Drug has ability to cure type of leukemia

October 3, 2007

In people with chronic myeloid leukemia (CML), the drug Imatinib has been shown to drive cancer into remission, but the disease often returns when treatment is stopped. New research by UC Irvine scientists indicates that Imatinib could cure CML under certain circumstances if it is taken over a long enough period of time.

Mathematician Natalia Komarova and biologist Dominik Wodarz also developed a tool that eventually could help doctors determine which combination of drugs would be most beneficial to a CML patient, and they determined why, in some cases, Imatinib does not block cancer growth. The results of their study will appear Oct. 3 in the journal PLoS ONE.

CML is a quick-progressing cancer that starts in the bone marrow and moves into the blood. The disease proceeds in three stages, the last one characterized by patient survival of only a few months. In 2007, an estimated 4,570 people in the United States will develop CML, and 490 people will die from it, according to the National Cancer Institute, a division of the U.S. National Institutes of Health.

The drug Imatinib is a promising cancer treatment because it has few side effects, and it specifically targets cancer cells. In their study, the UCI scientists focused on Imatinib and the behavior of cancerous stem cells. Just as normal stem cells maintain organs and a functioning body, cancer stem cells are thought to maintain cancer growth and are tough to kill with treatment.

Many scientists believe that Imatinib can kill regular cancer cells but not stem cells. When treatment ends, the remaining stem cells can produce more cancer cells, thus exacerbating the disease. According to this view, there is no hope to cure CML.

The UCI scientists, however, believe Imatinib can kill cancerous stem cells but not when the stem cells temporarily stop dividing, a state known as quiescence. All cancerous stem cells have the ability to enter the quiescent state. Evidence indicates that when such sleeping stem cells wake up, Imatinib can kill them.

In their paper, the scientists present a mathematical formula that can calculate how long it would take to kill all of the stem cells and cure the cancer. This length of time – which could be different for each patient – is based on how often the cancerous stem cells fall asleep and how quickly they wake up. Once the scientists can test their theory with patients, they will be able to determine how long the cure might take.

“There is evidence that a complete cure is possible. Several patients have been reported to have no symptoms after two months without therapy, which is thought to suggest a complete cure,” Komarova said. “This evidence supports our theory. Basically, one has to be on therapy long enough for all of the stem cells to wake up and be killed by the drug.”

In addition to sleeping stem cells, another barrier to eradication by Imatinib is that cancer cells can mutate to become unresponsive to certain drugs. Conventional thought is that if sleeping stem cells prolong a cure, other cancer cells will have ample time to mutate and become drug resistant.

The UCI scientists, however, have proved this theory wrong. Their calculations show that mutant cells develop early on, in many cases before the patients know they are sick, and do not develop during the treatment process. Using mathematics, they developed a way to calculate the probability that certain mutations exist in a patient. Based on this, one can determine what course of treatment should be used to overcome the resistance.

“The model requires the number of cancer cells that exist, how fast the cells divide and die, and how fast they go to sleep and wake up,” Wodarz said. “Once you have those numbers, you can determine how many drugs to use in combination to make sure drug resistant mutants do not become problems.”

Source: Public Library of Science

Explore further: New findings explain how UV rays trigger skin cancer

Related Stories

New findings explain how UV rays trigger skin cancer

October 18, 2017
Melanoma, a cancer of skin pigment cells called melanocytes, will strike an estimated 87,110 people in the U.S. in 2017, according to the Centers for Disease Control and Prevention. A fraction of those melanomas come from ...

Team finds a potentially better way to treat liver cancer

October 12, 2017
A Keck School of Medicine of USC research team has identified how cancer stem cells survive. This finding may one day lead to new therapies for liver cancer, one of the few cancers in the United States with an incidence rate ...

Scientists pinpoint surprising origin of melanoma

October 12, 2017
Led by Jean-Christophe Marine (VIB-KU Leuven), a team of researchers has tracked down the cellular origin of cutaneous melanoma, the deadliest form of skin cancer. The team was surprised to observe that these very aggressive ...

Bolstering fat cells offers potential new leukemia treatment

October 16, 2017
Killing cancer cells indirectly by powering up fat cells in the bone marrow could help acute myeloid leukemia patients, according to a new study from McMaster University.

German research advances in cancer and blood disorders reported in human gene therapy

October 18, 2017
Virotherapy capable of destroying tumor cells and activating anti-tumor immune reactions, and the use of engineered hematopoietic stem cells (HSCs) to deliver replacement genes that have the potential to cure blood diseases ...

Scientists identify biomarker for progression and drug response in brain cancer

October 16, 2017
Scientists at the Icahn School of Medicine at Mount Sinai, Sema4, and collaborating institutions including Colorado State University and Fred Hutchinson Cancer Center reported results today from a glioblastoma study in which ...

Recommended for you

Vaccinating against psoriasis, allergies and Alzheimer's a possibility, research shows

October 23, 2017
Research from the Universities of Dundee and Oxford has shown how combining the tetanus vaccine with a viral particle that normally affects cucumbers can be used to treat psoriasis and allergies, and may even protect against ...

Fighting opioid addiction in primary care—new study shows it's possible

October 18, 2017
For many of the 2 million Americans addicted to opioids, getting good treatment and getting off prescription painkillers or heroin may seem like a far-off dream.

With no morphine, 25 million die in pain each year: report

October 13, 2017
Every year, some 25 million people—one in ten of them children—die in serious pain that could have been alleviated with morphine at just a few cents per dose, researchers said Friday.

Study finds few restrictions on Rx opioids through Medicare

October 9, 2017
Medicare plans place few restrictions on the coverage of prescription opioids, despite federal guidelines recommending such restrictions, a new Yale study finds. The research results highlight an untapped opportunity for ...

Nocebo effect: Does a drug's high price tag cause its own side effects?

October 5, 2017
Pricey drugs may make people more vulnerable to perceiving side effects, a new study suggests—and the phenomenon is not just "in their heads."

Pre-packaged brand version of compounded medication to prevent preterm births costs 5,000 percent more

October 2, 2017
Preventing a preterm birth could cost as little as $200 or as much as $20,000, depending on which one of two medications a doctor orders, according to a new analysis from Harvard Medical School.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.