miR-302b enhances breast cancer cell sensitivity to cisplatin by regulating E2F1 and the cellular DNA damage response

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Chemotherapy resistance is a major challenge in breast cancer treatment, negatively impacting patient outcomes.
• Understanding the molecular mechanisms of resistance is crucial for developing effective therapeutic strategies.
• MicroRNAs (miRNAs) are increasingly recognized for their roles in cancer development and treatment response.

Purpose of the Study:

• To investigate the role of miR-302b in modulating breast cancer cell resistance to cisplatin.
• To identify the molecular targets and pathways regulated by miR-302b in this context.

Main Methods:

• Utilized breast cancer cell lines to study the effects of miR-302b overexpression on cisplatin sensitivity.
• Employed molecular techniques to identify direct and indirect targets of miR-302b.
• Assessed cell viability, proliferation, cell-cycle progression, DNA damage repair, and apoptosis.

Main Results:

• Overexpression of miR-302b significantly increased sensitivity of breast cancer cells to cisplatin, reducing viability and proliferation.
• E2F1 was identified as a direct target of miR-302b; miR-302b negatively regulated E2F1 expression.
• miR-302b indirectly modulated ATM expression via E2F1, leading to cell-cycle arrest and impaired DNA repair, thereby enhancing cisplatin-induced apoptosis.

Conclusions:

• miR-302b plays a critical role in breast cancer cell response to cisplatin by regulating the E2F1/ATM pathway.
• miR-302b impairs DNA damage repair mechanisms and promotes apoptosis in response to cisplatin.
• miR-302b represents a promising therapeutic candidate for overcoming cisplatin resistance in breast cancer.