title: Intraoperative imaging of metastatic lymph nodes using a fluorophore-conjugated antibody in a HER2/neu-expressing orthotopic breast cancer mouse model.
abstract: We investigated in this study whether fluorescence imaging with a fluorophore-conjugated anti-human epidermal growth factor receptor 2 (HER2)/neu probe could be used to differentiate metastatic lymph nodes (LN) from normal LN to guide surgical resection. A fluorescent probe for detecting HER2/neu-expressing cells was generated by conjugation of the humanized anti-HER2/neu antibody trastuzumab with rhodamine. The green fluorescent protein-expressing breast cancer cell line 4T1-GFP was used for in vitro binding analysis and for the establishment of a model of HER2/neu expressing LN-metastatic breast cancer. All tumor-bearing mice were given a single intravenous injection of either rhodamine-conjugated anti-HER2/neu probe, or conjugated control IgG antibody, when LN metastasis developed. Each animal was imaged with both green and red fluorescence to assess in vivo binding of the rhodamine-conjugated anti-HER2/neu probe to the tumors and LN metastases. Hematoxylin and eosin (H&E) staining and immunohistochemistry was performed to confirm the presence of tumor and metastasis as well as HER2/neu expression. The imaging probe was able to bind to HER2/neu-expressing 4T1-GFP tumor cells in vitro. The primary tumors and LN metastases from the animals which were treated with rhodamine-conjugated anti-HER2/neu probe exhibited a visible red fluorescence signal. The fluorescent axillary LN metastasis was easily distinguishable from the surrounding normal tissue and normal LN. Sensitivity of 78% (14 out of 18) and specificity of 100% (20 out of 20) could be achieved with the rhodamine-conjugated anti-HER2/neu probe for the detection of LN metastasis. These data support further investigation of the fluorophore-conjugated anti-HER2/neu antibody to detect LN metastasis in the surgical setting.
authors: 42 Baiziting Road, Nanjing, Jiangsu 210009, PR China. wujzh1528@126.com
authors: Jianzhong
authors: J
authors: Wu
authors: Rong
authors: R
authors: Ma
authors: Haixia
authors: H
authors: Cao
authors: Zhuo
authors: Z
authors: Wang
authors: Changwen
authors: C
authors: Jing
authors: Yu
authors: Y
authors: Sun
authors: Yong
authors: Y
authors: Zhang
authors: Zhijian
authors: Z
authors: Yang
authors: Robert M
authors: RM
authors: Hoffman
authors: Jinhai
authors: J
authors: Tang
mesh_terms: D000818:Animals; D000906:Antibodies; D061067:Antibodies, Monoclonal, Humanized; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D003952:Diagnostic Imaging / Q000379:methods*; D004195:Disease Models, Animal; D005260:Female; D049452:Green Fluorescent Proteins; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D051379:Mice; D008807:Mice, Inbred BALB C; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D012235:Rhodamines; D012680:Sensitivity and Specificity; D000068878:Trastuzumab
chemical_list: D000906:Antibodies; D061067:Antibodies, Monoclonal, Humanized; D049452:Green Fluorescent Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D012235:Rhodamines; D000068878:Trastuzumab; C524056:Erbb2 protein, mouse