Preclinical targeted therapy for retinoblastoma using EpCAM Aptamer siRNA chimeras

siRNAs have played a major role in cancer drug discovery, but their potential is hampered due to off-target effects. Thus, delivery systems like RNA aptamers have been used to enhance the specific delivery of these siRNAs to cancer stem cells. We report the efficacy of three different EpCAM aptamer siRNA chimeras, which were investigated both in vitro and in vivo for their ability to reduce cancer cell progression. Using these chimeras, we demonstrated specific gene knockdown in EpCAM positive cells which ultimately led to the apoptosis. To study the efficacy of these aptamer chimeras in vivo, retinoblastoma xenografts bearing NCC Rb C 51 cells were created for the first time. Systemic administration of these aptamer chimeras reduced tumour growth to about 50%. We further investigated the central Role of PLK1 in Cancer Progression and demonstrated the anti-cancer effects of targeted EpCAM siPLK1 approach. Using SILAC-Mass spectrometry analysis, we showed that silencing PLK 1 gene can lead to p53 mediated cell cycle arrest. Thus, we establish EpCAM-siRNA chimeras as potential markers for targeted anti-cancer applications, which paves a platform for efficient second line of therapies in addition to existing chemotherapy options.