Can Tiny Fish Cure Cancer? Zebrafish Research Sheds New Light

Zebrafish avatars are shedding new light on bladder cancer treatment, revealing how macrophages triggered by the BCG vaccine can destroy cancer cells. This innovative approach offers a faster way to personalize cancer therapies.

Using zebrafish “Avatars,” an animal model developed by the Cancer Development and Innate Immune Evasion lab at the Champalimaud Foundation (CF), led by Rita Fior, Mayra Martínez-López – a former PhD student at the lab now working at the Universidad de las Américas in Quito, Ecuador – and colleagues studied the initial steps of the Bacillus Calmette-Guérin (BCG) vaccine’s action on bladder cancer cells. Their results, which are published today (August 1, 2024) in the journal Disease Models and Mechanisms, show that macrophages – the first line of immune cells activated after an infection – literally induce the cancer cells to commit suicide and then rapidly eat away the dead cancer cells.

The idea behind zebrafish Avatars (zAvatars), which are still an experimental, but very promising model, is fairly straightforward: take tumor cells from a cancer patient and inject them into zebrafish embryos. The tumors will then grow inside the embryos, effectively turning them into Avatars of that specific cancer patient. The various treatment options available for that patient can then be tested on the zAvatars – and, in a matter of days rather than several weeks, or even months, that it takes using the traditional testing in mice, it will be possible to determine the best treatment for that patient. The test has been developed and studied with samples from colorectal cancer patient samples.