The Correlation Between PARP1 and BRCA1 in AR Positive Triple-negative Breast Cancer

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Triple-negative breast cancer (TNBC) lacks targeted therapies due to absent estrogen receptor (ER), progesterone receptor (PR), and HER-2 expression.
• Androgen receptor (AR)-positive TNBC may respond to anti-androgen therapy, while poly (ADP-ribose) polymerase (PARP) inhibitors show efficacy in BRCA1-deficient cancers.

Purpose of the Study:

• To investigate the potential of combining an AR antagonist (bicalutamide) with a PARP inhibitor (ABT-888) for AR-positive TNBC treatment.
• To explore the novel correlations among AR, PARP1, and BRCA1 in TNBC.

Main Methods:

• In vitro and in vivo experiments were conducted to assess the efficacy of bicalutamide and ABT-888 combination therapy.
• Correlation studies involving AR, PARP1, and BRCA1 were performed using cell lines and a tissue microarray of TNBC patient samples.

Main Results:

• The combination of bicalutamide and ABT-888 significantly inhibited cell viability and induced apoptosis in AR-positive TNBC models.
• BRCA1 overexpression led to decreased AR and PARP1 expression.
• AR positively regulated PARP1, and PARP1 up-regulated AR expression in vitro.
• BRCA1 expression was negatively correlated with AR and PARP1 in TNBC patient tissues.

Conclusions:

• Combination therapy with bicalutamide and a PARP inhibitor represents a potential therapeutic strategy for AR-positive TNBC.
• Further clinical evaluation is warranted to validate this promising treatment approach for TNBC patients.