ABSTRACT
@#Objective To investigate the effects of long non-coding RNA(LncRNA) growth arrest specific transcript 5(GAS5) negatively regulating nucleophosmin 1(NPM1) on cisplatin(DDP) resistance of gastric cancer cells.Methods The normal human gastric mucosa cell line GES-1 and human gastric cancer cell lines BG3-823,MGC-803 and AGS were selected as the research objects,of which the level of LncRNA GAS5 in each cell was measured by qRT-PCR.The drug resistance of AGS cells to DDP(AGS/DDP) was induced,and the experiment was divided into control group,empty plasmid group(BC group),GAS5 nonsense interference group(pLJM-GAS5 NC group) and GAS5 overexpression group(pLJM-GAS5 group).MTT method was used to determine the effect of DDP on the proliferation of AGS and AGS/DDP cells;and the levels of NPM1,multidrug resistance 1(MDR1),excision repair cross complementation group 1(ERCC1),multidrug resistance-associated protein 1(MRP1) and N-cadherin in AGS and AGS/DDP cells were measured by Western blot.Results Compared with the normal gastric mucosa GES-1 cells,the level of LncRNA GAS5 in BG3-823 and AGS cells decreased significantly,and among them,the level of LncRNA GAS5 in AGS cells was the lowest,so AGS cells were used for the follow-up experiments.Compared with the control group,the level of LncRNA GAS5 in AGS cells of BC group and pLJM-GAS5 NC group decreased significantly,while the levels of NPM1,MDRl,ERCC1,MRP1 and N-cadherin increased significantly;compared with BC group and pLJM-GAS5 NC group,the level of LncRNA GAS5 in AGS/DDP cells of pLJM-GAS5 group increased significantly,while the levels of NPM1,MDR1,ERCC1,MRP1 and N-cadherin decreased significantly;after treatment with DDP of the same concentration(except 0 μmol/L),compared with the control group,the inhibition rate of AGS/DDP cell proliferation in BC group and pLJM-GAS5 NC group decreased significantly;compared with BC group and pLJM-GAS5 NC group,the inhibition rate of AGS/DDP cell proliferation in pLJM-GAS5group was significantly higher.The semi inhibitory concentration(IC_(50)) of DDP on AGS/DDP cells in pLJM-GAS5 group for 48 h was(65.38±5.04) μmol/L,which was significantly lower than(120.74±4.17) μmol/L and(120.24±4.29) μmol/L in BC group and pLJM-GAS5 NC group.Conclusion Up-regulating the level of LncRNA GAS5 in AGS/DDP cells can reverse the drug resistance of AGS/DDP cells,which may be related to the down-regulation of NPM1expression
ABSTRACT
Objective: To investigate the effect of nucleophosmin 1 (NPM1) mutant A on TGF-β1-induced K562 cell proliferation and AKT phosphorylation. Methods: K562 cells were infected with Ad5-NPM1 to create an NPM1 over-expression cell model. NPM1 levels were determined by ELISA and Western blot analysis. The levels of AKT and P-AKT were determined by Western blot. MTT was used to measure the proliferation of K562 cells. Results: NPM1 protein levels in K562 cells increased in an Ad5-NPM1-MOI-dependent manner. Cell proliferation and NPM1 levels in the supernatant were significantly increased in K562 cells infected with Ad5-NPM1-30 and Ad5-NPM1-100 compared to those infected with Ad5-vector-100 (P<0.01). Treatment with (10 ng/mL) TGF-β1 increased P-AKT levels, but not total AKT levels in K562 cells. TGF-β1-induced phosphorylation of AKT was significantly increased by infection of K562 cells with Ad5-NPM1-100. No significant differences were found in total AKT levels among all groups. TGF-β1 (10 ng/mL) treatment also in-creased the proliferation of K562 cells. TGF-β1-induced K562 cell proliferation was significantly increased by infection with Ad5-NPM1-100 (P<0.01). Conclusions: NPM1 improves TGF-β1-induced cell proliferation by up-regulating AKT phosphorylation levels.