Long non-coding RNA AC105118.1 affects glycolysis to facilitate oxaliplatin resistance in colorectal cancer cells by modulating the miR-378a-3p/KIF26B axis

Background: Oxaliplatin is a first-line chemotherapy drug for colorectal cancer (CRC), but many patients eventually lose treatment efficacy due to acquired resistance. AC105118.1 is a long non-coding RNA with unknown biological function. This research attempts to probe into the molecular regulatory mechanism of AC105118.1 in CRC oxaliplatin resistance.

Methods: The expression level of AC105118.1 in CRC tissues and cells was measured based on The Cancer Genome Atlas (TCGA) data and quantitative reverse transcription polymerase chain reaction (qRT-PCR). We utilized dual-luciferase assay and RNA immunoprecipitation to analyze the interaction between AC105118.1, miR-378a-3p, and their downstream target KIF26B. CCK-8, colony formation assay, and flow cytometry were employed to assess the half inhibitory concentration (IC₅₀), cell proliferation, and apoptosis rate of HCT116/L-OHP cells treated with oxaliplatin. The glycolysis evaluation was completed by measuring the extracellular acidification rate (ECAR), glucose consumption, lactate production, and glycolysis-related proteins (HK2, GLUT1, and LDHA). TUNEL staining was used to detect the level of apoptosis.

Results: AC105118.1 was specifically upregulated in CRC tissues and cells. AC105118.1 indirectly facilitated the expression of miRNA target gene KIF26B by sequestering miR-378a-3p. In HCT116/L-OHP cells, transfection with si-AC105118.1 resulted in a decrease in glycolysis level, a lower maximum IC₅₀ required for oxaliplatin-treated cells, inhibited cell proliferation, and an increase in apoptosis rate. All of these effects were alleviated when simultaneously transfecting miR-378a-3p inhibitor or oe-KIF26B. Knockdown of AC105118.1 significantly inhibited oxaliplatin resistance to CRC in mice.

Conclusion: AC105118.1 facilitates glycolysis and increases CRC cells' resistance to oxaliplatin by targeting the miR-378a-3p/KIF26B axis. The present work shed new insights into the function and mechanism of AC105118.1 in molecular function and suggested that the AC105118.1/miR-378a-3p/KIF26B axis is a promising target for intervening CRC oxaliplatin resistance.