RADIOSENSITIZATION OF MALIGNANT GLIOMAS BY VIRAL TRANSDUCTION WITH WILD-TYPE P53

描述：(申请者描述)P53功能紊乱如下 在恶性胶质瘤中很常见，可能是导致 对电离辐射(IR)的不稳定性和抗性 这些肿瘤的预后不良。P53与P53蛋白表达的关系 细胞凋亡提示野生型(Wt)p53的病毒转导可能是 用于抑制胶质瘤细胞的增殖并增强其敏感性 致IR。初步研究表明，大鼠恶性胶质瘤细胞 在体外转导wt-P53后，克隆存活率下降 IR暴露后细胞凋亡率增加。植入同基因大鼠体内， 转导p53的细胞形成类似于对照细胞的脑内肿瘤 但接受p53转导细胞的动物存活显著。 比有对照细胞的要长。IR似乎进一步延长 在这个群体中生存。初步证据表明， 病毒转基因在脑和脑肿瘤中的直接表达 实质内可控速率输注。据推测，病毒 输液量的颗粒浓度和相关参数， 速度和压力将具有最大分布的最佳值 转导，同时将组织破坏降至最低。 在四个具体目标中，该项目将检验以下假设 Vt-P53腺病毒转导啮齿动物和人脑胶质瘤细胞 增强其在体外和体内的放射敏感性；(1)p53 状态(wt与突变体)和对腺病毒转导的易感性 将在胶质瘤细胞系中进行研究，以便于解释其 P53转导后对IR暴露的反应。的可变性 转导效率将在初选的人类中确定 肿瘤细胞培养。(2)体外研究将确定 转导wt-p53基因抑制缺血再灌注后细胞增殖和促进细胞凋亡 在啮齿动物和人脑胶质瘤细胞中暴露。(3)控制率 大鼠脑内正压注入腺病毒载体 脑内胶质瘤将决定关键参数的传递和 体内肿瘤细胞的转导。配送量和百分比 在监测行为或组织学时，将检查转导 有毒性的证据。(4)P53信号转导对细胞增殖的影响 将研究体内胶质瘤细胞对辐射的敏感性 组织学、细胞凋亡、肿瘤生长和动物存活。人类细胞系 将通过正压输注在体内转导后进行研究 在照射之前。

DESCRIPTION: (Applicant' Description) Derangements of p53 function are common in malignant gliomas and may be responsible for the genetic instability and resistance tot ionizing radiation (IR) that contribute to the poor prognosis of these tumors. The relationship between p53 and apoptosis suggests that viral transduction of wild-type (wt) p53 could be used to impair proliferation and enhance the sensitivity of glioma cells to IR. Preliminary studies demonstrate that rat malignant glioma cells when transduced with wt p53 in vitro exhibit decreased clonogenic survival and increased apoptosis after IR exposure. Implanted in syngeneic rats, p53 transduced cells form intracerebral tumors similar to control cells but animals receiving the p53 transduced cells survive significantly longer than those with control cells. IR appears to further prolong survival in this group. Preliminary evidence indicates the feasibility of viral transgene expression in brain and brain tumors by direct intraparenchymal controlled-rate infusion. It is hypothesized that viral particle concentrations and interrelated parameters of infusion volume, rate and pressure will have optima for maximum distribution of transduction while minimizing tissue disruption. In four Specific Aims, this project will test the hypothesis that adenoviral transduction of rodent and human glioma cells with vt p53 can enhance their radiosensitivity both in vitro and in vivo; (1) the p53 status (wt versus mutant) and susceptibility to adenoviral transduction will be studied in glioma cell lines to facilitate interpretation of their responses to IR exposure after p53 transduction. Variability in transduction efficiency will be determined in a selection of primary human tumor cell cultures. (2) In vitro studies will determine the ability of transduced wt p53 to impair proliferation and enhance apoptosis after IR exposure in rodent and human glial tumor cells. (3) Controlled-rate positive pressure infusion of adenoviral vector into rat brain and intracerebral gliomas will determine parameters critical for delivery and transduction of tumor cells in vivo. Volume of distribution and per cent transduction will be examined while monitoring behavioral or histological evidence of toxicity. (4) The effects of p53 transduction on the radiosensitivity of glioma cells in vivo will be studied with respect to histology, apoptosis, tumor growth and animal survival. Human cell lines will be studied after transduction in vivo by positive pressure infusion prior to irradiation.