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MicroRNA-574 enhances doxorubicin resistance through down-regulating SMAD4 in breast cancer cells

F-D Sun1, P-C Wang, R-L Luan

  • 1Department of Pharmacy, Yantai Yuhuangding Hospital, Yantai, China. zshzqf@163.com.

European Review for Medical and Pharmacological Sciences
|March 23, 2018
PubMed
Abstract

Insights

MicroRNA 574 (miR-574) promotes doxorubicin resistance in breast cancer by down-regulating SMAD4. This finding offers a new therapeutic target for improving breast cancer chemotherapy outcomes.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • Drug resistance is a major challenge in breast cancer treatment, particularly for advanced stages.
  • MicroRNAs play a role in drug resistance, but the specific function of miR-574 in doxorubicin resistance remains unclear.

Purpose of the Study:

  • To investigate the role of miR-574 in doxorubicin-resistant breast cancer.
  • To identify the molecular mechanisms underlying miR-574's function in drug resistance.

Main Methods:

  • Quantitative Real-time PCR (qRT-PCR) to measure miR-574 expression.
  • Cell-based assays (MTT, flow cytometry) to assess drug sensitivity, cell growth, and apoptosis.
  • Dual-luciferase and Western blot assays to identify and validate miR-574 targets.

Main Results:

  • miR-574 expression was significantly higher in doxorubicin-resistant MCF-7/Adr cells compared to MCF-7 cells.
  • Overexpression of miR-574 enhanced cell growth and promoted cell cycle transition while inhibiting apoptosis.
  • Knockdown of miR-574 reduced doxorubicin resistance and cell growth in MCF-7/Adr cells.
  • SMAD4 was identified as a direct target of miR-574, with miR-574 down-regulating SMAD4 protein expression.
  • Higher miR-574 levels were observed before chemotherapy compared to after chemotherapy in patient blood samples.

Conclusions:

  • miR-574 promotes doxorubicin resistance in breast cancer by down-regulating SMAD4.
  • miR-574 represents a potential therapeutic target for overcoming doxorubicin resistance in breast cancer.

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