RT Journal Article T1 Synthetic Circular miR-21 Sponge as Tool for Lung Cancer Treatment. A1 Rama, Ana R A1 Quiñonero, Francisco A1 Mesas, Cristina A1 Melguizo, Consolación A1 Prados, Jose K1 circular sponges K1 lung cancer K1 miRNA K1 miRNA-21 AB Lung cancer is the most common cancer in the world and several miRNAs are associated with it. MiRNA sponges are presented as tools to inhibit miRNAs. We designed a system to capture miRNAs based on circular RNAs (circRNA). To demonstrate its usefulness, we chose miR-21, which is upregulated and implicated in lung cancer. We constructed a miR-21 sponge and inserted it into a vector that facilitates circular RNA production (Circ-21) to study its effect on growth, colony formation, and migration in lung cancer cell lines and multicellular tumor spheroids (MTS). Circ-21 induced a significant and time-dependent decrease in the growth of A549 and LL2 cells, but not in L132 cells. Furthermore, A549 and LL2 cells transfected with Circ-21 showed a lower number of colonies and migration than L132. Similar findings were seen in A549 and LL2 Circ-21 MTS, which showed a significant decrease in volume growth, but not in L132 Circ-21 MTS. Based on this, the miR-21 circular sponge may suppress the processes of tumorigenesis and progression. Therefore, our system based on circular sponges seems to be effective, as a tool for the capture of other miRNAs. PB MDPI AG YR 2022 FD 2022-03-04 LK http://hdl.handle.net/10668/21142 UL http://hdl.handle.net/10668/21142 LA en NO Rama AR, Quiñonero F, Mesas C, Melguizo C, Prados J. Synthetic Circular miR-21 Sponge as Tool for Lung Cancer Treatment. Int J Mol Sci. 2022 Mar 9;23(6):2963. DS RISalud RD Apr 10, 2025