Forkhead Box M1 Regulates the Proliferation,Invasion,and Drug Resistance of Gastric Cancer Cells via circ_NOTCH1 / 中国医学科学院学报

Objective To investigate the impacts of forkhead box M1(FOXM1)on the proliferation,invasion,and drug resistance of gastric cancer cells by regulating the circular RNA circ_NOTCH1.Methods Western blotting and real-time quantitative PCR were performed to determine the expression of FOXM1 protein and circ_NOTCH1,respectively,in the gastric cancer tissue,para-carcinoma tissue,human normal gastric mucosa epithelial cell line GES-1 and gastric cancer cell lines MGC-803,HGC-27,and BGC-823.BGC-823 cells were classified into the following groups:control,short hairpin RNA FOXM1(sh-FOXM1)and negative control(sh-NC),small interfering RNA circ_NOTCH1(si-circ_NOTCH1)and negative control(si-NC),and sh-FOXM1+circ_NOTCH1 overexpression plasmid(sh-FOXM1+pcDNA-circ_NOTCH1)and sh-FOXM1+negative control(sh-FOXM1+pcDNA).CCK-8 assay and clone formation assay were employed to measure the cell proliferation,and Transwell assay to measure cell invasion.After treatment with 1.0 mg/L adriamycin for 48 h,the cell resistance in each group was analyzed.Western blotting was employed to determine the expression levels of FOXM1,proliferating cell nuclear antigen(PCNA),Bax,multi-drug resistance-associated protein 1(MRP1),and multi-drug resistance gene 1(MDR1).RNA pull-down and RNA immunoprecipitation were employed to examine the binding of circ_NOTCH1 to FOXM1 protein.Results Compared with those in the para-carcinoma tissue,the expression levels of FOXM1 protein and circ_NOTCH1 in the gastric cancer tissue were up-regulated(all P<0.001).Compared with GES-1 cells,MGC-803,HGC-27,and BGC-823 cells showed up-regulated expression levels of FOXM1 protein and circ_NOTCH1(all P<0.001).Compared with the control group and sh-NC group,the sh-FOXM1 group with down-regulated expression of FOXM1 protein and circ_NOTCH1 showed decreased optical density value,clone formation rate,cell invasion number,and cell viability,down-regulated expression of PCNA,MRP1,and MDR1,and up-regulated expression of Bax protein in BGC-823 cells(all P<0.001).Compared with the control group and the si-NC group,the si-circ_NOTCH1 group with down-regulated expression of circ_NOTCH1 showed decreased optical density value,clone formation rate,cell invasion number,and cell viability,down-regulated expression of PCNA,MRP1,and MDR1,and up-regulated expression of Bax protein in BGC-823 cells(all P<0.001).Compared with sh-FOXM1 group and sh-FOXM1+pcDNA group,the sh-FOXM1+pcDNA-circ_NOTCH1 group with up-regulated expression of circ_NOTCH1 showed increased optical density value,clone formation rate,cell invasion number,and cell viability,up-regulated expression of PCNA,MRP1,and MDR1,and down-regulated expression of Bax protein(all P<0.001).FOXM1 protein was able to interact with circ_NOTCH1.Conclusion Interference with FOXM1 may inhibit the proliferation,invasion,and drug resistance of gastric cancer cells by silencing circ_NOTCH1 expression.

Effect of lncRNA HULC knockdown on rat secreting pituitary adenoma GH3 cells

Pituitary adenoma is one of the most common tumors in the neuroendocrine system. This study investigated the effects of long non-coding RNAs (lncRNAs) highly up-regulated in liver cancer (HULC) on rat secreting pituitary adenoma GH3 cell viability, migration, invasion, apoptosis, and hormone secretion, as well as the underlying potential mechanisms. Cell transfection and qRT-PCR were used to change and measure the expression levels of HULC, miR-130b, and FOXM1. Cell viability, migration, invasion, and apoptosis were assessed using trypan blue staining assay, MTT assay, two-chamber transwell assay, Guava Nexin assay, and western blotting. The concentrations of prolactin (PRL) and growth hormone (GH) in culture supernatant of GH3 cells were assessed using ELISA. The targeting relationship between miR-130b and FOXM1 was verified using dual luciferase activity. Finally, the expression levels of key factors involved in PI3K/AKT/mTOR and JAK1/STAT3 pathways were evaluated using western blotting. We found that HULC was highly expressed in GH3 cells. Overexpression of HULC promoted GH3 cell viability, migration, invasion, PRL and GH secretion, as well as activated PI3K/AKT/mTOR and JAK1/STAT3 pathways. Knockdown of HULC had opposite effects and induced cell apoptosis. HULC negatively regulated the expression of miR-130b, and miR-130b participated in the effects of HULC on GH3 cells. FOXM1 was a target gene of miR-130b, which was involved in the regulation of GH3 cell viability, migration, invasion, and apoptosis, as well as PI3K/AKT/mTOR and JAK1/STAT3 pathways. In conclusion, HULC tumor-promoting roles in secreting pituitary adenoma might be via down-regulating miR-130b, up-regulating FOXM1, and activating PI3K/AKT/mTOR and JAK1/STAT3 pathways.