scholarly journals Detection of HER2 through Antibody Immobilization Is Influenced by the Properties of the Magnetite Nanoparticle Coating

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Enrique Villegas-Serralta ◽  
Oscar Zavala ◽  
Israel Alejandro Flores-Urquizo ◽  
Perla E. García-Casillas ◽  
Christian Chapa González
Keyword(s):  
Growth Factor Receptor ◽  
Antibody Immobilization ◽  
Single Chain Variable Fragment ◽  
X Ray Diffraction ◽  
Single Chain ◽  
Her2 Protein ◽  
Magnetite Nanoparticle ◽  
X Ray ◽  
Epidermal Growth ◽  
Her2 Antigen

Considerable effort has been focused on improving the control of size, shape, and surface modifications to detect proteins. The purpose of this study was to compare the efficiencies of aminosilane-coated magnetite (As-M) nanoparticles (NPs), dextran-coated magnetite nanoparticles (Dx-M), and bare nanoparticles for conjugating single-chain variable fragment antibodies (scFvs) with the aim of detecting the human epidermal growth factor receptor 2 (HER2) protein. Dx-M and As-M NPs were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and Raman spectroscopy. Dx-M and As-M were conjugated with a monoclonal scFv for active targeting of the HER2 antigen. Aminosilane surface coating enhanced the scFv conjugation efficiency over twofold compared to that of the dextran-coated magnetite NPs for the detection of HER2 proteins.

scholarly journals Generation of MANAbodies specific to HLA-restricted epitopes encoded by somatically mutated genes

2015 ◽  
Vol 112 (32) ◽  
pp. 9967-9972 ◽  
Author(s):  
Andrew D. Skora ◽  
Jacqueline Douglass ◽  
Michael S. Hwang ◽  
Ada J. Tam ◽  
Richard L. Blosser ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Phage Display Library ◽  
Full Length ◽  
Cancer Genes ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Mutant Peptide ◽  
Epidermal Growth ◽  
Selection Protocol ◽  
Single Chain Variable Fragments

Mutant epitopes encoded by cancer genes are virtually always located in the interior of cells, making them invisible to conventional antibodies. We here describe an approach to identify single-chain variable fragments (scFvs) specific for mutant peptides presented on the cell surface by HLA molecules. We demonstrate that these scFvs can be successfully converted to full-length antibodies, termed MANAbodies, targeting “Mutation-Associated Neo-Antigens” bound to HLA. A phage display library representing a highly diverse array of single-chain variable fragment sequences was first designed and constructed. A competitive selection protocol was then used to identify clones specific for mutant peptides bound to predefined HLA types. In this way, we obtained two scFvs, one specific for a peptide encoded by a common KRAS mutant and the other by a common epidermal growth factor receptor (EGFR) mutant. The scFvs bound to these peptides only when the peptides were complexed with HLA-A2 (KRAS peptide) or HLA-A3 (EGFR peptide). We converted one scFv to a full-length antibody (MANAbody) and demonstrate that the MANAbody specifically reacts with mutant peptide–HLA complex even when the peptide differs by only one amino acid from the normal, WT form.

scholarly journals The Prognostic Impact of HER2 Genetic and Protein Expression in Pancreatic Carcinoma—HER2 Protein and Gene in Pancreatic Cancer

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 653
Author(s):  
Song-Hee Han ◽  
Ki Hyun Ryu ◽  
Ah-Young Kwon
Keyword(s):  
Protein Expression ◽  
Genetic Heterogeneity ◽  
Growth Factor Receptor ◽  
Ductal Adenocarcinoma ◽  
Prognostic Impact ◽  
Her2 Expression ◽  
Her2 Protein ◽  
Epidermal Growth ◽  
Her2 Heterogeneity

Pancreatic ductal adenocarcinoma (PDAC) is a lethal and clinically heterogeneous disease with a limited benefit from human epidermal growth factor receptor 2 (HER2)-targeted therapy. Recently, some studies have addressed the antitumoral effect of novel anti-HER2 drugs in HER2 low-expressing tumors. However, there have been few studies on the significance of low HER2 expression and genetic heterogeneity in PDAC. Using immunohistochemistry and dual-color silver-enhanced in situ hybridization based on the Trastuzumab for a gastric cancer scoring scheme, we evaluated HER2 protein expression, gene amplification, and genetic heterogeneity in three groups (HER2-neg, HER2-low, HER2-pos) of 55 patients. Among the 55 cases, 41.8% (23/55) showed HER2 expression of any intensity. HER2 amplification independent of HER2 expression was 25.5% (14/55). Patients in both these groups had a shorter overall survival than did patients in the HER2-neg group. HER2 genetic heterogeneity was identified in 37 (70.9%) of the 55 cases, mainly in HER2-neg and HER2-low groups. HER2 genetic heterogeneity significantly correlated with worse survival in the HER2-low and HER2-neg groups of PDAC. These findings support the hypothesis that low-level HER2 expression and heterogeneity have significant clinical implications in PDAC. HER2 heterogeneity might indicate the best strategies of combination therapies to prevent the development of subdominant clones with resistance potential.

Anti-Human Epidermal Growth Factor Receptor 2 Single-Chain Fv Fragment-Decorated DM1 Nanoparticles for Specific Targeting of Human Epidermal Growth Factor Receptor 2-Positive Breast Tumor Cells

2021 ◽  
Vol 17 (3) ◽  
pp. 447-455
Author(s):  
Ling Ni ◽  
You-Xin Li
Keyword(s):  
Breast Cancer ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Single Chain ◽  
Human Epidermal Growth Factor ◽  
Single Chain Fv ◽  
Epidermal Growth ◽  
Single Chain Fv Fragment

Purpose: Although monoclonal antibodies are used to decorate nanoparticles to target specific cells, penetration of tumor tissues by monoclonal antibodies is limited by their large size. Therefore, we prepared DM1 nanoparticles decorated with the small anti-HER2 single-chain Fv fragment (scFvHER2) of trastuzumab (TMAB) for targeting to human epidermal growth factor receptor 2 (HER2) overexpressing in breast cancer effectively. Methods: ScFvHER2 fragment was coupled with DM1 nanoparticles (NPs) via covalent thiol-maleimide linkages. Their physicochemical properties, uptake by cells, and toxicity to tumor cells were investigated. Their vivo biodistribution was assessed employing liquid chromatographytandem mass spectrometry, while their antitumor activity was investigated in nude mice burdened with BT-474 tumor. Results: Viability of BT-474 cells incubated with scFvHER2-DM1-Nanoparticles (scFv-DM1-NPs) was significantly lower than that of BT-474 cell treated with TMAB-DM1-Nanoparticles (TMAB-DM1-NPs) (P < 0 05). Uptake by cells of scFvDM1-NPs was significantly higher than TMAB-DM1-NPs (P < 0 01). Accumulation of scFv-DM1-NPs in tumor tissue was notably higher than TMAB-DM1-NPs (P < 0 05). scFv-DM1-NPs exhibited improved antitumor effects compared to TMABDM1-NPs (P < 0 05), showing a tumor inhibition rate of more than 70%. Conclusions: ScFvHER2 fragment could serve as a more effective targeting ligand than TMAB, and scFv-DM1-NPs could be developed as a possible drug delivery system to target HER2-positive breast cancer.

scholarly journals Inhibition of osimertinib-resistant epidermal growth factor receptor EGFR-T790M/C797S

2019 ◽  
Vol 10 (46) ◽  
pp. 10789-10801 ◽  
Author(s):  
Jonas Lategahn ◽  
Marina Keul ◽  
Philip Klövekorn ◽  
Hannah L. Tumbrink ◽  
Janina Niggenaber ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor Receptor ◽  
Binding Mode ◽  
Drug Resistant ◽  
X Ray ◽  
Covalent Inhibitors ◽  
Epidermal Growth ◽  
Resistant Mutants ◽  
Insight Into ◽  
Egfr T790m

We present inhibitors of drug resistant mutants of EGFR including T790M and C797S. In addition, we present the first X-ray crystal structures of covalent inhibitors in complex with C797S-mutated EGFR to gain insight into their binding mode.

scholarly journals Evaluation of the HER2 and Hormone Receptor Status in Metastatic Breast Cancer Using Cell Blocks: A Multi-Institutional Study

2018 ◽  
Vol 62 (4) ◽  
pp. 288-294 ◽  
Author(s):  
Rieko Nishimura ◽  
Yuya Murata ◽  
Kiyoshi Mori ◽  
Katsushige Yamashiro ◽  
Kazuya Kuraoka ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Hormone Receptors ◽  
Growth Factor Receptor ◽  
Metastatic Breast ◽  
Routine Practice ◽  
Her2 Positive ◽  
Her2 Protein ◽  
Breast Cancer Metastases ◽  
Cancer Metastases ◽  
Epidermal Growth

Objective: We explore the problems associated with the cell block (CB) method for receptor analysis in breast cancer metastases and propose a method for reporting the results. Study Design: Nine institutions used the CB method for the analysis of hormone receptors (HRs) and HER2 (human epidermal growth factor receptor 2) protein in cytological specimens of breast cancer metastases in routine practice. The stained slides were independently evaluated by 8 pathologists. Dual in situ hybridization assay was performed in cases of discordant results for HER2 protein. Based on the results, we propose a method for receptor scoring in the CB method. Results: Of 61 specimens, 57 contained tumor cells. Two or more pathologists disagreed on the results for the estrogen receptor, progesterone receptor, and HER2 protein in 3 (5.3%), 13 (22.8%), and 19 (33.3%) cases, respectively. The discrepant results for the HRs were attributed to the presence of a few positive cells or faintly stained cells. The high interobserver discordance rate for HER2 protein was explained by interobserver differences in the scoring criteria. Conclusion: The use of categorical scoring into positive and negative is recommended for evaluating the HR expressions. Use of strict criteria for HER2 protein 2+ and 3+ cases is recommended, as HER2-positive cases should not be missed.

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