Activation of nuclear factor-κ B is linked to resistance to neoadjuvant chemotherapy in breast cancer patients

• Published in: Endocrine-related cancer Vol. 13; no. 2; pp. 607 - 616
• Main Authors: Montagut, C, Tusquets, I, Ferrer, B, Corominas, J M, Bellosillo, B, Campas, C, Suarez, M, Fabregat, X, Campo, E, Gascon, P, Serrano, S, Fernandez, P L, Rovira, A, Albanell, J
• Format: Journal Article
• Language: English
• Published: England BioScientifica 01-06-2006
• Subjects: Adult; Aged; Anthracyclines - therapeutic use; Breast Neoplasms - drug therapy; Breast Neoplasms - metabolism; Breast Neoplasms - therapy; Cytoplasm - chemistry; Drug Resistance, Neoplasm; Female; Humans; Immunohistochemistry; Middle Aged; Neoadjuvant Therapy; NF-kappa B - analysis; NF-kappa B - metabolism; Prognosis; Transcription Factor RelA - analysis; Transcription Factor RelA - metabolism; Up-Regulation
• ISSN: 1351-0088; 1479-6821
• DOI: 10.1677/erc.1.01171

The nuclear factor (NF)-κB system is a promising anticancer target due to its role in oncogenesis and chemoresistance in preclinical models. To provide evidence in a clinical setting on the role of NF-κB in breast cancer, we aimed to study the value of basal NF-κB/p65 in predicting resistance to neoadjuvant chemotherapy, and to characterise the pharmacodynamic changes in NF-κB/p65 expression following chemotherapy in patients with locally advanced breast cancer. Pre- and post-chemotherapy tumour specimens from 51 breast cancer patients treated with anthracycline- and/or taxane-containing neoadjuvant chemotherapy were assayed by immunohistochemistry for NF-κB/p65 subcellular expression. We studied NF-κB/p65, a well-characterised member of the NF-κB family that undergoes nuclear translocation when NF-κB is activated. Activation of NF-κB (i.e. nuclear NF-κB/p65 staining in pre-therapy specimens) was linked to chemoresistance. Patients with NF-κB/p65 nuclear staining in pre-treatment samples had a 20% clinical response rate, while patients with undetected nuclear staining had a 91% response rate to chemotherapy (P = 0.002). Notably, four patients achieved a complete histological response and none of them had pre-treatment NF-κB/p65 nuclear staining. Moreover, the number of patients with NF-κB/p65 activation increased after chemotherapy exposure. It is concluded that NF-κB/p65 activation assayed by immunohistochemistry is a predictive factor of resistance to neoadjuvant chemotherapy in breast cancer patients. Moreover, NF-κB activation was inducible following chemotherapy in a proportion of breast cancer patients. These novel clinical findings strengthen the rationale for the use of NF-κB inhibitors to prevent or overcome chemoresistance in breast cancer.