Identification of microRNA expression profiles of CD44+ ovarian cancer stem cells

Abstract

Purpose: The aim of our study was to investigate microRNA (miRNA) expression profiles in CD44⁺ ovarian cancer stem cells (ovarian CSCs).

Methods: In this study, we enriched CD44⁺ ovarian CSCs using magnetic activated cell sorting (MACS). A combination of real-time quantitative PCR (qRT-PCR), western blot and sphere formation assays was used to demonstrate stem cell-like properties. RNA sequencing was used to detect the miRNA expression profiles in CD44⁺ ovarian CSCs. Transient transfection, qRT-PCR, western blot and sphere formation assays were further used to test the function of miR-181a-2-3p.

Results: We found that CD44⁺ ovarian CSCs showed enhanced sphere formation and expression of stemness-associated genes (NANOG, OCT4, SOX2) compared to ovarian cancer cells. The RNA sequencing results showed that the miRNA expression profiles of CD44⁺ ovarian CSCs were different from those of ovarian cancer cells. GO and KEGG pathway analyses indicated that these miRNAs regulate stem cell-like properties in CD44⁺ ovarian CSCs. In addition, miR-181a-2-3p negatively regulates the stem cell-like properties of CD44⁺ ovarian CSCs by targeting EGR1.

Conclusion: Our data suggest that miRNAs play important roles in regulating the stem cell-like properties of CD44⁺ ovarian CSCs.

Keywords: CD44; Ovarian cancer stem cells; Stem cell-like properties; miRNAs.