KIF4A facilitates oxaliplatin resistance and stemness in colon cancer by boosting glucose metabolism.

Background: Colon cancer (CC) is a malignant tumor commonly found in the intestines with high incidence and mortality rates. Oxaliplatin (OXA) is a platinum-based chemotherapy drug widely used to treat CC. However, frequent drug resistance in patients results in suboptimal treatment outcomes. Though kinesin family member 4A (KIF4A) has been reported to be upregulated in various cancers and linked with poor prognosis in patients, its regulatory mechanism in cellular metabolism remains unclear.

Methods: The Human CC/OXA-resistant cell line (HCT116-R) was constructed. CCK-8 assay was employed to calculate the half-maximal inhibitory concentration (IC50) of CC cells. The level of cell stemness was assessed by cell sphere formation assay. The enrichment of KIF4A in signaling pathways of CC was analyzed through gene set enrichment analysis (GSEA). The bioinformatics analysis was applied to reveal the differential expression of KIF4A in CC and its correlation with genes related to stemness or glycolysis. The assessment of lactate in the supernatant was finished by utilizing the lactate detection kit. The oxidative phosphorylation and glycolysis levels in cells were measured by a Seahorse analyzer. The mRNA expression level of KIF4A was detected by quantitative real-time PCR. Furthermore, the western blot (WB) was employed to determine the protein expression of glycolysis-related enzymes in cells. A mouse OXA-resistant CC xenograft tumor model was established, with changes in tumor volume and final weight recorded. TUNEL was utilized to detect the apoptosis level in tissues and immunohistochemistry (IHC) to examine the distribution of KIF4A and ki-67 in tissues. The levels of stemness-related proteins in tissues were detected through WB.

Results: KIF4A was upregulated in CC, exhibiting a positive association with OXA resistance. High expression of KIF4A promoted cancer cell survival and cancer stemness. In GSEA prediction, KIF4A in CC may be linked with the glycolysis pathway. Correspondingly, the expression of KIF4A in CC was positively correlated with the expression of glycolysis-related proteins. Tests for lactate content and glycolysis/oxidative phosphorylation levels revealed that knocking down KIF4A repressed glycolytic function in the drug-resistant strain but reinforced mitochondrial oxidative phosphorylation. Furthermore, KIF4A overexpression effectively boosted the OXA resistance and stemness of cells, which was reversed by glycolysis inhibitor. The mouse model validated the above results.

Conclusion: KIF4A is significantly upregulated in CC to reinforce the glycolysis of cancer cells, thus facilitating cell stemness and resistance to OXA-based therapy.