Enhanced radiosensitivity of malignant glioma cells after adenoviral p53 transduction
Enhanced radiosensitivity of malignant glioma cells after adenoviral p53 transduction
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DOI：
10.3171/jns.1999.91.6.0997
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发表时间：
1999-12-01
影响因子：
4.1
通讯作者：
Fillmore, HL
中科院分区：
文献类型：
--
作者：
Broaddus, WC;Liu, Y;Fillmore, HL
物体。本研究的目的是确定腺病毒载体介导的人野生型P53基因的表达是否可以增强表达天然野生型P53的恶性胶质瘤细胞的放射敏感性。P53基因被认为在大多数恶性胶质瘤中功能异常，尽管已被证明只有大约30%的突变。这导致了一些研究，在这些研究中，腺病毒转导野生型人p53试图减缓肿瘤细胞的生长。最近的研究表明，野生型P53的重组可以使细胞更容易受到辐射诱导的死亡，主要是通过P53介导的凋亡。用逆转录聚合酶链式反应和序列分析的方法分析大鼠RT2胶质瘤细胞中P53的天然状态，并用Western印迹分析P53的表达。克隆存活率和末端脱氧核苷转移酶介导的三磷酸脱氧尿苷缺口末端标记法分别检测含p53和对照的腺病毒载体转导和未转导的RT2细胞的放射敏感性和细胞凋亡。将转导和非转导的rt2细胞植入脑内，观察动物的存活时间，发现rt2细胞表达野生型p53，而腺病毒p53腺病毒转导后，rt2细胞明显过表达人p5 3。在辐射剂量为2~6Gy时，联合应用P53转导和放射治疗可显著降低RT2细胞的存活率，增加细胞凋亡率。脑内植入预先转导P53基因的RT2细胞后接受头颅放射治疗的动物存活时间显著长于对照组(P<；0.01)。通过使用腺病毒转导诱导P53的过度表达来增强表达野生型P53的恶性胶质瘤细胞的放射敏感性的能力，为这种方法作为一种治疗策略提供了希望，不仅在表达突变P53的人脑胶质瘤中，而且在表达野生型P53的人脑胶质瘤中也是如此。
Object. The goal of this study was to determine whether adenoviral vector-mediated expression of human wildtype p53 can enhance the radiosensitivity of malignant glioma cells that express native wild-type p53.The p53 gene is thought to function abnormally in the majority of malignant gliomas, although it has been demonstrated to be mutated in only approximately 30%. This has led to studies in which adenoviral transduction with wildtype human p53 has been investigated in an attempt to slow tumor cell growth. Recent studies suggest that reconstitution of wild-type p53 can render cells more susceptible to radiation-mediated death, primarily by p53-mediated apoptosis.Methods. Rat RT2 glioma cells were analyzed for native p53 status by reverse transcriptase-polymerase chain reaction and sequence analysis and for p53 expression by Western blot analysis. Clonogenic survival and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay were used to characterize RT2 cell radiosensitivity and apoptosis, respectively, with and without prior transduction with p53-containing and control adenoviral vectors. Animal survival length was monitored after intracerebral implantation with transduced and nontransduced RT2 cells, with and without cranial radiation.The RT2 cells were demonstrated to express native rat wild-type p53 and to markedly overexpress human p53 following adenoviral p53 transduction. The combination of p53 transduction followed by radiation resulted in marked decreases in RT2 cell survival and increases in apoptosis at radiation doses from 2 to 6 Gy. Animals receiving cranial radiation after intracerebral implantation with RT2 cells previously transduced with p53 survived significantly longer than control animals (p < 0.01).Conclusions. The ability to enhance the radiosensitivity of malignant glioma cells that express wild-type p53 by using adenoviral transduction to induce overexpression of p53 offers hope for this approach as a therapeutic strategy, not only in human gliomas that express mutant p53, but also in those that express wild-type p53.