A New Outlook On Cancer Research


Haley Noone and Kelsey Daly

In 1884, a tropical, freshwater fish native to the Southeast was discovered. The Zebrafish can be found in slow streams and rice paddies. They can only grow up to 2.5 inches. Due to their size and similar body structures, the Zebrafish belongs to the minnow family. All of the fish’s major organs appear within the first 36 hours of birth. It takes about 6 months for the fish to be fully grown and for their skin to become opaque.

At first, the Zebrafish became popular for its looks. People liked the way the fish looked when they were translucent at their young age. While translucent, you can see foods and liquids pass through them. Not only that, but people loved the blue and silver striping across their small bodies. Since they are freshwater fish, it was easy for people to take care of them. People keep them in tanks at their house because they do not have to maintain a saltwater tank. Eventually, scientists took interest in these fish and made life-changing discoveries.

Recently, scientists have learned that humans share 12,719 genes in common with the Zebrafish. That is 70% of all the total genes our DNA produces. This discovery then posed an important hypothesis: since we share more than half of the same genes, Zebrafish could be used in order to study human genes and diseases plague them. After some intensive research and experimentation, scientists found these fish are able to develop most of the types of tumors that humans can. More studies have also revealed that Zebrafish spontaneously develop almost any type of tumor known to humans. In recent research experiments, they have been used to model melanoma, leukemia, pancreatic cancer, and hepatocellular carcinoma (liver cancer). In order to speed up the process, scientists inject the type of cancer that is being tested into the embryos of the fish and saw if they accepted or rejected the cancer.

So, how can these fish actually help us, not just allow us to do research? One example has to do with leukemia; when a human has leukemia, their bone marrow starts producing a lot of abnormal white blood cells, called leukemic cells. They do not do the work of normal white blood cells, rather, they grow faster and they don not stop when they should. With this, these white blood cells are not fully developed. In order to test this, Leukemia cells were injected in embryonic Zebrafish to be studied as the fish grew. Since the fish have similar blood development and cellular structure to that of humans, the scientists could use the Zebrafish to find and tag these blood deficiencies.

Another good example of how Zebrafish are helping us move toward a brighter tomorrow goes with Pancreatic Cancer. Pancreatic cancer begins in the the pancreas, the organ lying behind the lower part of the stomach. It is a more rare form of cancer, having fewer than 200,000 U.S. cases per year. Although both the exocrine and endocrine cells of the pancreas can form cancer cells, the exocrine cancer cells are far more common than the endocrine cancer cells. By studying altered genes in Zebrafish, researchers can monitor the initiation, growth, and fatal effects of pancreatic tumors and their spread to other organs.

All in all, this small, freshwater fish has changed the cancer research field immensely. According to Ipswich High School’s Marine and Coastal teacher, Mrs. Lafrance, this was a huge step forward. “Coming from previously working in the medical field I truly believe this is a huge step forward in cancer research. Along with the new technology today, the Zebrafish has opened a new door to a cure for cancer.”