title: Detection of cell surface calreticulin as a potential cancer biomarker using near-infrared emitting gold nanoclusters.
abstract: Calreticulin (CRT) is a cytoplasmic calcium-binding protein. The aim of this study was to investigate CRT presence in cancer with the use of fluorescent gold nanoclusters (AuNCs) and to explore AuNC synthesis using mercaptosuccinic acid (MSA) as a coating agent. MSA-coated AuNCs conferred well-dispersed, bio-stable, water-soluble nanoparticles with bioconjugation capacity and 800-850 nm fluorescence after broad-band excitation. Cell-viability assay revealed good AuNC tolerability. A native CRT amino-terminus corresponding peptide sequence was synthesised and used to generate rabbit site-specific antibodies. Target specificity was demonstrated with antibody blocking in colorectal and breast cancer cell models; human umbilical vein endothelial cells served as controls. We demonstrated a novel route of AuNC/MSA manufacture and CRT presence on colonic and breast cancerous cell surface. AuNCs served as fluorescent bio-probes specifically recognising surface-bound CRT. These results are promising in terms of AuNC application in cancer theranostics and CRT use as surface biomarker in human cancer.
authors.affiliation: Research Department of Nanotechnology, Division of Surgery and Interventional Science, University College London, Pond Street, London NW3 2QG, UK.
authors.forename: Bala Subramaniyam
authors.initials: BS
authors.lastname: Ramesh
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Giorgakis
authors.forename: Victor
authors.initials: V
authors.lastname: Lopez-Davila
authors.forename: Ashkan Kamali
authors.initials: AK
authors.lastname: Dashtarzheneha
authors.forename: Marilena
authors.initials: M
authors.lastname: Loizidou
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor; D037282:Calreticulin; D002977:Clergy; D005453:Fluorescence; D006046:Gold; D006801:Humans; D049329:Nanostructures
chemical_list: D014408:Biomarkers, Tumor; D037282:Calreticulin; D006046:Gold