Back to all posts
Cancer therapies are rapidly emerging.
Among them, immunotherapies have excelled in the treatment of malignancies. However, their use in solid tumors has been hampered by their reduced ability to penetrate and function in the tumor’s immunosuppressive environment. Investigators from Caltech demonstrated in their new article in Nature Communications a specialized strain of (E. coli) bacteria that seek out and penetrate specifically to cancerous tumors when injected into a patient’s body. Once the bacteria have reached their destination, pulses of ultrasound trigger them to produce anti-cancer drugs, allowing a temporal activation of the therapy inside the tumor.
To turn the bacteria into a useful tool for treating cancer, the team engineered them to contain two new sets of genes; One set of genes is for producing therapeutic proteins that allow the immune system to attack the tumor. The other set of genes allows a sustained activation of these therapeutic bacteria by a thermal state switch, allowing their activation by an outside source.
In pre-clinical trials, the researchers found that mice treated with this strain of bacteria and ultrasound showed much slower tumor growth than control mice. Thus, this technology provides a new and fascinating tool for the spatiotemporal targeting of potent bacterial therapeutics in a variety of cancers, specifically, in the treatment of solid tumor cancers.
They established an innovative system for targeted probiotic immunotherapy that couples the special ability of therapeutic bacteria to infiltrate solid tumors and activate their therapeutic function.