Human tumours grown in the lab

A major obstacle to researching radiation-induced cancers has been cracked by scientists. They have found a way of inducing such cancers in human cells growing in a petri dish. Until now scientists have been able to grow rodent cells in the lab, blast them with radiation and watch a tumour grow. But human cells have proved stubborn.

Now scientists from Brunel and St Andrews universities have worked out how to induce the tumours. The breakthrough means that they can test controversial theories, such as that cancer is induced by overhead power lines, in the laboratory.

Janet Arrand, of Brunel University, said that the discovery came when her colleagues wondered whether an extra trigger was required to stimulate lab-grown cells to develop cancer. They thought that the trigger might lurk among the chemicals inside an animal. So they exposed lab-grown cells to radiation and then injected them under the skin of a mouse. A tumour began to grow. The mouse does not suffer in this process and the cells are painlessly removed after the cancer has been triggered.

Professor Arrand said: "People have been trying for years to do this."

She said the researchers still do not know why the animal environment allows the cancer to develop, but they suspect some hormone or other component of the animal's blood supply. The scientists now plan to irradiate cells to different degrees and test each time to see if they have become precancerous.

They and three other European institutions are awaiting confirmation of funding worth Ecus690,000 from the European Union. They will then compare cells taken from children in Belarus, who developed thyroid tumours after being exposed to fallout from the Chernobyl nuclear disaster in 1986, with model human thyroid cell tumours induced in the laboratory by ionising radiation.

Ultimately, said Professor Arrand, it may be possible to identify and eliminate precancerous cells. The researchers are also starting an investigation of the connection between cancer and electromagnetic fields emitted by high voltage power lines, electrical wiring and domestic appliances - no conclusive link has yet been demonstrated.

The EMF Biological Research Trust has funded a custom-designed piece of equipment which produces electromagnetic fields in the laboratory and will allow uniform exposure of a sufficient number of cells to detect rare changes.

Professor Arrand says changes may not have been detected in the past because cells were studied in insufficient numbers. Also, the wrong types of tissue and cells may have been studied.

The research will involve Brunel's bioengineers, biologists and biochemists.