VLA-4与急性白血病化疗耐药

VLA-4 and acute leukemia chemotherapy resistance

白血病是一种早期造血细胞分化受阻的恶性克隆性疾病。近年来，急性白血病（AL）在化疗、放疗、造血干细胞移植等综合治疗的基础上，缓解率及无病生存率明显提高，但仍有部分患者出现化疗不缓解或缓解后复发，阻碍了白血病的彻底治愈。

Summary Leukemia is a disruption of early hematopoietic cell differentiation of malignant clonat disease. In recent years,the remission rate and disease-free survival of acute leukemia on the basis of chemotherapy, radiation therapy,hematopoietic stem cell transplantation and comprehensive treatment was significantly improved. However,there are still some patients who appear to be non-remission or recurrence followed by chemotherapy that inter feres completely cured of leukemia. Recent researches show that the very late antigen-4 （VLA-4） is abundantly ex pressed on the surface of leukemic blasts and the interaction between VLA-4 and fibronectin on the bone marrow stromal cells activates PI3K/Akt/Bcl-2 signaling,which contributes to drug resistance in acute leukemia. While the interaction between VLA-4 and vascular cell adhesion molecule-1 is correlated with chemoresistanee. In addition, the expression of a carrier epitope bearing the membrane-proximal KXGFFKR motif of a4 integrin is also able to confer adhesion-independent chemoresistance. While VLA-4 remains controversial in prognosis of different types of acute leukemia,high expression of VLA-4 causing a poor prognosis in childhood acute lymphoblastic leukemia has reached a consensus. Therefore, VLA-4 may be the indicator of chemotherapy resistance, relapse and adverse prog- nosis of acute leukemia which could be a potential target for effective treatment.