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Updated: Jun 23, 2025
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Investigation of the Transcriptional Role of a RUNX1 Intronic Silencer by CRISPR/Cas9 Ribonucleoprotein in Acute Myeloid Leukemia Cells
Published on: September 1, 2019
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RUNX3 exerts tumor-suppressive role through inhibiting EXOSC4 expression
Nan Wang1, Xiaodan Miao1, Wenxin Lu1
1Department of Pathology, Xuzhou Medical University, Xuzhou, China.
Functional & Integrative Genomics
|June 24, 2024
Summary
RUNX3 suppresses estrogen receptor positive breast cancer by inhibiting EXOSC4 expression. This mechanism impacts cancer stem cell traits and patient survival, highlighting RUNX3
Area of Science:
- Oncology
- Molecular Biology
- Cancer Research
Background:
- Estrogen receptor-positive (ER+) breast cancer, prevalent in 70% of cases, is significantly impacted by cancer stem cells (CSCs) driving relapse and metastasis.
- RUNX3, a tumor suppressor, is frequently inactivated in ER+ breast cancer, but its role in regulating CSC traits remains unclear.
- Understanding RUNX3's regulatory mechanisms in ER+ breast cancer is crucial for developing targeted therapies.
Purpose of the Study:
- To elucidate the mechanism by which RUNX3 regulates cancer stem cell traits in estrogen receptor-positive breast cancer.
- To identify direct targets of RUNX3 involved in breast cancer progression.
- To investigate the functional role of EXOSC4 in breast cancer stemness and patient survival.
Main Methods:
- Utilized cut-and-tag assay in BT474 and T47D cells to determine RUNX3 binding profiles.
- Investigated the effect of EXOSC4 on breast cancer cell proliferation, invasion, and mammosphere formation.
- Analyzed the correlation between EXOSC4 expression and patient survival in Luminal B/Her2 breast cancer subtypes.
Main Results:
- Confirmed EXOSC4 as a direct transcriptional target of RUNX3, with RUNX3 binding to the EXOSC4 promoter to suppress its expression.
- Demonstrated that increased EXOSC4 expression enhances colony formation, invasion, and mammosphere formation, upregulating SOX2 and ALDH1.
- Found that higher EXOSC4 levels are associated with poorer survival in Luminal B/Her2 breast cancer patients, indicating its role in mediating RUNX3's tumor-suppressive function.
Conclusions:
- RUNX3 directly suppresses EXOSC4 expression by binding to its promoter region in ER+ breast cancer cells.
- EXOSC4 promotes breast cancer stemness and is linked to adverse patient outcomes, mediating the tumor-suppressive role of RUNX3.
- This study reveals a novel RUNX3-EXOSC4 axis critical for understanding and potentially targeting ER+ breast cancer progression.
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