Exosomal miR-224-3p promotes lymphangiogenesis and lymph node metastasis by targeting GSK3B in gastric cancer.

Abstract

Background: Patients with gastric cancer (GC) are prone to lymph node metastasis (LNM), which is an important factor for recurrence and poor prognosis of GC. Nowadays, more and more studies have confirmed that exosomes can participate in tumor lymphangiogenesis. An in-depth exploration of the pathological mechanism in the process of LNM in GC may provide effective targets and improve the diagnosis and treatment effect.

Materials and methods: We used sequencing analysis of collected serum to screen out exo-miRNA related to LNM in GC. ELISA, qRT-PCR, Western Blot, RNA pull-down assay, Transwell assay, animal experiments, and other experiments were used to verify the results.

Results: In this study, we screened out miR-224-3p related to GC progression and LNM in a vascular endothelial growth Factor C (VEGFC)-independent manner. We found that exo-miR-224-3p derived from GC cells could enter human lymphatic endothelial cells (HLECs) and promote the tube formation and migration of HLECs. In addition, it was revealed that miR-224-3p could bind to the 3'UTR region of GSK3B mRNA. Then, we proved that inhibiting the expression of GSK3B could suppress the phosphorylation of β-catenin and promote the transcription of PROX1, thus leading to tumor lymphangiogenesis. Furthermore, it was also found that hnRNPA1 mediated the sorting of miR-224-3p into exosomes, and the high expression of PKM2 promoted the secretion of exo-miR-224-3p.

Conclusions: Our discovery of the exo-miR-224-3p/GSK3B/β-catenin/PROX1 axis may provide a new direction for the clinical treatment of GC.