Cationic vesicles for efficient shRNA transfection in the MCF-7 breast cancer cell line.

Introduction: Novel and safe delivery solutions for RNAi therapeutics are essential to obtain the full potential of cancer gene therapy.

Methods: In this study, cationic vesicular nanocarrier was applied for delivering lnc urothelial carcinoma-associated 1 (lnc UCA1) shRNA expression vector to MCF-7 cells. The physicochemical characteristics, cytotoxicity, and transfection efficiency of cationic vesicles prepared from various molar ratios of amphiphilic surfactant Tween 80 (T), squalene (S), cationic charge lipid didodecyldimethylammonium bromide, and polyethylenimine were investigated. The particle sizes of the vesicles in the nanosize range were determined by dynamic light scattering and transmission electron microscopy.

Results: Gel protection assay with agarose gel electrophoresis showed cationic vesicles can protect the shRNA plasmid from DNase 1 enzyme. 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium, inner salt result showed no significant cytotoxicity was caused in MCF-7 cancer cell line by (T:S):polyethylenimine cationic vesicles. 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium, inner salt assay, fluorescence microscope images, and flow cytometry analyses confirmed that (T:S) with 4.3 μg/mL of PEI vesicles provided effective transfection without significant cytotoxicity. Furthermore, we found efficient UCA1 shRNA transfection and significant (<0.05) cell cycle arrest and apoptosis in MCF-7 cancer cells.

Conclusion: The novel nonviral vesicular nanocarrier, (T:S) with 4.3 μg/mL of PEI, might be safe and efficient for cancer gene therapy and can be used in further in vitro and in vivo studies.