Characterization and comparison of hypoxia inducing factors on tumor growth and metastasis between two- and three-dimensional cancer models.

The monocarboxylic acid transporter 4 (Mct-4), a downstream biomarker of hypoxia inducing factor (HIF)-1α, is involved in the cellular response to hypoxia, as indicated by the hypoxic response element in its promoter region. Using a tumorsphere assay as an in vitro 3-dimensional (3D) model generated using 384-well ultra-low attachment (ULA) plates for cell proliferation analysis using a plate-based image cytometer, we identify a hypoxic response in the tumorsphere model that is distinct from that of cells grown under 2-dimensional (2D) normoxic conditions and demonstrate a key role for Mct-4 in enabling 3D growth. The tumorsphere model yields evidence of an essential role for Mct-4 in multiple cell lines, which were genetically modified to underexpress and overexpress Mct-4, evidence not apparent in a standard 2D model of growth in the same cell lines.

RDEA119/BAY 869766: a potent, selective, allosteric inhibitor of MEK1/2 for the treatment of cancer.

The RAS-RAF-mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK pathway provides numerous opportunities for targeted oncology therapeutics. In particular, the MEK enzyme is attractive due to high selectivity for its target ERK and the central role that activated ERK plays in driving cell proliferation. The structural, pharmacologic, and pharmacokinetic properties of RDEA119/BAY 869766, an allosteric MEK inhibitor, are presented.

Association of dopamine D(3) receptors with actin-binding protein 280 (ABP-280).

Proteins that bind to G protein-coupled receptors have been identified as regulators of receptor localization and signaling. In our previous studies, a cytoskeletal protein, actin-binding protein 280 (ABP-280), was found to associate with the third cytoplasmic loop of dopamine D(2) receptors. In this study, we demonstrate that ABP-280 also interacts with dopamine D(3) receptors, but not with D(4) receptors.

Interaction of gamma-COP with a transport motif in the D1 receptor C-terminus.

Truncations at the carboxyl termini of G protein-coupled receptors result in defective receptor biogenesis and comprise a number of inherited disorders. In order to evaluate the structural role of the C-terminus in G protein-coupled receptor biogenesis, we generated a series of deletion and substitution mutations in the dopamine D1 receptor and visualized receptor subcellular localization by fusion to a green fluorescent protein. Alanine substitutions of several hydrophobic residues within the proximal C-terminus resulted in receptor transport arrest in the ER.