Vaccine hope for prostate cancer

19 June 2011 Last updated at 17:13 GMT By James Gallagher Health reporter, BBC News Cancer vaccines make the immune system target tumours A new approach to developing cancer vaccines has been used to treat prostate tumours, an international team of scientists has said.

DNA from healthy cells was used to create a vaccine which cured 80% of mice, Nature Medicine reports.

The researchers believe the principle could be applied to other cancers and have begun studies on melanoma.

Cancer Research UK said it was a significant development, but human trials would be needed.

Cancer vaccines are not new. Unlike traditional vaccines which protect against infection, these work by making the immune system attack tumours already in the body.

Specifically they target markers on the surface of cancerous cells, known as antigens.

Professor Alan Melcher, of the University of Leeds, said: "The biggest challenge in immunology is developing antigens that can target the tumour without causing harm elsewhere."

Mobilising defences

Researchers in Leeds and at the Mayo Clinic, in the US, broke up chunks of DNA from healthy prostate cells and inserted them into a virus.

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This is an interesting and significant study which could really broaden out the field of immunotherapy research”

End Quote Professor Peter Johnson Cancer Research UK The mice were then repeatedly infected with the virus.

The prostate DNA made the virus produce a wide range of prostate antigens, so when the immune system battled the virus it learned to attack the cancerous prostate cells.

Crucially, healthy prostate cells and other parts of the body were not affected.

In the lab, a course of nine injections with the virus cured 80% of mice with prostate tumours.

Professor Melcher said human trials were years rather than months away.

"We have reason to be quite excited. It's not out-of-the-blue research, but based on immunotherpay and virus treatments which are looking very promising and that is what is really exciting," he added

Doctors recently claimed that the drug Ipilimumab, which stimulates the immune system to fight cancer, could increase life expectancy.

Researchers say using healthy DNA is a "proof of principle" which could have implications for vaccines for other cancers. They are trialing the same technique in mice with skin cancer.

Professor Peter Johnson, Cancer Research UK's chief clinician, said: "This is an interesting and significant study which could really broaden out the field of immunotherapy research.

"Although the vaccine didn't trigger the immune system to overreact and cause serious side effects in mice, it will need to be further developed and tested in humans before we can tell whether this technique could one day be used to treat cancer patients."

Dr Kate Holmes, research manager at the Prostate Cancer Charity, said the study provided "new hope".

"Although we are hopeful that the results of this study could help to form the basis of a new cancer vaccine in future, it is important to remember that the researchers have only investigated the potential of their vaccine in mice.

"Further research looking at its effect in men is needed. We look forward to the outcome."

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Frog-skin drug could treat cancer

7 June 2011 Last updated at 05:52 GMT A protein from the waxy monkey frog can inhibit the growth of blood vessels Scientists at Queen's University Belfast have won an award for work on frog and toad skins which could lead to treatments for over 70 major diseases.

The researchers received the commendation at the Medical Futures Innovation Awards in London on Monday.

The research, led by Professor Chris Shaw at Queen's School of Pharmacy, has identified two proteins which can regulate how blood vessels grow.

The team are the only entry from NI to win at this year's awards.

They discovered that a protein from the waxy monkey frog can inhibit the growth of blood vessels and could be used to kill cancer tumours.

Professor Shaw said that most cancer tumours can only grow to a certain size before they need blood vessels to grow into the tumour to supply it with vital oxygen and nutrients.

"Stopping the blood vessels from growing will make the tumour less likely to spread and may eventually kill it," he said.

"This has the potential to transform cancer from a terminal illness into a chronic condition."

The team have also discovered that the giant firebellied toad produces a protein which can stimulate blood vessel growth and could help patients recover from injuries and operations much more quickly.

Serendipity

"This has the potential to treat an array of diseases and conditions that require blood vessels to repair quickly, such as wound healing, organ transplants, diabetic ulcers, and damage caused by strokes or heart conditions," Professor Shaw said.

According to the professor, scientists and drugs companies around the world, despite an investment of around $4-5bn, have yet to develop a drug that can effectively target, control and regulate the growth of blood vessels.

"The aim of our work at Queen's is to unlock the potential of the natural world - in this case the secretions found on frog and toad skins - to alleviate human suffering. We are absolutely convinced that the natural world holds the solutions to many of our problems, we just need to pose the right questions to find them.

"It would be a great shame to have something in nature that is potentially the wonder drug to treat cancer and not aim to do everything in our power to make it work."

Commenting on the work of Professor Shaw and his colleagues, Professor Brian Walker and Dr Tianbao Chen, the judging panel said they wanted to encourage the researchers to take their work to "the next level".

"Many of the great discoveries have been through serendipity and Professor Shaw's idea is indeed very innovative and exciting in an area of much unmet need," the panel said

"It is important to realise that the innovation is at an early stage and much work needs to be done to turn this in to a clinical therapy."

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Mobiles 'may cause brain cancer'

31 May 2011 Last updated at 16:43 GMT By James Gallagher Health reporter, BBC News Is there a risk of brain cancer from using a mobile phone? The World Health Organization's cancer research agency says mobile phones are "possibly carcinogenic".

A review of evidence suggests an increased risk of a malignant type of brain cancer cannot be ruled out.

However, any link is not certain - they concluded that it was "not clearly established that it does cause cancer in humans".

A cancer charity said the evidence was too weak to draw strong conclusions from.

A group of 31 experts has been meeting in Lyon, France, to review human evidence coming from epidemiological studies.

They said they looked at all relevant human studies of people using mobile phones and exposure to electromagnetic fields in their workplace.

The WHO's International Agency for Research on Cancer (IARC) can give mobile phones one of five scientific labels: carcinogenic, probably carcinogenic, possibly carcinogenic, not classifiable or probably not carcinogenic.

It concluded that mobiles should be rated as "possibly carcinogenic" because of a possible link with a type of brain cancer - glioma.

Ed Yong, head of health information at Cancer Research UK, said: "The WHO's verdict means that there is some evidence linking mobile phones to cancer but it is too weak to draw strong conclusions from.

"The vast majority of existing studies have not found a link between phones and cancer, and if such a link exists, it is unlikely to be a large one.

"The risk of brain cancer is similar in people who use mobile phones compared to those who don't, and rates of this cancer have not gone up in recent years despite a dramatic rise in phone use during the 1980s.

"However, not enough is known to totally rule out a risk, and there has been very little research on the long-term effects of using phones."

The WHO estimated that there are five billion mobile phone subscriptions globally.

Christopher Wild, director of the IARC, said: "Given the potential consequences for public health of this classification and findings it is important that additional research be conducted into the long term, heavy use of mobile phones.

"Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands free devices or texting."

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