CD20特异性启动子调控腺病毒分泌stTRAIL对淋巴瘤细胞的抑制作用

Inhibiting effect of CD20 promoter-driven recombinant adenovirous-st TRAIL on lymphoma cell growth

目的:研究腺病毒携带CD20启动子调控的TRAIL基因特异性杀伤B-NHL细胞的作用。方法:人工合成含有CD20启动子片段-分泌信号-异亮氨酸拉链-s TRAIL(aa114~aa281)-真核poly(A)序列的融合基因,装入腺病毒载体Ad Easy系统,包装出携带P20-st TRAIL序列的腺病毒感染细胞,采用荧光素酶报告基因法研究CD20启动子在CD20+细胞系中的特异性转录,Western blotting验证TRAIL蛋白在细胞内的特异性表达,体外MTT法检测TRAIL特异性抑制CD20+细胞生长的作用。结果:成功构建携带P20-st TRAIL序列的腺病毒载体并分别感染CD20阳性和阴性淋巴瘤细胞系后发现,CD20启动子仅在CD20+的BJAB淋巴瘤细胞中具有转录活性、启动s TRAIL表达并在体外形成具有生物学功能的同源三聚体结构;在细胞中和培养上清中均检测到st TRAIL在mRNA和蛋白水平的表达,但在CD20-细胞系中则无明显表达。体外功能实验显示,BJAB细胞在被Ad P20-st TRAIL感染后自身生长受到明显抑制,而Ad P20-st TRAIL感染的CD20阴性细胞以及空白载体感染的细胞未见生长抑制现象。结论:CD20启动子可以特异性调控腺病毒携带的治疗基因st TRAIL的表达,实现TRAIL对CD20+B-NHL细胞的靶向杀伤。

Objective: To evaluate the effect of a CD20 promoter-driven recombinant adenovirus-soluble trimeric tumor necrosis factor-related apoptosis-inducing ligand( st TRAIL) vector on the growth of lymphoma cells in vitro. Methods: An adenoviral vector encoding st TRAIL driven by the CD20 promoter whose activity was confirmed in lymphoma cell lines by luciferase assay was constructed. The constructed vector was infected into CD20 positive and CD20 negative lymphoma cell lines respectively. Protein content of st TRAIL was assessed by Western blotting and cell viability was determined by MTT assay in infected cells. Results: Soluble trimeric TRAIL protein was detected in CD20 positive lymphoma cells but not in CD20 negative lymphoma cells after infection with Ad P20-st TRAIL( P < 0. 05). Overexpression of st TRAIL in BJAB cells resulted in a significant increase in apoptotic cell death( P < 0. 05). Conclusion: The CD20 promotor is capable of enhancing st TRAIL transcription in CD20 positive lymphoma cells,thereby having significant clinical implications in targeted cancer therapy.