January 13, 2006

BIOLOGICAL CHEMISTRY: Transcription Apparatus Seen to Uncoil—and Recoil—DNA
Over the years, seminal contributions from the labs of Fred Winston (front), Kevin Struhl (back), and Stephen Buratowski (left) have substantially changed the understanding of transcription, revealing how the transcriptional machinery plays a crucial role in not only unwinding but rewinding DNA around core histones. Now, a paper by Struhl and postdoctoral fellow Amita Joshi in the Dec. 22 Molecular Cell and another by Buratowski, postdoc Michael Keogh (right), and their colleagues in the Nov. 18 Cell, show how RNA polymerase–dependent deacetylation of histones plays a key role in the reassembly of chromatin. The findings help crystallize the concept, proposed independently by Winston and Struhl, that restoring repressive chromatin is essential to prevent rogue transcription at internal start sites.

PATHOLOGY: Molecule that Inflames Cancer May Also Dampen Spread of Disease
Two teams of HMS researchers have found hidden benefits of a molecule that has been clearly implicated in the growth and survival of cancer cells. The culprit, Akt, is so frequently activated in human tumors that more than 20 companies are looking for new ways to treat cancer by shutting it down. In unexpected findings, independent studies from the labs of Alex Toker and Joan Brugge show that at least one version of Akt blocks the migration and invasion of human breast cancer cells in culture. The findings, in the Nov. 23 Molecular Cell and the Dec. 19 Journal of Cell Biology, respectively, may lead to more precisely targeted anticancer agents even as they raise concerns about a new generation of promising drugs in the pipeline that might inadvertently promote the spread of disease. In the photo are Toker (front), Brugge (back), and postdoctoral fellows Merav Yoeli-Lerner (left) and Hanna Yoko Irie.

IMAGING: Technique Demonstrates Whole-body Fluorescent Scanning
Fluorescent proteins have become ubiquitous tools in the lab and are regularly used in animal models. A new imaging technique published in the Dec. 20 Proceedings of the National Academy of Sciences allows researchers to locate and quantify fluorescent proteins throughout the body in living mice. This technology, developed by a team led by Vasilis Ntziachristos, should enable researchers to track cells that express fluorescent proteins within the entire mouse body—for instance, to monitor the growth of tumors or the delivery of viral genes.