Long non‑coding RNA DANCR aggravates breast cancer through the miR‑34c/E2F1 feedback loop

Area of Science:

• Molecular Biology
• Genetics
• Oncology

Background:

• Long non-coding RNAs (lncRNAs) are increasingly recognized for their roles in cancer.
• The specific functions and mechanisms of the lncRNA DANCR in breast cancer are not fully elucidated.
• Understanding DANCR's role is crucial for developing novel breast cancer therapies.

Purpose of the Study:

• To investigate the mechanism of action of the lncRNA DANCR in breast cancer.
• To explore the regulatory interactions between DANCR, miR-34c-5p, and E2F1.
• To assess the impact of DANCR on breast cancer cell behavior.

Main Methods:

• Lentiviral vectors were used to manipulate DANCR expression (knockdown and overexpression) in MCF7 and MDA-MB-231 breast cancer cells.
• Quantitative PCR and Western blotting were employed to measure gene and protein expression levels.
• Chromatin immunoprecipitation, dual-luciferase reporter assays, and fluorescence in situ hybridization were used to validate molecular interactions and localization.
• Cell proliferation, migration, and invasion assays (EdU, wound healing, Transwell) were performed to assess functional effects.

Main Results:

• DANCR acts as a competing endogenous RNA, upregulating E2F1 by sequestering miR-34c-5p in breast cancer cells.
• E2F1 was found to promote DANCR transcription by binding to its promoter region.
• A positive feedback loop involving DANCR, miR-34c-5p, and E2F1 was identified, enhancing breast cancer cell proliferation, migration, and invasion.

Conclusions:

• The DANCR/miR-34c-5p/E2F1 feedback loop plays a significant role in promoting breast cancer progression.
• Targeting DANCR presents a potential therapeutic strategy for breast cancer treatment.
• Further research into this regulatory network could lead to improved clinical interventions.