Oxaliplatin-Induced Upregulation of Exosomal miR-424-3p Derived from Human Bone Marrow Mesenchymal Stem Cells Attenuates Progression of Gastric Cancer Cells

Introduction Chemotherapy, particularly with oxaliplatin, is a key treatment for advanced gastric cancer (GC), and exosomes derived from human bone marrow mesenchymal stem cells (hBM-MSCs) play a vital role in the tumor microenvironment. Objectives The study aims to elucidate the previously unexplored role of exosomes derived from hBM-MSCs in GC tumorigenesis, especially under the influence of chemotherapy. Methods We conducted an integrated study, utilizing miRNA sequencing and biological experiments, to analyze the tumorigenicity of exosomal miR-424-3p secreted by hBM-MSCs and its target gene RHOXF2 in GC cell lines. The results were confirmed through experimentation using a xenograft mouse model. Results This study demonstrated the role of hBM-MSCs in the GC microenvironment, focusing on their Epithelial-Mesenchymal Transition (EMT) facilitation through exosomes, which led to enhanced tumorigenicity of in GC cells. Intriguingly, this pro-tumor effect was abrogated when hBM-MSCs were treated with oxaliplatin. Exosomal miRNA sequencing revealed that oxaliplatin can upregulate the levels of miR-424-3p in exosomes secreted by hBM-MSCs, thereby inhibiting the EMT process in GC cells. Furthermore, miR-424-3p was identified to target and downregulate RHOXF2 expression, impeding the malignant behavior of GC cells both in vitro and in the mouse model. Conclusions These findings uncover a potential hidden mechanism of oxaliplatin's anti-tumor action and propose the delivery of miR-424-3p via exosomes as a promising avenue for anti-tumor therapy. hBM-MSCs that were exposed to PBS or oxaliplatin (0.25uM) were cultured in a serum-free culture system for 48 hours and then centrifuged at 1 200 g for 25 min at 4 °C to remove the cell debris and dead cells. Exosomes were isolated by using differential centrifugal speeds. The cells were filtered through a 0.2 mm filter, followed by ultracentrifugation at 4 ° C and 20 000 g for 30 min to remove the large cell blisters. The collected supernatant was filtered through a 0.22-μm filter and centrifuged again at 4°C and 100 000 g for 90 min. After removing the supernatant, the white sedimentation from the tube bottom was suspended in 500 μL of PBS and stored at −80 °C for future experiments.