Circ_0001535 Facilitates Tumor Malignant Progression by miR-485-5p/LASP1 Axis in Colorectal Cancer

BACKGROUND: Increasing evidence revealed that circular RNAs (circRNAs) are involved in colorectal cancer progression. However, the potential function of circ_0001535 in colorectal cancer remains unclear. AIMS: To investigate the mechanism of circ_0001535 by silencing circ_0001535 in colorectal cancer cells and nude mice. STUDY DESIGN: A cell study. METHODS: Expressions of circ_0001535, LIM and SH3 protein 1 (LASP1) mRNA, and miR-485-5p were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Western blot analyses of LASP1, PCNA, cleaved caspase 3, snail 1, and OCT4 protein expression were performed. CCK-8, EdU, flow cytometry, transwell assays, and sphere formation were conducted to evaluate colorectal cancer cell proliferation, apoptosis, invasion, and stemness. Luciferase reporter assays, RNA pull-down, and RIP validated binding. A nude mice xenograft model was constructed. RESULTS: Circ_0001535 was significantly upregulated in colorectal tissues and cells. Circ_0001535 knockdown suppressed the malignant behavior of colorectal cells such as proliferation, invasion, stemness, and tumor growth in vivo. This knockdown also induced apoptosis by sponging miR-485-5p and upregulating LASP1 expression. CONCLUSION: Circ_0001535 promotes colorectal cancer cell development by absorbing miR-485-5p and upregulating LASP1.