Objective To explore the molecular mechanism by which circular RNA circHECTD1 (hsa_circ_0002301) regulates the miR-375/CADM1 axis to inhibit proliferation and migration in colorectal cancer (CRC).

Methods The expression level of circHECTD1 in CRC cell lines was detected by quantitative real-time PCR, and the circular characteristics of circHECTD1 in CRC cell lines were verified. CCK-8 assay, colony formation assay, and Transwell assay were performed to determine the effects of circHECTD1 on the proliferation and migration of CRC cells. A nude mouse subcutaneous xenograft tumor model was utilized to investigate the effect of circHECTD1 on tumor growth in vivo. For mechanistic studies, bioinformatic databases and dual-luciferase reporter assay were used to predict and validate the target miRNAs and mRNAs interacting with circHECTD1 and investigate its competing endogenous RNA interaction network.

Results The overexpression of circHECTD1 significantly inhibited the proliferation and migration of CRC cells, whereas knockdown of circHECTD1 produced the opposite effects. In vivo animal experiments demonstrated that the overexpression of circHECTD1 inhibited the growth of CRC cells. Mechanistically, circHECTD1 inhibited CRC cell proliferation and migration by regulating the miR-375/CADM1 axis, and miR-375 overexpression partially reversed the effects of circHECTD1 knockdown on CRC proliferation.

Conclusion CircHECTD1 inhibits the progression of CRC by regulating the miR-375/CADM1 axis.