Rama, Ana RQuiñonero, FranciscoMesas, CristinaMelguizo, ConsolaciónPrados, Jose2023-05-032023-05-032022-03-04Rama 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.http://hdl.handle.net/10668/21142Lung 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.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/circular spongeslung cancermiRNAmiRNA-21Cell Line, TumorCell ProliferationGene Expression Regulation, NeoplasticHumansLungLung NeoplasmsMicroRNAsRNA, Circularresearch article35328383open accessARN circularHumanosLínea celular tumoralMicroARNsNeoplasias pulmonaresProliferación celularPulmónRegulación neoplásica de la expresión génica10.3390/ijms230629631422-0067PMC8955967https://www.mdpi.com/1422-0067/23/6/2963/pdf?version=1646832861https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8955967/pdf