NEW YORK (Reuters Health) - Canadian researchers have found an intrinsically death-resistant cell-of-origin that gives rise to retinoblastoma, they report in the June issue of Cancer Cell.
It is known that loss of the Rb gene is involved in human retinoblastoma, and Dr. Rod Bremner and colleagues at the University of Toronto used a mouse model involving Rb/p107 deficient animals to study how this genetic knockout affects cellular processes.
As Dr. Bremner told Reuters Health, treatments for this childhood cancer “include removal of eyes or therapies that can lead to loss of sight or enhance rates of other cancers later in life. Less detrimental treatments are required.”
Dr. Bremner and his colleagues induced retinoblastoma by specifically knocking out the Rb gene in the mouse retina. “Our data identified the type of retinal cell that is the source of retinoblastoma,” he said.
Moreover, he continued, “our results show that retinoblastoma arises from a cell type that has a property that resembles a cancer cell. That is, it is resistant to cell death.”
Apoptosis “is a powerful way in which tissues prevent cancer. Peeling skin after sunburn is a classic example of this protective process,” he continued. Cells that are the source of retinoblastoma “appear to lack this critical defense. Thus, they have a head start in the cancer race.”
“If we can figure out the wiring that makes these cells naturally death resistant,” he concluded, “it may be possible to design drugs that overcome this weakness. In that way, we could halt retinoblastoma at a very early stage.”
Moreover, “the Rb gene is involved in many kinds of human cancer, thus what we learn in the retina will likely have broad implications for other malignancies.”
Source: Cancer Cell 2004;5:539-551. [ Google search on this article ]
MeSH Headings:DNA-Binding Proteins: Nuclear Proteins: Phosphoproteins: Retinoblastoma Protein: Genes, RetinoblastomaCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
