Role and mechanism of long non-coding RNA BANCR in astrocytoma

Abstract

Objective To explore the expression, role and mechanism of long non-coding RNA (lncRNA) BANCR in astrocytoma. Methods (1) Twenty-four astrocytoma tissues and 6 normal brain tissues were collected from patients accepted surgical resection and conformed by pathology in our hospital from January 2016 to September 2017; the mRNA expressions of BANCR and signal transduction and transcriptional activator 3 (STAT3) were detected by real-time quantitative(qRT)-PCR; the glioma dataset GSE4290 including astrocytomas were downloaded and BANCR expressions in GSE4290 were analyzed by the web software R2. (2) Astrocytoma cell line LN18, cultured in vitro were divided into short hairpin RNA (shBANCR) group, full-length BANCR (BANCR) group, shControl group and empty vector group; cells in these groups were transfected with recombinant lentiviruses packing genomes encoding short hairpin RNA (shBANCR), full-length BANCR (BANCR), or their corresponding controls (shControl and empty vector); BANCR and STAT3 mRNA expressions in the 4 groups were detected by qRT-PCR; the cell proliferation, migration and invasion, and apoptosis were detected by CCK-8 assay, Transwell assay and flow cytometry, respectively; Western blotting was employed to detect the protein expressions of STAT3, matrix metalloproteinase (MMP)2, MMP9 and mitogen-activated protein kinase (MAPK), and Akt pathway protein expression. (3) Astrocytoma cell line LN18 were divided into si398 group, si1265 group, negative control group I, and blank control group I; cells in the blank control group I were transfected with lipofectamine 2000, and cells in the other three groups were transfected with small interfering RNA si398, si1265 and negative control nonsense sequences targeting STAT3; 48 h after transfection, BANCR and STAT3 mRNA expressions were detected by qRT-PCR; Western blotting was employed to detect the STAT3 protein expression. Results (1) In collected samples and glioma dataset GSE4290: the BANCR mRNA expression in astrocytoma tissues was significantly decreased as compared with that in the normal brain tissues (P<0.05); a positive correlation was noted between BANCR and STAT3 mRNA expressions in astrocytomas (P<0.05). (2) As compared with the negative control group, the shBANCR group had significantly decreased BANCR mRNA expression, and the BANCR mRNA expression in the BANCR group was significantly increased as compared with that in the empty vector group (P<0.05); the number of migration and invasion cells in the shBANCR group was significantly larger as compared with that in the negative control group, and that in the BANCR group was significantly increased as compared with that in the empty vector group (P<0.05); the protein levels of MMP2, MMP9, phosphorylated (p)-extracellular regulated protein kinase and p-mitogen-activated protein kinase in the shBANCR group were significantly increased as compared with those in the negative control group, and those in the BANCR group was significantly increased as compared with those in the empty vector group (P<0.05). (3) As compared with negative control group I and blank control group I, si398 group and si1265 group had significantly decreased STAT3 and BANCR mRNA expressions and STAT3 protein expression (P<0.05). Conclusion The BANCR expression is decreased in astrocytoma; STAT3-induced BANCR can inhibit cell migration and invasion by modulating MMP2, MMP9 and MAPK signaling pathway in astrocytoma. Key words: Astrocytoma; Signal transduction and transcriptional activator 3; BANCR