Role of BMI1 in epithelial ovarian cancer: investigated via the CRISPR/Cas9 system and RNA sequencing

J Ovarian Res. 2018 Apr 23;11(1):31. doi: 10.1186/s13048-018-0406-z.

Abstract

Background: B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1) might be an appropriate biomarker in the management of epithelial ovarian cancer (EOC). However, the biological role of BMI1 and its relevant molecular mechanism needs further elaboration. Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system is an excellent genome-editing tool and is scarcely used in EOC studies.

Methods: We first applied CRISPR/Cas9 technique to silence BMI1 in EOC cells; thereafter we accomplished various in vivo and in vitro experiments to detect biological behaviors of ovarian cancer cells, including MTT, flow cytometry, Transwell, real-time polymerase chain reaction and western blotting assays, etc.; eventually, we used RNA sequencing to reveal the underlying molecular traits driven by BMI1 in EOC.

Results: We successfully shut off the expression of BMI1 in EOC cells using CRISPR/Cas9 system, providing an ideal cellular model for investigations of target gene. Silencing BMI1 could reduce cell growth and metastasis, promote cell apoptosis, and enhance the platinum sensitivity of EOC cells. BMI1 might alter extracellular matrix structure and angiogenesis of tumor cells through regulating Focal adhesion and PI3K/AKT pathways.

Conclusion: BMI1 is a potential biomarker in EOC management, especially for tumor progression and chemo-resistance. Molecular traits, including BMI1 and core genes in Focal adhesion and PI3K/AKT pathways, might be alternatives as therapeutic targets for EOC.

Keywords: B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1); Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9; Epithelial ovarian cancer (EOC); Focal adhesion pathway; PI3K/AKT pathway.

MeSH terms

  • Animals
  • Apoptosis
  • CRISPR-Cas Systems*
  • Carcinoma, Ovarian Epithelial
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Flow Cytometry
  • Focal Adhesions / genetics
  • Gene Expression Regulation, Neoplastic
  • Gene Silencing
  • High-Throughput Nucleotide Sequencing / methods*
  • Humans
  • Mice
  • Neoplasm Invasiveness / genetics
  • Neoplasms, Glandular and Epithelial / genetics*
  • Neoplasms, Glandular and Epithelial / pathology
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / pathology
  • Polycomb Repressive Complex 1 / antagonists & inhibitors
  • Polycomb Repressive Complex 1 / genetics*
  • Sequence Analysis, RNA
  • Xenograft Model Antitumor Assays

Substances

  • BMI1 protein, human
  • Polycomb Repressive Complex 1