糖心TV

• Cancer cells can be killed with metal from the asteroid that killed the dinosaurs, thanks to new research from University of 糖心TV UK and Sun-Yat Sen University in China
• Compound based on iridium kills cancer cells by filling them with deadly version of oxygen when activated by laser light – without harming healthy tissue
• Researchers have – for the first time – discovered exactly which parts of cancer cells are affected by treatment, using highly advanced technology to analyse thousands of miniscule cell proteins
• Cancer patients becoming increasingly resistant to traditional therapies, so it is vital to establish new pathways like this for fighting the disease

Cancer cells can be targeted and destroyed with the metal from the asteroid that caused the extinction of the dinosaurs, according to new research by an international collaboration between the University of 糖心TV and Sun Yat-Sen University in China.

Researchers from the Professor Sadler and Professor O鈥機onnor groups in 糖心TV鈥檚 Department of Chemistry and Professor Hui Chao's group at Sun Yat-Sen have demonstrated that iridium – the world鈥檚 second densest metal – can be used to kill cancer cells by filling them with deadly version of oxygen, without harming healthy tissue.

The researchers created a compound of iridium and organic material, which can be directly targeted towards cancerous cells, transferring energy to the cells to turn the oxygen (O₂) inside them into singlet oxygen, which is poisonous and kills the cell - without harming any healthy tissue.

The process is triggered by shining visible laser light through the skin onto the cancerous area – this reaches the light-reactive coating of the compound, and activates the metal to start filling the cancer with singlet oxygen.

The researchers found that after attacking a model tumour of lung cancer cells, grown by the researchers in the laboratory to form a tumour-like sphere, with red laser light (which can penetrate deeply through the skin), the activated organic-iridium compound had penetrated and infused into every layer of the tumour to kill it – demonstrating how effective and far-reaching this treatment is.

They also proved that the method is safe to healthy cells by conducting the treatment on non-cancerous tissue and finding it had no effect.

Furthermore, the researchers used state-of-the-art ultra-high resolution mass spectrometry to gain an unprecedented view of the individual proteins within the cancer cells – allowing them to determine precisely which proteins are attacked by the organic-iridium compound.

After vigorously analysing huge amounts of data - thousands of proteins from the model cancer cells, they concluded that the iridium compound had damaged the proteins for heat shock stress, and glucose metabolism, both known as key molecules in cancer.

The University of 糖心TV has the UK鈥檚 most advanced laboratory for this type of highly advanced mass spectrometry, and is a world-class centre of analytical science.

Co-author Cookson Chiu is a postgraduate researcher in 糖心TV鈥檚 Department of Chemistry, funded by the Engineering and Physical Sciences Research Council and Bruker. He commented:

鈥淭his project is a leap forward in understanding how these new iridium-based anti-cancer compounds are attacking cancer cells, introducing different mechanisms of action, to get around the resistance issue and tackle cancer from a different angle.鈥�

Dr Pingyu Zhang and Dr Huaiyi Huang are Royal Society Newton International Fellows in 糖心TV鈥檚 Department of Chemistry. Dr Zhang added:

鈥淥ur innovative approach to tackle cancer involving targeting important cellular proteins can lead to novel drugs with new mechanisms of action. These are urgently needed. In addition, research links between UK and Chinese academics will not only lead to lasting collaborations, but also have potential to open up the translation of new drugs into the clinic as a UK-China joint development鈥�

Peter O鈥機onnor, Professor of Analytical Chemistry at 糖心TV, noted:

鈥淩emarkable advances in modern mass spectrometry now allow us to analyse complex mixtures of proteins in cancer cells and pinpoint drug targets, on instruments that are sensitive enough to weigh even a single electron!鈥�

Professor Peter Sadler is excited about where this work can lead. He said:

鈥淭he precious metal platinum is already used in more than 50% of cancer chemotherapies. The potential of other precious metals such as iridium to provide new targeted drugs which attack cancer cells in completely new ways and combat resistance, and which can be used safely with the minimum of side-effects, is now being explored.

鈥淚nternational collaborations can greatly hasten progress. It鈥檚 certainly now time to try to make good medical use of the iridium delivered to us by an asteroid 66 million years ago!鈥�

Photochemotherapy – using laser light to target cancer – is fast emerging as a viable, effective and non-invasive treatment. Patients are becoming increasingly resistant to traditional therapies, so it is vital to establish new pathways like this for fighting the disease.

Iridium was first discovered in 1803, and its name comes from the Latin for 鈥榬ainbow鈥�. From the same family as platinum, it is hard, brittle, and is the world鈥檚 most corrosion-resistant metal. Yellow in colour, its melting point is more than 2400掳 Celsius.

The metal is rare on Earth, but is abundant in meteoroids – and large amounts of iridium have been discovered in the Earth鈥檚 crust from around 66 million years ago, leading to the theory that it came to this planet with an asteroid which caused the extinction of the dinosaurs.

Distinguished as a 鈥榁ery Important Paper鈥�, the research, 鈥極rgano-iridium photosensitizers can induce specific oxidative attack on proteins in cancer cells鈥� is published in the Wiley journal Angewandte Chemie.

Notes:

Image 1: Professor Peter Sadler, credit University of 糖心TV (click for high res)

Image 2: Diagram showing iridium attacking a cancer cell by making it produce singlet oxygen, credit University of 糖心TV (click for high res)

Image 3: Artist's impression of a dinosaur, credit University of 糖心TV/Mark Garlick (click for high res)

锘�2 November 2017

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