中文摘要：

目的：基于前期利用靶向PPP2R5C基因的小干扰RNA（PPP2R5C-siRNA）抑制白血病T细胞增殖的结果，进一步了解 PPP2R5C-siRNA 对 T-ALL 样本中 TCR Vβ亚家族基因谱系及其克隆性增殖情况．方法：利用PPP2R5C-siRNA 转染2例初发未治疗T-ALL病人外周血单个核细胞（PBMC），设无关序列对照组（SC）和空白对照组（NC）；利用实时定量PCR检测PPP2R5C基因表达水平．利用RT-PCR扩增各组样本中24个TCR Vβ亚家族基因的互补决定区3（CDR3）；阳性产物进一步经基因扫描分析CDR3长度，了解其Vβ亚家族T细胞克隆性．结果：PPP2R5C-siRNA 处理后明显下调PBMC中PPP2R5C基因表达水平．2例初发T-ALL外周血中分别可检测到10和17个Vβ亚家族，多数Vβ亚家族T细胞为多克隆性，病例1中Vβ9和Vβ17为寡克隆性，而病例2中，Vβ14和Vβ16呈寡克隆性；经过RNA干扰处理后，TCR Vβ亚家族表达率降低，仅检测到3和4个Vβ亚家族，分别为Vβ2， Vβ3，Vβ16和Vβ17．其中2个Vβ家族的寡克隆性模式发生改变，病例1中，Vβ17转为多克隆，而病例2中，Vβ16也转变为多克隆．结论：RNA 干扰下调白血病T细胞PPP2R5C基因表达抑制细胞增殖时，在一定程度上影响TCR Vβ亚家族T细胞增殖和克隆模式变化，对正常T细胞功能可能存在一定影响．

英文摘要：

Aim：Based on the results that small interfering RNA targeting PPP2R5C gene＆amp;nbsp;（PPP2R5C-siRNA）inhibited the proliferation of leukemia T cells,we further analyze the effect of PPP2R5C-siRNA on the distribution and clonality of T cells receptor （TCR）Vβsubfamily in T cells of patients with T cell-acute lymphoblastic leukemia （T-ALL）.Methods：Peripheral blood mononuclear cells （PBMC）from 2 cases with de novo and untreated T-ALL were transfected using PPP2R5C-siRNA. A scrambled non-silencing siRNA control （sc）and untreated cells were used as controls.PPP2R5C gene expression were detected by real-time PCR.The complementarity determining region 3 （CDR3 ）of TCR Vβ24 subfamily genes were amplified using RT-PCR.The PCR positive products were further labeled by fluorescein and then analyzed by genescan technique for determination of the CDR3 length （T cell clonal-ity analysis）.Results：PPP2R5C gene expression levels in PBMC were significantly reduced after RNA interference.10 or 17 Vβsubfamilies were detected in PBMC from the two cases with T-ALL respective-ly,and polyclonality was observed in most of the Vβsubfamily T cells,while oligoclonality was observed in Vβ9 and Vβ17 from case 1 ,and in Vβ14 and Vβ16 from case 2.Low expression frequencies of TCR Vβsubfamily were found in PBMC treated with PPP2R5C-siRNA,only 3 or 4 Vβsubfamilies could be i-dentified,including Vβ2,Vβ3,Vβ16 and Vβ17.In addition,the oligoclonal patterns of both Vβ17 from case 1 and Vβ16 from case 2 had changed into polyclonality.Conclusion：During the inhibition of T-ALL cell proliferation by down-regulating PPP2R5C gene with RNA interference,it may impair the proliferai-ton and clonality of TCR Vβsubfamily T cells,which might influence on the normal T-cell function.