Cancer cells can be targeted and destroyed using the iridium-based compounds from the
asteroid that caused the extinction of the dinosaurs, says study.
- Iridium-based compound that caused
destruction of dinosaurs may be used to target and destroy cancer cells.
- Laser activation causes the metal to
react and fill cancer cells with poisonous oxygen monoxide which kills the
- The highlight of the iridium-based therapy is that
there is no damage caused to healthy tissue.
The study was conducted as an international collaboration between the
University of Warwick and Sun Yat-Sen University in China. With a large number of patients becoming
resistant to traditional cancer treatments, the need for developing advanced
cancer therapies is increasing by the hour. The new iridium-based therapy
may provide a future to cancer
therapy without adverse side effects and damage of healthy tissue. The findings
of the study are published in the Wiley journal Angewandte Chemie.
The world's most corrosive resistant metal and the second densest
metal—iridium was discovered in 1803. It comes from the same family as platinum
and is hard, brittle and yellow in color. While it is rare on earth, it is found in abundance in
meteoroids. A large amount of iridium was found on the earth's crust believed to be around 66
million years old. This lead to the theory that iridium came to earth with an asteroid that
caused the extinction
Iridium in cancer therapy
Photo-chemotherapeutic effect of two strongly luminescent
iridium (III) complexes, [Ir(C,N)2(S,S)] and [Ir(C,N)2(O,O)]
were studied. Photo-chemotherapy uses
laser light to activate particles that target cancer cells.
It is growing field of cancer treatment that is both effective and
The iridium-organic material compound becomes activated when a laser
light hits its light-reactive coating. The laser light is shown through the
skin on the cancerous region. When active, the compound transfers enough energy
to convert the oxygen in the cells to singlet oxygen or oxygen monoxide which
is poisonous for the cancer cells and kills them. Since oxygen monoxide is
short lived and has a short diffusion distance, the healthy cells around the
cancer do are not damaged by the cytotoxic effect.
‘Laser activation fills the cancer cells with oxygen monoxide that kills the cancer cells without harming the healthy non-cancerous cells.’
"This 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." co-author Cookson Chiu said.
Other significant findings from the study
When red laser light was used to attack a spheroid lung cancer cell
model, it was observed that the iridium-organic compound penetrated to all layers of the cancer and
killed the entire tumor. It was also proved that the therapy does not harm
healthy cells and is safe to use.
The study, for the first time has also identified what proteins of the
cell the cancer treatment majorly attacks by using state-of-the-art ultra-high
resolution mass spectrometry. Upon analyzing huge amount of proteins in the cancer cell, it was found
that the iridium compound damaged heat shock proteins and proteins involved in
glucose metabolism, the key molecules in cancer.
- Cancer cells destroyed with dinosaur extinction metal - (https://www.eurekalert.org/pub_releases/2017-11/uow-ccd110217.php)
- Zhang, P., Chiu, C. K. C., Huang, H., Lam, Y. P. Y., Habtemariam, A., Malcomson, T., Paterson, M. J., Clarkson, G. J., O'Connor, P. B., Chao, H. and Sadler, P. J. (2017), Organoiridium Photosensitizers Induce Specific Oxidative Attack on Proteins within Cancer Cells. Angew. Chem. Int. Ed.. doi:10.1002/anie.201709082