Substance tackles skin cancer from two sides

Nov 02, 2008

By playing it safe and using a two-pronged attack, a novel designer molecule fights malignant melanoma. It was created and tested by an international team of researchers led by the University of Bonn. On the one hand, the substance is similar to components of viruses and in this way alerts the immune system. The body's own defences are also strengthened against cancer cells in this process. At the same time, the novel molecule also puts pressure on the tumour in a different way. It switches off a specific gene in the malignant cells, thus driving them to suicide. With mice suffering from cancer, the researchers have thus been able to fight metastases in the lung. In Nature Medicine's November issue they report about this promising strategy.

For their research project, the scientists drew on the latest insights into biology's box of tricks. A close relative of the nuclear DNA, known as RNA, served them as therapy. It has only been known for a few years that small RNA molecules can basically be used to target certain genes and switch them off. This effect is called RNA interference; the Americans Craig Mellow and Andrew Fire were awarded the Nobel Prize in 2006 for its discovery.

'We used this method in order to drive the tumour cells to suicide,' the Bonn dermatology researcher Professor Thomas Tüting explains. Every single body cell is equipped with a corresponding suicide programme. It is activated, for example, if the cell becomes malignant. It dies before it can do any more harm. 'But in tumours a gene is active that suppresses this suicide programme,' Professor Tüting, who is head of the Experimental Dermatology Laboratory, explains. 'We have pinpointed this gene and switched it off by using RNA interference.'

At the same time the researchers also crept up on cancer by another route: 'We basically "disguised" our RNA,' Professor Gunther Hartmann, director of the Institute of Clinical Chemistry and Pharmacology says. 'That is why the immune system took it for the genetic makeup of a virus.' Many viruses actually do use RNA to store information. So if the body discovers RNA fragments which it takes to be the genetic makeup of a virus, it mounts an attack on them. By means of this trick the body's defences were prompted to tackle the tumour cells far more aggressively than normal.

RNA is also present in the body's own cells. For a long time it was not known how the immune system distinguishes between 'harmful' and 'harmless' RNA. Only two years ago, Professor Hartmann was able to shed light on the problem in a sensational article in the journal 'Science'. The scientists used this knowledge in order to modify the RNA substance in such a way that it was able to alert the immune system.

'The beauty of this method is that we can attack the cancer with one designer molecule along two completely different routes,' Professor Hartmann says. 'This way the tumour is deprived of opportunities of sidestepping the attack that make successful therapy so difficult in other cases.' Initial experiments in mouse models have shown that growth of metastases in the lungs is inhibited significantly by the new molecule. The therapy even led to the secondary tumours becoming smaller or even disappearing entirely.

Despite this, the research team warns against excessive optimism: 'What works in mice does not necessarily prove successful in humans as well,' Professor Tüting warns. 'Apart from that, many issues need to be addressed before a trial with cancer patients can even be thought of.' Still, the approach appears very promising, especially as the therapeutic RNA molecule can be easily customised to suit different kinds of cancer.

This article is available online from November 2nd (doi: 10.1038/nm.1887).

Source: University of Bonn

Explore further: A healthy lifestyle before bowel cancer diagnosis could help improve survival

Related Stories

A phone with the ultimate macro feature

Apr 29, 2015

If you thought scanning one of those strange, square QR codes with your phone was somewhat advanced, hold on to your seat. Researchers at the University of California, Los Angeles (UCLA) have recently developed ...

Weighing and imaging molecules one at a time

Apr 27, 2015

Building on their creation of the first-ever mechanical device that can measure the mass of individual molecules, one at a time, a team of Caltech scientists and their colleagues have created nanodevices ...

Single cells seen in unprecedented detail

Apr 27, 2015

Researchers have developed a large-scale sequencing technique called Genome and Transcriptome Sequencing (G&T-seq) that reveals, simultaneously, the unique genome sequence of a single cell and the activity ...

How RNA machinery navigates our genomic obstacle course

Apr 24, 2015

Once upon a time, scientists thought RNA polymerase—the molecule that kicks off protein synthesis by transcribing DNA into RNA—worked like a wind-up toy: Set it down at a start site in our DNA and it ...

Recommended for you

Psychologists aim to help Dr Google

9 hours ago

Psychologists are to improve online health information on lung cancer after research showed that family members are more likely to search online to encourage loved ones to seek help.

New method detects more breast cancer in screening

13 hours ago

Tomosynthesis detects 40% more breast cancers than traditional mammography does, according to a major screening study from Lund University, Sweden. This is the first large-scale study to compare the screening ...

Women's use of talc powder may be tied to ovarian cancer

May 05, 2015

Deane Berg's doctor called her in the day after Christmas 2006 to give her the crushing news. She'd had her ovaries removed, the pathology results were back, and the information could not have been much worse. Berg had stage ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

E_L_Earnhardt
1 / 5 (1) Nov 03, 2008
Amazing work! Still, I am more interested in CORRECTING the malfunctions of the cell than KILLING it. SLOWING mitosis to a normal rate seems more natural than KILLING IT! Modifying cyroablation to accomplish this seems better!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.