Hsa-miR-214-3p inhibits breast cancer cell growth and improves the tumor immune microenvironment by downregulating B7H3

Sep 21, 2026

Uploaded by Theodora

Immune checkpoint inhibitors show limited clinical efficacy in many breast cancers, while the immunological role of B7H3 in patients remains unclear. This study analyzed B7H3 expression in breast cancer using TCGA and GEO data, selected microRNAs from TarBase, miRTarBase, and miRBase, and validated hsa-miR-214-3p targeting of B7H3 via dual-luciferase assays. Expression in tissues was measured by Western blotting and qPCR. Functional effects on proliferation, apoptosis, and immune interactions were assessed using in vitro assays, ELISA, and flow cytometry.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages19

Reading Time48 min

AccessFree to download

Introduction

Breast cancer burden and immunotherapy limitations

Rationale for targeting B7H3 (CD276)

Abstract

Background, methods, and results

Conclusions and clinical implications

ONCOLOGY RESEARCH 2025 33(1): 103-121 ARTICLE Hsa-miR-214-3p inhibits breast cancer cell growth and improves the tumor immune microenvironment by downregulating B7H3 YAN LU 1,2,\#; KANG WANG3,\#; YUANHONG PENG3,4; MENG CHEN5; LIN ZHONG3,4; LUJI HUANG3,4; FU CHENG3,4; XINDAN SHENG4,6; XIN YANG4,6; MANZHAO OUYANG3,4; GEORGE A. CALIN5,*; ZHIWEI HE 1,* 1 China-America Cancer Research Institute, Guangdong Medical University, Dongguan, 523808, China 2 GCP Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Shunde, 528300, China 3 Department of Gastrointestinal Surgery, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Shunde, 528300, China 4 The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510080, China 5 Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA 6 Department of Oncology, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Shunde, 528300, China Key words: Breast cancer, B7H3, Hsa-miR-214-3p, Immunotherapy Abstract: Background: Immune checkpoint inhibitors play an important role in the treatment of solid tumors, but the currently used immune checkpoint inhibitors targeting programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen-4 (CTLA-4) show limited clinical efﬁcacy in many breast cancers. B7H3 has been widely reported as an immunosuppressive molecule, but its immunological function in breast cancer patients remains unclear. Methods: We analyzed the expression of B7H3 in breast cancer samples using data from the Cancer Genome Atlas Program (TCGA) and the Gene Expression Omnibus (GEO) databases. MicroRNAs were selected using the TarBase, miRTarBase, and miRBase databases. The regulatory role of the microRNA hsa-miR-214-3p on B7H3 was investigated through dual-luciferase reporter assays, which identiﬁed the speciﬁc action sites of interaction. The expression levels of B7H3 and hsa-miR-214-3p in human breast cancer tissues and adjacent normal tissues were quantiﬁed using Western blotting and quantitative PCR (qPCR) . In vitro experiments were performed to observe the effects of modulating the expression of B7H3 or hsa-miR-214-3p on breast cancer cell proliferation and apoptosis. Additionally, the regulatory impact of hsa-miR-214-3p on B7H3 was examined. Enzyme-linked immunosorbent assays (ELISA) and ﬂow cytometry were employed to assess the effects of co-cultured breast cancer cells and normal human peripheral blood mononuclear cells (PBMCs) on immune cells and associated cytokines. Results: In breast cancer tissues, the expression level of B7H3 is inversely correlated with that of hsa-miR-214-3p, as well as with the regulatory effects on breast cancercell behavior. Hsa-miR-214-3p was found to inhibit breast cancer cell growth by downregulating B7H3 . Importantly, our research identiﬁed, for the ﬁrst time, two binding sites for hsa-miR-214-3pon the 3’ UTR of B7H3, both of which exert similar effects independently. Co-culture experiments revealed that hsamiR-214-3p obstructs the suppressive function of B7H3 on CD8+ T cells and natural killer cells. Conclusions: This study conﬁrms the existence of two hsa-miR-214-3p binding sites on the 3’ UTR of B7H3, reinforcing the role of hsamiR-214-3p as a regulatory factor for B7H3 . In breast cancer, hsa-miR-214-3p reduces tumor cell proliferation and enhances the tumor immune microenvironment by downregulating B7H3 . These ﬁndings suggest new potential targets for the clinical treatment of breast cancer. *Address correspondence to: George A. Calin, [gcalin@mdanderson.org](gcalin@mdanderson.org); Zhiwei He, [hezhiwei@gdmu.edu.cn](hezhiwei@gdmu.edu.cn) \#These authors contributed equally to this work Received: 19 August 2024; Accepted: 19 November 2024; Published: 20 Dece

FAQs

Why study B7H3 in breast cancer immunotherapy?

Existing immune checkpoint inhibitors targeting PD-1/PD-L1 and CTLA-4 show limited efficacy for many breast cancers, and B7H3 is widely reported as immunosuppressive, though its specific immunological function in breast cancer patients is unclear.

How was the relationship between hsa-miR-214-3p and B7H3 tested?

B7H3 expression was analyzed using TCGA and GEO datasets, microRNAs were selected from TarBase/miRTarBase/miRBase, and hsa-miR-214-3p targeting of B7H3 was validated using dual-luciferase reporter assays to identify interaction sites.

What immune and tumor effects did hsa-miR-214-3p show?

Hsa-miR-214-3p inhibited breast cancer cell growth by downregulating B7H3 and obstructed B7H3’s suppressive function on CD8+ T cells and natural killer cells, thereby enhancing the tumor immune microenvironment.

Sep 21, 2026

Uploaded by Theodora