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

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.

• Authors: Adrián Sanz-Moreno, Sonia Palomeras, Kim Pedersen, Beatriz Morancho, Tomas Pascual, Patricia Galván, Sandra Benítez, Jorge Gomez-Miragaya, Marina Ciscar, Maria Jimenez, Sonia Pernas, Anna Petit, María Teresa Soler-Monsó, Gemma Viñas, Mansour Alsaleem, Emad A Rakha, Andrew R Green, Patricia G Santamaria, Celine Mulder, Simone Lemeer, Joaquin Arribas, Aleix Prat, Teresa Puig, Eva Gonzalez-Suarez
• Journal: Breast cancer research : BCR (Breast Cancer Res) Vol. 23 Issue 1 Pg. 42 (03 30 2021) ISSN: 1465-542X [Electronic] England
• PMID: 33785053 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• NF-kappa B
• Receptor Activator of Nuclear Factor-kappa B
• TNFRSF11A protein, human
• Lapatinib
• ERBB2 protein, human
• Receptor, ErbB-2
• Trastuzumab

Topics

• Breast Neoplasms (drug therapy, metabolism, pathology)
• Cell Line, Tumor
• Drug Resistance, Neoplasm (genetics)
• Female
• Gene Expression Regulation, Neoplastic (drug effects)
• Humans
• Lapatinib (therapeutic use)
• NF-kappa B (metabolism)
• Neoadjuvant Therapy
• Protein Binding
• Receptor Activator of Nuclear Factor-kappa B (genetics, metabolism)
• Receptor, ErbB-2 (antagonists & inhibitors, metabolism)
• Signal Transduction
• Trastuzumab (therapeutic use)