| Title |
A FISH-based method for assessment of HER-2 amplification status in breast cancer circulating tumor cells following CellSearch isolation
|
|---|---|
| Published in |
OncoTargets and therapy, November 2016
|
| DOI | 10.2147/ott.s118502 |
| Pubmed ID | |
| Authors |
Henrik Frithiof, Kristina Aaltonen, Lisa Rydén |
| Abstract |
Amplification of the HER-2/neu (HER-2) proto-oncogene occurs in 10%-15% of primary breast cancer, leading to an activated HER-2 receptor, augmenting growth of cancer cells. Tumor classification is determined in primary tumor tissue and metastatic biopsies. However, malignant cells tend to alter their phenotype during disease progression. Circulating tumor cell (CTC) analysis may serve as an alternative to repeated biopsies. The Food and Drug Administration-approved CellSearch system allows determination of the HER-2 protein, but not of the HER-2 gene. The aim of this study was to optimize a fluorescence in situ hybridization (FISH)-based method to quantitatively determine HER-2 amplification in breast cancer CTCs following CellSearch-based isolation and verify the method in patient samples. Using healthy donor blood spiked with human epidermal growth factor receptor 2 (HER-2)-positive breast cancer cell lines, SKBr-3 and BT-474, and a corresponding negative control (the HER-2-negative MCF-7 cell line), an in vitro CTC model system was designed. Following isolation in the CellSearch system, CTC samples were further enriched and fixed on microscope slides. Immunocytochemical staining with cytokeratin and 4',6-diamidino-2'-phenylindole dihydrochloride identified CTCs under a fluorescence microscope. A FISH-based procedure was optimized by applying the HER2 IQFISH pharmDx assay for assessment of HER-2 amplification status in breast cancer CTCs. A method for defining the presence of HER-2 amplification in single breast cancer CTCs after CellSearch isolation was established using cell lines as positive and negative controls. The method was validated in blood from breast cancer patients showing that one out of six patients acquired CTC HER-2 amplification during treatment against metastatic disease. HER-2 amplification status of CTCs can be determined following CellSearch isolation and further enrichment. FISH is superior to protein assessment of HER-2 status in predicting response to HER-2-targeted immunotherapy in breast cancer patients. This assay has the potential of identifying patients with a shift in HER-2 status who may benefit from treatment adjustments. |
Mendeley readers
The data shown below were compiled from readership statistics for 31 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 31 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Master | 4 | 13% |
| Student > Ph. D. Student | 4 | 13% |
| Student > Bachelor | 3 | 10% |
| Other | 3 | 10% |
| Student > Postgraduate | 2 | 6% |
| Other | 4 | 13% |
| Unknown | 11 | 35% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 10 | 32% |
| Biochemistry, Genetics and Molecular Biology | 7 | 23% |
| Agricultural and Biological Sciences | 2 | 6% |
| Chemistry | 1 | 3% |
| Materials Science | 1 | 3% |
| Other | 0 | 0% |
| Unknown | 10 | 32% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 07 August 2017.
All research outputs
#17,285,668
of 25,373,627 outputs
Outputs from OncoTargets and therapy
#1,146
of 3,016 outputs
Outputs of similar age
#205,210
of 317,808 outputs
Outputs of similar age from OncoTargets and therapy
#39
of 74 outputs
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