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The East African : February 24th 2014
34 The EastAfrican OUTLOOK FEBRUARY 22-28,2014 S CI E N C E Seven new genes for head and neck cancer dicovered Scientists used methods that take less time and ≥esou≥ces fo≥ dete≥mining gene functions By A SPECIAL CORRESPONDENT I n the hunt for genetic mutations that cause cancer, there is a lot of white noise. Although genetic sequencing has identified hundreds of genetic alterations linked to tumoars, it’s still an enormous challenge to figure out which ones are actually responsible for the growth and metastasis of cancer. Scientists at Rockefeller Uni- versity Laboratory of Mammalian Cell Biology and Development in New York have created a new technique that can weed out that noise — eliminating the random bystander genes and identifying the ones that are critical for cancer. Applying their technique to head and neck cancers, they have discovered seven new tumoar-suppressor genes whose role in cancer was previously unknown. The new technique, which the lab recently applied to a screen for skin tumoar genes, is particularly useful because it takes a fraction of the resources and much less time than the traditional method for determining gene function — breeding genetically modified animals to study the impact of missing genes. “Using knockout mice, which are model organisms bred to have a particular gene missing, is not feasible when there are 800 potential head and neck cancer genes to sort through,” says Daniel Schramek, a postdoctoral fellow in the lab, which is headed by Professor Elaine Fuchs. “It can take about two years per gene. Our method can assess about 300 genes in a single mouse, in as little as five weeks.” The researchers made use of RNA interference, a natural process whereby RNA molecules inhibit gene expression. They took short pieces of RNA, which are able to turn off the function of specific genes, attached them to highly concentrated viruses, and then, using ultrasound to guide the needle without damaging surrounding tissue, they injected the viruses into the sacs of mouse embryos. “The virus is absorbed and in- tegrated into the chromosomes of the single layer of surface cells that cover the tiny embryo,” said Prof Fuchs. “As the embryo develops, this layer of cells becomes the skin, mammary glands and oral tissue, enabling us to efficiently, selectively and quickly eliminate the expression of any desired gene in these tissues. The non-invasive method “It can take about two years per gene. Our method can assess about 300 genes in a single mouse, in as little as five weeks” Prof Elaine Fuchs BRIEFS Clinical trials exploiting poor Kenyans Cases of loosely regulated clinical trials have increased in Kenya. A report released by Dutch nongovernmental organisation Wemos, says that at least 200 clinical trials are currently taking place in Kenya to test new drugs and medical . The report noted that many poor Kenyans have signed up for trials because they get free treatment, food and transport. The report said ethics are being violated because of weak laws and lack of scrutiny by human rights and healthcare activists. Tropical highlands could be malaria prone areas A researcher in a laboratory. Scientists have discovered seven genes responsible for neck and head cancer. Picture: File avoids triggering a wound or inflammatory response that is typically associated with conventional methods to knockdown a gene in cultured cells and then engraft the cells onto a mouse,” she added. When the mice grew, the re- searchers determined which genes, when turned off, were promoting tumor growth, and what they found was surprising. “Among the seven novel tumor suppressor genes we found, our strongest hit was Myh9, which codes for the protein myosin IIa, a motor protein with well-known function in cell structure and cell migration,” said Schramek. “Through further functional studies we found that myosin IIa is also required for activation of the main guardian of the genome — a tumoar suppressor protein called p53.” The lab showed that when the myosin IIa gene was mutated, p53 was not able to build up in the cell nucleus, and chaos ensued: Genes responsible for repairing damaged cells and killing off tumoar cells were not activated, and invasive carcinomas spread within three months. The researchers devised a strat- egy to reactivate p53 in these cells, and showed in vitro that tumoar suppression was restored. Head and neck cancers are the sixth most deadly type of cancer worldwide. ScienceDaily Mo≥e fa≥me≥s now emb≥ace biotech c≥ops globally By CHRISTABEL LIGAMI Special Correspondent AT LEAST 18 million farmers in 27 countries globally planted biotech crops in 2013, representing a three per cent growth over the one year. A new report by the International Service for the Acquisition of Agri-biotech Applications (Isaaa) shows that global biotech crop hectarage has increased from 1.7 million hectares in 1996 to over 175 million hectares in 2013. The United States continues to lead global biotech crop plantings at 70.1 million hectares or 40 per cent of total global hectares. “Accumulated hectarage of biotech crops planted worldwide to date stands at 1.6 billion hectares or 150 per cent of the total landmass of China,” said Clive James, author of the report and Isaaa founder. “Each of the top 10 countries planting biotech crops during 2013, planted more than one million hectares, providing a broad foundation for future growth,” he added. According to the report, more than 90 per cent, or 16.5 million of farmers planting biotech Kenyan farmers demonstrate against GMOs in the streets of Nairobi. Picture: File crops are small and resource-poor. Of the countries planting biotech crops, eight are industrialied and 19 are developing countries. For the second year, developing countries planted more hectares of biotech crops than industrialised countries, representing the confi- dence and trust of millions of risk-adverse farmers around the world who have experienced the benefits of these crops. Nearly 100 per cent of farmers who try bio- tech crops continue to plant them year after year, the report notes. Biotech drought-tolerant maize technology has been donated to Africa through the Water Efficient Maize for Africa project, a public/ private partnership by Monsanto and BASF, funded by the Gates and Buffet foundations and implemented through the International Maize and Wheat Improvement Center (Cimmyt) in Mexico and the Kenya-based African Agricultural Technology Foundation. Planting of biotech drought-tolerant maize in Africa is expected in 2017. Drought is the biggest constraint to maize productivity in Africa; and maize is the crop on which 300 million Africans depend for survival. “Growth in industrial countries and mature markets in developing countries continued to plateau in 2013 as adoption rates were sustained at 90 per cent or more, leaving little room for expansion,” said Dr James. More people may contract malaria in the tropical highlands of Africa, Asia and South America as global warming makes the climate in these areas more suitable for the disease’s transmission. A study has noted that further studies will be needed to account for other factors that may influence the disease’s spread, including economic development, changes in human population patterns and adaptations in the mosquitoes that transmit malaria. The study was published in the proceedings of the National Academy of Sciences and used five existing malaria impact models to make predictions. Female Anopheles mosquitoes, which spread malaria Pic: File Kagame assures Rwandans of quality healthcare Rwanda is committed to ensuring that access to high quality healthcare remains a right and not a privilege for citizens, President Paul Kagame has said. Addressing researchers in the Faculty of Health at the University of California San Francisco, President Kagame observed that 17 per cent of Rwanda’s national budget is dedicated to health and that providing quality health services will remain a key priority. Govts urged to support young researchers Early career researchers in Africa must receive financial support from their governments if they are to establish themselves in their fields. According to the Volkswagen Foundation, young scientists’ networking opportunities, quality of teaching and the range of doctorate subjects offered by institutions are other areas that must be improved. “Financial difficulties do not end once researchers have gained their doctorate,” said Pauline Mwinzi, a research officer at the Kenya Medical Research Institute.
February 17th 2014
March 3rd 2014