Scientists unlock genetics of kids’ brain tumour

May 19, 2010 By Leave a Comment

Washington, May 19 (ANI): An important cancer gene that could lead to more effective drugs being developed to fight pediatric high grade glioma – a disease that currently has a poor prognosis, has been identified.

Gliomas are the most common brain tumour in children.

Scientists at The Institute of Cancer Research (ICR) and The University of Nottingham on behalf of the UK Children’s Cancer and Leukaemia Group, and St Jude Children’s Research Hospital in the US, conducted by far the most comprehensive analysis to date of pediatric high-grade glioma, making a detailed scan of the genome of 78 newly-diagnosed patients.

They compared these pediatric tumour samples with the genome of adult gliomas, looking through 500,000 individual pieces of DNA for variations in the number of copies of each.

In pediatric gliomas, a gene called PDGFRA on chromosome 4q12 was commonly amplified and there were often extra copies of chromosome 1q. These changes are rarely seen in the adult form of the disease.

Clinical differences between gliomas in adults and youth had already been observed, for example growth in disparate areas of the brain, but this is the first study to establish that the underlying genetics differ.

“We found significant differences between the genomes of adult and young people’s gliomas. This is an important finding because it means studies on adult gliomas cannot simply be applied to younger patients, and it has particular implications for drug trials,” said Dr Chris Jones, Leader of the Paediatric Molecular Pathology Team at the ICR.

The researchers also tracked gene activity in 53 of the tumour samples, and compared the results with adult gliomas. Paediatric glioma tumours that did not have the PDGFRA alteration were nevertheless found to have associated genes switched on, suggesting that this biological pathway is a key to the development of this childhood cancer.

The PDGFRA gene carries instructions for making a protein found on the cell surface, which is part of a pathway that helps control cell growth, proliferation and survival — processes that are commonly disrupted in cancer.

“This cancer gene is unusually active in pediatric high-grade gliomas and is likely to be an important drug target,” said Professor Richard Grundy from the Children”s Brain Tumour Research Centre at The University of Nottingham.

In addition, 10 children in the study had glioma that arose after they were treated with radiotherapy to the brain for a previous cancer. Analysis of these children’s tumours revealed they had the gene alterations at even higher frequency than the other cancers studied, which had been triggered by other factors.

The presence of these alterations irrespective of the trigger for the cancer also indicates that they are crucial to glioma development.

The study has been published in the Journal of Clinical Oncology. (ANI)

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Landmark ruling deems cancer gene patents invalid

March 31, 2010 By Leave a Comment

A district court judge in the United States has ruled that patents should not have been awarded over the breast and ovarian cancer genes BRCA1 and 2.

The decision raises serious concerns about whether patents should be awarded on human and other genes and proteins found in nature.

It is the first time a court has found patents on genes unlawful and calls into question the validity of patents now held on about 2,000 human genes.

The case, brought by the American Civil Liberties Union (ACLU), was prompted by the actions of patent owner Myriad Genetics who claims the exclusive right to test for BRCA1 and BRCA2.

The tests show whether a woman is more susceptible to developing breast and ovarian cancer.

ACLU attorney Chris Hansen said: “Today’s ruling is a victory for the free flow of ideas in scientific research.”

Myriad Genetics charges women in the US around $3,700 for the test and the company does not allow second opinions.

The exclusive licence for the tests in Australia is owned by Genetic Technologies Limited which has “gifted” its intellectual property rights to Australian institutions and does not impose royalties here.

In 2003 and 2008, however, Genetic Technologies Limited sent legal letters to Westmead Hospital and the Peter MacCallum Cancer Institute in Victoria to cease testing for the BRCA1 and 2 genes.

In the district court in New York, Judge Robert Sweet found that certain respects of the seven patents awarded over the human genes are invalid.

Judge Sweet found that removing the gene from its natural environment, the body, is not sufficiently different to what is found in nature, therefore such processes are a “discovery” and not an “invention”, making any patent invalid.

On the diagnostic side, the judgment also says the use of the gene material in the test does not make the test patentable.

There is no transformation that happens to the biological materials themselves that means the company can claim an “invention” and therefore be awarded a patent over the genes.

Myriad Genetics has yet to announce whether it will appeal the decision.

In Australia, a Senate inquiry into gene patents is expected to report in June.

It has heard evidence from both sides of the argument including from Australia’s biotech industry, which says any moves to ban patents on genes will be disastrous for investment and the biotech industry as a whole.

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Potential therapeutic target for breast cancer identified

March 15, 2010 By Leave a Comment

London, March 15 (ANI): Scientists have identified a potential target for the treatment of breast cancer.

They have discovered a protein, which could stop cancer tumours from growing and spreading.

Professor Reuven Agami, of the Netherlands Cancer Institute in Amsterdam, found that the protein, known as BRD7, activates an anti-cancer gene, P53, which is already known to combat breast and other tumours.

Without the protein, the gene cannot function to stop tumours spreading.

The tumour suppressor P53 gene, present in all of us, is implicated in up to half of all tumours.

Agami found that the protein BRD7 activates P53 and could therefore suppress the development of cancer.

His said that although it is not clear how BRD7 can prevent the formation of a tumour, it is known that it is not always present in breast cancer.

Agami found that BRD7 activates P53, but when it is not present healthy cells can develop into a tumour.

“This research is very interesting because it identifies for the first time that this protein could have a role to play in a significant proportion of breast and other cancers,” the Daily Express quoted Dr Caitlin Palframan, policy manager at Breakthrough Breast Cancer, as saying.

“Further studies are now needed to confirm this protein’s role in cancer before it could be considered a potential target for new treatments,” she added.

The study has been published online in Nature Cell Biology. (ANI)

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Veggies, whole grains could encourage cancer growth in some cases

August 20, 2009 By Leave a Comment

Washington, Aug 20 (ANI): A new study has cast doubt on the cancer-fighting power of antioxidants- found in many vegetables and whole grains – by showing that they can also help cancer cells to survive and thrive in some situations.

Antioxidants have previously been found to prevent the formation of tumours by preventing free radicals, or highly reactive molecules, from causing DNA damage.

Now, scientists have shown that antioxidants may have the opposite effect in human breast cells.

In the new study, antioxidants behaved like cancer-causing agents, protecting cells that should otherwise have died-which allowed them to multiply and become cancerous.

“The survival of these cells could be contributing to [tumour creation], rather than the opposite,” National Geographic News quoted study leader Zachary Schafer of the University of Notre Dame in Indiana as saying.

Schafer and a team at Harvard Medical School cultured breast-tissue cells using simulated scaffolding that mimics how cells grow in the body.

The cells formed a spherical structure that became hollowed out as the cells in the center detached from the cells on the scaffolding and died.

However, when the researchers introduced a cancer gene into the mix, the detached cells did not die-just as happens in the body.

“This happens in early breast cancer lesions,” said Schafer.

Meanwhile, the researchers noticed that the normal, detached cells without the cancer gene were being damaged by naturally occurring free radicals.

Also, the detached cells were not producing enough ATP, a critical energy molecule.

The researchers added high concentrations of antioxidants to the cell culture in an effort to suppress the harmful free radicals and boost ATP production.

They found that antioxidants have exactly the same effect as the cancer gene: The detached cells did not die.

This is because the antioxidants are helping the cells recover their ability to produce ATP, Schafer said. The cancer gene also restored ATP production in the cells.

The researchers, however, insist that the findings should not alarm cancer patients as the research is laboratory based and the results may not replicate in people.

The study has been reported online in the journal Nature. (ANI)

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