Circular RNA hsacirc₀005939 Regulates UHRF1BP1L Expression by Targeting miR-4693-3p to Promote Colorectal Cancer Progression

Introduction: Colorectal cancer (CRC) is the second most common and fatal cancer in China. circRNAs are different expressed between tumor and non-tumor tissues, and they are proved to be correlated with tumorigenesis and cancer progression. Objective: We aimed to explore the biological and molecular function of hsacirc₀005939 in CRC. Methods: We collected and compared ten CRC tissues and four noncancerous tissues and performed circRNA sequencing. We investigated the hsacirc₀005939 expression in fresh tissues from CRC and adjacent tissues by qPCR. Meanwhile, functional roles of hsacirc₀005939 in CRC cells were explored by CCK-8, colony formation, wounding healing, cell apoptosis and western blot assays. RNA-FISH was used to confirm the cellular distribution of hsacirc₀005939. Bioinformatic prediction and luciferase reporter assay were used to determine the mechanisms of hsacirc₀005939. Results: Our results indicated that hsacirc₀005939 was up-regulated in CRC tissues and cells. Up-regulation of hsacirc₀005939 was associated with the occurrence and the number of lymph node metastasis of CRC. Hsacirc₀005939 down-regulation inhibited cell proliferation, increased cell apoptosis and caused G2 phase arrest of CRC cells. Mechanistically, luciferase assay revealed that hsacirc₀005939 acts as a molecular sponge for miR-4693-3p and then enhanced Ubiquitin Like With PHD And Ring Finger Domains 1 binding protein 1 like (UHRF1BP1L) expression. Conclusion: Our findings indicated an oncogenic role of hsacirc₀005939 in CRC, and it enhanced malignant phenotypes of CRC cells through miR-4693-3p/UHRF1BP1L axis. Our study may offer promising biomarkers and therapeutic targets for CRC.