MicroRNA-140-5p inhibits invasion and angiogenesis through targeting VEGF-A in breast cancer

Area of Science:

• Molecular Biology
• Oncology
• Biochemistry

Background:

• MicroRNAs (miRNAs) regulate gene expression and are implicated in cancer progression, including metastasis and angiogenesis.
• miR-140-5p has been identified as a tumor suppressor in various human cancers, but its specific role in breast cancer invasion and angiogenesis requires further elucidation.

Purpose of the Study:

• To investigate the molecular mechanism by which miR-140-5p affects breast cancer invasion and angiogenesis.
• To identify the direct target of miR-140-5p involved in these processes.

Main Methods:

• Quantitative analysis of miR-140-5p expression in breast cancer tissues.
• In vitro assays (Transwell invasion, tube formation) using miR-140-5p mimics in breast cancer cell lines (MCF-7, MDA-MB-231).
• In vivo validation using immunohistochemistry and Western blot to assess invasion and angiogenesis markers (VEGF-A, CD31, MMP-9), and dual-luciferase reporter assays to confirm target interaction.

Main Results:

• Decreased miR-140-5p mRNA levels were observed in metastatic breast cancer tissues compared to non-metastatic ones.
• Overexpression of miR-140-5p significantly inhibited breast cancer cell invasion and angiogenesis in vitro.
• VEGF-A was identified and validated as a direct target of miR-140-5p, with its expression reduced upon miR-140-5p mimic transfection.

Conclusions:

• miR-140-5p suppresses breast cancer invasion and angiogenesis by directly targeting VEGF-A.
• The findings reveal a novel molecular mechanism for miR-140-5p in breast cancer.
• This study provides a strong foundation for developing novel microRNA-based therapeutic strategies for breast cancer treatment.