Delivery of survivin siRNA into breast cancer cell line using new synthetic nanoparticles and determination of the anticancer activity of the nanoplexes

Abstract

Introduction: Breast cancer is one of the life threatening malignancies worldwide. Using small interfering RNA (siRNA) strands to suppress the antiapoptotic genes -such as survivin- in breast cancer cells is under survey. Here, three various magnetic nanoparticles were synthesized to carry survivin siRNA into MCF-7 cells. Aim: Delivery of survivin siRNA into breast cancer cell line using new synthetic nanoparticles and determination of the anticancer activity of the nanoplexes. Methods: Various nanoparticles as: (1) Fe3O4-PEG-LAC-chitosan-PEI (2) Fe3O4-poly acrylate (PA)-PEI (3) Fe3O4-polyaspartic acid (PAA)-PEI were synthesized and studied through FT-IR. Physic-chemical properties including size, zeta potential, cytotoxicity and cellular uptake on MCF-7 cells were determined. Gel retardation assay determined the siRNA loading efficiency. DAPI staining and Annexin V assays were performed to evaluate the apoptosis. Survivin mRNA and protein levels were assessed through real time PCR and western blotting. Mitoxantrone (MTX) was also used as well to determine its probable combinational effect. Results: The synthesized nanoparticles all had sizes varying from 34 to 48 nm in diameter and positive zeta potential. The siRNA loading efficiency of the PA-based nanoparticle was more than PEG-LAC-based and PAA-based ones. The nanoplexes were stable against time pass. The nanoparticles had acceptable cellular uptake in MCF-7 cells: PEG-LAC> PAA>PA. Annexin V and DAPI staining assays proved the apoptotic effect of the nanoplexes. The apoptosis induction abilities of NPs were found to be as: PEG-LAC-based > PA-based > PAA-based. Real time PCR analyses revealed that the survivn mRNA level has significantly became less after exposure to nanoplexes. MTX had synergistic effect on PEG-LAC-based and PA-based nanoparticles, where its effect was additive on PAA-based one. Reduction observed in survivin protein level was as below: PA-based > PAA-based > PEG-LAC-based. Discussion: In conclusion, designed nanoparticles can form efficient complexes with survivin siRNA and deliver it safely into MCF-7 breast cancer cells.