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Aptamer‐mediated complement system killing of MCF‐7 and MEAR cancer cells
Author(s) -
Stecker John R,
Bruno John G,
Koke Joseph R
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.622.4
Subject(s) - aptamer , biotinylation , streptavidin , chemistry , microbiology and biotechnology , nucleic acid , complement system , biochemistry , cancer cell , biophysics , biology , antibody , biotin , cancer , immunology , genetics
Aptamer MUSC1‐5TR‐1 has high affinity for Mucin 1 (MUC1) which is over expressed in the adenocarcinoma cell line MCF‐7. Aptamer TLS‐11a recognizes BNL 1ME A.7R.1 (MEAR) hepatocarncinoma cells (Shangguan, D, et al., Anal Chem 80, no. 3: 721–728). Biotinylation of the aptamers' 5′ end allowed conjugation to streptavidin that was in turn conjugated to C1q, the first protein in the classical complement immune response pathway. Killing of MCF‐7 and MEAR cells in vitro by complement‐mediated lysis resulting from exposure to the biotinylated aptamers‐streptavidin‐C1q, in the presence of human complement protein serum, was visualized using SYTOX Green nucleic acid stain. SYTOX Green (Invitrogen) brightly labels nucleic acid in cells with compromised membrane integrity. MCF‐7 and MEAR cells exposed to the full treatment both showed increased nuclear staining within a few hours, whereas cells not exposed to the aptamer, streptavidin‐C1q conjugate, or complement protein serum showed little to no nuclear staining. Future experiments will incorporate FRET detection of membrane potential changes resulting from MAC formation, and will utilize immuno‐fluorescence and immuno‐gold to localize components of the MAC by laser scanning confocal and electron microscopy. Supported by funding from OTC Biotechnologies, LLC and NSF DBI‐0821252 to JK.