title: Accurate sensitivity of quantum dots for detection of HER2 expression in breast cancer cells and tissues.
abstract: Here we introduce novel optical properties and accurate sensitivity of Quantum dot (QD)-based detection system for tracking the breast cancer marker, HER2. QD525 was used to detect HER2 using home-made HER2-specific monoclonal antibodies in fixed and living HER2(+) SKBR-3 cell line and breast cancer tissues. Additionally, we compared fluorescence intensity (FI), photostability and staining index (SI) of QD525 signals at different exposure times and two excitation wavelengths with those of the conventional organic dye, FITC. Labeling signals of QD525 in both fixed and living breast cancer cells and tissue preparations were found to be significantly higher than those of FITC at 460-495 nm excitation wavelengths. Interestingly, when excited at 330-385 nm, the superiority of QD525 was more highlighted with at least 4-5 fold higher FI and SI compared to FITC. Moreover, QDs exhibited exceptional photostability during continuous illumination of cancerous cells and tissues, while FITC signal faded very quickly. QDs can be used as sensitive reporters for in situ detection of tumor markers which in turn could be viewed as a novel approach for early detection of cancers. To take comprehensive advantage of QDs, it is necessary that their optimal excitation wavelength is employed.
authors.affiliation: Department of Biology, Faculty of Basic Sciences, Islamic Azad University, East Tehran Branch (Ghiamdasht), Tehran, Iran.
authors.forename: Akram-Sadat
authors.initials: AS
authors.lastname: Tabatabaei-Panah
authors.forename: Mahmood
authors.initials: M
authors.lastname: Jeddi-Tehrani
authors.forename: Roya
authors.initials: R
authors.lastname: Ghods
authors.forename: Mohammad-Mehdi
authors.initials: MM
authors.lastname: Akhondi
authors.forename: Nazanin
authors.initials: N
authors.lastname: Mojtabavi
authors.forename: Ahmad-Reza
authors.initials: AR
authors.lastname: Mahmoudi
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Mirzadegan
authors.forename: Sorour
authors.initials: S
authors.lastname: Shojaeian
authors.forename: Amir-Hassan
authors.initials: AH
authors.lastname: Zarnani
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D057230:Limit of Detection; D045663:Quantum Dots; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human