Breast Cancer Therapeutic Agents Based on Telomerase Misfunction

加州大学旧金山分校乳腺癌孢子项目#4的目标是开发和评估 我们开发的药物可以在乳腺癌中强制端粒酶干扰。本项目的重点是 开发一种新的临床应用策略：将活性端粒酶的作用转化为对乳房的作用 癌细胞。在当前的筹资周期中，我们已经成功地证明， 突变模板端粒酶RNA(MT-hTer)基因在人乳腺癌细胞中的充分表达 对这些细胞有很强的杀伤和生长抑制作用。MT-hTer作用产生的端粒 对细胞有“毒性”，诱导强烈的细胞凋亡反应。此外，在之前的孢子资助期间 在此期间，布莱克本实验室对端粒酶的研究产生的新科学也导致了两个] 意想不到的发现：首先，只是通过核酶或RNA降低内源性端粒酶水平 靶向方法迅速降低了癌症的可能性。具体地说，我们发现降低整体端粒酶 降低体内癌细胞的转移潜能，并迅速抑制乳房和其他组织的生长 体外培养的癌细胞。第二，MT-hTer表达诱导的细胞死亡是显性的，不需要 P53或pRb检查点通路。基于这些发现，我们随后证明了结合表达 小干扰RNA靶向肿瘤细胞内源性WT-hTER的MT-hTer 协同增强MT-hTer杀灭癌细胞的效力。以下是具体的 目标是将这项工作带到临床上，目的是：#1进一步测试和表征 先前开发的由Her2靶向抗体组成的免疫脂质体(ILs) 含有MT-hTer/抗hTER siRNA构建体(“MT-Rx”试剂)的孢子项目3？为了监控 MT-Rx疗效我们将使用相关生物标志物对该试剂进行反应，适用于早期临床 审判。#2确定基于端粒/端粒酶的生物标记物模式预测细胞凋亡反应 抗癌治疗和特定的MT-Rx治疗。我们将确定乳腺癌的亚群(S) 对现有疗法和使用(I)60个乳腺癌细胞系的MT-Rx最敏感 按基因组和表达谱、端粒维持状态和其他临床相关性分组 特征和(2)患者来源的原代乳腺癌细胞，包括干细胞/祖细胞系； 以确定的最敏感的患者亚群为目标。#3.验证和优化以下检测方法 肿瘤和活检标本上端粒酶和端粒状态的生物标记物，目的是验证] 这些检测是根据CLIA的规定在CLIA认证的实验室中进行的，以便结果可以用于临床。) 对于MT-Rx的翻译，我们将最终确定产品配置，进行初始制造密封 UP，并评估MT-Rx制剂在啮齿动物模型中全身靶向递送的初步毒理学。

The goal of UCSF Breast Cancer SPORE Project #4 is to develop and assess the translational potential of agents we have developed that force telomerase interference in breast cancer. This Project focuses on exploitation for clinical use of a new strategy: to turn the action of active telomerase against the breast cancer cells. In this current funding cycle, we have successfully demonstrated that a low threshold of expression of mutant-template telomerase RNA (MT-hTer) genes in human breast cancer cells is sufficient for a potent killing and growth inhibitory effect on these cells. The telomeres that result from MT-hTer action are "toxic" to cells, inducing a robust apoptotic response. Additionally, during the previous SPORE funding period, new science arising from the Blackburn laboratory's research on telomerase also led to two] unanticipated discoveries: first, that simply decreasing the endogenous telomerase level by ribozyme or RNA targeting methods rapidly decreased cancer potential. Specifically, we found that lowering overall telomerase diminishes the metastatic potential of cancer cells in vivo, and rapidly inhibited the growth of breast and other cancer cells in vitro. Second, cell death induced by MT-hTer expression is dominant and does not require the p53 or pRb checkpoint pathways. Based on these findings, we then showed that combining the expression of MT-hTer with small interfering RNA directed against the endogenous WT-hTER of cancer cells synergistically increases the potency of the MT-hTer effects in killing cancer cells. The following Specific Aims, which have the goal of bringing this work to the clinic, are to: #1 Further test and characterize the previously developed immunoliposome ("ILS") constituted with Her2-targeting antibody¿developed in SPORE Project 3¿containing the MT-hTer/anti-hTER siRNA construct ("MT-Rx" agent). In order to monitor MT-Rx efficacy we will use relevant biomarkers of response to the agent, suitable for early stage clinica trials. #2 Identify telomere/telomerase-based biomarker patterns predictive of apoptotic response t anticancer treatments and to specific MT-Rx therapy. We will identify the subset(s) of breast cancers that wil be most responsive to existing therapies and to "MT-Rx" using (i) a panel of 60 breast cancer cell line grouped by genomic and expression profiling, telomere maintenance status and other clinically relevan characteristics and (ii) patient-derived primary breast cancer cells, including stem/progenitor cell lines; tha targets the most sensitive patient subpopulation, as identified. #3. Validate and optimize the assays fo biomarkers of telomerase and telomere status on tumor and biopsy specimens, with the goal of validating] these assays per CLIA regulations in a CLIA certified laboratory such that the results can be used clinically.) Toward translation of MT-Rx, we will finalize the product configuration, perform initial manufacturing seal up, and evaluate initial toxicology targeted systemic delivery of MT-Rx agent in rodent models.