Clipping Board » Research Report ─ The latest medical research reports and related news.
Update Date: 2008/09/01 01:20
(AFP, Paris, 31st)
According to a research report disclosed today, American researchers have unraveled the mystery of the enzyme "telomerase," which plays a crucial role in the growth of most cancers, paving the way for the potential development of novel anti-cancer drugs.
Other scientists who reviewed this research hailed it as a significant breakthrough in basic cancer biology but also cautioned that much work remains to be done before these findings can be translated into a new generation of therapies.
Dr. Skordalakes, a professor at the Wistar Institute in Philadelphia who led the study, stated that telomerase "is an ideal target for chemotherapy because it is active in almost all human cancer tumors but inactive in the vast majority of normal cells."
Skordalakes said, "This means that drugs inhibiting telomerase are likely to be effective against all cancers with few side effects."
Human telomerase synthesizes DNA fragments called telomeres, which attach to the ends of chromosomes, preventing damage and loss of genetic information during cell division. This enzyme is primarily active in frequently proliferating cells such as embryonic stem cells but remains inactive in normal cells to avoid uncontrolled cell proliferation.
However, in cancer cells, telomerase is activated, allowing diseased cells to continuously divide and proliferate, achieving what scientists refer to as "cellular immortality," a hallmark of all cancers.
A decade-long study on telomerase inhibitors has been hindered by a lack of in-depth understanding of the enzyme's structure.
Skordalakes and his colleagues were the first to provide a complete structure of the crucial proteins within the enzyme's molecule. They revealed at the atomic level how the enzyme replicates the telomeres at the ends of chromosomes, a process critical to tumor development.
The same mechanism also involves the aging process, suggesting that any new inhibitors might also help extend lifespan.
The main obstacle in studying the complex structure of this enzyme was the inability to obtain sufficient quantities of the enzyme, whether from humans or yeast.
Skordalakes screened a wide range of organisms, including protozoa and insects, and finally discovered that the red flour beetle, a pest found in barns, could produce a stable and abundant quantity of telomerase.
He said, "This is a real breakthrough. Once we found that the genes of this organism produced the protein in the quantities we needed, we were able to make rapid progress."
The researchers used "X-ray crystallography" to analyze the three-dimensional structure of the enzyme's active region produced by X-rays shining on molecular crystals. Understanding the structure of this region, known as telomerase reverse transcriptase (TERT), allowed them to unravel the mystery of how the enzyme operates.
Skordalakes stated, "This is the first time we have been able to understand how telomerase synthesizes at the ends of chromosomes when it begins to replicate telomeres."
Several scientists who previewed the study before its disclosure praised the significance of these findings. However, they also noted that this is just one of a series of important steps toward novel cancer therapies.
Dr. Newell, head of translational research at the UK Cancer Research Association, told AFP, "There is no doubt that determining the structure of telomerase is crucial to understanding cancer biology and may help in the development of telomerase inhibitors. But it is still too early to say whether these inhibitors will ultimately become effective anti-cancer therapies."
Source: http:/ / tw. news. yahoo. com/ art……url/ d/ a/ 080901/ 19/ 154kb. html
US Scientists Unlock Key Enzyme Secrets, Open New Cancer-Fighting Path
(AFP, Paris, 31st)
According to a research report disclosed today, American researchers have unraveled the mystery of the enzyme "telomerase," which plays a crucial role in the growth of most cancers, paving the way for the potential development of novel anti-cancer drugs.
Other scientists who reviewed this research hailed it as a significant breakthrough in basic cancer biology but also cautioned that much work remains to be done before these findings can be translated into a new generation of therapies.
Dr. Skordalakes, a professor at the Wistar Institute in Philadelphia who led the study, stated that telomerase "is an ideal target for chemotherapy because it is active in almost all human cancer tumors but inactive in the vast majority of normal cells."
Skordalakes said, "This means that drugs inhibiting telomerase are likely to be effective against all cancers with few side effects."
Human telomerase synthesizes DNA fragments called telomeres, which attach to the ends of chromosomes, preventing damage and loss of genetic information during cell division. This enzyme is primarily active in frequently proliferating cells such as embryonic stem cells but remains inactive in normal cells to avoid uncontrolled cell proliferation.
However, in cancer cells, telomerase is activated, allowing diseased cells to continuously divide and proliferate, achieving what scientists refer to as "cellular immortality," a hallmark of all cancers.
A decade-long study on telomerase inhibitors has been hindered by a lack of in-depth understanding of the enzyme's structure.
Skordalakes and his colleagues were the first to provide a complete structure of the crucial proteins within the enzyme's molecule. They revealed at the atomic level how the enzyme replicates the telomeres at the ends of chromosomes, a process critical to tumor development.
The same mechanism also involves the aging process, suggesting that any new inhibitors might also help extend lifespan.
The main obstacle in studying the complex structure of this enzyme was the inability to obtain sufficient quantities of the enzyme, whether from humans or yeast.
Skordalakes screened a wide range of organisms, including protozoa and insects, and finally discovered that the red flour beetle, a pest found in barns, could produce a stable and abundant quantity of telomerase.
He said, "This is a real breakthrough. Once we found that the genes of this organism produced the protein in the quantities we needed, we were able to make rapid progress."
The researchers used "X-ray crystallography" to analyze the three-dimensional structure of the enzyme's active region produced by X-rays shining on molecular crystals. Understanding the structure of this region, known as telomerase reverse transcriptase (TERT), allowed them to unravel the mystery of how the enzyme operates.
Skordalakes stated, "This is the first time we have been able to understand how telomerase synthesizes at the ends of chromosomes when it begins to replicate telomeres."
Several scientists who previewed the study before its disclosure praised the significance of these findings. However, they also noted that this is just one of a series of important steps toward novel cancer therapies.
Dr. Newell, head of translational research at the UK Cancer Research Association, told AFP, "There is no doubt that determining the structure of telomerase is crucial to understanding cancer biology and may help in the development of telomerase inhibitors. But it is still too early to say whether these inhibitors will ultimately become effective anti-cancer therapies."
Source: http:/ / tw. news. yahoo. com/ art……url/ d/ a/ 080901/ 19/ 154kb. html