Resistance to HER2-targeted anti-cancer drugs is associated with immune evasion in cancer cells and their derived extracellular vesicles

Autor: Vanesa G. Martinez, Sadhbh O'Neill, Josephine Salimu, Susan Breslin, Aled Clayton, John Crown, Lorraine O'Driscoll
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: OncoImmunology, Vol 6, Iss 12 (2017)
Druh dokumentu: article
ISSN: 2162-402X
2162402X
DOI: 10.1080/2162402X.2017.1362530
Popis: Neuromedin U (NmU) -a neuropeptide belonging to the neuromedin family– plays a substantial role in HER2-positive breast cancer, correlating with increased aggressiveness, resistance to HER2-targeted therapies and overall significantly poorer outcome for patients. However, the mechanism through which it exerts these effects remains unclear. To elucidate this, initially we used HER2-positive breast cancer cells stably over-expressing NmU. These cells and their released extracellular vesicles (EVs) had increased amounts of the immunosuppressive cytokine TGFβ1 and the lymphocyte activation inhibitor PD-L1. Furthermore, these cells also showed enhanced resistance to antibody-dependent cell cytotoxicity (ADCC) mediated by trastuzumab, indicating a role of NmU in enhancing immune evasion. All these features were also found in HER2-targeted drug-resistant cells which we previously found to express higher levels of NmU than their drug-sensitive counterparts. Interestingly, EVs from drug-resistant cells were able to increase levels of TGFβ1 in drug-sensitive cells. In our neo-adjuvant clinical trial, TGFβ1 levels were significantly higher in EVs isolated from the serum of patients with HER2-overexpressing breast cancers who went on to not respond to HER2-targeted drug treatment, compared with those who experienced complete or partial response. Taken together, our results report a new mechanism-of-action for NmU in HER2-overexpressing breast cancer that enhances resistance to the anti-tumor immune response. Furthermore, EV levels of TGFβ1 correlating with patients' response versus resistance to HER2-targeted drugs suggests a potential use of EV-TGFβ1 as a minimally-invasive companion diagnostic for such treatment in breast cancer.
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