Media Releases
» Go to news mainDalhousie zebrafish research tests safer, less toxic cancer therapies
(HALIFAX, N.S.) April 16, 2015 - Two new cancer studies out of Dalhousie Medical School have shown success in testing safer, less toxic treatments for a rare form of pediatric leukemia called T-cell acute lymphocytic leukemia (T-ALL). The studies were published by first-year medical student, Victoria Bentley, and Drs. Graham Dellaire and Jason Berman, associate professors in the Departments of Pathology and Pediatrics, respectively.
“There are about 300 cases of childhood acute leukemia in Canada each year,” says Dr. Dellaire. “80 per cent of those are acute lymphoblastic leukemia (ALL). T-ALL—specifically targets our body’s T-cells and accounts for approximately 15 per cent of these cases.”
“The studies are important because T-ALL is a high risk subset of leukemia that needs better therapies with less toxicities,” says Bentley. “We need better ways to screen drugs before they enter clinical trials and better ways to design a patient’s treatment plan. It’s possible to do both with the zebrafish xenotransplant model.”
The first study, published in Haematologica, demonstrates for the first time that T-cell leukemia from a patient’s bone marrow can be successfully xenografted—where tissues of one species are transplanted to another—in zebrafish.
The process involves microinjecting a patient’s tumor cells into the yolk sac of a 48-hour-old zebrafish embryo. As the zebrafish continues its natural growth, the T-ALL cells engraft in the zebrafish, allowing treatment response to be tested in the lab. An effective drug is identified when the xenografted cells in the zebrafish no longer divide—or ultimately die—compared to cells without a drug treatment.
“Our zebrafish xenograft model allowed us to determine the susceptibility of a patient’s T-ALL within three days,” says Dr. Dellaire. “If we were using this information to guide therapy, we could rapidly identify an effective drug and personalize a patient’s therapy, reducing side-effects and improving outcome.”
The co-authors are also using a zebrafish model to test protectants for cardiotoxicity: the damaging effects of chemotherapy on the heart.
Published in Science Translational Medicine, the group’s second, high-impact study examined the chemotherapy drug doxorubicin, a common treatment for leukemias and many adult cancers, including breast cancer.
“When zebrafish embryos are treated in water with doxorubicin, they develop abnormalities of the heart,” explains Dr. Berman. “Children treated with doxorubicin for leukemia often suffer heart damage, predisposing them to heart failure for many years following treatment.”
The group’s studies on chemoprotectants began through a collaboration with Dr. Randall Peterson at Massachusetts General Hospital and Harvard Medical School. The group identified a number of compounds that protects the heart against doxorubicin, the most promising being a drug called visnagin.
It was discovered that when visnagin was used in the group’s leukemia zebrafish transplant model, the doxorubicin treatment retained it’s ability to effectively kill the human leukemia cells xenografted in the zebrafish, but the visnagin prevented damage to the zebrafish heart.
“Clearly, if doxorubicin-like drugs are going to continue to be used, we need to be able to give these safely,” says Dr. Berman. “Identifying new heart protective drugs is really important. Ultimately, drugs like visnagin may be combined with chemotherapy given to patients. The combination isn’t planned for clinical trial yet, but is something that we hope to pursue in the future.”
-30-
Images
![]() |
Zebrafish Research Dalhousie Medical School researchers have successfully been able transplant human leukemia cells into zebrafish embryos (shown above) to study their growth and test anti-cancer therapies.Photo Credit: Nick Pearce Download Hi-Res image |
Contacts
Cory Burris
Dalhousie Medical School Communications
cory.burris@dal.ca
1-902-494-4247
Comments
comments powered by Disqus
Recent News
- Media opportunity: Being involved in extracurricular activities really does matter when it comes to 'mattering': Dalhousie University research
- Media opportunity: Podcast by Dalhousie researcher and Halifax photographer looks at barriers to Nova Scotia's coastline, decreasing access to waterfronts and problems with litter, marine debris in public coastal areas
- Media opportunity: Dalhousie University researcher pioneers new cancer treatment ‑‑ cutting‑edge CAR‑T cell therapy
- Media opportunity: Research sheds light on the difficulty temporary foreign workers can face in securing permanent residency in P.E.I.
- Media opportunity: World's largest stores of unfrozen freshwater projected to warm and affect cold‑water habitats, geothermal energy resources and drinking water quality : Dalhousie University research
- Media release: Dalhousie University research reveals conservation benefits are doubled for reef sharks and rays in fully protected marine areas that also have strong fisheries management
- Media release: New program partners Dalhousie researcher and IWK Health to tackle violence against women
- Media opportunity: Dalhousie University researchers and an international team identify new strain of mpox virus in Africa that can spread through heterosexual sex and community contact