Golden bullet for breast cancer uses precious metal thinner than a human hair

A breast cancer patient undergoes an MRI scan. The technique is useful for monitoring advanced cancer. Scientists think gold particles could be used to increase the effectiveness of drugs (posed)

A 'golden bullet' against breast cancer is being developed by scientists.
Used with radiotherapy, the tiny shards of gold heat up and destroy the deadly cells that help tumours grow and ease their spread around the body.
More resistant to radiotherapy and chemotherapy than other cells, these cancer 'mother cells' or stem cells live on when other cells in the tumour die, allowing it to recur after treatment.
Breast cancer affects some 45,000 British women a year and kills more than 1,000 a month.
The researchers used the 'gold nanoshells' to damage tumour cells, including the mother cells, making it them more vulnerable to radiotherapy.
In experiments on mice, tiny pieces of silica, each thinner than a human hair, were coated in gold and injected into breast tumours.
A day later, a laser was used to heat up the particles to 45c and the animals were given radiotherapy.
High temperatures are known to damage the inside of cells, making them more vulnerable to radiation.
But scientists have, until now, struggled to find a way to heat up breast tumours without also harming healthy tissue.
Injecting gold and heating it with a laser helped them get round this.
The combination treatment, which is known as hyperthermia, not only shrank the tumours but also cut the number of stem cells.
Transplanting the treated tumours into other mice showed them to be less aggressive than before.
The researchers, from Baylor College of Medicine, in Houston, Texas, then conducted a similar experiment on tumours formed from human cells.
Again, the cancer stem cells proved more sensitive to radiation.
A similar technique is already being trialled in people with head and neck cancers.
The journal Science Translational Medicine reports: 'One of the biggest hurdles to beating breast cancer is that a small population of stem cell-like cells within the tumour are stubbornly resistant to radiation therapy and chemotherapy.
'It is this sub-population that is responsible for relapse after successful treatment with radiation and drugs.
'Although the gold nanoshells still require further testing, hyperthermia treatments are already in clinical trials and radiation is a staple of cancer therapy.
'This suggests the dual hyperthermia-radiation cancer therapy should be amenable to a clinical setting.'