Silencing c-myc gene by siRNA delivered by cationic niosomes in MCF-7 cells.

Objectives: Gene therapy has a strong potential to treat different cancer types cancers with high therapeutic outcomes. c-myc is believed to be responsible for more than 15% of all gene regulation and functions as a transcription factor for proteins essential for cell proliferation. This study aimed to develop niosome nanocarriers to knockdown c-myc expression using anti-c-myc short-interfering RNA (siRNA) in MCF-7 cells. Altering the activity of the c-myc proto-oncogene has been identified as an important element in minimizing cancer cell growth because anti-c-myc siRNA degrades c-myc mRNA.

Methods: Noisomes were prepared from Tween 85, cholesterol, and didodecyldimethylammonium bromide at 50:40:10 and 40:40:20 molar ratios. Anti-c-myc siRNA was loaded in the prepared niosomes and then applied on MCF-7 cells.

Key findings: Niosomes had a total positive charge formed electrostatic interactions with siRNA. Niosomes were spherical with a size range of 70-100 nm. The prepared niosomes were nontoxic to MCF-7 cells, with IC50 values of >250 µg/ml for both formulations. After encapsulation of anti-c-myc siRNA, nioplexes reduced c-myc mRNA expression by more than 50% compared with the untreated cells. Empty niosomes did not affect c-myc mRNA expression levels, indicating that the effect was due to siRNA rather than the particles themselves.

Conclusions: This study provides evidence that niosomes can function as suitable carriers for siRNA delivery to knockdown the c-myc oncogene in MCF-7 cells, thus reducing cancer cell growth.