Abstract
Aberrant expression of circular RNAs (circRNAs) has been reported to play an important biological regulatory role in gastric cancer (GC). For the purpose of silencing cancer-related genes, a new approach for cancer treatment using nanocarriers to deliver siRNA has been proposed. In this study, abundantly expressed circMAP2K2 (hsa_circRNA_102415) is identified in GC cells. CircMAP2K2 regulates the PCBP1/GPX1 axis through proteasome-mediated degradation, which further mediates the activation of the AKT/GSK3β/epithelial-to-mesenchymal transition (EMT) signaling pathway and enhances the proliferation and metastatic ability of GC cells. To establish novel GC treatment, epigallocatechin-3-gallate-lysozyme (EGCG-LYS) fibrils are synthesized, and in vitro experiments demonstrate that EGCG-LYS has a higher siRNA delivery efficiency than Lipofectamine 2000 (lipo2000), which effectively silences the expression of circMAP2K2. Further studies show that EGCG-LYS carrying siRNA can successfully achieve lysosome escape, which allows it to be located in the cytoplasm to achieve post-transcriptional gene silencing. In addition, EGCG-LYS carrying si-circMAP2K2 has good circulating stability, excellent biosafety and antitumor ability in vivo. The EGCG-LYS fibrils delivery system provides a new tool and approach for the treatment of GC.