RESUMEN
Objective:To investigate the effects of mitochondrial arginyl-tRNA synthase (RARS2) on cell proliferation, invasion, migration and chemotherapy resistance of pancreatic cancer.Methods:Human pancreatic cancer cell lines AsPC-1 and PANC-1 were divided into negative control group, RARS2 interference group-1, RARS2 interference group-2, RARS2 overexpression control group and RARS2 overexpression group. Cell proliferation and sensitivity to gemcitabine were detected by CCK-8 assay, and cell invasion and migration were detected by Transwell assay. Western blot was used to detect the expression of RARS2 under different concentrations and different times of gemcitabine treatment. Western blot and PCR were used to detect the expression of RARS2 in gemcitabine-resistant AsPC cell.Results:Inhibition of RARS2 expression in AsPC-1 and PANC-1 cells significantly inhibited cell proliferation and enhanced sensitivity of gemcitabine to chemotherapy. Overexpression of RARS2 enhanced cell proliferation and decreased sensitivity to gemcitabine. In AsPC-1 cells, the number of migrated cells (100×) in negative control group, RARS2 interference group-1, RARS2 interference group-2, RARS2 overexpression control group and RARS2 overexpression group were (586.7±37.4) cells/field, (195.7±18.6) cells/field, (237.0±17.1) cells/field, (157.7±19.1) cells/field, (456.0±23.1) cells/field, the number of invasive cells were (87.7±13.2) cells/field, (24.7±6.5) cells/field, (31.7±6.1) cells/field, (29.3±4.5) cells/field, (94.3±9.3) cells/field, respectively. The migration and invasion ability of cells were decreased after the expression of RARS2 was decreased, and the migration and invasion ability of cells were enhanced after the expression of RARS2 was increased. PCR and Western blot assay showed that RARS2 expression in the gemcitabine-resistant AsPC-1 was higher than that in the common cell line. In AsPC-1 cells, the expression of RARS2 increased with increasing gemcitabine concentration and treatment time.Conclusion:RARS2 promotes cell proliferation, invasion, migration and chemoresistance of pancreatic cancer, and expression of RARS2 is positively correlated with gemcitabine concentration and treatment time.
RESUMEN
The expression changes of Rars gene in ischemia-injured neurons were investigated by detecting its translational product arginyl-tRNA synthetase (ArgRS), and the inhibitory effects of ischemic preconditioning (IPC) on Rars gene were explored. Both IPC model and prolonged ischemia (PI) model were established by using the classic oxygen glucose deprivation (OGD) method. The primary cultured neurons were assigned into the following groups: the experimental group (IPC+PI group), undergoing PI after a short period of IPC; the conditional control group (PI control group), subjected to PI without IPC; blank control group, the normally cultured neurons. The Rars transcriptional activities and ArgRS expression levels were measured at different time points after re-oxygenation (3 h/6 h/12 h/24 h). Data were collected and statistically analyzed. Compared to the blank control group, the Rars activities and ArgRS levels were significantly increased in PI control group, peaking at the time point of 6 h after re-oxygenation. Rars activities and ArgRS levels were significantly lower in the experimental group than in the PI control group at different time points after re-oxygenation. PI insult can induce an escalating activity of Rars and lead to ArgRS over-expression in primary cultured neurons. IPC can inhibit the increased Rars activity and down-regulate ArgRS expression of ischemia-insulted neurons. This mechanism may confer ischemic tolerance on neurons.