The findings, by researchers with the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, may have important implications for controlling cancer growth and progression.
Done in primary cells and in animal models, the findings from the three-year study appear Dec. 2, 2010 in the early online edition of the peer-reviewed journal Cell Stem Cell.
The protein, called Bmi-1, is often up-regulated in prostate cancer, has been associated with higher grade cancers and is predictive of poor prognosis, according to previous studies. However, its functional roles in prostate stem cell maintenance and prostate cancer have been unclear, said Dr. Owen Witte, who is director of the Broad Stem Cell Research Center, a Howard Hughes Medical Institute investigator and senior author of the study.
A study of loss and gain of function in prostate stem cells indicated that Bmi-1 expression was required for self-renewal activity and maintenance of prostate stem cells with highly proliferative abilities. Loss of Bmi-1 expression blocks the self-renewal activity, protecting prostate cells from developing abnormal growth changes which can lead to cancer.
More importantly, Bmi-1 inhibition slowed the growth of an aggressive form of prostate cancer in animal models, in which the PTEN tumor suppressor gene was removed allowing the cancer to run wild, Witte said.
“We conclude by these results that Bmi-1 is a crucial regulator of self-renewal in adult prostate cells and plays important roles in prostate cancer initiation and progression,” Witte said. “It was encouraging to see that inhibiting this protein slows the growth of even a very aggressive prostate cancer, because that could give us new ways to attack this disease.”
UCLA stem cell researchers have been studying the mechanisms of prostate stem cells for years on the theory that the mechanism that gives the cells their unique ability to self-renew somehow gets high jacked by cancer cells, allowing the malignant cells to grow and spread. If the mechanism for self-renewal could be understood, researchers could find a way to interrupt it once it is taken over by the cancer cells, Witte said.
Rita Lukacs, a doctoral student in Witte’s laboratory and first author of the study, found that Bmi-1 inhibition also stops excessive self-renewal driven by other pathways. This suggests that the Bmi-1 pathway may be dominant to other genetic controls that affect the cancer phenotype.
“Prostate cancer can be initiated by so many different mutations, if we can find a key regulator of self-renewal, we can partially control the growth of the cancer no matter what the mutation is,” Lukacs said. “We’re attacking the process that allows the cancer cells to grow indefinitely. This provides us an alternate way of attacking the cancer by going to the core mechanism for cancer cell self-renewal and proliferation.”
Witte said future work will be centered on searching for methods to control these pathways in human prostate cancer cells.
Prostate cancer is the most frequently diagnosed non-skin cancer and the second most common cause of cancer-related deaths in men. This year alone, more than 277,000 men in the United States will be diagnosed with prostate cancer. Of those, 32,000 men will die from the disease.
This study was funded by the California Institute for Regenerative Medicine, Howard Hughes Medical Institute, Prostate Cancer Foundation, Ovarian Cancer Research Fund, a Stewart and Lynda Resnick Prostate Cancer Foundation Grant and a Stein/Oppenheimer Clinical Translational Seed Grant.
The stem cell center was launched in 2005 with a UCLA commitment of $20 million over five years. A $20 million gift from the Eli and Edythe Broad Foundation in 2007 resulted in the renaming of the center. With more than 200 members, the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research is committed to a multi-disciplinary, integrated collaboration of scientific, academic and medical disciplines for the purpose of understanding adult and human embryonic stem cells. The center supports innovation, excellence and the highest ethical standards focused on stem cell research with the intent of facilitating basic scientific inquiry directed towards future clinical applications to treat disease. The center is a collaboration of the David Geffen School of Medicine, UCLA’s Jonsson Cancer Center, the Henry Samueli School of Engineering and Applied Science and the UCLA College of Letters and Science. To learn more about the center, visit our web site at http://www.stemcell.ucla.edu. To learn more about the center, visit our web site at http://www.stemcell.ucla.edu.
Further reports about: > Cancer > Medical Wellness > Regenerative Therapien > Science TV > Stem cell innovation > UCLA > animal models > cancer cells > cell death > clinical application > embryonic stem cell > human embryonic stem cell > methanol fuel cells > prostate > prostate cancer > stem cell research > stem cells
Immune Defense Without Collateral Damage
23.01.2017 | Universität Basel
The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering