Abstract:

Objective To analyze the expression differences of ANXA1 mRNA and protein between glio⁃ blastoma and normal brain tissue，and the relationship between ANXA1 expression in glioblastoma and prognosis of glioblastoma patients，and to investigate the effects of ANXA1 on the proliferation，migration，invasion and apoptosis of glioblastoma cell lines in vitro. Methods （1）The expression of glioblastoma tissues and normal brain tissues and corresponding clinical data were obtained from public databases. The difference of ANXA1 mRNA expression between glioblastoma tissues and normal brain tissues，and the difference of survival time of glioblastoma patients between high and low ANXA1 mRNA expression groups were compared.（2）The localization of ANXA1 protein in U251 cells was obtained from the Human Protein Atlas Public database. The expression of ANXA1 pro⁃ tein in glioblastoma tissues and adjacent tissues was detected by immunohistochemistry.（3）Glioblastoma cell lines U87 and U251 were cultured in vitro，and ANXA1⁃ siRNA knockdown ANXA1 gene expression was constructed and transferred into U87 and U251 cells. qRT⁃PCR and western blotting were used to detect mRNA and protein expression. Cell counting kit（CCK⁃8），Transwell and flow cytometry were used to detect cell proliferation，cell migration and invasion，and cell apoptosis，respectively. Results （1）ANXA1 mRNA expression was significantly up⁃regulated in glioblastoma tissues in TCGA，Rembrandt and GSE16011 cohorts，showing statistical significance （P<0.05）. In addition，the overall survival time of patients with high ANXA1 mRNA expression was significantly lower than that of patients with low ANXA1 mRNA expression in all the three cohorts（P<0.001）.（2）qRT ⁃PCR and western blotting showed that compared with that in the negative control group，the expression level of ANXA1 in the ANXA1⁃siRNA group was significantly decreased，and the difference was statistically significant（P<0.001）. （3）CCK ⁃8 detection results showed that after knockdown of ANXA1 expression，the proliferation ability of U87 and U251 cells was significantly lower than that of negative control group，and the difference was statistically significant（P<0.001）. Transwell cell migration assay showed that the migration of U87 and U251 cells was lower than that of corresponding negative control group after knockdown of ANXA1 expression（experimental group： （25.40 ± 2.70），（11.20 ± 4.44）；negative control group：（55.20 ± 8.70），（32.20 ± 8.11）and invasion［experi⁃ mental group：（19.60 ± 3.21），（12.80 ± 4.66）；negative control group：（43.40 ± 5.13），（38.6 ± 7.37）］were significantly lower than those of the negative control group，indicating statistical significance（P < 0.001）. The results of flow cytometry showed that the apoptotic cells（11.84 ± 2.50）% and（29.96 ± 2.57）% in the U87 and U251 cell groups were significantly higher than those in the corresponding negative control group（7.42 ± 2.56）% and（18.39 ± 1.89）%，and the differences were statistically significant（P<0.05）. Conclusion ANXA1 is up⁃ regulated in glioblastoma tissues and is associated with poor prognosis. Down⁃regulation of ANXA1 gene expression can inhibit the proliferation，migration and invasion of glioblastoma cells，and promote the apoptosis of glioblastoma cells.

Key words:

ANXA1, glioma, survival prognosis, gene expression