The Long Noncoding RNA DUXAP8 Facilitates the Malignant Progression of Colon Cancer via the microRNA-378a-3p/FOXQ1 Axis.

BACKGROUND/AIMS: The long noncoding RNA DUXAP8 is a pivotal regulator in cancer pathogenesis, but the molecular mechanism underlying the role of DUXAP8 in colon cancer progression is underexplored. METHODS: In addition to bioinformatic analyses, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to assess DUXAP8, microRNA-378a-3p, FOXQ1 expression in colon cancer tissues, and clinical data were analyzed to determine the correlation between DUXAP8 expression and colon cancer patient outcomes. Nuclear/cytoplasmic RNA fractionation was utilized to analyze the subcellular distribution of DUXAP8. Dual-luciferase and RNA immunoprecipitation assays were performed to confirm the binding of DUXAP8/FOXQ1 and microRNA-378a-3p. After cell transfection, qRT-PCR was performed to evaluate the modulatory relationship of DUXAP8/microRNA-378a-3p/FOXQ1. Cell Counting Kit-8, MTT, scratch healing, and Transwell assays were performed to evaluate the impact of DUXAP8/microRNA-378a-3p/FOXQ1 expression on colon cancer cell functions. RESULTS: The results revealed that the expression of DUXAP8 and FOXQ1 was upregulated in colon cancer tissues, while the expression of microRNA-378a-3p was down-regulated. The increased DUXAP8 expression was positively correlated with lymph node metastasis and TNM stage. Dual-luciferase and RNA immunoprecipitation assays demonstrated that DUXAP8 was a sponge for microRNA-378a-3p and targeted the ability of microRNA-378a-3p to regulate FOXQ1. In addition, functional experiment results revealed that overexpressed DUXAP8 facilitated the growth and migratory ability of colon cancer cells. DUXAP8 also reversed the tumor-suppressive effect of microRNA-378a-3p. However, silencing FOXQ1 could reverse the cancer-promoting effects of high DUXAP8 expression. CONCLUSIONS: DUXAP8 expression was significantly increased in colon cancer, which was associated with lymph node metastasis and unfavorable outcomes in colon cancer patients. DUXAP8 may hasten malignant progression of colon cancer cells through its effects on microRNA-378a-3p/FOXQ1.