Background: Circular RNAs (circRNAs) play a crucial role in a variety of cancers, including colorectal cancer (CRC). This study aimed to explore the role of hsa_circ_0136666  (circ-PRKDC ) in CRC and its potential mechanism.
Methods: The levels of circ-PRKDC , miR-198  and discoidin domain receptor 1 (DDR1 ) were measured using quantitative real-time polymerase chain reaction or Western blot. Cell viability was detected using cell counting kit-8 (CCK-8) assay. Cell apoptosis and cycle were evaluated via flow cytometry. Cell migration and invasion were examined using transwell assay. CyclinD1 protein level was determined via Western blot. The interaction among circ-PRKDC , miR-198  and DDR1  was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation assay. Xenograft assay was performed to analyze tumor growth in vivo.
Results: Circ-PRKDC  and DDR1  levels were increased, and miR-198  level was decreased in CRC tissues and cells. Circ-PRKDC  depletion inhibited proliferation, migration and invasion, and expedited apoptosis and cell cycle arrest in SW480 and HCT116 cells. Silence of circ-PRKDC  impeded CRC progression by sponging miR-198 . Overexpression of miR-198  hindered CRC development via targeting DDR1 . Moreover, circ-PRKDC  silencing suppressed tumor growth in vivo.
Conclusion: Knockdown of circ-PRKDC  inhibited CRC progression via modulating miR-198 /DDR1  pathway.
Keywords: colorectal cancer, circ-PRKDC , miR-198 , DDR1 , cell cycle