Fluorescent immunolabeling of cancer cells by quantum dots and antibody scFv fragment.

Semiconductor quantum dots (QDs) coupled with cancer-specific targeting ligands are new promising agents for fluorescent visualization of cancer cells. Human epidermal growth factor receptor 2/neu (HER2/neu), overexpressed on the surface of many cancer cells, is an important target for cancer diagnostics. Antibody scFv fragments as a targeting agent for direct delivery of fluorophores offer significant advantages over full-size antibodies due to their small size, lower cross-reactivity, and immunogenicity. We have used quantum dots linked to anti-HER2/neu 4D5 scFv antibody to label HER2/neu-overexpressing live cells. Labeling of target cells was shown to have high brightness, photostability, and specificity. The results indicate that construction based on quantum dots and scFv antibody can be successfully used for cancer cell visualization.

[1]  Sergey M Deyev,et al.  Multivalency: the hallmark of antibodies used for optimization of tumor targeting by design. , 2008, BioEssays : news and reviews in molecular, cellular and developmental biology.

[2]  V. Lobachov,et al.  Key role of barstar Cys‐40 residue in the mechanism of heat denaturation of bacterial ribonuclease complexes with barstar , 1999, FEBS letters.

[3]  L. Harris,et al.  The HER2 extracellular domain as a prognostic and predictive factor in breast cancer. , 2002, Clinical breast cancer.

[4]  R. Hartley,et al.  Barnase and barstar. Expression of its cloned inhibitor permits expression of a cloned ribonuclease. , 1988, Journal of molecular biology.

[5]  P. Mulvaney,et al.  The effects of chemisorption on the luminescence of CdSe quantum dots. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[6]  Tomonobu M. Watanabe,et al.  Reduction in nonfluorescence state of quantum dots on an immunofluorescence staining. , 2006, Biochemical and biophysical research communications.

[7]  Andreas Plückthun,et al.  Design of multivalent complexes using the barnase·barstar module , 2003, Nature Biotechnology.

[8]  Shuming Nie,et al.  Emerging use of nanoparticles in diagnosis and treatment of breast cancer. , 2006, The Lancet. Oncology.

[9]  Igor Nabiev,et al.  Biocompatible fluorescent nanocrystals for immunolabeling of membrane proteins and cells. , 2004, Analytical biochemistry.

[10]  Anna M Wu,et al.  Arming antibodies: prospects and challenges for immunoconjugates , 2005, Nature Biotechnology.

[11]  M. Moasser,et al.  The epidermal growth factor receptor family: Biology driving targeted therapeutics , 2008, Cellular and Molecular Life Sciences.

[12]  A. Plückthun,et al.  High thermal stability is essential for tumor targeting of antibody fragments: engineering of a humanized anti-epithelial glycoprotein-2 (epithelial cell adhesion molecule) single-chain Fv fragment. , 1999, Cancer research.

[13]  S. Deyev,et al.  Visualization of cancer cells by means of the fluorescent EGFP-barnase protein , 2007, Doklady Biochemistry and Biophysics.

[14]  P. Trail,et al.  Monoclonal antibody drug immunoconjugates for targeted treatment of cancer , 2003, Cancer Immunology, Immunotherapy.

[15]  Noriaki Ohuchi,et al.  In vivo real-time tracking of single quantum dots conjugated with monoclonal anti-HER2 antibody in tumors of mice. , 2007, Cancer research.

[16]  J. Ross,et al.  The HER‐2/neu Oncogene in Breast Cancer: Prognostic Factor, Predictive Factor, and Target for Therapy , 1998, Stem cells.

[17]  Xiaogang Peng,et al.  Kinetics of II-VI and III-V Colloidal Semiconductor Nanocrystal Growth: “Focusing” of Size Distributions , 1998 .

[18]  J. Matthew Mauro,et al.  Self-Assembly of CdSe−ZnS Quantum Dot Bioconjugates Using an Engineered Recombinant Protein , 2000 .

[19]  D. Dirin,et al.  Synthesis and optical properties of PbSe and CdSe colloidal quantum dots capped with oleic acid , 2004 .

[20]  K. Jain,et al.  Applications of nanobiotechnology in clinical diagnostics. , 2007, Clinical chemistry.

[21]  P. N. Wang,et al.  Enhancement of Intracellular Delivery of CdTe Quantum Dots (QDs) to Living Cells by Tat Conjugation , 2007, Journal of Fluorescence.

[22]  S. Nie,et al.  In vivo cancer targeting and imaging with semiconductor quantum dots , 2004, Nature Biotechnology.

[23]  D. Balding,et al.  HLA Sequence Polymorphism and the Origin of Humans , 2006 .

[24]  Noriaki Ohuchi,et al.  In vivo single molecular imaging and sentinel node navigation by nanotechnology for molecular targeting drug-delivery systems and tailor-made medicine , 2008, Breast cancer.

[25]  M. Bruchez,et al.  Immunofluorescent labeling of cancer marker Her2 and other cellular targets with semiconductor quantum dots , 2003, Nature Biotechnology.

[26]  Masato Yasuhara,et al.  Physicochemical Properties and Cellular Toxicity of Nanocrystal Quantum Dots Depend on Their Surface Modification , 2004 .

[27]  K. D. Hardman,et al.  Single-chain antigen-binding proteins. , 1988, Science.