Profiling Analysis of Histone Modifications and Gene Expression in Lewis Lung Carcinoma Murine Cells Resistant to Anti-VEGF Treatment

PLoS One. 2016 Jun 30;11(6):e0158214. doi: 10.1371/journal.pone.0158214. eCollection 2016.

Abstract

Tumor cells become resistant after long-term use of anti-VEGF (vascular endothelial growth factor) agents. Our previous study shows that treatment with a VEGF inhibitor (VEGF-Trap) facilitates to develop tumor resistance through regulating angiogenesis-related genes. However, the underlying molecular mechanisms remain elusive. Histone modifications as a key epigenetic factor play a critical role in regulation of gene expression. Here, we explore the potential epigenetic gene regulatory functions of key histone modifications during tumor resistance in a mouse Lewis lung carcinoma (LLC) cell line. We generated high resolution genome-wide maps of key histone modifications in sensitive tumor sample (LLC-NR) and resistant tumor sample (LLC-R) after VEGF-Trap treatment. Profiling analysis of histone modifications shows that histone modification levels are effectively predictive for gene expression. Composition of promoters classified by histone modification state is different between LLC-NR and LLC-R cell lines regardless of CpG content. Histone modification state change between LLC-NR and LLC-R cell lines shows different patterns in CpG-rich and CpG-poor promoters. As a consequence, genes with different level of CpG content whose gene expression level are altered are enriched in distinct functions. Notably, histone modification state change in promoters of angiogenesis-related genes consists with their expression alteration. Taken together, our findings suggest that treatment with anti-VEGF therapy results in extensive histone modification state change in promoters with multiple functions, particularly, biological processes related to angiogenesis, likely contributing to tumor resistance development.

MeSH terms

  • Animals
  • Carcinoma, Lewis Lung / genetics*
  • Cell Line, Tumor
  • CpG Islands / drug effects
  • Drug Resistance, Neoplasm*
  • Epigenesis, Genetic / drug effects
  • Gene Expression Profiling / methods*
  • Gene Expression Regulation, Neoplastic / drug effects
  • Histone Code / drug effects*
  • Mice
  • Promoter Regions, Genetic / drug effects
  • Receptors, Vascular Endothelial Growth Factor
  • Recombinant Fusion Proteins / pharmacology*

Substances

  • Recombinant Fusion Proteins
  • aflibercept
  • Receptors, Vascular Endothelial Growth Factor

Grants and funding

This study was supported by grants from National Key Basic Research Program of China (973 Program), China (2015CB553706 and SQ2015CB050449), National Natural Science Foundation of China, China (31270987 and 31470896), grants from Shanghai Committee of Science and Technology, China (10PJ1409400, 12431901000) (http://www.stcsm.gov.cn), and Suzhou Science and Technology Project, China (ZXY2012029). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.