Two wrongs rarely make a right, but scientists may have found a way to make two nasty illnesses cancel each other out to produce a cure. By genetically modifying the bacteria responsible for salmonella food poisoning, researchers were able to convert it into a tumor-busting weapon with the capacity to destroy some of the most hard-to-treat brain cancers.
Glioblastoma is an extremely aggressive type of brain tumor that can’t be defeated with medications as the blood-brain barrier prevents most chemicals from reaching it. Because of this, survival rates are extremely low for those diagnosed with the condition.
Yet some microbes can cross this barrier, so researchers at Duke University decided to use a detoxified version of the bacteria Salmonella typhimurium to try and treat glioblastoma in rats.
First, they genetically modified the bacteria to lack a crucial protein called purine, which happens to be produced in abundance by tumors. This caused the microbes to flock to the site of the cancer in an attempt to steal some of its purine.
However, the microbes had also been altered to release two compounds, the first of which – a protein called p53 – acts as a tumor suppressor, while the second, known as Azurin, causes cells to self-destruct in conditions of low oxygen. Since oxygen levels are always low at tumor sites, the cancerous cells were induced to die via a process called apoptosis.
The results of this experiment have now been published in the journal Molecular Therapy – Oncolytics, and reveal that the treatment led to 19 percent of rats surviving for more than 100 days, which is the equivalent of 10 human years.
In contrast, rats that didn’t receive treatment survived for an average of just 26 days.
While the technique only worked for around a fifth of the animals involved in the study, the results nevertheless represent a major breakthrough in the treatment of glioblastoma. In a statement, study co-author Johnathan Lyon explained that “since glioblastoma is so aggressive and difficult to treat, any change in the median survival rate is a big deal.”