Cancer-specific metabolites as cues to engineer and target anti-tumor therapeutic bacteria

摘要 随着合成生物学的不断进步，治疗性细菌在癌症治疗中的应用正在被广泛应用。 现在更接近成为现实。然而，实现这一目标仍然需要更好地靶向治疗。 细菌对癌症部位，以提高疗效和安全性的治疗。在这里，我们建议使用 一种在结直肠癌和其他肿瘤中产生的关键癌症代谢物，作为激活遗传回路的线索 在治疗细菌内控制这些细菌并将它们靶向癌症部位。实现这一 目标，我们将克隆这种代谢产物的天然转录调节因子， 工程治疗性E. coli中进行了优化。与此同时，我们将使用特定的RNA 我们已经为这种代谢物开发了适体，来构建合成的核糖开关来控制蛋白质 在工程化的大肠杆菌菌株中表达。随后，这两个工具，转录， 调节器和合成核糖开关，将结合使用，在细胞内建立遗传电路。 工程E. coli菌株。这些基因电路将1）指导工程E。coli（沿着这个键 代谢物浓度梯度）朝向肿瘤部位，2）通过控制其运动性， 本E. 3）诱导肿瘤细胞内治疗性分子的产生， 肿瘤微环境对这种关键代谢物的反应。 在这段时间内，我们将致力于开发这些E。大肠杆菌基因电路， 在生理相关浓度下对这种代谢物产生反应，我们将测试这些 工程E.大肠杆菌对癌细胞系的作用。今后的工作将通过随后的赠款进行， 包括在结肠癌小鼠模型中尝试这些工程细菌。

Abstract With the ongoing advances in synthetic biology, the application of therapeutic bacteria for cancer treatment is now closer to becoming a reality. Achieving this goal, however, still needs better targeting of the therapeutic bacteria towards the cancer sites to improve the efficacy and safety of the treatment. Here, we propose to use a key cancer metabolite produced in colorectal cancers and other tumors as a cue to activate genetic circuits inside the therapeutic bacteria to control those bacteria and target them to the cancer site. To achieve this goal, we are going to clone the naturally occurring transcriptional regulator for this metabolite into engineered therapeutic E. coli and optimize its performance. In parallel, we will employ specific RNA aptamers which we already developed for this metabolite, to build synthetic riboswitches to control protein expression in the engineered Escherichia coli strain. Subsequently, these two tools; the transcription regulator, and the synthetic riboswitches, will be used in combination to build genetic circuits inside the engineered E. coli strain. These genetic circuits will then 1) Direct the engineered E. coli (along this key metabolite concentration gradient) towards the tumor site through controlling its motility, 2) Induce the attachment of this E. coli to the tumor cells, and 3) Induce the production of a therapeutic molecule within the tumor microenvironment in response to this key metabolite. During the time frame of this grant, we will be working on developing these E. coli genetic circuits which can respond to this metabolite at the physiologically relevant concentrations and we are going to test these engineered E. coli on cancer cell lines. Future work, which will be pursued through subsequent grants, will involve trying these engineered bacteria in mice models for colon cancer.