MEME KANSERİ HÜCRELERİNE mTOR ANTİSENS OLİGONÜKLEOTİTLERİNİ HEDEFLEYECEK TRANSFERRİN KAPLANMIŞ ALTIN NANOPARTİKÜLLERİN TASARIMI SENTEZİ VE UYGULANMASI

Abstract

Breast cancer is the most frequent cancer in women. The type and molecular characteristics of breast cancer determines prognosis and helps design effective therapy regimes. mTOR, the mammalian target of Rapamycin is one of the molecular targets to which novel drugs are being designed recently. Targeted breast cancer therapy may take the advantage of gene therapy. Delivery of antisens oligonucleotides or similar inhibitory nucleic acids is hampered by the polianionic nature of DNA or RNA. Therefore, a variety of vectors are used and designed for efficient gene delivery. Gold nanoparticles (AuNP) are potent nanodrugs having optoelectronical properties, low toxicity and wide surface area. This study aims to forming gold nanoparticles functionalized with transferrin and antisense oligonucleotides (ASODN) and small inhibitory RNA (siRNA) for gene delivery to highly metastatic human breast cancer cell line, namely MDA-MB-231. Since transferrin receptors are over expressed in these cells, it is postulated that transferrin attached gold nanorticles will be taken up by specific receptors to deliver the ASODN or siRNA. mTOR specific ASODN was found to bind on gold nanopaticles through reduced transferrin as depicted by polyacrylamide and agarose gel electrophoresis. ASODN molecules reduced cell viability 24%, 14% and 0.9 % in 24h, 48h, 72h respectively as compared to control cells. In AuNP bound form cell viability was 38% , 30% and 10% in 24h, 48h and 72 hours respectively. However, this was not statistically significant. Transferrin bound ASODN functionalized AuNPs led to a decrease of 85% , 89% and 93% in 24h, 48h and 72 hours respectively. These results were found to be statistically important. Similarly, free mTOR specific siRNA applied to cells led to a decrease of 10 %, 23%and 15.8% in 24h, 48h and 72 hours but this was not significant. On the other hand, when transferrin bound and mTOR siRNA functionalized AuNPs were applied the cell viability was decreased by 82% , 57 % and 93 % in 24h, 48h and 72 hours significantly. mTOR expression of treated cells were analysed by immunehistochemistry and the expression as well as cell number was found to be significantly decreased. Therefore, gold nanoparticles may be suitable vectors for AS ODN or siRNA when functionalized with transferrin that allowed attachment of nucleic acid agents as well as their receptor mediated delivery. It is concluded that further studies are needed to understand the biocompatibility and in vivo efficiency of these constructs, thus, the feasibility of their use in therapy.