Existing cancer therapies, such as radiotherapy, chemotherapy, surgery, and targeted drugs, are not effective enough for mid- to late-stage cancers, especially recurrent and metastatic cancers. Cancer patients suffer from short survival periods, severe pain due to treatment, and high medical costs. Therefore, the development of more effective cancer therapies is an urgent need. Microbial therapy aims to recognize and treat tumors by equipping microorganisms such as bacteria and viruses with various therapeutic modules. In this project, we use synthetic biology to engineer bacteria to develop novel therapies that can target a broad range of solid tumors and effectively inhibit cancer metastasis and recurrence.

A major challenge for bacterial cancer therapy development, either through domesticating and screening natural strains or modifying bacteria with conventional genetic engineering, is to reduce the toxicity to the human body while in the meantime, improving the specificity and efficiency in tumor inhibition. So far in the world, a number of clinical trials using bacteria to treat tumors have proven the safety of bacterial therapy, but none of them has achieved the desired therapeutic effects, nor has there been any reports of bacteria-based anti-cancer medications being put on the market.

The development of synthetic biology in recent years has turned the possibility of treating cancer with bacteria into a reality. Using synthetic biology techniques, it is possible to engineer bacterial cells to load them with more information and implement more complex functions than conventional genetic engineering is able to. Engineered bacteria will carry multiple recognition mechanisms, allowing intelligent targeting and treatment of a broad spectrum of cancer cells – identifying, suppressing, and killing cancer cells of different genotypes; killing cancer cells in well-developed tumors as well as detecting and wiping out residual cancer cells to prevent recurrence and metastasis. In this way, engineered bacteria will