What do you think when you hear the word “bacteria”? Infection? Disease? Yogurt? Do you know that you could add the words “cancer therapy” to your list? 

Cancer results from uncontrolled cell division, which in most cases harms the body. Traditionally, “chemotherapy” is given to kill cancer cells. It’s an aggressive chemical treatment that targets both cancer cells and cells that divide normally. For example, hair cells and the stomach lining might also be affected, resulting in hair loss and nausea. 

Scientists have constantly been trying to find better ways to treat cancer. Recently, a breakthrough was made by the Shapiro Lab at Caltech. These scientists have engineered a precise approach to cancer treatment with genetically engineered bacteria E.Coli. This bacterial strain (Nissle 1917) infiltrates tumors and is approved for medical use in humans. 

Here’s how it works. First, the bacteria is given thermosensing (heat sensing) genes, which respond to ultrasound. Next, it’s injected into the bloodstream so that it can enter the tumor. Meanwhile, the immune system destroys the bacteria within the rest of the body. Then, scientists use ultrasound to heat the tumor (between 42-43 degrees Celsius) so that the bacteria (with their thermosensors) are activated. Upon activation, the bacteria release nanobodies, or anti-cancer drugs. These antibodies are therapeutic proteins, which shut down the signals tumors use to protect themselves from an immune attack. Hence, the tumor can be killed by the immune system. 

Studies have shown that this therapy is effective in slowing down tumor growth in mice. Mikhail Shapiro, the lead scientist on the study, told CalTech news that “this is a very promising result, because it shows that we can target the right therapy to the right place at the right time”. 

Further research is being completed  right now, and this technique is being improved. They want to look at ways to “see” the bacteria in action, and make it cost effective, to ultimately develop an efficient treatment for cancer. Hence, sound controlled bacteria is a novel and promising way to fight cancer!