 |
|
Drug has ability to cure type of leukemia
October 03, 2007Imatinib can kill cancerous stem cells if given enough time, study says
Irvine, Calif. - 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."
Public Library of Science
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."
Public Library of Science
Stem Cells Current Events and Stem Cells News RSSPure insulin-producing cells produced in mouse
Singapore researchers have developed an unlimited number of pure insulin-producing cells from mouse embryonic stem cells (ESCs).
Adult stem cell breakthrough
The first tissue-engineered trachea (windpipe), utilising the patient's own stem cells, has been successfully transplanted into a young woman with a failing airway. The bioengineered trachea immediately provided the patient with a normally functioning airway, thereby saving her life.
First trachea transplant without immunosuppression
After 4 years of going from consultation to consultation, Claudia Castillo finally found a solution to her respiratory problems. The young Colombian woman suffered from a cough that took a long time to be diagnosed as tuberculosis.
First Trial in the U.S. to Treat Both Ischemic & Non-Ischemic Heart Failure to be Performed by U of U Researchers Using Patient's Own Stem Cells
Researchers at the University of Utah are enrolling people in a new clinical trial that uses a patient's own stem cells to treat ischemic and non-ischemic heart failure.
New imaging technique tracks cancer-killing cells over prolonged period
Coaxing a patient's own cells to hunt down and tackle infected or diseased cells is a promising therapeutic approach for many disorders.
Exercise increases brain growth factor and receptors, prevents stem cell drop in middle age
A new study confirms that exercise can reverse the age-related decline in the production of neural stem cells in the hippocampus of the mouse brain, and suggests that this happens because exercise restores a brain chemical which promotes the production and maturation of new stem cells.
Intraspinal implant of mesenchymal stem cells may not heal the demyelinated spinal cord
Multiple sclerosis is a disease caused by the loss of the myelinated sheath surrounding the nerve fibers of the spinal cord.
Protein can nurture or devastate brain cells, depending on its 'friends,' researchers find
Researchers at UT Southwestern Medical Center have uncovered new insights into the "Dr. Jekyll and Mr. Hyde" nature of a protein that stimulates stem-cell maturation in the brain but, paradoxically, can also lead to nerve-cell damage.
The bonsai effect: Wounded plants make jasmonates, inhibiting cell division, stunting growth
It is well known that plants growing under unfavourable conditions are generally smaller than those growing in stress-free conditions: indeed it is estimated that in the US, abiotic stress reduces the yield of agricultural crops by an average of 22%.
Stem Cells from Monkey Teeth Can Stimulate Growth and Generation of Brain Cells
Researchers at the Yerkes National Primate Research Center, Emory University, have discovered dental pulp stem cells can stimulate growth and generation of several types of neural cells. Findings from this study, available in the October issue of the journal Stem Cells, suggest dental pulp stem cells show promise for use in cell therapy and regenerative medicine, particularly therapies associated with the central nervous system.
More Stem Cells Current Events and Stem Cells News Articles
 | The Stem Cell Divide: The Facts, the Fiction, and the Fear Driving the Greatest Scientific, Political, and Religious Debate of Our Time by Michael Bellomo As politics, religion, and the media weigh in on the complex stem cell issue, more and more of the scientific reality is getting lost. In the search for the truth, "The Stem Cell Divide" does not take sides and debunks the distortions and exaggerations that come from every camp, while providing a complete picture of what scientists have accomplished so far, what they're currently doing and what... |
 | Stem Cell Now by Christopher Thomas Scott The essential account of the most important scientific advance—and most volatile ethical debate—of our time While many believe stem cell research holds the key to curing a wide range of ailments, others see this research as opening a Pandora’s box that will devalue human life. In Stem Cell Now, Christopher Scott—executive director of Stanford University’s Stem Cells and Society... |
 | Stem Cell Research: Medical Applications And Ethical Controversy (The New Biology) by Joseph, Ph.D. Panno This is an informative reference to the technological advances, applications, and issues of stem cell research. The past few years have seen controversy and debate surrounding stem cell research. Because skin cells have the capability to divide - unlike most of the cells in our body - our skin can heal itself through the division of cells. Scientists have attempted to apply this concept to major... |
 | The Stem Cell Controversy: Debating the Issues (Contemporary Issue Series) Stem cell research is headline news. Researchers are eager to move forward, state governments and private foundations are rushing to support it, and the sick and afflicted are desperate for its benefits. Yet powerful forces in our society - led by President George W. Bush - find it morally troubling and they are doing all in their powers to restrict its development beyond a very limited scale.... |
 | Fundamentals of the Stem Cell Debate: The Scientific, Religious, Ethical, and Political Issues Few recent advances in science have generated as much excitement and controversy as human embryonic stem cells. The potential of these cells to replace diseased or damaged cells in virtually every tissue of the body heralds the advent of an extraordinary new field of medicine. Controversy arises, however, because current techniques required to harvest stem cells involve the destruction of the... |
 | Essentials of Stem Cell Biology by Robert Lanza, E. Donnall Thomas, James Thomson, Roger Pedersen, John Gearhart, Brigid Hogan, Douglas Melton, Michael West This abridged version of the bestselling reference Handbook of Stem Cells, Two-Volume Set attempts to incorporate all the essential subject matter of the original two-volume edition in a single volume. The material has been reworked in an accessible format suitable for students and general readers interested in following the latest advances in stem cells, including full color presentation... |
 | Stem Cell Century: Law and Policy for a Breakthrough Technology by Russell Korobkin The explosion of interest in stem cell research raises a raft of controversial policy questions. When should human embryos be used to create stem cells? Should cloning be outlawed? Should egg and tissue donors be paid? Should we allow scientists to patent stem cells? Is the government entitled to a portion of the revenue from stem cell technology created with public funds? How should the... |
 | The Stem Cell Dilemma: Beacons of Hope or Harbingers of Doom? by Leo Furcht, William Hoffman TodayÕs scientists are showing us how stem cells create and repair the human body. Unlocking these secrets has become the new Holy Grail of biomedical research. But behind that search lies a sharp divide. Stem cells offer the hope of creating or repairing tissues lost to age, disease, and injury. Yet because of this ability, stem cells hold the potential to incite an international biological... |
 | Cell of Cells: The Global Race to Capture and Control the Stem Cell by Cynthia Fox Positioned at the cutting edge of science, Cell of Cells charts the international race to utilize the stem cell.From a lab in the Sahara, where one problem is sand in the petri dishes, to an Israeli lab that narrowly escapes a terrorist bomb, stem cells have gone global. Not only are the cells studied in an escalating number of labs—and lands—but they are already being used. In Japan, a... |
 | Stem Cell Wars: Inside Stories from the Frontlines by Eve Herold Americans have become the victims of misinformation about stem cell research. Over the last few years, the stem cell debate has been intensely political, religious, and confusing to many people. Now, Eve Herold explains what this science is all about, who is for and against it, and why it must go forward. She pulls together fascinating stories to highlight every aspect of this multifaceted... |
| © 2008 BrightSurf.com |