American researchers have developed a hybrid approach using ultrasound and the immune system to eliminate cancerous tumors through a double defense mechanism.
A hybrid process
The idea of using sound waves to treat different ailments non-invasively is proving particularly appealing. In recent weeks alone, various studies have shown that they can destroy kidney stones in record time, induce genetically modified bacteria to attack tumors and even treat diabetes in preclinical trials.
Called histotripsy, the technique used by the team atuniversity of michigan involves targeting cancerous tissue with bursts of high-intensity ultrasound lasting a few microseconds, causing tiny bubbles to form in the tissue, which quickly expand and collapse. The resulting mechanical stress kills cancer cells and disintegrates the tumour, the fragments of which can then be safely absorbed by the body.
Since these potentially contain the ingredients needed to induce immunogenic cell death (in which the immune system attacks tumor cells), the team explored the possibility of partially destroying the tumor using bursts of ultrasound, in order to to induce the body’s defenses to finish the job. This could prove particularly useful when these cancerous structures are very large or difficult to target in their entirety due to their location.
Particularly promising first results
Detailed in the review Cancers, the experiments involved the destruction of 50-75% of liver tumors in rats using ultrasound, which effectively resulted in an intensification of the immune response, having eliminated the rest. Even more impressively, no signs of recurrence or metastasis were observed in 80% of rodents treated in this way.
« Even if we don’t target the entire tumor, we can regress it and reduce the risk of future metastases “, highlighted Zhen Xulead author of the study.
While the team’s ultimate goal obviously remains the clinical adoption of this hybrid treatment, the next steps will consist of precisely determining the immune mechanisms involved, and adapting the approach in order to destroy tumors at different stages.