Melatonin Modulation of Radiation-Induced Molecular Changes in MCF-7 Human Breast Cancer Cells

Area of Science:

• Oncology
• Molecular Biology
• Radiotherapy Research

Background:

• Radiation therapy is a cornerstone of cancer treatment but can cause significant side effects.
• Adjuvant molecules are explored to enhance radiation efficacy and reduce normal tissue damage.
• Melatonin, a pineal gland hormone, shows potential as a radiosensitizer and radioprotector in breast cancer.

Purpose of the Study:

• To investigate the molecular mechanisms by which melatonin modulates radiotherapy effects in breast cancer.
• To evaluate melatonin's role in potentiating anti-proliferative effects and altering gene/microRNA expression post-irradiation.
• To assess melatonin's impact on tumor vascularization in vivo.

Main Methods:

• MCF-7 breast cancer cells were treated with ionizing radiation and melatonin.
• Gene expression analysis was performed to identify radiation-induced and melatonin-modulated genes.
• MicroRNA expression profiling was conducted to assess melatonin's influence.
• In vivo assays were used to evaluate the effect of melatonin and radiation on tumor vascularization.

Main Results:

• Melatonin potentiated the anti-proliferative effects of radiation in MCF-7 cells.
• Melatonin modulated the expression of key genes, including upregulating PTEN and NME1, and downregulating AKT, SNAI2, and ERBB2.
• Melatonin enhanced radiation's effect on specific microRNAs (miR-20a, miR-19a, miR-93, miR-20b, miR-29a, miR-34a) and counteracted others (miR-17, miR-141, miR-15a).
• In vivo, melatonin combined with radiation inhibited new tumor vascularization.

Conclusions:

• Melatonin acts as both a radiosensitizer and radioprotector in breast cancer.
• Melatonin effectively modulates molecular pathways altered by radiation, enhancing anti-cancer effects.
• Clinical application of melatonin may improve therapeutic outcomes by increasing cancer cell sensitivity to radiation and overcoming resistance.