Breakthrough treatment may halt spread of cancer by 'breaking the legs' of tumour cells
A new treatment halts the spread of cancer by "breaking the legs" of tumour cells.
Scientists used tiny gold rods to smash the leg-like protrusions, called filopodia, that help cancer cells up-anchor and move.
Laboratory tests on human cancer cells showed that rendering them limbless thwarted their ability to migrate and spread, or metastasise.
It is the deadly spread of tumours to vital organs, such as the liver or brain, that is most likely to kill a cancer patient.
Targeting filopodia, which extend out from a weave of fibres called lamellipodia on the cell's fringes, could be a game-changer in the fight against metastasis, the scientists believe.
Researcher Yue Wu, a graduate student in bioanalytical chemistry at the Georgia Institute of Technology in the US, said: "All these lamellipodia and filopodia give the cancer cells legs. The metastasis requires those protrusions, so the cells can travel."
The scientists used the gold nanorods to immobilise cancer by heating them up with a low-energy, near-infrared laser.
The hot rods partially melted the cancer cells and "mangled" their legs. In addition, the rods were coated with chemicals that suppressed the generation of new filopodia.
Animal experiments showed that a gentle laser worked considerably better than a hotter beam, which risked triggering inflammation.
No toxic effects were seen from the gold treatment and healthy cells - which also need to move - were not harmed, said the researchers writing in the journal 'Proceedings of the National Academy of Sciences'.
Team leader Professor Mostafa El-Sayed, also from the Georgia Institute of Technology, said: "The method appears to be very effective as a locally administered treatment that...protects the body from cancer's spread away from the treated tumours.
"It is also very mild, so it can be applied many times over if needed."
The researchers envisage treating head, neck, breast and skin cancers with a lower-power laser and gold nanorods injected two to three centimetres deep inside tissue.
More entrenched tumours would have to be treated with deeper injections of the gold rods and a fibre-optic laser.