANG; Zaifu JIAN

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.