| 1. |
- Magnusson, Kristina, et al.
(författare)
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SATB2 in Combination With Cytokeratin 20 Identifies Over 95% of all Colorectal Carcinomas
- 2011
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Ingår i: American Journal of Surgical Pathology. - 0147-5185 .- 1532-0979. ; 35:7, s. 937-948
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Tidskriftsartikel (refereegranskat)abstract
- The special AT-rich sequence-binding protein 2 (SATB2), a nuclear matrix-associated transcription factor and epigenetic regulator, was identified as a tissue type-specific protein when screening protein expression patterns in human normal and cancer tissues using an antibody-based proteomics approach. In this respect, the SATB2 protein shows a selective pattern of expression and, within cells of epithelial lineages, SATB2 expression is restricted to glandular cells lining the lower gastrointestinal tract. The expression of SATB2 protein is primarily preserved in cancer cells of colorectal origin, indicating that SATB2 could function as a clinically useful diagnostic marker to distinguish colorectal cancer (CRC) from other types of cancer. The aim of this study was to further explore and validate the specific expression pattern of SATB2 as a clinical biomarker and to compare SATB2 with the well-known cytokeratin 20 (CK20). Immunohistochemistry was used to analyze the extent of SATB2 expression in tissue microarrays with tumors from 9 independent cohorts of patients with primary and metastatic CRCs (n = 1882). Our results show that SATB2 is a sensitive and highly specific marker for CRC with distinct positivity in 85% of all CRCs, and that SATB2 and/or CK20 was positive in 97% of CRCs. In conclusion, the specific expression of SATB2 in a large majority of CRCs suggests that SATB2 can be used as an important complementary tool for the differential diagnosis of carcinoma of unknown primary origin.
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| 2. |
- Nordberg, Erika, et al.
(författare)
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Cellular studies of binding, internalization and retention of a radiolabeled EGFR-binding affibody molecule
- 2007
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 34:6, s. 609-618
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The cellular binding and processing of an epidermal growth factor receptor (EGFR) targeting affibody molecule, (Z(EGFR:955))(2), was studied. This new and small molecule is aimed for applications in nuclear medicine. The natural ligand epidermal growth factor (EGF) and the antibody cetuximab were studied for comparison. METHODS: All experiments were made with cultured A431 squamous carcinoma cells. Receptor specificity, binding time patterns, retention and preliminary receptor binding site localization studies were all made after (125)I labeling. Internalization was studied using Oregon Green 488, Alexa Fluor 488 and CypHer5E markers. RESULTS: [(125)I](Z(EGFR:955))(2) and [(125)I]cetuximab gave a maximum cellular uptake of (125)I within 4 to 8 h of incubation, while [(125)I]EGF gave a maximum uptake already after 2 h. The retention studies showed that the cell-associated fraction of (125)I after 48 h of incubation was approximately 20% when delivered as [(125)I](Z(EGFR:955))(2) and approximately 25% when delivered as [(125)I]cetuximab. [(125)I]EGF-mediated delivery gave a faster (125)I release, where almost all cell-associated radioactivity had disappeared within 24 h. All three substances were internalized as demonstrated with confocal microscopy. Competitive binding studies showed that both EGF and cetuximab inhibited binding of (Z(EGFR:955))(2) and indicated that the three substances competed for an overlapping binding site. CONCLUSION: The results gave information on cellular processing of radionuclides when delivered with (Z(EGFR:955))(2) in comparison to delivery with EGF and cetuximab. Competition assays suggested that [(125)I](Z(EGFR:955))(2) bind to Domain III of EGFR. The affibody molecule (Z(EGFR:955))(2) can be a candidate for EGFR imaging applications in nuclear medicine.
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| 3. |
- Nordberg, Erika, et al.
(författare)
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In vivo and in vitro uptake of In-111, delivered with the affibody molecule(Z(EGFR:955))(2), in EGFR expressing tumour cells
- 2008
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Ingår i: Oncology Reports. - : Spandidos Publications. - 1021-335X .- 1791-2431. ; 19:4, s. 853-857
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Tidskriftsartikel (refereegranskat)abstract
- The epidermal growth factor receptor, EGFR, is overexpressed in many carcinomas. Targeting this receptor with radionuclides is important for imaging and therapy applications in nuclear medicine. We investigated the in vitro and in vivo properties of a new high affinity EGFR binding affibody molecule, (Z(EGFR:955))(2), when conjugated with CHXA"-DTPA and labelled with In-111. The binding time patterns and retention studies were performed using cultured squamous carcinoma A431 cells that overexpress EGFR. In the in vivo studies, female BALB/c nu/nu mice carrying tumours from xenografted A431 cells were used. The in vitro studies showed EGFR specific binding, high uptake and good retention of In-111 when delivered as [In-111](Z(EGFR:955))(2). The retention after 72 h of incubation was 38.0 +/- 1.15% of the initial level. The biodistribution study showed a tumour specific In-111 uptake of 3.8 +/- 1.4% of injected dose per gram turnout tissue 4 h post-injection. The tumour to blood ratio was 9.1 and the tumours could easily be visualized with a gamma camera at this time-point. In-111 delivered with [In-111](Z(EGFR:955))(2) gave an EGFR specific uptake and the results indicated that the (Z(EGFR:955))(2) affibody molecule is a candidate for radionuclide-based tumour imaging. Potential therapy applications are discussed.
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