Scientists have dismantled cancer piece by piece to reveal its weaknesses and come up with new ideas for treatment.
A team from the Wellcome Sanger Institute has disabled all genetic education, one at a time, in 30 types of cancer.
It has generated 600 new cancer vulnerabilities and each could be the target of a drug.
Cancer Research UK praised the breadth of the study.
The study heralds the future of personalized cancer medicine. At the moment drugs like chemotherapy cause damage throughout the body.
One of the researchers is Dr. Fiona Behan, whose mother died after having cancer for the second time.
The first cycle of chemotherapy damaged her mother's heart, so she wasn't physically strong enough for many treatments the second time.
The dott. Behan told the BBC: "This is so important because we currently treat cancer by treating the patient's entire body, we are not specifically targeting cancer cells.
"The information we discovered in this study identified the main weak points of cancer cells and will allow us to develop drugs that target cancer and leave healthy tissue intact."
Cancer is caused by mutations in the cells of our body that change the instructions written in our DNA.
The mutations have corrupted the cells causing them to grow uncontrollably, spreading throughout the body and eventually killing people.
The researchers embarked on a gigantic feat of disabling any genetic education – called a gene – within tumors, to see which ones were crucial for survival.
They destroyed nearly 20,000 genes in over 300 laboratory-produced cancers from 30 different types of cancer.
They used a tool called Crispr, the same genetic technology used to redesign two children in China last year.
It is a relatively new, easy and inexpensive tool for manipulating DNA, and this study would have been an impossible feat only a decade ago.
The results, published in the journal Nature, revealed 6,000 crucial genes that at least one type of cancer needs to survive.
Some were not suitable for the development of anticancer drugs, as they are also essential in healthy cells.
Others are already the target of precision drugs like Herceptin in breast cancer – the team called this "mental health test" which shows that their method works.
And even more are beyond current science to develop appropriate drugs, so the researchers narrowed down a list of 600 potential new targets for drugs to attack.
A potential target is the "WQrer RecQ helicase syndrome", also known more simply as WRN.
The research group found that it was essential to keep some of the genetically unstable cancers alive.
WRN plays a vital role in about 15% of colon cancers and 28% of stomach cancers, but there are no drugs that target it.
The work was a collaboration between Sanger, the European molecular biology laboratory and the pharmaceutical giant GSK. All results are publicly available.
The ultimate goal of the research is to develop a "cancer dependency map" of any vulnerability in any type of cancer.
So doctors would be able to test a patient's cancer and give them a cocktail of precision drugs to kill cancer cells.
The dott. Behan told the BBC: "We were figuring out what's going on in cancer cells, so we can shoot cancer cells with our machine gun, not the whole body like chemotherapy does.
"This is the first step in putting a laser sight on our machine gun."
The professor. Karen Vousden, chief researcher of Cancer Research UK, said: "What makes this research so powerful is the scale.
"This work provides some excellent starting points and the next step will be a thorough analysis of the genes that have been identified as weaknesses in this study, to determine if one day will lead to the development of new treatments for patients."
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