The aim of the investigation was to study microRNA expression and its influence on signaling pathways activity in radioresistant and radiosensitive cell lines exposed to radiation.Materials and Methods. Radioresistant K562 cell line and radiosensitive HL-60 and Raji cell lines were used in the study. Cell survival was estimated after exposure to 4 Gy gamma radiation. MicroRNA composition was studied 1, 4 and 24 h after radiation exposure using massively parallel sequencing method. Bioinformatics analysis was performed using GenXpro and PANTHER database.Results. After single 4 Gy radiation exposure, the number of cells with the signs of necrosis increased several times in radiosensitive cell lines as compared to control samples. MicroRNA hsa-miR-590-3p was found in each studied cell line at every stage of the experiment. The most significant differences between radioresistant and radiosensitive cell lines were observed in dynamics of microRNA influence on Integrin signaling pathway and General transcription by RNA polymerase I pathway.Conclusion. MicroRNA hsa-miR-590-3p dynamics and expression level were found to correlate with cancer cell radiosensitivity. Its influence on radioresistant and radiosensitive cell lines was different: in radioresistant K562 cell line, the inhibitory effect of microRNA on Integrin signaling pathway was reduced and this effect on General transcription by RNA polymerase I pathway was increased.