scholarly journals A Cell-Based High-Throughput Assay for the Screening of Small-Molecule Inhibitors of p53–MDM2 Interaction

2011 ◽  
Vol 16 (4) ◽  
pp. 450-456 ◽  
Author(s):  
Jing Li ◽  
Shuyong Zhang ◽  
Linghuan Gao ◽  
Ying Chen ◽  
Xin Xie

The p53 tumor suppressor is a potent transcription factor that regulates cell growth inhibition and apoptosis. The oncoprotein MDM2 suppresses p53 activity by direct inhibition of its transcriptional activity and enhances the degradation of p53 via the ubiquitin–proteosome pathway. Overexpression of MDM2, found in many human tumors, impairs p53-mediated cell death effectively. Inhibition of the p53–MDM2 interaction can stabilize p53 and may offer a novel strategy for cancer therapy. To search for new inhibitors of the p53–MDM2 interaction, the authors developed a cell-based high-throughput assay system based on mammalian two-hybrid technology. They also used a dual-luciferase reporter system to rule out false- positive hits due to the cytotoxic effect of compounds. Using this assay, they screened a library consisting of 3840 compounds and identified one compound that activates p53 pathway and induces growth arrest in tumor cells.

2021 ◽  
Vol 16 (1) ◽  
pp. 266-276
Author(s):  
Zhenfen Wang ◽  
Qing Liu ◽  
Ping Huang ◽  
Guohao Cai

Abstract Gastric cancer (GC) is ranked the fourth leading cause of cancer-related death, with an over 75% mortality rate worldwide. In recent years, miR-299-3p has been identified as a biomarker in multiple cancers, such as acute promyelocytic leukemia, thyroid cancer, and lung cancer. However, the regulatory mechanism of miR-299-3p in GC cell progression is still largely unclear. Cell viability and apoptosis tests were performed by CCK8 and flow cytometry assay, respectively. Transwell assay was recruited to examine cell invasion ability. The interaction between miR-299-3p and PAX3 was determined by the luciferase reporter system. PAX3 protein level was evaluated by western blot assay. The expression of miR-299-3p was downregulated in GC tissues and cell lines (MKN-45, AGS, and MGC-803) compared with the normal tissues and cells. Besides, overexpression of miR-299-3p significantly suppressed proliferation and invasion and promoted apoptosis in GC. Next, we clarified that PAX3 expression was regulated by miR-299-3p using a luciferase reporter system, qRT-PCR, and western blot assay. Additionally, downregulation of PAX3 repressed GC cell progression. The rescue experiments indicated that restoration of PAX3 inversed miR-299-3p-mediated inhibition on cell proliferation and invasion. miR-299-3p suppresses cell proliferation and invasion as well as induces apoptosis by regulating PAX3 expression in GC, representing desirable biomarkers for GC diagnosis and therapy.


2016 ◽  
Vol 22 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Aleksandra R. Dukic ◽  
David W. McClymont ◽  
Kjetil Taskén

Connexin 43 (Cx43), the predominant gap junction (GJ) protein, directly interacts with the A-kinase-anchoring protein (AKAP) Ezrin in human cytotrophoblasts and a rat liver epithelial cells (IAR20). The Cx43-Ezrin–protein kinase (PKA) complex facilitates Cx43 phosphorylation by PKA, which triggers GJ opening in cytotrophoblasts and IAR20 cells and may be a general mechanism regulating GJ intercellular communication (GJIC). Considering the importance of Cx43 GJs in health and disease, they are considered potential pharmaceutical targets. The Cx43-Ezrin interaction is a protein-protein interaction that opens possibilities for targeting with peptides and small molecules. For this reason, we developed a high-throughput cell-based assay in which GJIC can be assessed and new compounds characterized. We used two pools of IAR20 cells, calcein loaded and unloaded, that were mixed and allowed to attach. Next, GJIC was monitored over time using automated imaging via the IncuCyte imager. The assay was validated using known GJ inhibitors and anchoring peptide disruptors, and we further tested new peptides that interfered with the Cx43-Ezrin binding region and reduced GJIC. Although an AlphaScreen assay can be used to screen for Cx43-Ezrin interaction inhibitors, the cell-based assay described is an ideal secondary screen for promising small-molecule hits to help identify the most potent compounds.


1996 ◽  
Vol 237 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Edoardo Sarubbi ◽  
Stephen D. Yanofsky ◽  
Ronald W. Barrett ◽  
Maurizio Denaro

2008 ◽  
Vol 73A (4) ◽  
pp. 312-320 ◽  
Author(s):  
Jun Chen ◽  
Jianhong Zhou ◽  
Weon Bae ◽  
Claire K. Sanders ◽  
John P. Nolan ◽  
...  

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1786-1792 ◽  
Author(s):  
Takashi Yazawa ◽  
Miki Uesaka ◽  
Yoshihiko Inaoka ◽  
Tetsuya Mizutani ◽  
Toshio Sekiguchi ◽  
...  

We have shown previously that Cyp11b1, an 11β-hydroxylase responsible for glucocorticoid biosynthesis in the adrenal gland, was induced by cAMP in androgen-producing Leydig-like cells derived from mesenchymal stem cells. We found that Cyp11b1 was induced in male Leydig cells, or female theca cells, when human chorionic gonadotropin was administered in immature mice. Expression of Cyp11b1 in rodent gonads caused the production of 11-ketotestosterone (11-KT), a major fish androgen, which induces male differentiation or spermatogenesis in fish. As in teleosts, plasma concentrations of 11-KT were elevated in human chorionic gonadotropin-treated mice. In contrast to teleosts, however, plasma concentrations of 11-KT were similar in both sexes, despite levels of testosterone, a precursor substrate, being about 20 times higher in male mice. Because expression of 11β-hydroxysteroid dehydrogenase type 2, was much higher in the mouse ovary than in the testis, conversion of testosterone into 11-KT may occur more efficiently in the ovary. In a luciferase reporter system that was responsive to and activated by androgens, 11-KT efficiently activated mammalian androgen receptor-mediated transactivation. Our results suggest that the androgen metabolic pathway is conserved between teleosts and mammals, despite sexual dominance and reproductive functions of 11-KT being altered during evolution.


2019 ◽  
Vol 66 (5) ◽  
pp. 755-762 ◽  
Author(s):  
Yuan‐Yuan Hei ◽  
Yuan‐Xu Guo ◽  
Cong‐Shan Jiang ◽  
Si Wang ◽  
She‐Min Lu ◽  
...  

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