Anti-RBPJ (aa 370-419) polyclonal antibody

Background: Recombination signal-binding protein J (RBPJ) is a crucial downstream effector of Notch signaling, which is involved cell proliferation, differentiation, and apoptosis. It plays an important role in tumorigenesis although the further studies and concrete evidence are still needed. Especially for endometrial carcinoma, the functions and mechanism of RBPJ are still elusive. Methods: The RNA expressions of RBPJ, miR-155, NF-kappa B, TNF-alpha and kappa B-Ras1 were examined by rt-PCR, and their protein levels were determined by Western Blot. Their expressions were inhibited by transient transfection of related siRNAs. Wound healing and transwell invasion assays were performed in ECC003 cells for measuring the migration and invasion ability, respectively. The ROS levels were detected by flow cytometry with H2DCFDA. Purpose: This study was designed to investigate biological characteristics and molecular pathway of RBPJ in endometrial carcinoma cells, which may provide a potential therapeutic target for the treatments against endometrial carcinoma. Results: It was shown in our study that the expression levels of RBPJ were significantly downregulated in different endometrial carcinoma cell lines. And a siRNA-mediated reduction of RBPJ enhanced the migration and invasion ability of ECC003 obviously. Besides, the results showed that the reactive oxygenspecies (ROS) levels increase when inhibiting RBPJ. To investigate the molecular pathway of RBPJ, we examined the expression of nuclear factor-kappa B (NF-kappa B), NF-kappa B inhibitor interacting Ras-like protein 1 (kappa B-Ras1), tumor necrosis factor-alpha (TNF-alpha) and miR-155. The results suggested that the expression of NF-kappa B and TNF-alpha significantly was promoted, while kappa B-Ras1 was inhibited. An upregulated expression was observed with miR-155 as well, which suggested the inhibition of NF-kappa B signal pathway was mediated by miR-155. Our results of Notch intracellular domain (NICD) knockdown also demonstrated that NICD is required for the inhibition of RBPJ on miR-155. And knockdown of miR-155 could inhibit the mobility of endometrial carcinoma cells. Conclusion: Our study suggested that RBPJ can inhibit the movability of endometrial carcinoma cells by miR-155/NF-kappa B/ROS pathway.

To determine which nephron segments require Notch signals for development, we conditionally deleted Rbpj, a transcription factor required for canonical Notch signaling, in nephrogenic progenitors (NPs) of the metanephric mesenchyme. The retinoic acid receptor-beta 2 (Rarb2) promoter efficiently directed Cre-recombinase (Cre) activity to these progenitors. Conditional knockout of Rbpj in mice (Rarb2Cre(+)/Rbpj(f/-)) caused severe renal hypoplasia, as indicated by a 70-95% reduction in nephron number and the development of tubular cysts. To track the fate of NPs following Rarb2Cre expression, we labeled them with membrane-associated enhanced green fluorescent protein (GFP). In TomatoGFP(+)/Rarb2Cre(+) control mice, NPs differentiated into epithelia of all nephron segments, except into collecting ducts. In TomatoGFP(+)/Rarb2Cre(+)/Rbpj(f/-) conditional knockout mice, NPs developed into podocytes or distal tubular epithelia, indicating that canonical Notch signals were not required for mesenchymal-to-epithelial transition or for the specification of these nephron segments. Conversely, the few proximal tubules and associated cysts that developed in these mice were derived from the 5-10% of NPs that had failed to express Cre and, therefore, had intact Notch signaling. Thus, our fate mapping studies establish that the profound effect of Notch signaling on nephrogenesis is due to the specification of proximal but not distal tubules or podocytes. Kidney International (2011) 79, 1099-1112; doi:10.1038/ki.2010.553; published online 26 January 2011