RANK signaling increases after anti-HER2 therapy contributing to the emergence of resistance in HER2-positive breast cancer

Sanz-Moreno, Adri�n; Palomeras, Sonia; Pedersen, Kim; Morancho, Beatriz; Pascual, Tomas; Galv�n, Patricia; Ben�tez, Sandra; Gomez-Miragaya, Jorge; Ciscar, Marina; Jimenez, Maria; Pernas, Sonia; Petit, Anna; Soler-Mons�, Mar�a Teresa; Vi�as, Gemma; Alsaleem, Mansour; Rakha, Emad A.; Green, Andrew R.; Santamaria, Patricia G.; Mulder, Celine; Lemeer, Simone; Arribas, Joaquin; Prat, Aleix; Puig, Teresa; Gonzalez-Suarez, Eva

Abstract

Background
Around 15–20% of primary breast cancers are characterized by HER2 protein overexpression and/or HER2 gene amplification. Despite the successful development of anti-HER2 drugs, intrinsic and acquired resistance represents a major hurdle. This study was performed to analyze the RANK pathway contribution in HER2-positive breast cancer and anti-HER2 therapy resistance.

Methods
RANK and RANKL protein expression was assessed in samples from HER2-positive breast cancer patients resistant to anti-HER2 therapy and treatment-naive patients. RANK and RANKL gene expression was analyzed in paired samples from patients treated with neoadjuvant dual HER2-blockade (lapatinib and trastuzumab) from the SOLTI-1114 PAMELA trial. Additionally, HER2-positive breast cancer cell lines were used to modulate RANK expression and analyze in vitro the contribution of RANK signaling to anti-HER2 resistance and downstream signaling.

Results
RANK and RANKL proteins are more frequently detected in HER2-positive tumors that have acquired resistance to anti-HER2 therapies than in treatment-naive ones. RANK (but not RANKL) gene expression increased after dual anti-HER2 neoadjuvant therapy in the cohort from the SOLTI-1114 PAMELA trial. Results in HER2-positive breast cancer cell lines recapitulate the clinical observations, with increased RANK expression observed after short-term treatment with the HER2 inhibitor lapatinib or dual anti-HER2 therapy and in lapatinib-resistant cells. After RANKL stimulation, lapatinib-resistant cells show increased NF-κB activation compared to their sensitive counterparts, confirming the enhanced functionality of the RANK pathway in anti-HER2-resistant breast cancer. Overactivation of the RANK signaling pathway enhances ERK and NF-κB signaling and increases lapatinib resistance in different HER2-positive breast cancer cell lines, whereas RANK loss sensitizes lapatinib-resistant cells to the drug. Our results indicate that ErbB signaling is required for RANK/RANKL-driven activation of ERK in several HER2-positive cell lines. In contrast, lapatinib is not able to counteract the NF-κB activation elicited after RANKL treatment in RANK-overexpressing cells. Finally, we show that RANK binds to HER2 in breast cancer cells and that enhanced RANK pathway activation alters HER2 phosphorylation status.

Conclusions
Our data support a physical and functional link between RANK and HER2 signaling in breast cancer and demonstrate that increased RANK signaling may contribute to the development of lapatinib resistance through NF-κB activation. Whether HER2-positive breast cancer patients with tumoral RANK expression might benefit from dual HER2 and RANK inhibition therapy remains to be elucidated.

Citation

Sanz-Moreno, A., Palomeras, S., Pedersen, K., Morancho, B., Pascual, T., Galván, P., …Gonzalez-Suarez, E. (2021). RANK signaling increases after anti-HER2 therapy contributing to the emergence of resistance in HER2-positive breast cancer. Breast Cancer Research, 23(1), Article 42. https://doi.org/10.1186/s13058-021-01390-2

• Journal Article Type: Article
• Acceptance Date: Jan 11, 2021
• Online Publication Date: Mar 30, 2021
• Publication Date: Mar 30, 2021
• Deposit Date: Jun 22, 2021
• Publicly Available Date: Jun 22, 2021
• Journal: Breast Cancer Research
• Print ISSN: 1465-5411
• Electronic ISSN: 1465-542X
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 23
• Issue: 1
• Article Number: 42
• DOI: https://doi.org/10.1186/s13058-021-01390-2
• Keywords: Cancer Research; Oncology
• Public URL: https://nottingham-repository.worktribe.com/output/5718751
• Publisher URL: https://breast-cancer-research.biomedcentral.com/articles/10.1186/s13058-021-01390-2