Abstract: This study investigated how miR-556 affects proliferation, genome-wide transcription and gene-function networks in human glioblastoma U-87 MG cells. A miR-556-overexpressing line was generated by lentiviral transduction and puromycin selection; precursor and mature miR-556 levels were quantified by qRT-PCR and standard RT-PCR. Cell proliferation and clonogenic capacity were assessed with CCK-8 and crystal-violet assays, respectively. RNA-seq was used to map transcriptional and pathway changes. Relative to the control (rLV) group, the miR-556-overexpressing (rLV-miR-556) group exhibited significantly increasedin vitroproliferation and colony formation (P<0.01). RNA-seq revealed 2028 differentially expressed genes (165 up- and 1863 down-regulated) between the two groups. miR-556 up-regulatedHMOX1,SERPINB2andATOH8while down-regulatingMACF1,PEG10andHIF1A, thereby modulating pathways related to gene transcription, transmembrane transport, RNA polymerase Ⅱ activity, post-translational modification, protein metabolism, immune responses and disease-related pathways. These findings indicate that miR-556 enhances glioblastoma cell growth and reshapes the transcriptional landscape, providing a basis for future intervention strategies.

Key words: MiR-556, human glioblastoma cells, lentivirus expression plasmid, cell proliferation, transcriptomics