儿童难治性ALL的基因调控和分子治疗

MDM2 was transfected to acute lymphoblastic leukemia (ALL) line EU-4 cell which lacks P53 expression and expressing very low levels of MDM2. The results show that MDM2 up-regulated P65 expressing in mRNA level and protein level. The effect of adriamycin(ADM) on MDM2-transfected EU-4 cell was detected by MTT assay. It show that MDM2 transfection increased drug resistance of EU-4 cells to ADM compared with parent cells. Since the expression of E-selectin is P65 dependent, E-selectin promoter-CAT construct and P65 and MDM2 expression plasmids were co-transfected to EU-4 cells, we found that MDM2 increased P65-mediated transactivation of E-selectin promoter. Without P65, MDM2 had no effect on the transactivation of E-selectin. Moreover, MDM2 antisense can not change the transactivation of E-selectin. It was concluded that MDM2 could up-regulate trandcriptionally P65 expression; MDM2 increased drug resistance of leukemia cells to ADM.; MDM2 elevated NFKB activity in a P53-independent manner. To investigate the role of NFkB in TNFαinduced apoptosis in HL-60 cells. A mutant IKBαwas transfected into HL-60 cells. The results indicated that the resistance of HL-60 towards apoptosis induced by TNFαcan be mediated by NFkB activation. The inhibition of NFkB activation by mutant IkBa can attenuate the resistance of HL-60 cells and increase its sensitivity to TNFα

通过分子生物学方法，探讨了急性淋巴细胞白血病（ALL）患儿基因异常的原因和它们之间南嗷プ饔茫沂玖硕阎涡訟LL的化疗耐药性产生的分子机制，并基于此理论，应用反义寡核苷酸和基因转染技术阻断MDM2过度表达和NFKB的激活，从而抑制细胞增殖及啬白血病细胞对化疗的敏感性，为难治性儿童ALL的治疗提供新的途径。