March 2009 podcast transcript

00:00

Kat: Hello, I'm Dr Kat Arney. In this month's podcast we'll be finding out how our cells repair damage to DNA, and why this is so important in the development of cancer, plus we unveil the first in a series of national Cancer Research UK centres.

Coming up later, we hear about the importance of cervical screening. But first, here's the news with Nell Barrie.

00:53

Nell: A Cancer Research UK-funded study of over a million women has shown that drinking just one or two units of alcohol a day increases the risk of cancer. Two units is roughly the amount in a glass of wine, or a pint of beer.

The latest results from the Million Women Study were published in the Journal of the National Cancer Institute, and show that even drinking small amounts of alcohol can increase the risk of seven types of cancer, including breast, bowel and mouth cancer. The researchers think that alcohol causes around 5,000 cases of breast cancer every year in the UK.

Dr Lesley Walker, Director of Cancer Information at Cancer Research UK, explains what this finding means for women.

"Fundamentally the message is that the less you drink, the lower your risk. One of the things about this study is that it has given us a very clear indication that there is a risk associated with moderate drinking, that is maybe one drink every day.

Cancer Research UK is not putting out a hard and fast message about how much you should or shouldn't drink, but clearly the data show that the less you drink, the lower your risk."

Cancer Research UK's chief scientist Professor Sir David Lane and his team have made an important new discovery about p53, an important gene that normally protects us from cancer. P53 is known to be faulty in the majority of cancers.

Using zebra fish, the researchers found that different versions of p53, known as isoforms, play distinct roles within the cell, helping to maintain the balance between life and death. But in cancer, these controls go haywire, so damaged cells multiply out of control.

Here's Professor Lane, explaining more about the importance of his research.

"Because we've found this same isoform in humans, there are many issues about whether this new discovery will also be important for our understanding of p53 in human cancer. And we think that it will.

We know that the p53 response is very highly regulated – tiny differences in the level of the response affect human ageing, the frequency of cancer development, and also more recently fertility. So finding a new pathway that can control, feedback and regulate the p53 response is going to be very exciting."

AAnd finally, our Science Update Blog has been nominated for an award. The blog is nominated in Online Research Information category in the Association of Medical Research Charities annual Science Communication awards.

Since its launch last year, over 100,000 people have visited the blog, looking for reliable information about cancer stories in the news.

Kat: You can check out our Science Update blog at Scienceblog.cancerresearchuk.org And if you want find out more about these stories, or get the latest from the charity's scientists, and researchers around the world, then have a look at our News & Resources website.

03:50

Kat: SCancer Research UK recently announced the first in a series of national centres of excellence, which opened in Birmingham in February. The Liverpool centre has also now opened, and other major cities are set to follow over the coming year.

When you think of the words "cancer centre", you probably think of a big research building, or a hospital wing. But these new Cancer Research UK Centres are different – they're virtual centres.

The aim is to bring our scientists together with university researchers and local NHS doctors and nurses, to work together to push new discoveries from the lab to the clinic as fast as possible.

Each centre will have its own strategy, and will have specific areas of excellence that it will particularly focus on.

Here's the director of the Birmingham Cancer Research UK Centre, Professor Paul Moss, to explain more about the centre, and how it will work.

"The new centre's a really exciting vision because for the first time it's really going to bring together all forms of cancer research at many centres across the country. And it's really trying to facilitate interactions between scientists and doctors, to translate exciting science into clinical practice as quickly as possible.

As you know, Cancer Research UK envisaged these centres being rolled out across the whole country [building] areas of expertise. At Birmingham we're delighted that we're going to be the first centre in the country.

Birmingham is a large cancer centre, as befits the population in this area, and we've got a number of strengths in basic science, such as how viruses can cause cancer and how genes disrupt cells to cause cancer, and also in gene therapy.

But I like to think that what we're particularly strong on is the translational area – how we facilitate basic research into clinical trials and finally into patient therapy. That's something we've really been developing in the past few years.

It's really quite hard for people – even doctors – to appreciate quite how remarkable the advances in knowledge about cancer have been in the last twenty years.

We now have a tremendous understanding about how a cell becomes malignant, the changes that make a cancer develop. And we are just beginning to see new medicines being developed which take advantage of this knowledge.

And so there's an amazing opportunity over the next few decades to control many types of cancer in a far more effective way than we have in recent times. So it's a tremendously exciting time for cancer research.

We've worked with Cancer Research UK to set up a number of goals for the medium term. We will certainly be envisaging quite considerable advances in basic research in a number of areas, and we will promise to set up even more clinical trials, and translate our idea into practice.

But there are other things as well. We also want to really work with the communities across the West Midlands to improve understanding ad knowledge about what causes cancer and how to prevent cancer, and that's a very important aim.

And finally, training is important. We need to get bright young doctors, scientists and nurses working in cancer at this exciting time, so we'll be playing our part in training as well."

07:28

Kat: DNA is the instruction manual within all our cells, and damaged DNA is at the heart of cancer, as faulty DNA means faulty genes, which leads to cells multiplying out of control and forming tumours.

Our DNA is constantly under attack from substances in our environment such as tobacco smoke, and even from the chemical reactions that provide energy within our cells.

Simon Boulton is the head of the DNA Damage Response lab at Clare Hall laboratories in Hertfordshire. He spoke to our reporter Anna Lacey about DNA damage, DNA repair, and what this all has to do with cancer.

Simon Boulton package

"Everybody inherits DNA from their parents, and that information needs to be maintained at a very high level. If you lose any of that information, or it becomes damaged, there will be problems in interpreting that blueprint, and that gives rise to cancer.

So the reason why DNA repair and DNA damage sensing is so important for cancer, is because these are the machines that exist in our cells to detect and repair damage to the blueprint.

So if you don't have these repair or sensing mechanisms in place, then damage to the blueprint will be left unrepaired. Essentially these changes will become permanent and this will lead to accelerated problems and ultimately tumorigenesis.

People will be familiar with UV light from the sun – it causes changes to the DNA in your skin. Many people will be aware of melanoma – this is caused by excessive damage to DNA by sunlight.

But it's very important to realise that damage within us is occurring all the time. The very act of our cells living, metabolising. We produce energy, and certain by-products of that are called free radicals. These are highly reactive [chemicals] that can react with DNA and change it, and that's DNA damage.

That's not caused by something like UV light – it's part of the living process. So unfortunately your living causes problems and damage to DNA, and that must be repaired as well."

Because DNA is naturally damaged all the time, our bodies have evolved special DNA repair machines to fix it. However sometimes the DNA damage occurs in the machines themselves, meaning that they stop working properly.

"What we've discovered using basic research is that defects in one specific type of repair mechanisms leads to a specific kind of cancer. So a very good paradigm for this is a disease called xeroderma pigmentosum. This is defective in a DNA repair process called nucleotide excision repair. And if you're defective in that, then you get a lot of skin cancers."

Although researchers know that broken DNA repair machines can lead to cancer, no-one knows exactly how the machines work when they aren't broken. It's important to know this because whatever it is the machines are fixing, stops cancers from developing.

So if Simon studies the repair process at a molecular level, he'll be able to follow the machines to see where the DNA went wrong. To do this, Simon and his team are helped by an extremely useful organism.

"We use a worm – it's called C. elegans, it grows in the soil. The most important discovery from my lab was using a genetic approach in the worm to discover a gene that had been sought by the repair field for about three decades.

We have found, using the worm and extrapolating our findings to humans, how this thing works."

It's become clear in recent years that cancers are as unique as our own genetic blueprint – and as a result, we need to use genetics to develop drugs that home in on the cancer without harming healthy cells.

"These are the new generation, the next generation of drugs. What we're hoping to do is by improving the understanding of how DNA repair processes work, you can improve the efficacy of chemotherapy of radiotherapy treatments.

For example, by providing a drug that sensitises a tumour to radiotherapy, so you can use much lower doses than you currently have, that would be an obvious advantage. Because of you have a lower dose, you have less side effects and less influence on the normal cells of your body."

So it seems that some of the answers we're looking for in cancer will come from rather unlikely places. It could be from a sea urchin egg, or a fruit fly, or even a worm.

"It's not easy – we're basically trying to fill in a blank book of knowledge."

12:18

Kat: Cervical cancer has been in the news this month as a result of reality TV star Jade Goody's diagnosis with the disease.

While this is obviously a desperately sad time for Jade and her family, as it is for anyone going through cancer, we have seen a big increase in the number of people looking for information about cervical cancer and its symptoms, and about the national screening programme for the disease.

I spoke to one of our cancer information nurses, Jean Slocombe, to find out more about the importance of screening and the symptoms women should look out for.

"I would strongly advise any woman to take up her appointment if she's invited to go for cervical screening, because it's actually a really good test – it actually prevent cancer from developing.

The aim of the cervical cancer screening programme is to detect abnormal cells that might one day turn into cancer if they were left untreated, so it really does prevent a lot of women from developing cervical cancer.

Women are invited every three years, but once you get older – about 45 – if you've had no problems in the past, it might go down to 5-yearly.

Screening is good, but no test is completely 100 per cent infallible. So if somebody does have symptoms, even if they've been screened, then certainly go to your doctor and get them checked out. But it's important to remember that they're probably not going to be cervical cancer, but only your doctor can tell.

Basically speaking, [look out for] anything that's unusual for them – perhaps a discharge that's changed, particularly if it's bloodstained or very unpleasant, bleeding between sex, pain during sex if that's never happened before, and any kind of discomfort that's unusual for them."

14:14

Kat: We've reached the end once more so we hope you've enjoyed this month's podcast. You can keep up to date with all the latest progress in research from our Science Update blog.

And please let us know what you think of this podcast by leaving feedback on the blog, or emailing your comments to podcast@cancer.org.uk.

We'll be back next month with all the latest news from Cancer Research UK, so until then, goodbye!

Credits:
Presented and produced by Kat Arney
News by Nell Barrie and Kat Arney
Simon Boulton package by Anna Lacey
Original music written and performed by Kat Arney and Henry Scowcroft
With special thanks to all the participants