Figure 4.

GFP expression and RNAi efficiency in MCF-7 cells. (A) The GFP expression plasmid pCMV-GFP was transfected into MCF-7 cells in the absence or presence of PEI-SWNT. (B) The Hsp70B′ promoter-driven GFP expression plasmid pHSP-GFP was loaded onto PEI-SWNT and transfected into MCF-7 cells in the absence or presence of NIR (808 nm) irradiation. (C) The heat-inducible shRNA plasmid pHSP-shGFP targeting GFP was co-transfected into MCF-7 cells with the pCMV-GFP plasmid at a ratio of 1:1, followed by conditional exposure of the transfected cells to 808 nm NIR. The scale bar is 50 μm. (D) Cell viability of MCF-7 cells transfected with pHSP-shT, PEI-SWNT, and PEI-SWNT/pHSP-shT at different times. (E) mRNA and protein expression of hTERT in MCF-7 cells. Transfections were conducted at 3 μg plasmid and 0.5 μg PEI-SWNT per well in six-well plates. Cells were treated with 808 nm laser irradiation for 45 s. *P<0.01, PEI-SWNT/pHSP-shT versus the other three groups.

Abbreviations: GFP, green fluorescent protein; CMV, cytomegalovirus; HSP, heat-shock protein; NIR, near-infrared; hTERT, human telomerase reverse transcriptase; PEI-SWNT, polyetherimide-modified single-wall carbon nanotube; sh, short hairpin; shT, short hairpin RNA of human telomerase reverse transcriptase.