Simultaneous Targeting of p53 to the Nucleus and Mitochondria for Cancer Therapy

项目总结/摘要 该项目的目标是将肿瘤抑制因子（p53）靶向2个不同的细胞区室，作为新的双重靶点。 乳腺癌和其他类型癌症的基因治疗方法。在正常细胞中，p53蛋白主要位于 在细胞核中，它可以作为肿瘤抑制因子并引起细胞凋亡。在一定条件下， 当被导向线粒体时也具有抗肿瘤活性。在许多类型的癌症中，p53被错误定位于 细胞质或失活。事实上，p53已经成为癌症预防的主开关， 作为癌症的最终治疗靶点。为了使p53靶向细胞核，我们将使用我们的 新兴的蛋白质开关技术捕获细胞质中错误定位的p53，可以将其拖到 加入外部药物的核。一旦进入细胞核，p53就会导致癌细胞死亡。到 通过将p53靶向线粒体，将产生p53的改进的神经定向形式。这2- 基因治疗的方法很可能增加p53细胞杀伤能力的效力。最初的目标是 证明这项技术是乳腺癌，未来用于炎性乳腺癌（IBC），一个非常 侵袭性和致命性的乳腺癌。IBC有错误定位或突变的p53，因此应该 很容易对这种疗法产生反应。这种方法适用于涉及p53的所有类型的癌症。 错误定位、核排斥、突变或失活。该项目的目标如下：1） 证明具有核定位信号（NLS）的p53蛋白质开关版本将从细胞核转位。 在配体添加后，细胞质进入细胞核，并内在地引起细胞凋亡，或启动增强的细胞凋亡 当结合内源性错误定位的p53时; 2）证明p53的核定位缺陷形式 用改进的线粒体靶向信号工程化将通过内在的凋亡诱导因子触发凋亡。 3）评估核靶向蛋白质转换-p53从Aim 1的能力， 在联合治疗中优化来自Aim 2的p53以诱导乳腺癌细胞凋亡， 与单独的任一构建体的作用相比增加的效力。一种癌症特异性启动子及其在 还将测试使用腺病毒载体的细胞; 4）证实来自Aim 3的组合疗法 通过腺病毒载体递送将根除或减少人异种移植实体瘤鼠中的乳腺癌 体内模型。最后，这里描述的方法比当前的策略（包括 在某些情况下施用可恢复肿瘤抑制功能的野生型p53或小分子抑制剂） 因为将p53直接靶向细胞的活性区室将允许触发内源性 以特异性和同时或协同的方式抑制细胞凋亡的外源性途径。这种双重基因疗法 也有望对其他类型的侵袭性癌症有益， 治疗

Project Summary/Abstract The goal of this project is to target a tumor suppressor (p53) to 2 different cellular compartments as new dual gene therapy approach for breast and other types of cancers. In normal cells, p53 protein is located mostly in the nucleus of the cell where it can act as a tumor suppressor and cause apoptosis. Under certain conditions it is also apoptotically active when directed to the mitochondria. In many types of cancers, p53 is mislocalized to the cytoplasm or inactivated. Indeed, p53 has emerged as a master switch for cancer prevention and is actively pursued as the ultimate cancer therapeutic target. To target p53 to the nucleus, we will use our emerging protein switch technology to capture mislocalized p53 in the cell cytoplasm, which can be dragged to the nucleus with addition of an external drug. Once in the nucleus, p53 will cause death of the cancer cell. To target p53 to the mitochondria, an improved mitochondrially directed version of p53 will be created. This 2- gene therapy approach is likely to increase the potency of p53 cell-killing ability. The initial target to demonstrate this technology is breast cancer, with future use in inflammatory breast carcinoma (IBC), a very aggressive and deadly form of breast cancer. IBC has mislocalized or mutated p53 and therefore should readily respond to this type of therapy. This approach is applicable to all types of cancers involving p53 mislocalization, nuclear exclusion, mutation, or inactivation. The aims of this project are as follows: 1) Demonstrate that protein switch versions of p53 with nuclear localization signal (NLS) will translocate from the cytoplasm to the nucleus upon ligand addition and intrinsically cause apoptosis, or initiate enhanced apoptosis when binding endogenous mislocalized p53; 2) Prove that a nuclear-localization deficient version of p53 engineered with an improved mitochondrial targeting signal will trigger apoptosis via the intrinsic apoptotic pathway; 3) Assess the ability of the nuclear targeted protein switch-p53 from Aim 1, and the mitochondrially optimized p53 from Aim 2 in combination therapies to induce apoptosis in breast cancer cells, resulting in increased potency compared to the action of either construct alone. A cancer-specific promoter and delivery in cells using an adenoviral vector will also be tested; 4) Validate that the combination therapy from Aim 3 delivered via adenovirus vector will eradicate or reduce breast cancer in a human xenograft solid tumor murine model in vivo. Finally, the approach described here is more advantageous that current strategies (including administering wt p53 or small molecule inhibitors that can restore tumor suppressor function in some cases) because targeting of p53 directly to active compartments of the cell will allow triggering of both intrinsic and extrinsic pathways of apoptosis in a specific and simultaneous or synergistic manner. This dual gene therapy is also expected to be beneficial for other types of aggressive cancers that currently have no effective therapies.