Personalized medicine is the future of cancer therapy. A recent report shows that one lab has successfully tested the zebrafish cancer response and its potential to be used to personalize patient treatment.
Cancer is a heterogeneous disease. Not only are different types of cancers unique from one another, like brain cancer and breast cancer, but even the same type of cancer varies from person to person. What this ultimately suggests is that a drug that may work extremely well to treat brain cancer in one person may not show the same efficacy to treat the same type of brain cancer in another person. This leads us to personalized medicine, which many believe represents the future for cancer therapy.
Currently, most cancer patients will be treated with the drug that is readily available at a nearby treatment facility. However, imagine if clinicians could tailor a treatment plan to a specific cancer and specific person based on the response of a fish! Science magazine recently published an eye-opening article about a lab that that is implanting human cancer cells into zebrafish to grow tumors so that they may test different drugs and drug combinations in individual patient samples. Rita Fior’s lab uses these zebrafish as a way to model a patient’s cancer and use them as a drug screening tool in order to advance personalized medicine.
Fior and her colleagues initially wanted to determine if human tumor cells would behave similarly in zebrafish as they do in humans. The researchers did this by implanting human colorectal cancer cells into the embryos of these zebrafish and let them grow for four days. What they showed was that, just like in humans, the tumor in the zebrafish was able to rapidly grow, form new blood vessels to supply the tumor with oxygen and other nutrients, and even showed the ability to invade other parts of the zebrafish.
Next, they wanted to look at the zebrafish cancer response after therapy with two different chemotherapy cocktails that are used in the clinic to treat colorectal cancers. They did this by adding the drugs to the water that the zebrafish were housed in. What they saw was quite interesting. Some tumors completely shrank while others did at different degrees or didn’t at all. This suggests that colorectal tumors from different patients respond differently to the same drug. Furthermore, these patient-derived tumors in the zebrafish were almost 100% correct at predicting patient tumor relapse after surgery. These results of the zebrafish cancer response were reported in Science Magazine.
This development is important because the majority of the work that is being done with regards to personalized medicine in cancer is mostly in mice. However, studies using mice are not only time consuming (it can take anywhere between 3-6 months to grow a tumor in a mouse and a mere few days in the zebrafish), but they are also expensive. The advantages of the zebrafish model are tremendous, including low cost, fast to raise, and quick to multiply. It is important to keep in mind that zebrafish are not quite as similar to humans as are mice and not all drugs that are used in humans will work in zebrafish. Research of this type is in its infancy, and there remains much work to be done. Once these challenges are overcome, many clinicians believe that the zebrafish cancer response is paving the way to a future of personalizing cancer therapy.
Written by Ingrid Qemo, BSc.