ZNF703 is a common Luminal B breast cancer oncogene that differentially regulates luminal and basal progenitors in human mammary epithelium

The telomeric amplicon at 8p12 is common in oestrogen receptor-positive (ER+) breast cancers. Array-CGH and expression analyses of 1172 primary breast tumours revealed that ZNF703 was the single gene within the minimal amplicon and was amplified predominantly in the Luminal B subtype. Amplification was shown to correlate with increased gene and protein expression and was associated with a distinct expression signature and poor clinical outcome. ZNF703 transformed NIH 3T3 fibroblasts, behaving as a classical oncogene, and regulated proliferation in human luminal breast cancer cell lines and immortalized human mammary epithelial cells. Manipulation of ZNF703 expression in the luminal MCF7 cell line modified the effects of TGFβ on proliferation. Overexpression of ZNF703 in normal human breast epithelial cells enhanced the frequency of in vitro colony-forming cells from luminal progenitors. Taken together, these data strongly point to ZNF703 as a novel oncogene in Luminal B breast cancer.

Proteins involved in sterol synthesis interact with Ste20 and regulate cell polarity

The Saccharomyces cerevisiae p21-activated kinase (PAK) Ste20 regulates various aspects of cell polarity during vegetative growth, mating and filamentous growth. To gain further insight into the mechanisms of Ste20 action, we screened for interactors of Ste20 using the split-ubiquitin system. Among the identified proteins were Erg4, Cbr1 and Ncp1, which are all involved in sterol biosynthesis. The interaction between Ste20 and Erg4, as well as between Ste20 and Cbr1, was confirmed by pull-down experiments. Deletion of either ERG4 or NCP1 resulted in various polarity defects, indicating a role for these proteins in bud site selection, apical bud growth, cell wall assembly, mating and invasive growth. Interestingly, Erg4 was required for the polarized localization of Ste20 during mating. Lack of CBR1 produced no detectable phenotype, whereas the deletion of CBR1 in the absence of NCP1 was lethal. Using a conditional lethal mutant we demonstrate that both proteins have overlapping functions in bud morphology.

Fluorocarbons: properties and syntheses

The paper discusses custom syntheses of fluorocarbons for potential use as artificial blood substitutes. The term "fluorocarbon" designates a perfluorinated carbon compound which does not contain another halogen or hydrogen. Prominent requirements of an artificial blood substitute are: 1) efficient oxygen/carbon dioxide transport, 2) biological inertness, 3) low vapor pressure, 4) dispersibility to form emulsion. Fluorocarbons are superior to other liquids in dissolving oxygen and carbon dioxide. The most biologically inert halogenated alkanes are fully fluorinated. Introduction of another halogen or unsaturation decreases biological inertness. Boiling points of fluoroalkanes can be estimated from the Kinney equation. The most common method of fluorination, namely electrofluorination, is briefly described and applied to several types of organic compounds. Hydrocarbons give low yields of perfluoroalkanes. Alternatively, perfluoroalkanes may be prepared through reaction of functionalized substrates. Innert perfluorocyclic ethers are obtained from substrate ethers or acid fluorides. All types of amines perfluorinate but only perfluorotertiary amines are inert. Divalent organo-sulfur compounds afford inert perfluorinated products with sulfur in the hexavalent state. Sulfonyl fluorides give perfluorosulfonyl fluorides which can be pyrolytically coupled producing perfluoroalkanes. The Schoniger combustion method and neutron activation are described as analytical means for determining fluorine content.