Long Noncoding-RNA Component of Mitochondrial RNA Processing Endoribonuclease Promotes Carcinogenesis in Triple-Negative Breast Cancer Cells via the Competing Endogenous RNA Mechanism.

Abstract

PURPOSE:

Triple-negative breast cancer (TNBC) is a subtype of breast cancer. Increasing evidence supports that dysregulation of long noncoding RNAs (lncRNAs) plays a vital role in cancer progression. RNA component of mitochondrial RNA processing endoribonuclease (RMRP), a lncRNA, is characterized as a tumor-propeller in some cancers, but its mechanism in TNBC remains poorly understood. This study aimed to determine whether and how RMRP functions in TNBC.

METHODS:

Cell proliferation was determined by cell counting kit-8 (CCK-8) and colony formation assays and cell apoptosis by flow cytometry analysis and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. Cell migration and invasion were determined by transwell assays. RNA-binding protein immunoprecipitation (RIP), luciferase reporter, and RNA pulldown assays were implemented to assess the interaction of RMRP with other molecules in TNBC cells.

RESULTS:

RMRP expression was elevated in TNBC cells. RMRP knockdown repressed cell proliferation, migration, and invasion, but induced apoptosis in TNBC. In addition, RMRP was found to target microRNA-766-5p (miR-766-5p) in TNBC cells. Silencing miR-766-5p enhanced cell viability and decreased apoptosis, whereas miR-766-5p overexpression had opposite effects. Furthermore, miR-766-5p was found to bind to yes-associated protein 1 (YAP1). Moreover, miR-766-5p inhibition reversed the repressive effect of RMRP knockdown on the malignant progression of TNBC.

CONCLUSION:

The present study manifested that RMRP promotes the growth, migration, and invasion of TNBC cells via the miR-766-5p/YAP1 axis. These findings provide novel perspectives for TNBC treatment.

• Authors: Liqiang Qi, Bo Sun, Beibei Yang, Su Lu
• Journal: Journal of breast cancer (J Breast Cancer) Vol. 24 Issue 5 Pg. 428-442 (Oct 2021) ISSN: 1738-6756 [Print] Korea (South)
• PMID: 34652079 (Publication Type: Journal Article)
• Copyright: © 2021 Korean Breast Cancer Society.