%0 Journal Article %A Rama, Ana R %A QuiƱonero, Francisco %A Mesas, Cristina %A Melguizo, ConsolaciĆ³n %A Prados, Jose %T Synthetic Circular miR-21 Sponge as Tool for Lung Cancer Treatment. %D 2022 %U http://hdl.handle.net/10668/21142 %X 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. %K circular sponges %K lung cancer %K miRNA %K miRNA-21 %~