文本框: STUDIES OF THE MOLECULAR MECHANISM OF CENTRAL NERVOUS SYSTEM LEUKEMIA IN CHILDREN Wang NS, Li ZX, Yang XQ Children’s Hospital, Chongqing University of Medical Sciences, Chongqing, China Objective: The acute lymphoblastic leukemia (ALL) in children often infiltrates the central nervous system (CNS), which is one of the main source of relapse. The molecular mechanisms involved in this process were studied in order to prevent the CNS infiltration development. Methods: The adhesion molecule CD49d expression on leukemia cells was tested by FACS. The ELISA and FACS were performed for measuring the adhesion molecule receptor. Cell adhesion rate between AL cells and Human umbilical vens endothelial cells (HUVEC) were measured by MTT. Results: The CD49d expression of ALL and ANLL with infiltration were higher than those of control and without infiltration groups. The levels of VCAM-1 expression was paralleled with high binding between AL cells with high CD49 expression and HUVEC. The anti-CD49d and anti-VCAM-1 markedly reduced the adhesion between AL cells and HUVEC. Conclusion: The capacity of infiltration and metastasis of AL cells is related to the level of CD49d expressed on the AL cells. The Vla-4/VCAM-1 may be the main molecular basis for the binding between AL cells and vascular endothelial cells. The Moabs of the adhesion molecules are possible helpful for inhibiting the adhesion and to prevent CNS infiltration. 0544