Long Non-Coding RNA BCAR4 Promotes Oxaliplatin Resistance in Colorectal Cancer by Modulating miR-484-3p/RAB5C Expression

Abstract Background: Oxaliplatin-based chemotherapy resistance is a major cause of recurrence in patients with colorectal cancer (CRC). Increasing evidence indicates that lncRNA BCAR4 is involved in the occurrence and development of various cancers. However, the effect of BCAR4 on CRC chemotherapy resistance remains unclear. Methods: Real-time quantitative PCR and Western blotting were used to detect the expression levels of gene and protein, respectively. The role of BCAR4 in drug resistance was evaluated by cell viability and apoptosis experiments. Luciferase reporter assay and Western blot analysis confirmed the relationship between BCAR4, miR-483-3p, and RAB5C. Results: Luciferase reporter assay and Western blotting analysis confirmed the relationship among BCAR4, miR-483-3p, and RAB5C. The results showed that the expression levels of BCAR4 and RAB5C were increased in CRC tumor tissue. The expression levels of BCAR4 were increased in patients with chemotherapy resistance. Functional analysis showed that knockdown of BCAR4 reduced the expression levels of proteins related to stemness, decreased the activity of cells, and promoted apoptosis of CRC cells, while overexpression of RAB5C reversed these effects. Moreover, the results showed that BCAR4 promoted oxaliplatin resistance by inhibiting cell apoptosis. Mechanistically, BCAR4 sponged miR-483-3p and promoted the expression of RAB5C. Knockdown of BCAR4 reduced tumor size and enhanced cell sensitivity to oxaliplatin in vivo. Conclusion: The results suggested that BCAR4/miR-483-3p/RAB5C axis has the potential to be explored as a novel therapeutic target for CRC treatment.