51. MKAD-21 Suppresses the Oncogenic Activity of the miR-21/PPP2R2A/ERK Molecular Network in Bladder Cancer
- Author
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Swapna Mahurkar-Joshi, Allan J. Pantuck, Tong Luo, Marina Koutsioumpa, Alexandra Drakaki, Shawnt Issakhanian, Filippos Koinis, Hsiao-Wang Chen, Vassilis Georgoulias, Dimitrios Iliopoulos, Dennis J. Slamon, Christina Vorvis, Neil A. O'Brien, and Artin Soroosh
- Subjects
0301 basic medicine ,MAPK/ERK pathway ,Cancer Research ,Carcinogenesis ,MAP Kinase Signaling System ,Regulator ,Transcriptome ,Mice ,03 medical and health sciences ,In vivo ,Cell Line, Tumor ,Animals ,Humans ,Protein Phosphatase 2 ,Gene ,Cell Proliferation ,Chemistry ,Cell growth ,Protein phosphatase 2 ,Oligonucleotides, Antisense ,Xenograft Model Antitumor Assays ,Gene Expression Regulation, Neoplastic ,MicroRNAs ,030104 developmental biology ,Urinary Bladder Neoplasms ,Oncology ,Cell culture ,Cancer research - Abstract
Bladder cancer represents a disease associated with significant morbidity and mortality. MiR-21 has been found to have oncogenic activity in multiple cancers, including bladder cancer, whereas inhibition of its expression suppresses tumor growth. Here, we examine the molecular network regulated by miR-21 in bladder cancer and evaluate the effects of i.v. and i.p. administration of a novel miR-21 chemical inhibitor in vivo. LNA miR-21 reduced the oncogenic potential of bladder cancer cells, whereas the MKAD-21 chemically modified antisense oligo against miR-21 dose-dependently blocked xenograft growth. I.v. administration of LNA miR-21 was more effective in suppressing tumor growth than was i.p. administration. Integration of computational and transcriptomic analyses in a panel of 28 bladder cancer lines revealed a 15-gene signature that correlates with miR-21 levels. Protein Phosphatase 2 Regulatory Subunit Balpha (PPP2R2A) was one of these 15 genes and was experimentally validated as a novel miR-21 direct target gene. Gene network and molecular analyses showed that PPP2R2A is a potent negative regulator of the ERK pathway activation and bladder cancer cell proliferation. Importantly, we show that PPP2R2A acts as a mediator of miR-21–induced oncogenic effects in bladder cancer. Integrative analysis of human bladder cancer tumors and a large panel of human bladder cancer cell lines revealed a novel 15-gene signature that correlates with miR-21 levels. Importantly, we provide evidence that PPP2R2A represents a new miR-21 direct target and regulator of the ERK pathway and bladder cancer cell growth. Furthermore, i.v. administration of the MKAD-21 inhibitor effectively suppressed tumor growth through regulation of the PPP2R2A–ERK network in mice. Mol Cancer Ther; 17(7); 1430–40. ©2018 AACR.
- Published
- 2018
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