Splicing factor SF3b6 promotes proliferation and migration of gastric cancer cells through MAPK signaling pathway / 中国肿瘤生物治疗杂志

ABSTRACT

@#[Abstract] Objective: To explore the effect and mechanism of splicing factor 3b subunit 6 (SF3b6) on the proliferation, apoptosis, invasion and migration of gastric cancer cells. Methods: Tissue microarrays were used to detect the expression of SF3b6 in gastric cancer tissues and adjacent tissues. WB and qPCR were used to detect the expression of SF3b6 in normal immortalized gastric epithelial cells (GES-1) and gastric cancer cell lines (HGC27, AGS, BGC823, MGC803, SGC7901, MKN45). AGS and MGC803 cells were transfected with SF3b6 siRNA, and BGC823 and SGC7901 cells were transfected with SF3b6 over-expression plasmid for functional experiments. CCK-8 assay was used to detect the regulation of SF3b6 on the proliferation of gastric cancer cells; Transwell migration and invasion experiments were used to detect the effect of SF3b6 on the migration and invasion of gastric cancer cells; Flow cytometry was used to detect cell apoptosis; and WB was adopted to detect expressions of apoptosis and migration-related molecules and MAPK signaling pathway associated proteins. Results: The expression level of SF3b6 in gastric cancer MGC803 and AGS cells was significantly higher while in BGC823 and SGC7901 cells was significantly lower than that in normal gastric epithelial GES-1 cells (P<0.05 or P<0.01). SF3b6 knockdown inhibited the proliferation, migration and invasion, but promoted cell apoptosis of gastric cancer cell lines AGS and MGC803 (P<0.05 or P<0.01); However, over-expression of SF3b6 promoted the proliferation, migration and invasion of gastric cancer cell lines BGC823 and SGC7901 (P<0.05 or P<0.01). Mechanism study showed that SF3b6 knockdown promoted the activation of JNK and p38 and expression of apoptosis-related protein cleaved caspase-9, cleaved PARP and Bax (P<0.05 or P<0.01), and meanwhile inhibited the process of epithelial to mesenchymal transition (EMT) in gastric cancer cells. Conclusion: The splicing factor SF3b6 enhances cell proliferation and migration via MAPK signaling pathway, thereby promoting tumor progression.