Genes responsive to rapamycin and serum deprivation are clustered on chromosomes and undergo reorganization within local chromatin environments

Biochem Cell Biol. 2020 Apr;98(2):178-190. doi: 10.1139/bcb-2019-0096. Epub 2019 Sep 3.

Abstract

We previously demonstrated that genome reorganization, through chromosome territory repositioning, occurs concurrently with significant changes in gene expression in normal primary human fibroblasts treated with the drug rapamycin, or stimulated into quiescence. Although these events occurred concomitantly, it is unclear how specific changes in gene expression relate to reorganization of the genome at higher resolution. We used computational analyses, genome organization assays, and microscopy, to investigate the relationship between chromosome territory positioning and gene expression. We determined that despite relocation of chromosome territories, there was no substantial bias in the proportion of genes changing expression on any one chromosome, including chromosomes 10 and 18. Computational analyses identified that clusters of serum deprivation and rapamycin-responsive genes along the linear extent of chromosomes. Chromosome conformation capture (3C) analysis demonstrated the strengthening or loss of specific long-range chromatin interactions in response to rapamycin and quiescence induction, including a cluster of genes containing Interleukin-8 and several chemokine genes on chromosome 4. We further observed that the LIF gene, which is highly induced upon rapamycin treatment, strengthened interactions with up- and down-stream intergenic regions. Our findings indicate that the repositioning of chromosome territories in response to cell stimuli, this does not reflect gene expression changes occurring within physically clustered groups of genes.

Keywords: chromosome territory; expression génique; gene expression; interaction chromatinienne de longue distance; long-range chromatin interaction; quiescence; rapamycin; rapamycine; territoire chromosomique.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / genetics
  • Cell Proliferation
  • Chromatin / chemistry*
  • Chromosome Painting
  • Chromosomes, Artificial, Bacterial
  • Chromosomes, Human, Pair 10
  • Chromosomes, Human, Pair 18
  • Cluster Analysis
  • Computational Biology
  • Fibroblasts / metabolism*
  • Gene Expression Profiling
  • Gene Expression Regulation*
  • Gene Library
  • Genome, Human
  • Humans
  • In Situ Hybridization, Fluorescence
  • Interleukin-8 / metabolism
  • Multigene Family
  • Serum / metabolism*
  • Sirolimus / pharmacology*

Substances

  • CXCL8 protein, human
  • Chromatin
  • Interleukin-8
  • Sirolimus

Grant support