In the PNAS Early Edition this week, researchers at Massachusetts General Hospital present capture hybridization analysis of RNA targets, or CHART, "a hybridization-based technique that specifically enriches endogenous RNAs along with their targets from reversibly cross-linked chromatin extracts." The Mass General team applied its approach to map the Drosophila non-coding RNA roX2 genome-wide. The team reports genomic targets of roX2, demonstrating "how CHART can be used to study RNAs in a manner analogous to chromatin immunoprecipitation for proteins."
Elsewhere in the Early Edition, an international team led by investigators at the University of Nebraska Medical Center shows that PRDM1 is a tumor suppressor gene in natural killer cell lymphomas that's "inactivated by a combination of monoallelic deletion and promoter CpG island hypermethylation." When the team knocked down PRDM1 using an shRNA-based approach in normal natural killer cells, it found that those cells were positively selected for. Further, the team identifies "MYC and 4-1BBL as targets of PRDM1 in NK [natural killer] cells," and says "disruption of homeostatic control by PRDM1 may be an important pathogenetic mechanism for NKCL [natural killer cell lymphomas]."
In a paper published online in advance in PNAS this week, researchers at the University of Illinois at Chicago show that "Notch1 regulates the expression of the multidrug resistance gene ABCC1/MRP1 in cultured cancer cells." The team says its study points to "a unique regulatory mechanism of ABCC1 expression."
The University of California, San Francisco's Yuh-Nung Jan and his team show that partial loss of one isoform of the Ets transcription factor Pointed — PntP1 — its genetic mosaic clones, or ectopic expression of the Pnt antagonist Yan, an Ets family transcriptional repressor, "results in a reduction or elimination of INPs [intermediate neural progenitor cells] and ectopic expression of Ase in type II NBs [neuroblasts]."