A team of Worldwide Cancer Research scientists in France have studied the genetic code of fruit flies to investigate what goes wrong when inherited genes trigger a tumour to grow. The researchers hope that what they have learned in fruit flies could apply to cancer in humans, and in future lead to the development of drugs that can prevent familial or hereditary cancers from starting.
We had some really exciting observations that indicated that we had seen something that people hadn’t really noticed before, and we had a difficult time getting funding for this precisely because it was hard for others to believe that we had found something that had been overlooked. This was where Worldwide Cancer Research became really important for us and provided us with support at a critical moment in the project.
What is hereditary cancer?
Cancer is a genetic disease, which means it can develop when there is a problem, or 'mutation', in one piece of the genetic material that makes up the instructions our cells use to function properly. Some of these mutations happen in our bodies over time, and can be caused by things like sun damage or smoking.
Others can be passed on from parents to children, which is why certain types of cancer run in families. It can happen when the inherited gene that is affected is a tumour suppressor (one that, when working properly, prevents tumours from growing). Mutations that lose these tumour suppressors can lead to specific types of cancer, including some breast cancers, or syndromes like familial adenomatous polyposis, which puts those affected at a high risk of developing colorectal and other cancers.
Because we inherit two copies of each piece of genetic code, one from each biological parent, these inherited mutations usually exist without any issues. If only one copy has the mutation, our body can function normally by following the instructions in the healthy copy (heterozygosity). However on rare occasions, something causes the second copy to mutate too (loss of heterozygosity).
What is it that causes these genes to mutate?
And is there anything we can do to prevent it from happening?
With support from our Curestarters, the international cancer research team of Dr Allison Bardin, Lara Al Zouabi and Marine Stefanutti set out to find the answer to these questions.
Understanding this better could have huge consequences for families with a history of cancer and help us prevent hereditary cancers like retinoblastoma - a rare eye cancer that affects young children.
To investigate these genetic changes, the researchers looked at what happens in fruit fly intestines when cancer starts to develop.
Why are fruit flies used in genetic research?
Fruit flies are often used for genetic studies and they have been involved in crucial breakthroughs for cancer as well as diabetes, Down’s Syndrome and other diseases over the last hundred years.
The humble fruit fly is so useful for researchers because their genetic material is 16 times smaller than the genome of humans or other mammals, which makes it quicker and easier to study. Female fruit flies can lay hundreds of eggs in a few days so you can easily study genetics over different generations. They also have a short lifespan of only a few weeks, which makes studying the ageing process much quicker!
What did the researchers find?
Dr Bardin's team employed a technique called whole genome sequencing, using state-of-the-art technology at the Institut Curie in Paris. This allows the researchers to study each part of the genetic code in detail and identify where changes have occurred. The team successfully identified the mechanism that causes loss of heterozygosity and starts cancer - and also discovered that a particular bacterial infection can increase the chances of it happening.
This suggests that it is not only our genes, but also the bacteria that live inside our gut, also known as the microbiome, that can play a role in how cancer develops. Even more importantly, the researchers identified enzymes that can prevent loss of heterozygosity, paving the way for developing future treatments that could prevent cancers from starting.
The team’s next steps are to investigate how these changes evolve over time. They hope this discovery could be a jumping off point for other scientists to identify drugs that could tackle this process of gene mutation.
What could this breakthrough mean for the future?
This discovery is a crucial step in understanding how cancer starts, and how we can begin to prevent it in people who have a cancer gene that runs in their family. While inheriting a gene like this doesn’t mean you will definitely get cancer, learning that your genes increase your risk of developing cancer can be very worrying, and as yet we do not have very many preventative treatments for patients at high risk of familial cancers.
The future of cancer prevention through genetic insights
The more we can understand about hereditary cancer, the better we can prevent it. Discovery research is vital to give us more information about how inherited mutations trigger tumour development.
Having certain faulty genes in your family can make it more likely that you will develop breast cancer. Some people who are at a higher risk are screened for breast cancer more frequently or choose to have preventative surgery to reduce their risk.
As a cancer charity, we hope research will reveal more about the mutations involved in other hereditary cancers, so that we find new ways to stop cancer in its tracks.
Your hereditary cancer FAQs:
Why are fruit flies used in cancer research?
Fruit flies are used in cancer research, and a lot of other medical research, because they are an excellent model. We share 60% of our DNA with the fruit fly but they have a relatively simple genome that makes it much easier to study. They breed quickly and have a short life-span that means they are particularly useful for genetic studies.
How do fruit flies help us understand hereditary cancer?
Hereditary cancers arise because of genetic mutations that spread through families, passed on from one generation to the next. We share a lot of our DNA with fruit flies so they are a great model for looking at genetic mutations involved in hereditary cancers. Because they can have hundreds of babies within a few days and they have a short life span, it is easy to study different generations of fruit flies to discover more about hereditary mutations.
What is familial or hereditary cancer?
Hereditary cancers, sometimes called familial cancers, are caused because of a particular genetic mutation that is passed down in families. Only about 5-10% of cancers are hereditary. Most cancers are linked to lifestyle or environmental factors or come about because of random mutations.
Can inherited genes cause cancer?
Yes, in some cases inherited genes can cause cancer. But even if you have hereditary cancer in your family, it does not necessarily mean that you will develop cancer. If you have a strong family history of cancer and are worried about your increased risk, please talk to your doctor.
What role does the microbiome play in cancer?
The microbiome is the community of tiny microbes that live in and alongside you. Research has recently shown that our microbiome can influence cancer growth and also affect how we respond to different cancer treatments. Curestarter researchers have discovered that certain bacteria in our microbiome can change the properties of bowel cancer and they hope this will lead to more personalised treatments.
Are there any treatments for hereditary cancers?
There are some treatments for hereditary cancers and often treatments are tailored depending on different genetic mutations. Mutations to the BRCA1 or BRCA2 gene can run in families and cause a higher risk of several cancers including breast cancer and ovarian cancer. Thanks to research the game-changing cancer treatment olaparib is given to certain patients with these mutations, including our Curestarter Fiona.
What types of cancer can run in families?
Most cases of cancers are not hereditary - for about 90 to 95% of people diagnosed with cancer it will not be hereditary. But researchers have found inherited gene mutations for a variety of different types of cancer including breast cancer, bowel cancer, some types of blood cancer, ovarian cancer, prostate cancer and certain types of skin cancer. By better understanding how these gene mutations are involved in cancer development, we can find new ways to prevent or treat it.
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