HMGB3 Targeted by miR-145-5p Impacts Proliferation, Migration, Invasion, and Apoptosis of Breast Cancer Cells

This study focused on the investigation into how HMGB3 works in breast cancer (BC) progression. Firstly, we analyzed the relationship between HMGB3 and BC patients through the TCGA database. We performed qRT-PCR for determining the HMGB3 mRNA level and Western blot for detecting the protein level of HMGB3 in BC cell lines. CCK-8, flow cytometry, transwell, and wound healing assays were utilized to detect the effect of HMGB3 on BC cell phenotypes. Next, the prediction of the binding site shared by miR-145-5p and HMGB3 was performed by the bioinformatics method. The targeting relationship between miR-145-5p and HMGB3 was validated by using dual-luciferase assay. Finally, rescue experiments were employed for assessing the effect of the miR-145-5p/HMGB3 axis on BC cells. HMGB3 was demonstrated to have a high-level expression in BC cell lines and facilitated BC progression. On the contrary, miR-145-5p was shown a low-level expression in BC cell lines, which could target HMGB3. miR-145-5p restrained the proliferation, migration, and invasion of BC cells via inhibiting HMGB3.