Targeting melanoma hypoxia with lactic acid bacterium L. lactis

项目摘要 黑色素瘤是最具侵袭性的皮肤癌，如果通过真皮扩散， 预后高，病死率高。缺氧是肿瘤微环境的一个组成部分，它减少了 免疫和化疗都有效，导致临床结果不佳。因此，我们将利用 低氧微环境作为基因治疗的靶点，利用共生兼性厌氧细菌。这个 这项提案的总体目标是通过以下方式开发一种有效和安全的癌症基因治疗递送系统 以食品级乳酸菌(LAB)乳球菌(L. 乳酸菌)。与其他细菌相比，LAB的使用代表了一种更可取的交付策略 治疗基因比减毒的致病菌株更好，因为没有逆转的风险或潜在的煽动 免疫功能低下患者的宿主反应。因为识别肿瘤特异性聚集和 基因传递载体在体内的生物分布对于将这些药物转化到临床是必不可少的，我们将 利用一种新的技术--多光谱光声断层成像(MSOT)。Msot是一种混合体 探测由吸收电磁能量而产生的声波的一种方式，从而使 能够实现深度和实时的3D高分辨率。我们的初步数据显示乳乳杆菌 表达高水平的半乳糖苷酶(LacZ)，并与5-溴-4-氯-3-吲哚-β-D- 半乳糖苷(X-GAL)，产生强烈的蓝色，便于使用MSOT检测乳酸乳杆菌。vt.给出 根据这些发现，我们假设乳酸乳杆菌将优先定植于肿瘤的缺氧区。 以安全、肿瘤特异性和有效的方式传递治疗性基因的微环境。我们建议两个 目的：(1)评价乳酸乳杆菌作为基因载体在体外黑色素瘤细胞中的作用； 乳酸乳杆菌在转移性黑色素瘤中的生物分布和肿瘤特异性蓄积 老鼠。这项提案的成功完成将对基因治疗领域产生重大影响， 具体地说，利用兼性细菌作为肿瘤特异性靶向黑色素瘤的递送剂。

Project Summary Melanoma is the most aggressive form of skin cancer and, if disseminated through the dermis, has a poor prognosis with a high mortality rate. Hypoxia is a component of the tumor microenvironment, which reduces efficacy of both immuno- and chemo-therapies resulting in poor clinical outcome. Therefore, we will exploit the hypoxic microenvironment as a target for gene therapy, utilizing commensal facultative anaerobic bacteria. The overall goal of this proposal is to develop an effective and safe delivery system for cancer gene therapy by targeting the hypoxic tumor microenvironment with food-grade lactic acid bacteria (LAB) Lactococcus lactis (L. lactis). The use of LAB, as opposed to other bacteria, represents a much more desirable strategy to deliver therapeutic genes than attenuated pathogenic strains, as there is no risk of reversion or potential to instigate host reactions in immunocompromised patients. Because identification of tumor-specific accumulation and biodistribution of gene delivery vehicles in vivo is essential for translation of these agents to the clinic, we will utilize a newly emerging technology, multispectral optoacoustic tomography (MSOT). MSOT is a hybrid modality that detects sound waves generated by the absorption of electromagnetic energy, thus enabling the capability for 3D high-resolution at depth and in real time. Our preliminary data indicates that L. lactis expresses high levels of -galactosidase (LacZ), and in combination with 5-bromo-4-chloro-3-indolyl-β-D- galactopyranoside (X-gal), produces a strong blue color to facilitate detection of L. lactis using MSOT. Given these findings, we hypothesize that L. lactis will preferentially colonize the hypoxic areas of the tumor microenvironment to deliver therapeutic genes in a safe, tumor-specific, and effective manner. We propose two aims: (1) Evaluate the efficacy of L. lactis as a gene delivery vehicle in melanoma cells in vitro, and (2) determine the biodistribution and tumor-specific accumulation of L. lactis in metastatic melanoma-bearing mice. The successful completion of this proposal will substantially influence the field of gene therapy, specifically utilization of facultative bacteria as delivery agents for tumor-specific targeting of melanoma.