Akademik Veri Yönetim Sistemi
Journal of Drug Delivery Science and Technology, cilt.82, 2023 (SCI-Expanded)
With the discovery of genetic factors of diseases, gene therapy has become a promising treatment option for many diseases, especially for different types of cancer, one of which is breast cancer. Triple negative breast cancer (TNBC), with the lack of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2), represents the most aggressive subtype of breast tumors. Currently, there is no targeted therapy available for TNBC due to the absence of molecular targets. Signal transducer and activator of transcription 3 (STAT3) oncogene is overexpressed in TNBC and plays an important role in the tumor formation and metastasis, thus may be considered as a potential therapeutic target. Delivery of RNA interference molecules (siRNA, shRNA, miRNA) to block genes responsible for tumor development/proliferation is a promising strategy for cancer therapy. The present study aimed to develop a polyplex system for delivery of pDNA-encoded STAT3-shRNA into the 4T1 TNBC cells. Polyplexes were prepared at different polymer:pDNA (1:1, 2:1, 3:1 w/w) ratios by either branched (B1S, B2S, B3S) or linear (L1S, L2S, L3S) polyethylenimines (PEIs) and characterized in terms of particle size, polydispersity index and zeta potential. Condensation of plasmid DNA, serum stability, cytotoxicity and transfection activity of polyplexes were evaluated. Moreover, the effects of pDNA-encoded STAT3-shRNA on migration ability of TNBC cells were tested using wound healing assay. Particle sizes were 189.3 nm, 237 nm and 310.2 nm for B1, B2 and B3 polyplexes respectively and 172.8 nm, 382 nm and 441 nm for L1, L2 and L3 polyplexes respectively. Zeta potential values were B1: +11.8 mV, B2: +21.9 mV and B3: +32.7 mV and L1: +19.8 mV, L2: +23.8 mV and L3: +25.1 mV. The lowest PDI values were obtained by B1S (0.32) and B2S (0.24) polyplexes. The obtained cationic polyplexes exhibited pDNA binding and protection ability. When compared to control, L1S and L2S poyplexes did not showed cytotoxic effects. 4T1 TNBC cell migration was best inhibited by B1S and B2S polyplexes. At 72 h the remaining percentage of cell-free area compared to time zero was higher in the B2S polyplexes (70,4%), followed by the B1S polyplexes (33,3%). Opposed to this, branched PEI polymer, linear PEI polymer and linear PEI polyplexes had no inhibitor effect on cell migration ability. The mean difference between B1S and B2S (37.073%) was also highly significant. The box plot graph showed that between 0 and 72 h, the lowest migration change has been detected by B2S polypexes which has 2:1 w/w polymer:pDNA ratio. Wound healing studies revealed that migration was inhibited by delivery of pDNA-encoded STAT3-shRNA which might be a potential therapy against TNBC and branched PEI polyplexes could be considered promising polycation-mediated delivery vehicles for non-viral cancer gene therapy.