A peptide CORO1C-47aa encoded by circ-0000437 functions as a negative regulator in endometrium tumor angiogenesis

Circular RNAs (circRNA) are a novel class of widespread non-coding RNAs (ncRNAs) that regulate gene expression in mammals. Recent studies demonstrate that functional peptides can be encoded by short open reading frames (sORFs) in ncRNAs, including circRNAs. In this study, through deep RNA sequencing on human endometrial cancer (EC) samples and their paired adjacent normal tissues, we uncovered that the circRNA hsa-circ-0000437 is significantly reduced in EC compared to matched paracancerous tissue. The hsa-circ-0000437 contains a sORF encoding a functional peptide termed as CORO1C-47aa. Overexpression of CORO1C-47aa is capable of inhibiting angiogenesis at the initiation stage by suppressing endothelial cell proliferation, migration, and differentiation through competing with TACC3 to bind to ARNT and suppress VEGF. The anti-tumor effects of CORO1C-47aa on EC progression suggest that CORO1C-47aa has a potential value in anti-carcinoma therapies and deserves further investigation.