Transcription of carbonyl reductase 1 is regulated by DNA topoisomerase II beta.

Mushtaq M Khazeem,Caroline A Austin,John W Casement,Lauren F Harkin,Ian G Cowell

doi:10.1002/1873-3468.13904

Abstract

DNA topoisomerase II beta (TOP2B) has a role in transcriptional regulation. Here, to further investigate transcriptional regulation by TOP2B, we used RNA-sequencing and real-time PCR to analyse the differential gene expression profiles of wild-type and two independent TOP2B-null pre-B Nalm-6 cell lines, one generated by targeted insertion and the other using CRISPR-Cas9 gene editing. We identified carbonyl reductase 1 (CBR1) among the most significantly downregulated genes in these TOP2B-null cells. Reduced CBR1 expression was accompanied by loss of binding of the transcription factors USF2 and MAX to the CBR1 promoter. We describe possible mechanisms by which loss of TOP2B results in CBR1 downregulation. To our knowledge, this is the first report of a link between TOP2B and CBR1.

Highlights

DNA topoisomerase II beta (TOP2B) has a role in transcriptional regulation
This is the first report of a link between TOP2B and carbonyl reductase 1 (CBR1)
The pattern of differential gene expression is shown in a volcano plot in Fig. 1A, and genes significantly down- or upregulated in the TOP2B null cells (Nalm-6TOP2BÀ/À) compared to wildtype are listed in Tables S2 and S3

Summary

Introduction

DNA topoisomerase II beta (TOP2B) has a role in transcriptional regulation. To further investigate transcriptional regulation by TOP2B, we used RNA-sequencing and real-time PCR to analyse the differential gene expression profiles of wild-type and two independent TOP2B-null pre-B Nalm-6 cell lines, one generated by targeted insertion and the other using CRISPR-Cas gene editing. Analysis of the DNA sequences within TOP2B ChIP-seq peaks found enrichment for a number of transcription factor motifs including those for CTCF and SP1 [15]; subsequent studies have confirmed a strong overlap between TOP2B and CTCF binding across the genome [13,14]. To further investigate the role of TOP2B in transcriptional regulation, we carried out differential gene expression analysis comparing the pre-B-cell line, Nalm-6 and an established Nalm-6 TOP2B targeted.

Methods

Results

Conclusion