Fusion proteins of retinoid receptors antagonize TGF-β-induced growth inhibition of lung epithelial cells

Tumor suppressor menin: the essential role of nuclear localization signal domains in coordinating gene expression

“…On day 2, the cells were harvested and processed for Western blotting as previously described (La et al, 2003). Quantification of signals from classic Western blotting was performed by scanning the Western blot image, followed by quantifying the band intensity using Metamorph software.…”

Association of v-ErbA with Smad4 Disrupts TGF-β Signaling

“…The nuclear orphan receptor, ear2 (erbA related gene 2), is a member of the COUP-TF (NR2) subfamily of nuclear hormone receptors and shares homology with TR␣ (Miyajima et al, 1988). Whereas gag-ear2 fusion is artificially created during the construction of cDNA library, fusion proteins between a viral gag sequence and nuclear hormone receptors have been identified in nature (Grignani et al, 1998;Lin and Evans, 2000;La et al, 2003). An example is the oncoprotein v-ErbA, which is composed of an Nterminal gag sequence fused to a mutated form of thyroid hormone receptor ␣ (TR␣/c-ErbA; Vennstrom and Bishop, 1982).…”

“…Overexpression of oncoproteins is also implicated in the disruption of TGF-␤ signaling. Tumor cells insensitive to TGF-␤ are known to overexpress diverse oncoproteins such as Cdk4, Ski, Evi-1, Ras, Mdm2, E6/E7, E1A, and PLZF-RAR␣ (Pietenpol et al, 1990;Ewen et al, 1993;Datto et al, 1997;Kurokawa et al, 1998;Sun et al, 1998;Hanahan and Weinberg, 2000;Massague et al, 2000;La et al, 2003;Luo, 2004). Overexpression of HPV-16 E7 and E1A, for example, is shown to cause TGF-␤ resistance in skin keratinocytes by preventing TGF-␤-induced down-regulation of c-myc transcription (Pietenpol et al, 1990).…”

Menin Induces Apoptosis in Murine Embryonic Fibroblasts

“…The primary antibody against a human menin peptide (Ser 593 -Leu 610 ) (30) was raised in rabbits and was affinity-purified with the corresponding peptide-conjugated agarose beads. The bound primary antibodies were detected as described previously (31). To detect procaspase 8 expression, whole cell lysates were prepared from freshly isolated cells using CHAPS lysis buffer (10 mM Tris, pH 7.5, 0.5% CHAPS, 1 mM MgCl 2 , 1 mM EGTA, 10% glycerol, 1 mM sodium o-vanadate, and 0.1 mg/ml Pefabloc) supplemented with a protease inhibitor mixture (Calbiochem) as described previously (32).…”

“…The probes were hybridized to the Affymetrix murine GeneChip U74A array at the Penn Microarray Core Facility (Philadelphia, PA). Genes whose levels of expression varied 2-fold or more from the control were further analyzed by Northern blotting analysis, which was carried out as described previously (31).…”