The highly expressed GOLPH3 in colorectal cancer cells activates smoothened to drive glycolysis and promote cancer cell growth and radiotherapy resistance.

Background: Colorectal cancer (CRC) is a frequently diagnosed cancer across the world and has increased in prevalence over the last decade. This study aimed to assess the biological roles, influences on radiosensitivity, and possible molecular mechanism of Golgi phosphoprotein 3 (GOLPH3) in CRC.

Methods: Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), and immunohistochemistry (IHC) were used to examine GOLPH3 expression. In vivo and in vitro assays were carried out to clarify the function of GOLPH3 in CRC. The differentially expressed genes (DEGs) in CRC cells with knockdown of GOLPH3 were identified through RNA sequencing (RNA-seq). Based on the DEGs associated with GOLPH3 knockdown and the data from The Cancer Genome Atlas (TCGA) database, the pathways that could be regulated by GOLPH3 were predicted via Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis.

Results: In CRC, GOLPH3 was upregulated, and GOLPH3 upregulation was predictive of a poor prognosis. GOLPH3 knockdown inhibited CRC cell proliferation, migration, and invasion but promoted apoptosis and reduced radiotherapy resistance. Conversely, in CRC cells with GOLPH3 overexpression, malignant biological behavior and radiotherapy resistance were enhanced. In vivo, GOLPH3 knockdown impeded tumor growth. Mechanistically, GOLPH3 promoted the localization of smoothened (SMO) on the cell membrane, thereby activating AMP-activated protein kinase (AMPK)-mediated glycolysis. Additionally, the final product of glycolysis, lactate, induced H3 lysine 18 lactylation (H3K18), which could be enriched on the promoter of GOLPH3 and stimulate the transcription of GOLPH3.

Conclusions: GOLPH3 promoted CRC progression and enhanced radiotherapy resistance via glycolysis mediated by the SMO-AMPK axis.