〔Abstract〕 To explore the expression profile of core 1 β1 , 3-galactosyltransferase 1 (C1GALT1) in glio- blastoma (GBM) and to elucidate its impact on the initiation and progression of GBM . Methods The expression levels and prognostic significance of C1GALT1 in GBM were analyzed using the GEPIA and CGGA databases . Two representative glioblastoma cells (U251 and LN18) were selected to construct C1GALT1-knockdown cell lines and performed in vitro experiments . The Cell Counting Kit-8 (CCK-8) and Transwell assays were employed to evaluate the impact of C1GALT1 on proliferation , migration and invasion of GBM cells . Transcriptome data were analyzed to identify potential signaling pathways . Senescence β-Galactosidase Staining Kit was used to detect β-galactosidase activity . Results Analysis of GEPIA and CGGA databases revealed that C1GALT1 was significantly upregulated in GBM tissues compared to adjacent non-cancerous tissues (P < 0. 05) , and its high expression was associated with poor prognosis of patients (P < 0. 000 1) . The CCK-8 experiment demonstrated a significant reduction in prolifera- tion rate following C1GALT1 knockdown (P < 0. 05) . Transwell assay showed that cell migration and invasion de- creased after C1GALT1 was knocked down ( P < 0. 001) . Transcriptome sequencing and senescence β-galactosi- dase staining showed that C1GALT1 was involved in the cellular senescence signaling pathway , and the activity of β-galactosidase associated with cellular senescence significantly increased after C1GALT1 was knocked down(P < 0. 05) . Conclusion C1GALT1 is overexpressed in GBM tissues and may promote the proliferation , migration and invasion of GBM cells by inhibiting cellular senescence .