7USJ

BRD4-BD2 in complex with SF2523


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.08 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.219 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

Targeting BRD4 and PI3K signaling pathways for the treatment of medulloblastoma.

Sethi, B.Kumar, V.Jayasinghe, T.D.Dong, Y.Ronning, D.R.Zhong, H.A.Coulter, D.W.Mahato, R.I.

(2023) J Control Release 354: 80-90

  • DOI: https://doi.org/10.1016/j.jconrel.2022.12.055
  • Primary Citation of Related Structures:  
    7USG, 7USH, 7USI, 7USJ, 7USK

  • PubMed Abstract: 

    Medulloblastoma (MB) is a malignant pediatric brain tumor which shows upregulation of MYC and sonic hedgehog (SHH) signaling. SHH inhibitors face acquired resistance, which is a major cause of relapse. Further, direct MYC oncogene inhibition is challenging, inhibition of MYC upstream insulin-like growth factor/ phosphatidylinositol-4,5-bisphosphate 3-kinase (IGF/PI3K) is a promising alternative. While PI3K inhibition activates resistance mechanisms, simultaneous inhibition of bromodomain-containing protein 4 (BRD4) and PI3K can overcome resistance. We synthesized a new molecule 8-(2,3-dihydrobenzo[b] [1, 4] dioxin-6-yl)-2-morpholino-4H-chromen-4-one (MDP5) that targets both BRD4 and PI3K pathways. We used X-ray crystal structures and a molecular modeling approach to confirm the interactions between MDP5 with bromo domains (BDs) from both BRD2 and BRD4, and molecular modeling for PI3K binding. MDP5 was shown to inhibit target pathways and MB cell growth in vitro and in vivo. MDP5 showed higher potency in DAOY cells (IC 50 5.5 μM) compared to SF2523 (IC 50 12.6 μM), and its IC 50 values in HD-MB03 cells were like SF2523. Treatment of MB cells with MDP5 significantly decreased colony formation, increased apoptosis, and halted cell cycle progression. Further, MDP5 was well tolerated in NSG mice bearing either xenograft or orthotopic MB tumors at the dose of 20 mg/kg, and significantly reduced tumor growth and prolonged animal survival.


  • Organizational Affiliation

    Department of Pharmaceutical Sciences, the University of Nebraska Medical Center, Omaha, NE 68198, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Bromodomain-containing protein 4
A, B
109Homo sapiensMutation(s): 0 
Gene Names: BRD4HUNK1
UniProt & NIH Common Fund Data Resources
Find proteins for O60885 (Homo sapiens)
Explore O60885 
Go to UniProtKB:  O60885
PHAROS:  O60885
GTEx:  ENSG00000141867 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO60885
Sequence Annotations
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  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
82V BindingDB:  7USJ IC50: 1547 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.08 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.219 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 77.625α = 90
b = 77.625β = 90
c = 100.645γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Not funded--

Revision History  (Full details and data files)

  • Version 1.0: 2023-01-18
    Type: Initial release
  • Version 1.1: 2023-10-25
    Changes: Data collection, Refinement description