Analysis of alternative splicing pattern of ADAR2 pre-mRNA in human glioma cell lines / 中国肿瘤临床

ABSTRACT

Objective:This study aims to analyze the differences in the alternative splicing pattern of ADAR2 among glioma cell lines U87, U251, A172, and normal human astrocyte HA1800. Methods:A-to-I editing level at the Q/R-Site of GluR-2 was analyzed by RT-PCR and sequencing. Real-time PCR was performed to detect the expression level of each alternatively splicing variant using a specific primer that was confirmed to amplify only the targeted template and not other alternatively spliced variant fragments. Results:We verified that the Q/R-Site of GluR-2 is under-edited in glioma cell lines. Real-time PCR revealed that the ADAR2 pre-mRNA splic-ing pattern has no significant difference at exons 1a and 2 between glioma cell lines and normal human astrocyte. We also detected that the amount of alternative splicing variants, including exon 5a, was higher than that of alternative splicing variants not including exon 5a in human glioma cell lines. However, the expression of alternative splicing variants, including exon 5a, was lower than that of alterna-tive splicing variants not including exon 5a in human astrocyte. Conclusion:Evident differences in splicing were observed at the site of exon 5a between glioma cell lines and normal human astrocytes. The difference in the alternatively splicing pattern at exon 5a may be attributed to the decreased activity of ADAR2.