Discovery and preclinical evaluation of anti-miR-17 oligonucleotide RGLS4326 for the treatment of polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD), caused by mutations in either PKD1 or PKD2 genes, is one of the most common human monogenetic disorders and the leading genetic cause of end-stage renal disease. Unfortunately, treatment options for ADPKD are limited. Here we report the discovery and characterization of RGLS4326, a first-in-class, short oligonucleotide inhibitor of microRNA-17 (miR-17), as a potential treatment for ADPKD. RGLS4326 is discovered by screening a chemically diverse and rationally designed library of anti-miR-17 oligonucleotides for optimal pharmaceutical properties. RGLS4326 preferentially distributes to kidney and collecting duct-derived cysts, displaces miR-17 from translationally active polysomes, and de-represses multiple miR-17 mRNA targets including Pkd1 and Pkd2. Importantly, RGLS4326 demonstrates a favorable preclinical safety profile and attenuates cyst growth in human in vitro ADPKD models and multiple PKD mouse models after subcutaneous administration. The preclinical characteristics of RGLS4326 support its clinical development as a disease-modifying treatment for ADPKD.

Autosomal dominant polycystic kidney disease (ADPKD) is a leading genetic cause of end-stage renal disease with limited treatment options. Here the authors discover and characterize a microRNA inhibitor as a potential treatment for ADPKD.

Anti-miR-21 Suppresses Hepatocellular Carcinoma Growth via Broad Transcriptional Network Deregulation

Hepatocellular carcinoma (HCC) remains a significant clinical challenge with few therapeutic options available to cancer patients. MicroRNA 21-5p (miR-21) has been shown to be upregulated in HCC, but the contribution of this oncomiR to the maintenance of tumorigenic phenotype in liver cancer remains poorly understood. We have developed potent and specific single-stranded oligonucleotide inhibitors of miR-21 (anti-miRNAs) and used them to interrogate dependency on miR-21 in a panel of liver cancer cell lines. Treatment with anti-miR-21, but not with a mismatch control anti-miRNA, resulted in significant derepression of direct targets of miR-21 and led to loss of viability in the majority of HCC cell lines tested. Robust induction of caspase activity, apoptosis, and necrosis was noted in anti-miR-21-treated HCC cells. Furthermore, ablation of miR-21 activity resulted in inhibition of HCC cell migration and suppression of clonogenic growth. To better understand the consequences of miR-21 suppression, global gene expression profiling was performed on anti-miR-21-treated liver cancer cells, which revealed striking enrichment in miR-21 target genes and deregulation of multiple growth-promoting pathways. Finally, in vivo dependency on miR-21 was observed in two separate HCC tumor xenograft models. In summary, these data establish a clear role for miR-21 in the maintenance of tumorigenic phenotype in HCC in vitro and in vivo.

IMPLICATIONS

miR-21 is important for the maintenance of the tumorigenic phenotype of HCC and represents a target for pharmacologic intervention.

Abstract 4787: Targeting miR-21 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a significant unmet medical need with few therapeutic options available. Micro RNA 21 (miR-21) has been shown to be upregulated in HCC, however, contribution of this onco-miR to the maintenance of tumorigenic phenotype in liver cancer remains poorly understood. We have developed potent and specific single-stranded oligonucleotide inhibitors of miR-21 (anti-miR-21) and used them to interrogate dependency on miR-21 in a panel of 20 commercially available HCC cell lines in vitro. Upon lipid-mediated transfection, anti-miR-21, but not its mismatched (MM) control, caused significant de-repression of known direct targets of miR-21 (ANKRD46, DDAH1, RECK1) and inhibited survival of a large subset of HCC cell lines. Treatment of these sensitive HCC cell lines with anti-miR-21 resulted in dose- and time-dependent induction of caspase 3/7 activity. In contrast, non-responder HCC cell lines failed to significantly upregulate caspase activity and maintained viability in the presence of anti-miR compound. Further analysis of responder cell lines revealed robust induction of cell death, inhibition of cell migration and suppression of clonogenic growth upon treatment with miR-21 inhibitor. To better understand the consequences of miR-21 suppression in HCC, we carried out global gene expression profiling of anti-miR-21 treated sensitive liver cancer cells. Striking enrichment in miR-21 targets was noted among upregulated transcripts. Gene ontology analysis identified key cellular processes affected by miR-21 inhibition, including deregulation of metabolic pathways. In addition to the induction of direct miR-21 targets, cyclin H was found to be significantly downregulated upon miR-21 inhibition in the majority of responder cell lines. We hypothesize that inhibition of cyclin H expression, while an indirect effect of miR-21 suppression, could contribute to the activity of anti-miR-21 compounds. In summary, our data suggest that inhibition of miR-21 merits further investigation in the treatment of hepatocellular carcinoma.

Citation Format: Sonya Zabludoff, Timothy Wagenaar, Francisco Adrian, Charles Allerson, Heike Arlt, Raffaele Baffa, Bal Bhat, Hui Cao, Scott Davis, Carlos Garcia-Echeverria, Kathrin Heermeier, Shih-Min Huang, Lan Jiang, Eric Marcusson, Christiane Metz-Weidmann, Adam Pavlicek, Jack Pollard, Jennifer Rocnik, Sabine Scheidler, Chaomei Shi, Fangxian Sun, Tatiana Tolstykh, Qunyan Yu, Gang Zheng, Dmitri Wiederschain. Targeting miR-21 in hepatocellular carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4787. doi:10.1158/1538-7445.AM2014-4787