Whole-genome sequencing identifies recurrent mutations in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most deadly cancers worldwide and has no effective treatment, yet the molecular basis of hepatocarcinogenesis remains largely unknown. Here we report findings from a whole-genome sequencing (WGS) study of 88 matched HCC tumor/normal pairs, 81 of which are Hepatitis B virus (HBV) positive, seeking to identify genetically altered genes and pathways implicated in HBV-associated HCC. We find beta-catenin to be the most frequently mutated oncogene (15.

Development of a quantitative biochemical and cellular sphingomyelin synthase assay using mass spectrometry.

The last step in sphingolipid biosynthesis is the conversion of ceramide (Cer) to sphingomyelin (SM), which is catalyzed by sphingomyelin synthase (SMS). Two isoforms of SMS have been identified with differential subcellular localizations. It is not clear whether the two isoforms have any differences in biochemical or cellular SMS activities.

Characterization of the expression and activity of carboxylesterases 1 and 2 from the beagle dog, cynomolgus monkey, and human.

The carboxylesterases (CESs) are a family of serine hydrolases that hydrolyze compounds containing an ester, amide, or thioester. In humans, two dominant forms, CES1 and CES2, are highly expressed in organs of first-pass metabolism and play an important role in xenobiotic metabolism. The current study was conducted to better understand species-related differences in substrate selectivity and tissue expression of these enzymes.

Development of a novel sandwich ELISA for measuring cell lysate ABCA1 protein levels.

ATP-binding cassette transporter A-1 (ABCA1) mediates the transfer of cellular cholesterol to lipid-poor apolipoproteins. Liver X receptors (LXRs) are regulators of cholesterol homeostasis that increase transcription of ABCA1. Synthetic LXR agonists developed to date have been shown to induce ABCA1 mRNA expression and increase reverse cholesterol transport.

Effect of buffer components and carrier solvents on in vitro activity of recombinant human carboxylesterases.

Introduction: The effects of buffer and substrate solvent conditions on in vitro activity of carboxylesterases (CE) have not been previously described. Therefore, it is unknown if the many different assay conditions used by various laboratories have a substantial impact on the activity of CE enzymes.

Methods: Three human CEs were expressed and purified, and the hydrolysis of 4-nitrophenyl butyrate was measured to assess enzyme activity.

Secreted PCSK9 downregulates low density lipoprotein receptor through receptor-mediated endocytosis.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a protease that regulates low density lipoprotein receptor (LDLR) protein levels. The mechanisms of this action, however, remain to be defined. We show here that recombinant human PCSK9 expressed in HEK293 cells was readily secreted into the medium, with the prosegment associated with the C-terminal domain.