OBJECTIVE MicroR NA(miR NA)holds promise as a novel therapeutic tool for cancer treatment.However,the transfection efficiency of current delivery systems represents a bottleneck for clinical applications.Here,we demonstrate that gap junctions mediate an augmentative effect on the antiproliferation mediated by mi R-124-3p in U87 and C6 glioblastoma cells.METHODS The functional inhibition of gap junctions using either si RNA or pharmacological inhibition eliminated the mi R-124-3p-mediated antiproliferation,whereas the enhancement of gap junctions with retinoic acid treatment augmented this mi R-124-3p-mediated antiproliferation.A similar effect was observed in glioblastoma xenograft models.RESULTS More importantly,patch clamp and co-culture assays demonstrated the transmission of mi R-124-3p through gap junction channels into adjacent cells.In further exploring the impact of gap junction-mediated transport of mi R-124-3p on mi R-124-3p target pathways,we found that mi R-124-3p inhibited glioblastoma cell growth in part by decreasing the protein expression of cyclindependent kinase 6,leading to cel cycle arrest at the G0/G1phase;moreover,pharmacological regulation of gap junctions affected this cell cycle arrest.CONCLUSION Our results indicate that the″bystander″effects of functional gap junctions composed of connexin 43 enhance the antitumor effect of mi R-124-3p in glioblastoma cells by transferring mi R-124-3p to adjacent cells,thereby enhancing G0/G1cell cycle arrest.These observations provide a new guiding strategy for the clinical application of mi RNA therapy in tumor treatment. OBJECTIVE MicroR NA (miR NA) holds promise as a novel therapeutic tool for cancer treatment. However, the transfection efficiency of current delivery systems represents a bottleneck for clinical applications. Here, we demonstrate that gap junctions mediate an augmentative effect on the antiproliferationration mediated by mi R-124-3p in U87 and C6 glioblastoma cells. METHHODS The functional inhibition of gap junctions using either si RNA or pharmacological inhibition eliminated the mi R-124-3p-mediated antiproliferation, and the enhancement of gap junctions with retinoic acid treatment augmented this mi R-124-3p-mediated antiproliferation. A similar effect was observed in glioblastoma xenograft models .RESULTS More importantly, patch clamp and co-culture assays demonstrated the transmission of mi R-124-3p through gap junction channels into adjacent cells. In further exploring the impact of gap junction-mediated transport of mi R-124-3p on mi R-124-3p target pathways, we found that mi R-124-3-inhibited glioblastoma cell growth in part by decreasing the protein expression of cyclindependent kinase 6, leading to cel cycle arrest at the G0 / G1phase; moreover, pharmacological regulation of gap junctions affected this cell cycle arrest. CONCLUSION Our results indicate that the “bystander” effects of functional gap junctions composed of connexin 43 enhance the antitumor effect of mi R-124-3p in glioblastoma cells by transferring mi R-124-3p to adjacent cells, thereby enhancing G0 / G1cell cycle arrest. the observations provide a new guiding strategy for the clinical application of mi RNA therapy in tumor treatment.