The researchers from British Columbia (BC) say the discovery could improve treatments for many cancer patients.

The research team at the BC Cancer Agency conducted studies on mice which revealed that when the gene HACE1 was inactivated, spontaneous late-stage cancer developed.

The researchers first became interested in HACE1 several years ago, when they discovered that the gene, common to all humans, was effectively turned off in certain tumours, such as those caused by breast cancer, lung cancer and lymphoma.

That discovery led to the suspicion that HACE1, when working properly, in some way protects tissue from developing tumours.

They carried out tests on mice to test that hypothesis and found when mice without the HACE1 gene were exposed to environmental triggers for cancer, such as ultraviolet radiation, lung carcinogens and other genetic alterations, there was a surge in tumour development.

The mice developed breast, lung and liver cancers, as well as lymphomas, melanomas and sarcomas; when the HACE1 gene was reintroduced via injection into the mice, tumour growth was halted.

Dr. Poul Sorensen, senior scientist at the agency says the discovery of the gene is very exciting because it clearly has implications for a wide range of cancers, and provides a novel link between cellular stress and cancer.

Dr. Sorensen, says if scientists can learn how to reactivate HACE1 or block cancer cells from inactivating the gene, it may be possible to improve treatments for many cancer patients.

Sorensen says it has long been suspected that cancer is caused by a combination of genetic and environmental factors working together and their results give an insight into how the disease takes root when a single gene is inactivated.

The study is published in the current issue of the journal Nature Medicine and was conducted in collaboration with Dr. Josef Penninger of the Institute of Molecular Biotechnology of the Austrian Academy of Sciences.

The researchers suggest that the 'pleasure chemicals' released by the mother when eating junk foods might have an effect on the developing brain of the foetus.

Professor Neil Stickland, who led the research, says the research shows that while the government is trying to encourage healthier eating habits in schools, the process needs to begin during the foetal and suckling stages of life.

Professor Stickland says it is not just about genetics as the study shows a direct link to what the mothers eat and how it affects their children.

Experts warn against making women feel guilty about eating some unhealthy snacks during pregnancy and say that is when a balanced diet is important.

They also say data in human studies are needed to add support to the findings.

According to the World Health Organisation around 400 million people are now obese, including 20 million children under the age of five and obesity is a major issue worldwide as it raises the risk of diseases such as type 2 diabetes and heart problems.

The research was funded by the Wellcome Trust and is published in the British Journal of Nutrition.