A Nanoscale Solution to the $1,000 Genome
One day physicians may be able to personalize our medical care based on the genetic information we carry around with us on a thumb-drive. Using nano-scale structures, researchers are trying to develop inexpensive ways to sequence a complete genome, says Jeffery Schloss, Program Director for Technology Development Coordination at the National Human Genome Research Institute (NHGRI). At the May 2 Johns Hopkins NanoBio Symposium, hosted by the Institute for NanoBioTechnology, Schloss will discuss current research in this area, as well as the nanotechnology related activities of the National Institutes of Health (NIH).
The National Human Genome Research Institute is working on ways to bring down the cost of decoding an individual’s genome. The Human Genome Project spent $500 million over about 13 years to sequence the first human genome, Schloss states. But if the cost could be reduced to $1,000 a person and the process reduced to a matter of days, sequencing could become as accessible as other medical tests, he says.
Up until now, researchers have focused on sequencing the relevant protein-coding areas of the genome, which, Schloss says, account for just 1 percent of 30 billion base pairs. NHGRI’s goal is to sequence the DNA from end to end, including the parts that used to be called “junk.“ For it is in these non-protein-coding stretches, he says, that researches have found promoters, enhancers, and other triggering and regulatory sequences that, along with the protein-coding genes, can alter the timing and amount of gene expression or protein structure and upset the delicate balance the produces the state we know as “health.“ Furthermore, such comprehensive DNA analysis could also help to show how environmental pressures have impacted a person’s individual genetic make-up, providing clues to the environmental component of human health.
One approach to revealing these unexplored regions of DNA is to use biological or fabricated nanostructures, such as nano-pores and nano-channels. Among the ideas under development are nano-scale devices that can coax a single strand of DNA molecule to stretch out and move past an array of sensors to detect individual nucleotides. The goal, Schloss explains, is to distinguish between the four bases—A, T, G, and C—as well as make note of any genomic methylation patterns that indicate whether a particular gene is turned “on“ or “off.“
Using a chemical or electrical means of base detection eliminates the need for DNA labeling. “We should be able to do this less expensively and analyze native DNA isolated directly from cells,“ Schloss says. “Perhaps this could also be used on RNA and proteins as well.“
Schloss adds: “I am rather agnostic about how we achieve a cost-effective DNA sequence that would allow us to provide individual genomic information for health care, but I am optimist that nanotechnology will be a serious component of that method.“
Along with his efforts to cut the cost of DNA sequencing, Schloss represents NHGRI on NIH’s Bioengineering Consortium, co-chairs the Trans-NIH NANO Task force, and also co-chairs NIH’s Nanomedicine Roadmap Initiative. The focus of the Nanomedicine Roadmap Initiative is to “use nano-tools and nano-concepts to derive a deeper understanding of the biological processes at the nanoscale and to convert that information into something clinically relevant.“
To learn more about the grant programs Schloss coordinates, go to the NHGRI Genome Technology home page at http://www.genome.gov/10000368
To read about NIH’s nanotechnology programs, go to http://www.becon.nih.gov/nano.htm
For more information about the 2008 Johns Hopkins NanoBio Symposium, go to: http://inbt.jhu.edu/symposium
Methylation: adding methyl groups to nucleotides in genomic DNA; controls gene expression (http://www.biology-online.org/dictionary/Dna_methylation)
Story by Mary Spiro