AS1411-conjugated gold nanoparticles affect cell proliferation through a mechanism that seems independent of nucleolin

Abstract G-rich oligonucleotide, AS1411, has been shown to interact with nucleolinand to inhibit cancer cell proliferation and tumor growth. This antiproliferative action is increased when AS1411 is conjugated to different types of nanoparticles. However, the molecular mechanisms are not known. In this work, we show in several cell lines that optimized AS1411-conjugated gold nanoparticles (GNS-AS1411) inhibit nucleolinexpression at the RNA and protein levels. We observed an alteration of the nucleolar structure with a decrease of ribosomal RNAaccumulation comparable to what is observed upon nucleolinknock down. However, the expression of genes involved in cell cycle and the cell cycle blockage by GNS-AS1411 are not regulated in the same way that in cells where nucleolinhas been knocked down. These data suggest that the anti-proliferative activity of GNS-AS1411 is not the only consequence of nucleolintargeting and down-regulation.