| Walter and Eliza Hall Institute of Medical Research |
An important mechanism controlling the
growth of rapidly-dividing cells has been revealed. This may lead to new
treatments for cancer and other diseases.
Image: Nataliya Hora/Shutterstock
The finding has revealed an important mechanism controlling the growth of rapidly-dividing cells that may ultimately lead to the development of new treatments for diseases including cancer. The discovery was made by Associate Professor Joan Heath, Dr Yeliz Boglev and colleagues at the Melbourne-Parkville Branch of the Ludwig Institute for Cancer Research. Dr Kate Hannan, Associate Professor Rick Pearson and Associate Professor Ross Hannon at the Peter MacCallum Cancer Centre, also contributed to the work, which was published in the journal PLOS Genetics. Associate Professor Heath, a Ludwig Institute Member who recently transferred her research group to the Walter and Eliza Hall Institute, said the discovery was made while studying zebrafish embryos that harbour genetic mutations which prevent rapid cell growth during organ development. “Zebrafish embryos provide us with a great laboratory model for these studies because they are transparent, an attribute that allows us to track the growth of rapidly developing organs in live animals under a simple microscope. Moreover, the genes controlling growth and proliferation of developing tissues are essentially identical in zebrafish and humans, and are known to be frequently commandeered by cancer cells.” “We discovered that a mutation in a relatively under-studied gene called pwp2h leads to the faulty assembly of ribosomes, the ‘protein factories’ of cells, and stops cells from dividing,” she said. “What was intriguing was that cells under stress from ribosome failure did not die. Instead, the cells switched on a survival mechanism called autophagy and began obtaining nutrients by digesting their own intracellular components.” Ribosomes are large molecular machines in cells that manufacture proteins, and are critical for cell growth and division. Currently, there is great interest in developing therapeutics to block ribosome production, as a strategy to prevent cancer cells from dividing. “Our research could have implications for this type of cancer treatment,” Associate Professor Heath said. “We showed that when ribosome assembly is disrupted, cells stop growing as desired, but to our surprise they enter a survival state. An anti-cancer treatment that inadvertently promotes the survival of cancer cells through autophagy is clearly not desirable. However, our findings in zebrafish show that if ribosome assembly is blocked and, at the same time, autophagy is inhibited, cells die rapidly. It is possible that a combination of inhibitors that block ribosome function and autophagy could provide an effective anti-cancer treatment,” she said. Associate Professor Heath’s group is continuing its research at the Walter and Eliza Hall Institute, examining other genetic mutations in zebrafish that disrupt cell growth and division. “We are keen to enhance our approach by applying existing research technologies at the institute,” she said. “We have identified a number of cellular processes that rapidly dividing cells – including cancer cells – depend on, and the next stage is to test whether they could provide new targets for anti-cancer therapy.” The research was supported by the National Health and Medical Research Council and the Victorian Government.
Editor's Note: Original news release can be found here.
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A two-dimensional nano-material may be
converted to nano-transistors used in high-speed
electronics. The researchers say this may be the foundation of a new
electronics revolution.
Image: Image: Dr Daniel J White, Science FX
The material – made up of layers of crystal known as molybdenum oxides – has unique properties that encourage the free flow of electrons at ultra-high speeds. In a paper published in the January 2013 issue of Advanced Materials, the researchers explain how they adapted a revolutionary material known as graphene to create a new conductive nano-material. Graphene was created in 2004 by scientists in the UK and won its inventors a Nobel Prize in 2010. While graphene supports high-speed electrons, its physical properties prevent it from being used for high-speed electronics. The CSIRO's Dr Serge Zhuiykov said the new nano-material comprised layered sheets – similar to graphite layers that make up a pencil's core. "Within these layers, electrons can zip through at high speeds with minimal scattering," Dr Zhuiykov said. "The importance of our breakthrough is how quickly and fluently electrons – which conduct electricity – can flow through the new material." RMIT's Professor Kourosh Kalantar-Zadeh said the researchers were able to remove "roadblocks" that could obstruct the electrons, an essential step for developing high-speed electronics. "Instead of scattering when they hit roadblocks, as they would in conventional materials, they can simply pass through this new material and get through the structure faster," Professor Kalantar-Zadeh said. "Quite simply, if electrons can pass through a structure quicker, we can build smaller devices and transfer data at much higher speeds. "While more work needs to be done before we can develop actual gadgets using this new 2D nano-material, this breakthrough lays the foundation for a new electronics revolution, and we look forward to exploring its potential." In the paper titled 'Enhanced Charge Carrier Mobility in Two-Dimensional High Dielectric Molybdenum Oxide,' the researchers describe how they used a process known as "exfoliation" to create layers of the material ~11 nm thick. The material was manipulated to convert into a semiconductor, and nanoscale transistors were then created using molybdenum oxide. The result was electron mobility values of >1,100 cm2/Vs – exceeding the current industry standard for low dimensional silicon. The work, with RMIT doctoral researcher Sivacarendran Balendhran as the lead author, was supported by the CSIRO Sensors and Sensor Networks Transformational Capability Platform and the CSIRO Materials Science and Engineering Division. It was also a result of collaboration between researchers from Monash University, the University of California – Los Angeles (UCLA), CSIRO, Massachusetts Institute of Technology (MIT) and RMIT.
Editor's Note: Original news release can be found here.
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