USF1-Driven KIF2C promotes glioma progression by stabilizing SMC4 and enhancing glycolysis

Glioma progression is supported by coordinated changes in oncogenic signaling and cellular metabolism. Kinesin family member 2C (KIF2C) has been implicated in several malignancies, but its regulatory mechanisms and contribution to glycolytic reprogramming in glioma remain incompletely understood. This research investigated the KIF2C’s biological role and its upstream and downstream regulatory mechanisms in glioma. Public databases, including TIMER2.0, GEPIA, and UALCAN, were used to evaluate KIF2C expression and clinical relevance. KIF2C and upstream stimulatory factor 1 (USF1) expression levels were examined in glioma tissues and cell lines utilizing western blot, RT-qPCR, and immunohistochemistry. Colony-formation, EdU-incorporation, apoptosis, Transwell, and glycolysis assays were performed to assess cellular phenotypes. Luciferase reporter and chromatin immunoprecipitation assays were used to investigate transcriptional regulation. Co-immunoprecipitation, cycloheximide-chase, proteasome-inhibition, and ubiquitination assays were implemented to study the association between KIF2C and structural maintenance of chromosomes 4 (SMC4). The effects of KIF2C silencing on tumor growth were further evaluated in subcutaneous xenograft model. KIF2C was upregulated in glioma tissues and cell lines and was associated with advanced tumor grade and unfavorable patient survival. KIF2C overexpression enhanced glioma cell proliferation, migration, invasion, EMT-associated changes, and glycolytic activity while reducing apoptosis, whereas KIF2C silencing produced the opposite effects. KIF2C silencing also suppressed tumor growth and reduced EMT and glycolysis-related protein expression in subcutaneous xenografts. Mechanistically, USF1 associated with the KIF2C promoter and increased KIF2C transcription. Reciprocal rescue experiments supported KIF2C as an important downstream mediator of USF1-induced malignant and glycolytic phenotypes. KIF2C was also associated with SMC4 and enhanced its protein stability via limiting ubiquitin-mediated proteasomal degradation. Furthermore, SMC4 knockdown attenuated the effects of KIF2C overexpression on malignant behavior and glycolytic activity. These findings identify a USF1-KIF2C-SMC4 regulatory axis that links transcriptional dysregulation with glycolytic reprogramming and glioma progression. Although therapeutic-response studies are still required, the dependence of these malignant phenotypes on this axis provides a rationale for investigating whether its inhibition can enhance responses to temozolomide, radiotherapy, or metabolism-targeted treatments. Schematic model of the USF1-KIF2C-SMC4 axis during glioma progression. USF1 transcriptionally upregulates KIF2C mRNA expression by binding directly to its promoter, leading to increased KIF2C protein levels. KIF2C then physically binds SMC4 to inhibit its ubiquitin-mediated proteasomal degradation, thereby stabilizing SMC4 protein. Elevated activity of this USF1-KIF2C-SMC4 axis ultimately drives glioma progression by enhancing glycolytic reprogramming (increasing HK2, PKM2, GLUT1, lactate, and ATP) and promoting malignant phenotypes (proliferation, migration, invasion, and EMT while suppressing apoptosis) to fuel tumor growth in vivo (The figure was generated with AI tool Gemini). • USF1 transcriptionally upregulates KIF2C in glioma tissues and cell lines. • KIF2C binds SMC4 and prevents its ubiquitin-mediated proteasomal degradation. • The USF1-KIF2C-SMC4 axis enhances glioma proliferation, invasion, EMT, and glycolytic reprogramming. • Targeting the USF1-KIF2C-SMC4 axis may represent a candidate therapeutic strategy for glioma.