[Effect of platelet factor 4 on the adhesive property of leukemic CD34+ KG1a cell].
OBJECTIVE
To study the effect of PF4 on the adherence of leukemic CD34+ KG1a cell to human umbilical vein endothelial cell line ECV-304 cell and on the expression of adhesive molecules.


METHODS
Adhesion assay and adhesion blocking assay were respectively applied to measure the effect of PF4 and/or adhesion molecule monoclonal antibodies on the adhesion property of KG1a. The expressions of adhesion molecules were determined by RT-PCR and FACS analysis.


RESULTS
The adhesion of KG1a cells to ECV-304 was significantly enhanced in the presence of PF4. Such enhancement was also observed when KG1a or ECV-304 cells were separately treated with PF4 before interaction. The adhesion capacity of KG1a cells was reduced when cells were co-incubated with the blocking monoclonal antibodies (MoAbs) against CD49d, CD106, CD54, respectively. In contrast, MoAbs against CD62L, CD62P and CD62E had no such effect. During a period of 3 hours when KG1a or ECV-304 cells were respectively incubated with PF4, the mRNA expressions of CD49 d, CD54 were up-regulated. Furthermore, when KG1a or ECV-304 cells were incubated with PF4 for 2 hours, respectively, the percentages of CD49d+ KG1a cells and CD54+ ECV-304 were increased significantly.


CONCLUSIONS
PF4 can enhance KG1a cell adhesive capacity by increasing the expressions of adhesion molecules.
Zhang
Jing
J
State Key Laboratory of Experimental Hematology, Institute of Hematology, CAMS, PUMC, Tianjin 300020, China.
Ma
Yue-xia
YX
Han
Zhong-chao
ZC
D018952:Antigens, CD34 / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000378:metabolism; D045744:Cell Line, Tumor; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000276:immunology / Q000473:pathology*; D010978:Platelet Factor 4 / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology*
D018952:Antigens, CD34; D015815:Cell Adhesion Molecules; D010978:Platelet Factor 4