Lymph node metastasis-related circHELQ promotes progression and acts as a nanotherapeutic target in colorectal cancer

Studies have highlighted the important roles of circRNAs in various cancers. However, their specific functions in the lymph node metastasis (LNM) of colorectal cancer (CRC) remain largely unclear.

The Arraystar human circRNA microarray was used to identify circular RNAs (circRNAs) associated with LNM in colorectal cancer (CRC). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to measure circHELQ expression in CRC cell lines and tissue specimens. A series of in vitro and in vivo functional assays were subsequently conducted to investigate the role of circHELQ in LNM and CRC progression. Additionally, fluorescence in situ hybridization, dual-luciferase reporter assays, RNA pull-down, and Western blot experiments were carried out to elucidate the underlying regulatory mechanisms of circHELQ in CRC.

Our results demonstrated that circHELQ expression was significantly upregulated in CRC and that its expression level was closely correlated with LNM. Gain- and loss-of-function experiments revealed that circHELQ promotes CRC progression and metastasis-including proliferation, migration, invasion, lymphatic vessel formation, and LNM-both in vitro and in vivo. Mechanistically, circHELQ acts as a competing endogenous RNA (ceRNA) that sponges miR-4793-3p, thereby alleviating its suppression of VEGFC. This circHELQ/miR-4793-3p/VEGFC axis drives LNM in CRC by upregulating VEGFC expression. Furthermore, we developed a cancer cell membrane-based siRNA delivery system (cMDS) targeting circHELQ, and these nanoparticles effectively suppressed CRC proliferation and LNM.

CircHELQ drives CRC progression and LNM and is a candidate prognostic biomarker. Furthermore, its molecular function renders it a viable target for nanoparticle-based therapeutic strategies against CRC.