Expression data for developing a GE-HTS signature for neuroblastoma differentiation. Homo sapiens

Gene expression data from BE(2)-C cells treated in triplicate with either vehicle (DMSO), 5 μM all-trans retinoic acid (ATRA), 1 mM valproic acid (VPA), or 5 μM ATRA + 1 mM VPA for 6, 24, or 72 hours. Genome-wide expression profiling was performed using Affymetrix U133A microarrays. While cytotoxic chemotherapy remains the hallmark of cancer treatment, intensive regimens fall short in many malignancies, including high-risk neuroblastoma. One alternative strategy is to therapeutically promote tumor differentiation. We created a gene expression signature to measure neuroblast maturation, adapted it to a high-throughput platform, and screened a diversity oriented synthesis-generated small-molecule library for differentiation inducers. We identified BRD8430, containing a nine-membered lactam, an ortho-amino anilide functionality, and three chiral centers, as a selective Class I histone deacetylase (HDAC) inhibitor (HDAC1 > 2 > 3). Further investigation demonstrated that selective HDAC1/HDAC2 inhibition using compounds or RNA interference induced differentiation and decreased viability in neuroblastoma cell lines. Combined treatment with 13-cis retinoic acid augmented these effects and enhanced activation of retinoic acid signaling. Therefore, by applying a chemical genomic screening approach we identified selective HDAC1/HDAC2 inhibition as a strategy to induce neuroblastoma differentiation. Overall design: BE(2)-C cells were treated in triplicate with either vehicle (DMSO), 5 μM all-trans retinoic acid (ATRA), 1 mM valproic acid (VPA), or 5 μM ATRA + 1 mM VPA for 6, 24, or 72 hours. Genome-wide expression profiling was performed using Affymetrix U133A microarrays [HT-HG_U133A Early Access].