Combination Treatment with EGFR Inhibitor and Doxorubicin Synergistically Inhibits Proliferation of MCF-7 Cells and...

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Epidermal growth factor receptor (EGFR) plays a critical role in tumor progression and drug resistance in breast cancer.
• EGFR is frequently overexpressed in triple-negative breast cancer (TNBC), a subtype lacking targeted therapies.

Purpose of the Study:

• To investigate the synergistic potential of an EGFR inhibitor (EGFRi) combined with doxorubicin (Dox) in breast cancer cell lines.
• To evaluate the combination therapy's effects on cell viability, apoptosis, and EGFR gene expression.

Main Methods:

• Utilized estrogen-positive (ER+) MCF-7 and triple-negative breast cancer (TNBC) MDA-MB-231 cell lines.
• Assessed cytotoxicity using IC50 values for EGFRi and Dox alone and in combination.
• Confirmed synergistic drug interactions using the Bliss independence model.
• Measured Caspase-3/7 activation to quantify apoptosis induction.
• Analyzed EGFR gene expression changes via quantitative PCR.

Main Results:

• EGFRi and Dox combination therapy significantly reduced IC50 values in both MCF-7 (0.46 µM) and MDA-MB-231 (0.01 µM) cell lines, indicating enhanced cytotoxicity.
• Synergistic drug interactions were confirmed by the Bliss independence model.
• The combination treatment induced pro-apoptotic Caspase-3/7 activation in both cell lines.
• Both single agents and the combination downregulated EGFR gene expression in MCF-7 and MDA-MB-231 cells (p < 0.001).

Conclusions:

• EGFR inhibitor in combination with doxorubicin demonstrates significant synergistic potential against breast cancer cells.
• This combination therapy enhances growth inhibition, induces apoptosis, and downregulates EGFR expression.
• The findings suggest a promising therapeutic strategy for breast cancer, particularly TNBC, by targeting EGFR.