title: Intravesical delivery of small activating RNA formulated into lipid nanoparticles inhibits orthotopic bladder tumor growth.
abstract: Practical methods for enhancing protein production in vivo remain a challenge. RNA activation (RNAa) is emerging as one potential solution by using double-stranded RNA (dsRNA) to increase endogenous gene expression. This approach, although related to RNA interference (RNAi), facilitates a response opposite to gene silencing. Duplex dsP21-322 and its chemically modified variants are examples of RNAa-based drugs that inhibit cancer cell growth by inducing expression of tumor suppressor p21(WAF1/CIP1) (p21). In this study, we investigate the therapeutic potential of dsP21-322 in an orthotopic model of bladder cancer by formulating a 2'-fluoro-modified derivative (dsP21-322-2'F) into lipid nanoparticles (LNP) for intravesical delivery. LNP composition is based upon clinically relevant formulations used in RNAi-based therapies consisting of PEG-stabilized unilamellar liposomes built with lipid DLin-KC2-DMA. We confirm p21 induction, cell-cycle arrest, and apoptosis in vitro following treatment with LNP-formulated dsP21-322-2'F (LNP-dsP21-322-2'F) or one of its nonformulated variants. Both 2'-fluoro modification and LNP formulation also improve duplex stability in urine. Intravesical delivery of LNP-dsP21-322-2'F into mouse bladder results in urothelium uptake and extends survival of mice with established orthotopic human bladder cancer. LNP-dsP21-322-2'F treatment also facilitates p21 activation in vivo leading to regression/disappearance of tumors in 40% of the treated mice. Our results provide preclinical proof-of-concept for a novel method to treat bladder cancer by intravesical administration of LNP-formulated RNA duplexes.
authors.affiliation: Department of Urology and Helen Diller Comprehensive Cancer Center, University of California, San Francisco, California, USA.
authors.forename: Moo Rim
authors.initials: MR
authors.lastname: Kang
authors.forename: Glen
authors.initials: G
authors.lastname: Yang
authors.forename: Robert F
authors.initials: RF
authors.lastname: Place
authors.forename: Klaus
authors.initials: K
authors.lastname: Charisse
authors.forename: Hila
authors.initials: H
authors.lastname: Epstein-Barash
authors.forename: Muthiah
authors.initials: M
authors.lastname: Manoharan
authors.forename: Long-Cheng
authors.initials: LC
authors.lastname: Li
mesh_terms: D000283:Administration, Intravesical; D017209:Apoptosis / Q000235:genetics; D053148:Caspase 3 / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000235:genetics; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D019394:Ki-67 Antigen / Q000378:metabolism; D008055:Lipids / Q000737:chemistry*; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D047368:Tumor Burden / Q000235:genetics; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D023041:Xenograft Model Antitumor Assays / Q000379:methods*
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D019394:Ki-67 Antigen; D008055:Lipids; D012330:RNA, Double-Stranded; D053148:Caspase 3