Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom.
Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom.
Proc Natl Acad Sci U S A. 2020 Mar 24;117(12):6752-6761. doi: 10.1073/pnas.1918859117. Epub 2020 Mar 6.
A type of chromosome-free cell called SimCells (simple cells) has been generated from , , and The removal of the native chromosomes of these bacteria was achieved by double-stranded breaks made by heterologous I-CeuI endonuclease and the degradation activity of endogenous nucleases. We have shown that the cellular machinery remained functional in these chromosome-free SimCells and was able to process various genetic circuits. This includes the glycolysis pathway (composed of 10 genes) and inducible genetic circuits. It was found that the glycolysis pathway significantly extended longevity of SimCells due to its ability to regenerate ATP and NADH/NADPH. The SimCells were able to continuously express synthetic genetic circuits for 10 d after chromosome removal. As a proof of principle, we demonstrated that SimCells can be used as a safe agent (as they cannot replicate) for bacterial therapy. SimCells were used to synthesize catechol (a potent anticancer drug) from salicylic acid to inhibit lung, brain, and soft-tissue cancer cells. SimCells represent a simplified synthetic biology chassis that can be programmed to manufacture and deliver products safely without interference from the host genome.
一种称为 SimCells（简单细胞）的无染色体细胞已从 、 和 中生成。通过异源 I-CeuI 内切酶的双链断裂和内源性核酸酶的降解活性，实现了这些细菌的天然染色体的去除。我们已经表明，这些无染色体的 SimCells 中的细胞机制仍然保持功能，并能够处理各种遗传回路。这包括糖酵解途径（由 10 个基因组成）和诱导遗传回路。结果发现，糖酵解途径由于其能够再生 ATP 和 NADH/NADPH，显著延长了 SimCells 的寿命。在去除染色体后，SimCells 能够连续表达合成遗传回路长达 10 天。作为原理的证明，我们证明了 SimCells 可以用作细菌治疗的安全剂（因为它们不能复制）。SimCells 被用于从水杨酸合成儿茶酚（一种有效的抗癌药物）以抑制肺癌、脑癌和软组织癌细胞。SimCells 代表了一种简化的合成生物学底盘，可以对其进行编程以安全地制造和输送产品，而不会受到宿主基因组的干扰。
