A transcriptomic dataset used to derive biomarkers of chemically induced histone deacetylase inhibition (HDACi) in human TK6 cells

Transcriptomic biomarkers facilitate mode of action analysis of toxicants by detecting specific patterns of gene expression perturbations. We identified an 81-gene transcriptomic biomarker of histone deacetylase inhibitors (HDACi) using whole transcriptome data sets of TK6 human lymphoblastoid cells generated by Templated Oligo-Sequencing (TempO-Seq) after 4 h of exposure to 20 reference compounds (10 HDACi and 10 non-HDACi) [1]. The biomarker, named TGx-HDACi, was derived using the nearest shrunken centroid (NSC) method and can distinguish HDACi from non-HDACi compounds based on the expression pattern across the 81 genes. The classification capability of TGx-HDACi was evaluated by NSC probability analysis of 11 external validation compounds (4 HDACi and 7 non-HDACi) with a probability cut-off of 90%. Thus far, TGx-HDACi has demonstrated 100% accuracy in classifying the reference and validation compounds as HDACi or non-HDACi. Of the 81 TGx-HDACi genes, 19 genes are part of the S1500+ gene panel containing 2753 genes, developed for toxicological assessments [2]. Herein, we assessed the classification performance of the biomarker with this reduced gene set to determine if TGx-HDACi can be applied to analyze S1500+ gene expression profiles. The 20 reference compounds and 11 validation compounds were correctly classified as HDACi or non-HDACi by the NSC probability analysis, principal component analysis, and hierarchical clustering based on the expression of the 19 genes, demonstrating 100% accuracy.