UC Davis researchers shed new light on how chemotherapy-induced leukemia develops

November 16, 2005

(SACRAMENTO, Calif.) -- Topoisomerase II inhibitors are among the most successful chemotherapy drugs used to treat human cancer. But a small percentage of patients treated with these agents recover from their initial malignancy only to develop a second cancer, leukemia.

Researchers at UC Davis Cancer Center have shed new light on this poorly understood process. In a study to be published in the Nov. 22 issue of the journal Leukemia, the researchers report that topoisomerase II inhibitors do not directly cause leukemia -- and suggest that it may be possible to prevent therapy-induced leukemia. (The study was posted online in the journal on Sept. 29.)

"There are two competing theories of how these therapy-induced leukemias arise," said Andrew Vaughan, a radiation biologist at UC Davis Cancer Center and senior author of the new study. "One is that the topoisomerase II inhibitor drugs, in combination with the topoisomerase II enzyme they target, induce random genetic changes that lead to leukemia onset. The other is that another, potentially correctable process is at work."

In the study, Vaughan and his colleagues at Loyola University and the Sacramento Veterans Administration Hospital linked what appears to be the earliest molecular event involved in the development of therapy-induced leukemia, the rearrangement of the MLL gene (a gene involved in leukemia), to factors that activate apoptosis, or programmed cell death.

"This rearrangement appears to be independent of the topoisomerase II enzyme," Vaughan said. "This suggests that another process, such as apoptosis itself, is involved."

Topoisomerase II inhibitors work by goading cancerous cells into apoptosis. Vaughan suggests that therapy-induced leukemia may occur when some cancer cells fail to complete apoptosis and instead survive in a mutated form that contains the leukemia-inducing MLL gene.

"The good news is that apoptosis is a well-understood and potentially correctable process," Vaughan said. "Through genetic or pharmacologic means, we may be able to manipulate the cells that survive chemotherapy to complete apoptosis and die -- averting the development of leukemia."
-end-
UC Davis Cancer Center is the only National Cancer Institute-designated cancer center serving the Central Valley and inland Northern California, a region the size of Pennsylvania. Its cancer research program brings together 180 scientists on three campuses: the UC Davis Medical Center campus in Sacramento, the main UC Davis campus in Davis, Calif., and Lawrence Livermore National Laboratory in Livermore, Calif.

Media Contact:
Claudia Morain, UC Davis Cancer Center: (916) 734-9023
E-mail: claudia.morain@ucdmc.ucdavis.edu

Public Affairs
UC Davis Health System
4900 Broadway, Suite 1200
Sacramento, CA 95820
Phone: (916) 734-9040
FAX: (916) 734-9066
E-mail: publicaffairs@ucdmc.ucdavis.edu
Web address: http://www.ucdmc.ucdavis.edu/newsroom

University of California - Davis Health System

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.