Document Type : Research Paper

Authors

1 Department of Breast Surgery, Tangshan People’s Hospital, Tangshan, China

2 Breast center, Municipal Hospital Affiliated to Taizhou University, 381 Zhongshan East Road, Taizhou, Zhejiang, 318000, China

10.30498/ijb.2023.349450.3433

Abstract

Background: Breast cancer is a prevalent tumor with high aggressiveness among female populations. MiRNA-145-5p plays an important role in multiple cancers.

Objective：Our study is aimed at exploring how miRNA-145-5p functions in breast cancer cells.

Methods: qRT-PCR detected miRNA-145-5p and histone protein family member X (H2AFX) mRNA expression in breast cancer cells, and western blot determined the protein expression of H2AFX. After predicting the target genes via the bioinformatics methods, the targeting relationship between miRNA-145-5p and H2AFX was verified by dual-luciferase, RIP, and RNA pull-down assays. The relationship between H2AFX and clinical indexes was also analyzed. Furthermore, the effects of miRNA-145-5p/H2AFX regulatory axis on breast cancer cell progression were determined by colony formation, wound healing, CCK-8, and Transwell assays.

Results: The results suggested that miRNA-145-5p was markedly lowly-expressed in breast cancer tissue and cells, while H2AFX was upregulated, which had a positive correlation with T stages of breast cancer. Besides, overexpressed miRNA-145-5p was found to remarkably suppress progression of breast cancer cells. As bioinformatic analysis predicted that H2AFX was the potential target of miRNA-145-5p, the dual-luciferase assay was conducted, which demonstrated that miRNA-145-5p negatively regulated the expression of H2AFX by targeting its 3’-UTR. The rescue experiment demonstrated that overexpression of H2AFX could offset the inhibitory effects of miRNA-145-5p mimics on malignant progression.

Conclusion: Our findings confirmed that miRNA-145-5p hindered malignant progression of breast cancer by negatively regulating H2AFX. MiRNA-145-5p/H2AFX axis may be a novel therapeutic target for breast cancer.

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