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

描述：（申请人的描述）p53功能的紊乱是 常见于恶性神经胶质瘤，可能是导致 不稳定性和对电离辐射（IR）抗性， 这些肿瘤的不良预后。p53与 细胞凋亡表明野生型p53的病毒转导可能是 用于抑制神经胶质瘤细胞的增殖并增强其敏感性 初步研究表明，大鼠恶性胶质瘤细胞 当用野生型p53体外转导时， IR暴露后细胞凋亡增加。植入同系大鼠体内， p53转导的细胞形成与对照细胞相似的脑内肿瘤 但接受p53转导细胞的动物存活显著 比对照组细胞长。IR似乎进一步延长 在这个群体中生存。初步证据表明， 通过直接测序在脑和脑肿瘤中表达病毒转基因 实质内控制速率输注。据推测， 颗粒浓度和输注体积的相关参数， 速度和压力将有最佳的最大分布， 同时最小化组织破坏。 在四个具体目标中，本项目将检验以下假设： 用VT p53腺病毒转导啮齿动物和人神经胶质瘤细胞可以 在体外和体内增强其放射敏感性;（1）p53 状态（野生型与突变型）和对腺病毒转导的易感性 将在神经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。变异性 转导效率将在选择的原代人细胞中确定， 肿瘤细胞培养物。(2)体外研究将确定 转导的wt p53在IR后损害增殖并增强凋亡 啮齿动物和人类神经胶质肿瘤细胞中的暴露。(3)控制速率 将腺病毒载体正压输注到大鼠脑中， 脑内神经胶质瘤将决定递送的关键参数， 体内肿瘤细胞的转导。分发量和百分比 将在监测行为或组织学的同时检查转导 毒性的证据。(4)p53转导对细胞凋亡的影响 将研究胶质瘤细胞在体内的放射敏感性， 组织学、细胞凋亡、肿瘤生长和动物存活。人细胞系 将在通过正压输注进行体内转导后进行研究 在辐照之前。

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.