Gene delivery into breast cancer MDA-MB-231 cells via the internalization of NTSR1.

<p>(<b>A</b>) A representative micrograph of NTS-polyplex nanoparticles that are formed at an optimal molar ratio (1 (plasmid): 24 (NTS-carrier)), which was taken using a field emission scanning electron microscope. (<b>B</b>) Representative agarose gel showing the presence of the amplicons for NTSR1 and 18S after an RT-PCR assay. N1E = N1E-115; wMDA = wild type MDA-MB-231 cells; SiMDA = NTSR1-silenced MDA-MB-231 cells. L-929 = mouse fibroblast cell line. (<b>C</b>) Representative confocal micrographs of an immunofluorescence assay showing the presence of NTSR1 in MDA-MB-231 cells that were counterstained with TRITC-phalloidin and Hoechst 33258. One-micrometer optical sections in the x–y plane (horizontal) and in the z plane (vertical). (<b>D</b>) Representative confocal micrographs of propidium iodide (PI) NTS-polyplex harboring the plasmid pEGFP-N1 in MDA-MB-231 cells in the absence or presence of different pharmacological blockers. The cells were counterstained with Hoechst 33258 and calcein. (<b>E</b>) Representative micrographs showing GFP expression in MDA-MB-231 cells after exposure to NTS-polyplex nanoparticles carrying pEGFP-N1 plasmid. The cells were counterstained with Hoechst 33258.