1. Department of General Surgery, Shanghai Key Laboratory of Gastric Neoplasms, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
2. School of Biomedical Engineering, Bio-ID Center, Shanghai Jiao Tong University, Shanghai 200240, China.
*These authors contributed equally to this work.
Background: Gastric cancer (GC) is characterized by tissue invasion and metastasis, which lead to an aggressive and highly lethal disease. However, the underlying molecular mechanism remains largely unclear. Although multiple miRNAs are known to regulate crucial cellular events during cancer metastasis, their individual roles are still not fully described.
Methods: miR-29c overexpressed cell lines were constructed. The wound healing, migration and invasion assays were performed to investigate the effect of miR-29c on metastasis of GC. HUVECs proliferation and tube formation assays were used to test the ability of angiogenesis of miR-29c. The target gene VEGFA was predicted by bioinformatic algorithms and validated by luciferase activity assay. Peritoneal spreading and pulmonary metastasis mice models were applied in vivo.
Results: In the current study, we report the results that introduction of exogenous miR-29c inhibits GC cell migration, invasion and angiogenesis. Epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs) properties are participated in the miR-29c mediated cell metastasis. Furthermore, by performing tumor metastasis PCR array and luciferase reporter assay, we find that the expression of VEGFA is regulated by miR-29c through direct targeting of its 3'-UTR. In addition, we show that the VEGFA/VEGFR2/ERK pathway is involved in this process.
Conclusion: These data taken together reveal the crucial functions of miR-29c-VEGFA/VEGFR2/ERK signaling axis in the metastasis progression of GC via regulating EMT and CSCs properties, which make them potential targets for clinical intervention in GC.
Keywords: gastric cancer, miR-29c, VEGFA, epithelial-mesenchymal transition, cancer stem cells