MiR-181a targets STING to drive PARP inhibitor resistance in BRCA- mutated triple-negative breast cancer and ovarian cancer

Matias A Bustos; Takamichi Yokoe; Yoshiaki Shoji; Yuta Kobayashi; Shodai Mizuno; Tomohiro Murakami; Xiaoqing Zhang; Sreeja C Sekhar; SooMin Kim; Suyeon Ryu; Matthew Knarr; Steven A Vasilev; Analisa DiFeo; Ronny Drapkin; Dave S B Hoon

doi:10.1186/s13578-023-01151-y

MiR-181a targets STING to drive PARP inhibitor resistance in BRCA- mutated triple-negative breast cancer and ovarian cancer

Cell Biosci. 2023 Nov 6;13(1):200. doi: 10.1186/s13578-023-01151-y.

Authors

Matias A Bustos¹, Takamichi Yokoe¹, Yoshiaki Shoji¹, Yuta Kobayashi¹, Shodai Mizuno¹, Tomohiro Murakami¹, Xiaoqing Zhang¹, Sreeja C Sekhar^{2

3}, SooMin Kim⁴, Suyeon Ryu⁴, Matthew Knarr⁵, Steven A Vasilev⁶, Analisa DiFeo^{2

3}, Ronny Drapkin⁵, Dave S B Hoon^{7

8}

Affiliations

¹ Department of Translational Molecular Medicine, Saint John's Cancer Institute (SJCI) at Providence Saint John's Health Center (SJHC), 2200 Santa Monica Blvd, Santa Monica, CA, 90404, USA.
² Department of Obstetrics & Gynecology, University Michigan, Ann Arbor, MI, 48109, USA.
³ Department of Pathology, Rogel Cancer Center, University Michigan, Ann Arbor, MI, 48109, USA.
⁴ Department of Genome Sequencing, SJCI at Providence SJHC, Santa Monica, CA, 90404, USA.
⁵ Department of Obstetrics and Gynecology, Perelman School of Medicine, Penn Ovarian Cancer Research Center, University of Pennsylvania, Pennsylvania, PA, 19104, USA.
⁶ Department of Gynecologic Oncology Research, SJCI at SJHC, Santa Monica, CA, 90404, USA.
⁷ Department of Translational Molecular Medicine, Saint John's Cancer Institute (SJCI) at Providence Saint John's Health Center (SJHC), 2200 Santa Monica Blvd, Santa Monica, CA, 90404, USA. Dave.Hoon@providence.org.
⁸ Department of Genome Sequencing, SJCI at Providence SJHC, Santa Monica, CA, 90404, USA. Dave.Hoon@providence.org.

Abstract

Background: Poly (ADP-ribose) polymerase inhibitors (PARPi) are approved for the treatment of BRCA-mutated breast cancer (BC), including triple-negative BC (TNBC) and ovarian cancer (OvCa). A key challenge is to identify the factors associated with PARPi resistance; although, previous studies suggest that platinum-based agents and PARPi share similar resistance mechanisms.

Methods: Olaparib-resistant (OlaR) cell lines were analyzed using HTG EdgeSeq miRNA Whole Transcriptomic Analysis (WTA). Functional assays were performed in three BRCA-mutated TNBC cell lines. In-silico analysis were performed using multiple databases including The Cancer Genome Atlas, the Genotype-Tissue Expression, The Cancer Cell Line Encyclopedia, Genomics of Drug Sensitivity in Cancer, and Gene Omnibus Expression.

Results: High miR-181a levels were identified in OlaR TNBC cell lines (p = 0.001) as well as in tumor tissues from TNBC patients (p = 0.001). We hypothesized that miR-181a downregulates the stimulator of interferon genes (STING) and the downstream proinflammatory cytokines to mediate PARPi resistance. BRCA1 mutated TNBC cell lines with miR-181a-overexpression were more resistant to olaparib and showed downregulation in STING and the downstream genes controlled by STING. Extracellular vesicles derived from PARPi-resistant TNBC cell lines horizontally transferred miR-181a to parental cells which conferred PARPi-resistance and targeted STING. In clinical settings, STING levels were positively correlated with interferon gamma (IFNG) response scores (p = 0.01). In addition, low IFNG response scores were associated with worse response to neoadjuvant treatment including PARPi for high-risk HER2 negative BC patients (p = 0.001). OlaR TNBC cell lines showed resistance to platinum-based drugs. OvCa cell lines resistant to platinum showed resistance to olaparib. Knockout of miR-181a significantly improved olaparib sensitivity in OvCa cell lines (p = 0.001).

Conclusion: miR-181a is a key factor controlling the STING pathway and driving PARPi and platinum-based drug resistance in TNBC and OvCa. The miR-181a-STING axis can be used as a potential marker for predicting PARPi responses in TNBC and OvCa tumors.

Keywords: BRCA1/2 mutations; DNA damage; Extracellular microvesicles; Ovarian cancer; PARPi; STING; TMEM173; Triple-negative breast cancer; miR-181a-5p.