A 1536-well fluorescence polarization assay to screen for modulators of the MUSASHI family of rna-binding proteins Journal Article


Authors: Minuesa, G.; Antczak, C.; Shum, D.; Radu, C.; Bhinder, B.; Li, Y.; Djaballah, H.; Kharas, M. G.
Article Title: A 1536-well fluorescence polarization assay to screen for modulators of the MUSASHI family of rna-binding proteins
Abstract: RNA-binding proteins (RBPs) can act as stem cell modulators and oncogenic drivers, but have been largely ignored by the pharmaceutical industry as potential therapeutic targets for cancer. The MUSASHI (MSI) family has recently been demonstrated to be an attractive clinical target in the most aggressive cancers. Therefore, the discovery and development of small molecule inhibitors could provide a novel therapeutic strategy. In order to find novel compounds with MSI RNA binding inhibitory activity, we have developed a fluorescence polarization (FP) assay and optimized it for high throughput screening (HTS) in a 1536-well microtiter plate format. Using a chemical library of 6,208 compounds, we performed pilot screens, against both MSI1 and MSI2, leading to the identification of 7 molecules for MSI1, 15 for MSI2 and 5 that inhibited both. A secondary FP dose-response screen validated 3 MSI inhibitors with IC50 below 10 μM. Out of the 25 compounds retested in the secondary screen only 8 demonstrated optical interference due to high fluorescence. Utilizing a SYBR-based RNA electrophoresis mobility shift assay (EMSA), we further verified MSI inhibition of the top 3 compounds. Surprisingly, even though several aminoglycosides were present in the library, they failed to demonstrate MSI inhibitor activity challenging the concept that these compounds are pan-Active against RBPs. In summary, we have developed an in vitro strategy to identify MSI specific inhibitors using an FP HTS platform, which will facilitate novel drug discovery for this class of RBPs. © 2014 Bentham Science Publishers.
Keywords: fluorescence polarization; rna-binding protein; small-molecule inhibitors; musashi; hts; cancer
Journal Title: Combinatorial Chemistry and High Throughput Screening
Volume: 17
Issue: 7
ISSN: 1386-2073
Publisher: Bentham Science Publishers  
Date Published: 2014-01-01
Start Page: 596
End Page: 609
Language: English
DOI: 10.2174/1386207317666140609122714
PROVIDER: scopus
PMCID: PMC4135234
PUBMED: 24912481
DOI/URL:
Notes: Export Date: 2 September 2014 -- CODEN: CCHSF -- Source: Scopus
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MSK Authors
  1. Bhavneet Bhinder
    31 Bhinder
  2. Hakim Djaballah
    101 Djaballah
  3. Christophe Antczak
    40 Antczak
  4. Constantin Radu
    28 Radu
  5. Yueming Li
    132 Li
  6. David Shum
    54 Shum
  7. Michael Kharas
    96 Kharas