Aims: The availability of specific antibody-based test systems is essential to testing of HER2 protein expression. Here, we mapped epitopes recognized by three pharmacodiagnostic HER2 antibodies and investigated their specificity towards peptides and fusion proteins homologous to the intracellular domains of HER1, HER2, HER3 and HER4. The investigated antibodies were PATHWAY(®) HER2 (clone 4B5; Ventana Medical Systems Inc., Tucson, AZ, USA), HercepTest™ (Dako Denmark A/S, Glostrup, Denmark), and Oracle(®) HER2 (clone CB11; Leica Microsystems GmbH, Wetzlar, Germany).
Methods And Results: Epitopes were mapped using the alanine scanning method. Specificity was investigated in immunohistochemical stainings, competitive enzyme-linked immunosorbent assay (ELISA) and immunoblotting. All three antibodies reacted with HER2 proteins and peptides in immunohistochemical stainings, ELISA and immunoblotting. PATHWAY(®) HER2 also stained HER4-expressing cells, reacted with HER4 peptide in ELISA and detected HER4 fusion protein in an immunoblot. Oracle(®) HER2 weakly detected HER4 in immunohistochemical stainings, whereas the HercepTest™ antibody showed no cross-reactivity with other HER proteins.
Conclusion: Our study shows that the PATHWAY(®) HER2 antibody can bind HER4 peptides and fusion proteins in three different experimental settings. This should be investigated further to determine whether binding of HER4 also occurs in tissue samples and if such binding would have implications for therapy decisions for breast cancer patients.
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http://dx.doi.org/10.1111/j.1365-2559.2011.04034.x | DOI Listing |
Asia Ocean J Nucl Med Biol
January 2025
Nuclear Medicine Unit, National Cancer Institute (NCI), Cairo University, Cairo, Egypt.
Objectives: to investigate the capability of F-fluorodeoxyglucose positron emission tomography/computed tomography ([F]-FDG PET/CT) derived volumetric parameters to predict human epidermal growth factor receptor 2 (HER2) status in breast cancer patients.
Methods: retrospective study enrolled 47 female patients with breast cancer. All patients had pretreatment [F]-FDG PET/CT.
Front Oncol
December 2024
Department of Chemistry, Faculty of Science, University of Colombo, Colombo, Sri Lanka.
Triple-negative breast cancer (TNBC) is a highly aggressive and clinically challenging subtype of breast cancer, lacking the expression of estrogen receptor (ER), progesterone receptor (PR), and HER2/neu. The absence of these receptors limits therapeutic options necessitating the exploration of novel treatment strategies. Epigenetic modifications, which include DNA methylation, histone modifications, and microRNA (miRNA) regulation, play a pivotal role in TNBC pathogenesis and represent promising therapeutic targets.
View Article and Find Full Text PDFBreast J
January 2025
Department of Chemotherapy Jiangsu Cancer Hospital Jiangsu Institute of Cancer Research The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China.
Purpose: Endocrine therapy combined with cyclin-dependent kinase (CDK) 4/6 inhibitors (CDK4/6i) is the preferred treatment for hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). However, there are currently no recommendations for therapeutic strategies after progression on CDK4/6i-based treatment. This study aimed to examine the efficacy and safety of anlotinib plus chemotherapy in HR+/HER2- MBC after progression on CDK4/6 inhibitors.
View Article and Find Full Text PDFBreast J
January 2025
Department of Oncology University Hospital Center Split School of Medicine University of Split, Split, Croatia.
Introduction: Disease recurrence in patients with the early hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast tumor subtype is particularly challenging to manage due to its complex and very heterogeneous biological nature. Namely, due to primary and secondary resistance, one-quarter of patients with early-stage disease will experience disease recurrence. This variability in the timing of recurrence highlights the need to better identify key biomarkers that could predict therapeutic outcomes and guide personalized treatment strategies for these patients.
View Article and Find Full Text PDFBreast J
January 2025
Graduate School of Medicine, Faculty of Science Medicine and Health, University of Wollongong, Wollongong, NSW, Australia.
Introduction: Breast cancer management is complex, requiring personalised care from multidisciplinary teams. Research shows that there is unwarranted clinical variation in mastectomy rates between rural and metropolitan patients; that is, variation in treatment which cannot be explained by disease progression or medical necessity. This study aims to determine the clinical and nonclinical factors contributing to any unwarranted variation in breast cancer management in rural patients and to evaluate how these factors and variations relate to patient outcomes.
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