Carry-forward Scope: Multifunctional RNA nanoparticles for targeted delivery of siRNA for ovarian cancer (Yr 4 to 5)

The 3-way junction (3WJ) motif of the bacteriophage phi29 packaging RNA (pRNA) possesses unusual thermodynamically stable properties and does not dissociate at ultra-low concentrations in vitro and in vivo. We have demonstrated that RNA nanoparticles built with the 3WJ scaffold and harboring different functional modules retained their folding and independent functionalities for specific cell binding, cell entry, gene silencing, catalytic function and cancer targeting, both in vitro and in animal trials. We propose to assemble RNA nanoparticles using the pRNA-3WJ platform to carry EphA2 siRNA and (1) E-selectin and CD44 thioaptamers; or (2) X-aptamers and ENDO thioaptamers for targeted delivery and treatment of ovarian cancer. Using cell-SELEX, we have identified thioaptamers, which target Annexin A2, and specifically bind to the human ovarian cancer cells. More recently, using Next-Gen sequencing to screen millions of sequences, we have identified our first set of X-aptamers (aptamer-drug combinations) that target the E-selectin protein. In this proposal, we will further develop the Next-Gen X-aptamer candidates, based on the sequences of the identified thioaptamers, to increase the specificity and affinity towards their targets. These Next-Gen aptamers along with siRNA will be conjugated to pRNA-3WJ scaffold and then evaluated in ovarian cell cultures and animal models.