New light-activated platinum compound more effective at killing
cancer cells
21 Dec 2010
A newly discovered light-activated platinum-based compound is
up to 80 times more powerful than other platinum-based anti-cancer drugs
and can be used to kill cancer cells in a much more targeted way than
similar treatments.
A team led by the University of Warwick and including Ninewells
Hospital Dundee and the University of Edinburgh had already found a
platinum-based compound that they could activate with ultra-violet
light but that narrow wavelength of light would have limited its
use.
Their latest breakthrough has discovered a new platinum based
compound known as trans,trans,trans-[Pt(N3)2(OH)2(py)2] that can be
activated by normal visible blue or even green light. It is also
stable and easy to work with, and it is water soluble so it can
simply dissolve and be flushed out of the body after use.
The University of Warwick researchers passed the new compound to
colleagues at Ninewells Hospital Dundee, who tested it on
oesophageal cancer cells cultivated within lab equipment. Those
tests show that once activated by blue light the compound was highly
effective, requiring a concentration of just 8.4 micro moles per
litre to kill 50% of the cancer cells.
The researchers are also beginning to examine the compound’s
effectiveness against ovarian and liver cancer cells. Early results
there are also excellent but that testing work is not yet complete.
Professor Peter Sadler, from the Department of Chemistry from
University of Warwick, who led the research project, said: “This
compound could have a significant impact on the effectiveness of
future cancer treatments. Light activation provides this compound’s
massive toxic power and also allows treatment to be targeted much
more accurately against cancer cells.”
“The special thing about our complex is that it is not only
activated by ultraviolet light, but also by low doses of blue or
green light. Light activation generates a powerful cytotoxic
compound that has proven to be significantly more effective than
treatments such as cisplatin.
"We believe that photoactivated platinum complexes will make it
possible to treat cancers that have previously not reacted to
chemotherapy with platinum complexes,” says Sadler. “Tumours that
have developed resistance to conventional platinum drugs could
respond to these complexes and with less side-effects.”