Molecule zeroes in on tumours
A targeting molecule that zeroes in on a wide range of tumours could revolutionise cancer diagnosis and treatment, scientists believe.
The agent, known as APC (alkylphosphocholine), can deliver a radioactive “warhead” directly into the heart of cancer cells.
Alternatively, it can be labelled with a fluorescent “tag” to highlight areas where cancer has spread.
It is even able to cross the “blood brain barrier”, a biological wall that blocks access of many drugs to the brain.
In tests, versions of the molecule fixed themselves to 55 out of 57 different kinds of tumour including human breast, lung, bowel and brain cancers.
Lead scientist Dr John Kuo, director of the comprehensive brain tumour programme at University of Wisconsin-Madison in the US, said: “I was a sceptic; it’s almost too good to be true.
“It is a very broad cancer-targeting agent in terms of the many different cancers that tested positive. The APC analogues even sometimes revealed other sites of cancer in patients that were small, asymptomatic and previously undetected by physicians.”
Fluorescent APC imaging during surgery could make operations more effective and safer, he said.
Any cancer cells that are not removed could be targeted later with radioactive APC therapy.
As a diagnostic tool, APC was also likely to produce fewer false positives than standard scans.
Details of the research are published in the journal Science Translational Medicine.
Once injected into the bloodstream, APC spreads throughout the body - even to the brain - sticking to the outer membrane walls of solid cancer cells.
The tumour takes up the molecule, and its therapeutic or imaging payload, and holds on to it for days or weeks.
APC only targets tumours because of a biological weakness common to a large number of cancers.
It has the potential to pick out cancer stem cells that resist current treatments.