Regular science news
- Breast cancer history does not increase risk of uterine cancer
- Gene therapy may ease symptoms of liver disease
- Gene therapy shrinks pancreatic tumours in mice
- Genetic mutation against malaria discovered in Papua New Guineans
- Mouse genome sequenced with help from Queensland scientists
- New skin cancer treatments appear promising
- Three genes may be linked to heart attack risk
- White blood cells important factor in asthma attacks
Breast cancer history does not increase risk of uterine cancer
9 December – A large study at the US National Cancer Institute indicates that despite shared risk factors, women with a family history of breast cancer do not have an increased risk of endometrial cancer. However, survivors of breast cancer do indicate a higher risk of endometrial cancer, which is highly treatable if detected in its early stages. The study, involving more than 37,000 women followed for 14 years, surprised researchers with its results. Although women with a family history of breast cancer were more likely to develop endometrial cancer, the risk was not statistically significant.
[Source – Reuters Health – Merritt McKinney]
Gene therapy may ease symptoms of liver disease
3 December – Scientists in the Netherlands say gene therapy could ease the symptoms of a deadly human liver disease, Crigler-Najjar type I. The scientists conducted gene therapy on foetal rats which had been engineered to have a rare but lethal human liver disease. The liver of a person with this disease cannot produce an enzyme that allows the body to excrete the bile pigment, bilirubin. The enzyme functions by making bilirubin water-soluble, by linking it to glucuronic acid. In infants the lack of this enzyme leads to jaundice. Liver transplants can be a solution to the problem, but donors are limited and the patient must undergo life-long immune suppression to prevent organ rejection.
The Dutch scientists, led by Dr Jurgen Seppen, injected a genetically engineered virus, which carries a gene to make the enzyme, into individual rat foetuses at day 19 of the normal 22-day gestation period. They then allowed gestation to continue to term. According to Dr Seppen: 'There was a correction of about 50 per cent of the serum bilirubin that has been sustained for as long as we have studied, which is about 7 months ...'. The results of the study are expected to be published soon.
[Source – Reuters Health – Stephen Pincock]
Gene therapy shrinks pancreatic tumours in mice
6 December – Pancreatic cancer, which is the fifth leading cause of cancer death in the US, is generally incurable, partially because this type of cancer tends to be resistant to even the strongest chemotherapy. However, Japanese scientists have achieved dramatic results in shrinking pancreatic tumours in mice, using gene therapy. The treatment is effective on mice even if the cancer has spread beyond the pancreas. The results of the study have been published in the International Journal of Cancer. Human-derived pancreatic cancer cells were injected into mice. Scientists waited until the pancreatic cancer spread beyond the pancreas into surrounding tissue and then injected some of the mice with a harmless virus. This virus 'piggybacked' uracil phosphoribosyl transferase to the malignant area. The scientists say UPRT 'switches on' a gene which negates a cancer cell's resistance to chemotherapy. Mice treated with UPRT and a powerful cancer drug, 5-fluorouracil, experienced dramatic tumour shrinkage both within and beyond the pancreas without adverse affects.
[Source – Reuters Health]
Genetic mutation against malaria discovered in Papua New Guineans
11 December – Scientists have discovered a genetic mutation in Papua New Guineans that bars a newly discovered fourth pathway used by the malaria parasite to infect red blood cells. The discovery will be published in the January 2003 edition of Nature Medicine. Researchers fear the recently discovered pathway is unlikely to be the last. Professor Alan Cowman of The Walter and Eliza Hall Institute of Medical Research says the international team led by him will soon have data which he expects will identify at least one, and probably two or three, additional pathways. The researchers say the discovery could lead to new vaccines and treatments, but Professor Cowan says a lot more information must be collected about malaria pathways before scientists will know which vaccines are best.
[Source – ABC Science Online – Danny Kingsley]
Mouse genome sequenced with help from Queensland scientists
4 December – In a breakthrough heralded the most significant since the human genome was sequenced two years ago, scientists have mapped the mouse genome. The genome has been published in the science journal, Nature. By comparing the mouse and human genomes, scientists have discovered that mice and humans have many genetic similarities. Dr Jane Rogers, of the Wellcome Trust Sanger Institute in Cambridge, England, says: 'We share 99 per cent of our genes with mice, and we even have the genes that could make a tail'. According to Dr Robert Watson, director of the Genome Sequencing Centre at the Washington University School of Medicine in St Louis, about 5 per cent of our genetic material is identical to that of mice, the legacy of a common ancestor from around 75m years ago. Only 300 genes are unique to either creature. Most of the unique mice genes related to the sense of smell, or reproduction. 90 per cent of genes linked to human diseases are similar to those in mice. The comparison of the two genomes also led to the identification of 1,200 new human genes and 9,000 new mouse genes.
The sequencing of the mouse genome is the product of worldwide collaboration. The largest foreign contingent in the international consortium, led by the RIKEN Genome Sciences Centre in Yokohama, Japan, was a group of six researchers from Queensland's Institute for Molecular Bioscience. Head of the IMB team, Professor David Hume, says: 'The importance of the RIKEN Mouse Gene Encyclopedia project cannot be under-estimated. In my opinion, the RIKEN team is amongst the greatest technological innovators in genome science in the world'.
The important development will contribute to understanding human genes and how they contribute to various diseases.
[Source – Reuters – Patricia Reaney; Reuters Health – Todd Zwillich; IMB Media Release]
New skin cancer treatments appear promising
2 December – A vaccine and a new chemotherapy drug undergoing trials in Australia both show promise as skin cancer treatments. The vaccine was developed in Queensland and has been tested on 31 patients at the Mater Hospital in Brisbane. Spokesperson for the hospital, Dr Michael O'Rouke, says '25 per cent of patients we're treating are getting complete remission, the disease is disappearing and that's very exciting'. The vaccine will now be trialled on 50 patients.
The new chemotherapy agent is designed to be used when resistance has developed to other chemotherapy drugs. Sydney Cancer Centre spokesperson, Dr Michael Millward, says 'of the new chemotherapy drugs this is the most exciting class'.
[Source – ABC News Online]
Three genes may be linked to heart attack risk
11 December – Researchers in Japan have identified one gene variation in men and two in women which appear to increase the risk of heart attack. The study was conducted by Dr Yoshiji Yamada and colleagues at the Gifu International Institute of Biotechnology in Mitake, Japan. The researchers investigated 112 different variations in 71 candidate genes. They first tested 2,819 heart attack patients and 2,242 people who had not suffered heart attacks, before choosing 19 variations in men and 18 in women for further study. These gene variants were investigated in a further 4,152 patients. The scientists found that the C1019T form of the connexin 37 gene is more common in male heart attack patients than in other men. This was not the case for women. The 4G-668/5G form of a gene related to the body's dismantling of body clots and the 5A-1171/6A form of the gene involved in breaking down the network of material that surrounds cells seem to be linked to increased heart attack risk in women. It is unclear why the results suggest that different genes are linked to heart attack risk in men and women.
[Source – Reuters Health – Alison McCook]
White blood cells important factor in asthma attacks
2 December – A new asthma study published in The Lancet shows that treating inflammation caused by white blood cells, rather than treating asthma symptoms, more effectively reduces severe attacks. The study was conducted by Dr Ruth Green and colleagues at the Department of Respiratory Medicine at Glenfield Hospital in Leicester, UK. The general treatment for asthma involves using bronchodilators and anti-inflammatory agents in doses based on lung function measurements and symptom assessment. This approach largely ignores the role of 'eosinophils' (white blood cells). Previous research indicates that the levels of eosinophils in the lungs increase prior to an asthma attack. The new study was conducted on 74 people with moderate to severe asthma. Half the group were treated conventionally and the other half were treated with reference to eosinophil levels. When the percentage of eosinophil in the sputum (material from the respiratory tract) was more than 3 per cent, doses were increased. Doses were lowered when the levels fell to below 1 per cent. Co-author Dr Ian Pavord says the 'results show that a strategy directed at maintenance of a normal airway eosinophilic count caused a large reduction in the number of severe exacerbations in a group of patients with moderate to severe asthma compared with traditional management...'. Dr Simon Hogan, of the John Curtis School of Medical Research at the Australian National University, says the research supports an emerging theory that eosinophils are key in asthma response.
[Source – ABC Science Online – Anna Salleh]
