Metronidazole affects breast cancer cell lines

Area of Science:

• Oncology
• Pharmacology
• Molecular Biology

Background:

• Breast cancer exhibits heterogeneity, with estrogen receptor (ER) status significantly influencing treatment response.
• Metronidazole (MTZ), an antibiotic, has been investigated for potential anticancer properties.

Purpose of the Study:

• To investigate the differential effects of metronidazole (MTZ) on cytotoxicity and DNA synthesis in ER-positive (MCF-7) and ER-negative (MDA-MB-231) human breast cancer cell lines.

Main Methods:

• Cytotoxicity was assessed using the MTT assay.
• Cells were exposed to various MTZ concentrations (0.1-250 μg/ml) for 24, 48, and 72 hours.
• DNA synthesis was quantified by measuring [3H]-thymidine incorporation.

Main Results:

• MTZ demonstrated dose- and time-dependent effects.
• In MCF-7 cells, MTZ (250 μg/ml) increased proliferation at 24h but reduced viability at 72h (1-10 μg/ml).
• MDA-MB-231 cells showed increased viability with MTZ (250 μg/ml) at 24h and 72h, and suppressed proliferation at lower concentrations (0.1-50 μg/ml) after 72h.
• Increased [3H]-thymidine incorporation was observed in MCF-7 cells at 250 μg/ml MTZ after 24h.

Conclusions:

• Metronidazole exhibits distinct dose- and time-dependent effects on human breast cancer cell lines.
• The observed discrepancies in MTZ's impact on ER-positive versus ER-negative cells suggest a role for estrogen signaling.