09-01-08, 03:59 AM #1
Hopes raised for block on cancer??????????
Page last updated at 23:01 GMT, Sunday, 31 August 2008 00:01 UK
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Hopes raised for block on cancer
Cancer patient treated with drugs
Cancer cells keep dividing
Scientists say they have taken a big step towards blocking a chemical vital to the "growth of many cancers.
They have unpicked the structure of telomerase, an enzyme which, when active, helps keep cells in an "immortal" state.
The chemical is at work in more than nine out of ten types of tumour.
Researchers from Philadelphia's Wistar Institute, writing in the journal Nature, say their efforts could lead to drugs which switch it off.
All cells in the body have a natural clock - the telomeres - which shorten every time the cell divides.
The idea is that you could convert immortal cancer cells back into mortal ones by blocking telomerase in this way
Professor Rob Newbold
After a fixed number of divisions in most cells, the telomeres are reduced to a certain length, and the cell cannot continue dividing.
This change is responsible for changes within the ageing body, as cell division slows down.
Some cells, such as stem cells within the embryo, use the chemical telomerase to maintain telomere length.
Many tumours have hijacked the telomerase system to fuel their uninhibited growth.
The Wistar team has found a new way to map the structure of the most active part of the chemical.
'Few side effects'
Dr Emmanuel Skordalakes said that this detailed picture would help provide molecular targets for drugs.
"Telomerase is an ideal target for chemotherapy because it is active in almost all human tumours, but inactive in most normal cells.
"That means that a drug that deactivates telomerase would likely work against all cancers, with few side effects."
Last Updated: Friday, 5 May 2006, 23:37 GMT 00:37 UK
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Cancer agent mysteries revealed
Protein structure with groove highlighted in green
The protein has proved difficult to analyse
Scientists have cracked the structure of an essential part of an enzyme believed to play a key role in the development of many cancers.
The University of Colorado team hopes its work will help explain how the enzyme, telomerase, acts to make cancer cells "immortal".
The scientists also hope it could lead to a new generation of more effective cancer drugs.
Details are published in the journal Nature Structural & Molecular Biology.
Developing therapies that block the action of telomerase would be a great way to treat many types of cancer
Dr Kat Arney
It is thought that over-activity of telomerase contributes to the unchecked growth of as many as 90% of human tumours.
The researchers say a lack of detailed information about its structure has hindered attempts to develop agents to block its effect.
Telomerase plays a key role in the development of the human embryo during pregnancy, by extending important areas at the tips of chromosomes called telomeres.
In most healthy adult cells the enzyme is completely shut down.
However, cancer cells find a way to turn telomerase back on - triggering uncontrolled cell division.
'Difficult to study'
It has previously proved difficult to study telomerase in close detail because the enzyme tends to clump together outside of cells, preventing it from forming the ordered crystals necessary for structural analysis.
The Colorado team solved the problem by using a fluorescent green protein to highlight rare fragments of the enzyme that did not clump together in the usual way.
These came from a single-celled organism called a tetrahymena - the same organism in which telomerase was first discovered.
The researchers then used a few more biochemical tricks to crystallise out the protein fragments, and analyse them, eventually producing an extremely detailed three-dimensional atomic map.
They found that the protein fragment had a deep groove on its surface.
It is thought that this might be used to grab hold of the end of the chromosome in order to extend its telomere region, and trigger uncontrolled genetic division.
The researchers tested this theory by making tiny structural changes to this grooved area, and found this seemed to neutralise the enzyme's action.
Lead researcher Dr Thomas Cech said: "A molecule that would sit in that groove looks like it would completely abolish the ability of telomerase to work."
Dr Kat Arney, Science Information Officer at Cancer Research UK, said: "Developing therapies that block the action of telomerase would be a great way to treat many types of cancer.
"Thanks to this research, we now know more about the 3-D shape of the enzyme, so scientists around the world can get to work designing drugs to fit it precisely."
I find scientists are a hoot & so are doctors, they pinch eachothers work year in & out & present it as new findings every year.
"They have unpicked the structure of telomerase" >>>>>(dated 2008)
"Scientists have cracked the structure of an essential part of an enzyme believed to play a key role in the development of many cancers. explain how the enzyme, telomerase, acts to make cancer cells "immortal". >>>>>(dated 2006)
As one in 3 of us will develop cancer at some point in our life, why do we let these parasites mock us with these farcical findings, in both links dated 2 years apart they were saying they will develop new drugs to block Telomerase, i have no doubt what so ever that in a year or 2 & another bunch of eggheads will present the same findings in the lancet or british medical journal & once again giving people false hope.
Every year these morons say there will be a cure for all cancers in five years, i have been hearing that for the last 25 years of my adult life.
Why are doctors & scientists so detached from reality, the patients, & humanbeings in general, were like lab rats to them all, case in point would be that idiot antrax scientist in america who decided to test it on his fellow citizens in america or lab rats as he would see it.
With the exception of doctors without borders, i find all doctors as mercanary bastards who take sadistic glee in telling patients bad news, even when the patient is actually not sick, my mother was given the all clear after cyst removal, only to have a sadistic doctor making her cry by saying she is not out of the woods yet, later the nurses told her that he just enjoys being sadistic with patients much like HOUSE MD.
Most doctors actually have mediocre knowledge on alot of diseases & symptoms, you realy can make a fool of them if you spend all of 2 minutes reading up on your disease, as for cancer unless you have a lump, night sweats most of them say you dont have cancer, but the reality is when you do have that bump or the daily night sweats your immune system is failing & the cancer has spread, what they cant seem to comprehend is your supposed to find it before the patient gets the bump & sweats, continous lymph node inflammation & itching is a ideal canditate for cancer, especially in the neck area.
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