In Science this week, a team led by Massachusetts General Hospital researchers report how the genetic analysis of cancer cell culture models enabled them to identify drug combinations effective against resistant tumors. The researchers collected tumor samples from lung cancer patients whose tumors had become resistant to treatment and used those samples to establish cell lines in the laboratory. By studying genetic mutations within those cells and screening them against different drug combos, they were able to find treatments that stopped cancer growth. With optimization, the approach could offer a platform for tailoring therapies to patients based on the biology of their tumors.
Also in Science, researchers from the Massachusetts Institute of Technology describe an approach that uses DNA in living cells as a sort of "tape recorder" to keep track of long-term cellular event histories. Called SCRIBE — Synthetic Cellular Recorders Integrating Biological Events — the approach involves generating single-stranded DNA in vivo in response to arbitrary transcriptional signals. When co-expressed with a recombinase, these intracellularly expressed DNA strands target specific genomic DNA sites, triggering precise mutations that accumulate in cell populations as a function of the magnitude and duration of the inputs. The researchers expect their system could be used to build synthetic circuits that can control specific biological processes.
Finally, an international team of scientists report in Science on a series of high-resolution maps of meiotic DNA double-strand breaks in individual human genomes, providing new insights into the regulation of meiotic recombination and its impact on genome function.