Micro RNA-451 down-regulates glucose transporter-1 to affect LN229 glioma cells invasion and migration

Abstract

Objective To explore the expression levels of chemokine (C-C motif) ligand 18 (CCL18) in human glioma tissues and its effects on the invasion, migration and proliferation of glioma cells. Methods (1) Sixty samples were harvested from the glioma which was excised surgically and confirmed pathologically from the patients at the Department of Neurosurgery, Affiliated Hospital to Binzhou Medical College from January 2012 to December 2017. Of the samples, by the WHO grading, 26 belonged to grade II, 18 to grade III and 16 to grade IV. Ten samples of normal brain tissue were harvested as controls from the contemporary patients who underwent intracranial decompression and excision due to brain injury. CCL18 mRNA expression was determined by real-time RT-PCR and CCL18 protein expression in tumor cells by immunochemically histological staining. (2) U251 glioma cells cultured in vitro were incubated with CCL18 serum-free culture media (0 ng/mL, 5 ng/mL and 10 ng/mL) for 24 h before they were subjected to Transwell, scarification and CCK-8 assays to measure cellular invasion, migration and proliferation. Results (1) The expression of CCL18 mRNA was significantly increased in the order from normal brain, glioma of grade II, glioma of grade III to glioma of grade IV (P<0.05); the expression of CCL18 protein was significantly increased in the order from glioma of grade II, glioma of grade III to glioma of grade IV (P<0.05). (2) The 24 h Transwell assay for invasion showed that the number of transmembrane cells was significantly increased in the order from 0 ng/mL group to 5 ng/mL group to 10 ng/mL group (43.5±8.3, 202.0±18.5 and 279.7±18.6 cells) (P<0.05). The widths of scratch (pixels) in the scarification assay for migration were 498.4±75.3, 381.3±21.4 and 347.7±14.2 at 12 h, and 299.5±15.3, 284.6±7.8 and 237.3±20.6 at 24 h, respectively, showing significant differences between the groups of 0 ng/mL, 5 ng/mL and 10 ng/mL recombinant CCL18 (P<0.05). The cell growth in CCK-8 assay for proliferation was 1.000±0.019, 1.260±0.094 and 2.070±0.138 fold at 24 h, respectively, also showing significant differences between the groups of 0 ng/mL, 5 ng/mL and 10 ng/mL recombinant CCL18 (P<0.05). Conclusions Expression of CCL18 in glioma is associated with the malignancy of the tumor. As CCL18 promotes invasion, migration and proliferation of glioma cells, it may be a potential biomarker for detecting and grading human glioma. Key words: Glioma; Chemokine CC-motif ligand18; Invasion; Immigration; Proliferation