Introduction: Owing to its involvement in both the initiation and progression of various cancers, aberrant circular RNA (circRNA) expression has been researched extensively in the recent times. In the present study, we aim to investigate the effect of a novel circRNA has_circ_0025933 (circNELL2) in the progression of esophageal squamous cell carcinoma (ESCC).
Materials and Methods: Sanger sequencing and the detection of circNELL2 level after RNase R or actinomycin D treatment were performed to identify the existence of cirNELL2 in ESCC cells. WST, EDU staining and colony-formation assay were used to assess the proliferation while transwell assay was used to evaluate the migration of ESCC cells. Luciferase assay, RNA pull down and the FISH assay were performed to verify the interaction between circNELL2 and miR-127-5p as well as miR-127-5p and CDC6. Xenograft model was carried out to evaluate the effect of circNELL2 in vivo.
Results: circNELL2 was proved to exist in ESCC cells. The up-regulated expression of circNELL2 in the clinical ESCC specimens was also verified. Next, function studies suggested that circNELL2 knockdown inhibited the proliferation of ESCC cells in vitro and in vivo, while circNELL2 overexpression promotes that of ESCC cells. Besides, this study mechanically predicted and verified the target miR of circNELL2, which is miR-127-5p. It was found that miR-127-5p was capable of reversing the effect of circNELL2 on ESCC cells. Moreover, miR-127-5p was also found to target CDC6 to participate in the regulation of cell phenotype.
Discussion: circNELL2 promoted the progression of ESCC cells via sponging miR-127-5p, and it has the potential to serve as a novel prognostic and therapeutic target for ESCC.
Keywords: circular RNA circNELL2, miR-127-5p, esophageal squamous cell carcinoma