To explore the effects of long non coding RNA FGD5-AS1 (LncRNA FGD5-AS1) on the migration and invasion of gastric cancer cells by regulating the microRNA-302b-3p (miR-302b-3p)/E2F transcription factor 1 (E2F1) axis.

Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the mRNA expression of LncRNA FGD5-AS1, miR-302b-3p, and E2F1 in gastric cancer cell lines (SGC-7901, MKN-45, HGC-27, AGS, BGC-823) and human gastric epithelial cell line GES-1, in order to screen for the best intervention cells. Gastric cancer cells were separated into control group (NC group), sh-NC group, sh-FGD5-AS1 group, sh-FGD5-AS1+anti-miR-NC group, and sh-FGD5-AS1+anti-miR-302b-3p group. qRT-PCR was performed to detect the expression of LncRNA FGD5-AS1, miR-302b-3p, and E2F1 in the cells. MTT assay and flow cytometry were applied to measure cell proliferation and apoptosis, respectively. Scratch and Transwell assays were carried out to measure cell migration and invasion, respectively. Western blotting was carried out to measure the protein levels of E2F1, Ki-67, Bax and Bcl-2. Nude mouse model of transplantable subcutaneous tumor was established to verify the effect of LncRNA FGD5-AS1 on the growth of gastric cancer transplant tumors. Dual luciferase reporter gene and RNA pull-down assays were used to detect the targeting relationship of LncRNA FGD5-AS1 and E2F1 with miR-302b-3p.

Compared with the GES-1 cells, the gastric cancer cell lines SGC-7901, MKN-45, HGC-27, AGS and BGC-823 exhibited significantly increased mRNA levels of LncRNA FGD5-AS1 and E2F1, while decreased level of miR-302b-3p (P<0.05). AGS cells were finally selected for the following experiments. Silencing LncRNA FGD5-AS1 prominently up-regulated miR-302b-3p, down-regulated E2F1, and inhibited cell proliferation, migration, and invasion, and promoted cell apoptosis in gastric cancer AGS cells (P<0.05). Inhibition of miR-302b-3p partially weakened the effects of silencing LncRNA FGD5-AS1 on the proliferation, migration, invasion, and apoptosis of gastric cancer cells (P<0.05). In vivo experiments showed that silencing LncRNA FGD5-AS1 could prominently inhibit the growth of transplanted tumors in mice (P<0.05). RNA pull-down and dual luciferase reporter gene assays confirmed the targeted regulatory relationship of LncRNA FGD5-AS1 and E2F1 with miR-302b-3p.

LncRNA FGD5-AS1 is up-regulated in gastric cancer cells, and its silencing can inhibit the malignant progression of gastric cancer by regulating the miR-302b-3p/E2F1 axis.