A smart gene circuit for precise regulation of tumor cell behavior.

Personalized gene circuit is a robust mode of cellular regulation that can manipulate intracellular gene expression to achieve desired functional regulation. However, the construction of logic circuits that automatically sense the characteristics of a particular environment within a cell is often difficult and lacking in sensitivity. Here, we synthesize from scratch specific promoters capable of sensing in cells, and use the combination of different types of promoters to construct smart gene circuits that can regulate gene expression in specific cell types sensitively. In detail, the tumour-specific promoter and the prostate tissue-specific promoter were constructed to be combined together into generating an artificial AND-gate gene circuit using the CRISPR-Cas9 system which could identify prostate cancer selectively. We then utilized this artificial gene circuit to drive targeted genes expression, such as P21, E-cadherin and Bax, to inhibit multifunctional prostate cancer cells but not other cells. Moreover, we applied gene circuits to redirect endogenous genes within cells and significantly and specifically suppressed the tumor growth of prostate cancer in vivo. Overall, these results highlight the clinical potential of these gene circuits as specific tools for prostate cancer detection and treatment, which is a new method for specifically reprogramming prostate cancer cells and may serve as a promising treatment strategy.