Designing a gold nanoparticle based nanocarrier for microRNA transfection into prostate cancer cells

Nanotechnology has potential to facilitate advances in detection, diagnosis, and treatment of cancers. Especially, the efficient delivery of nucleic acids into cancer cells can be a significant improvement for medical and cell biology including the clinical treatment of genetic disorders. For instance, gold nanoparticles (AuNPs) have been used as a platform for novel experimental cancer therapy and have emerged as an alternative gene delivery system. Another important solution in cancer therapy is the use of microRNAs (miRNAs), which are 20-22 base nucleotides and induce post-transcriptional gene silencing, because they are inappropriately expressed by cancer cells. Particularly, the expression level of miRNAs that act as anti-oncogenes is frequently reduced in cancers because of chromosome aberrations. In the case of prostate cancer, hsa-miR-145, a specific type of miRNA, is down-regulated in prostate tumors in comparison to normal prostatic tissues. As a result, an efficient delivery of extra hsa-miR-145 to prostate cancer cells can assist the treatment of prostate cancer. In this thesis, we used an engineered AuNP as a nanocarier to deliver miRNAs to prostate cancer cells. 13 nm AuNPs were modified with thiolated RNAs and then, the hsa-miR-145 was hybridized to the RNAs chemically attached to the AuNPs. We show that the proposed AuNPs help the delivery of large amount of hsa-miR-145 into cancer cells. We also showed that the delivery was more efficient when the AuNP-RNA-miRNA carrier complex was formed at an elevated temperature of 72 °C.