In this week's Science, researchers from Harvard Medical School and Johns Hopkins University describe how DNA can be used to store information at greater densities than digital media. Even though the ability to store messages in DNA was first shown in 1988, the largest project to date encoded a mere 7,920 bits, reflecting the "difficulty of writing and reading long perfect DNA sequences." Using a novel approach based on next-generation DNA synthesis and sequencing technologies, the researchers now encoded an html-coded draft of a 53,000-word book with 11 JPG images and one JavaScript program in a 5.27 megabit bitstream. With continued technological advances, they noted, DNA could some day become a cheap and effective data-storage medium.
Also in Science, University of North Carolina at Chapel Hill investigators and their colleagues proposed a new scheme by which intestinal inflammation promotes colorectal cancer. In addition to directly altering physiology to facilitate tumor growth, inflammation was shown to modify the microbial composition in colitis-susceptible interleukin-10-deficient mice, reducing the overall number of species while boosting the growth of Escherichia coli. The result is the production of a genotoxin that appears to contribute to cancer independently of inflammation.
Over in Science Translational Medicine, a team led by Massachusetts Institute of Technology researchers detail the development of tumor-penetrating nanocomplexes capable of carrying therapeutic RNAi molecules deep into tumors. The delivery vehicles are comprised of siRNAs targeting the ovarian cancer oncogene ID4 that have been complexed with a tandem tumor-penetrating and membrane-translocating peptide. When delivered to mice, the nanocomplexes entered the tumor parenchyma, the siRNAs silenced their target, significantly suppressing tumor growth.