Long non-coding RNA BRCAT54 sponges microRNA-21 in vestibular schwannoma to suppress cell proliferation

BRCAT54 (also known as MRPS30 divergent transcript) is an anti-tumor long non-coding RNA (lncRNA) in lung cancer, while its role in vestibular schwannoma (VS) is unclear. We predicted that BRCAT54 could interact with microRNA (miR)-21, which suppresses VS cell proliferation. This study was then carried out to study the interaction between BRCAT54 and miR-21 in VS. A total of 56 VS samples and 42 normal vestibular nerve (VN) samples were included in this study. The expression of BRCAT54 and miR-21 in these samples were analyzed with RT-qPCR. Subcellular location of BRCAT54 in primary VS cells was analyzed by subcellular fractionation assay. The direct interaction between BRCAT54 and miR-21 was analyzed through RNA pull-down assay. Overexpression assay was performed to explore the interaction between BRCAT54 and miR-21. The role of BRCAT54 and miR-21 in primary VS cell proliferation was analyzed using BrdU assay. We found that BRCAT54 was downregulated in VS samples than that in VN samples, while miR-21 was upregulated in VS samples. BRCAT54 and miR-21 were not closely correlated. BRCAT54 was detected in both nuclear and cytoplasm samples, and BRCAT54 directly interacted with miR-21. However, BRCAT54 and miR-21 did not affect the expression of each other. BRCAT54 suppressed primary VS cell proliferation and inhibited the role of miR-21 in promoting cell proliferation. Therefore, BRCAT54 may sponge miR-21 to suppress cell proliferation in VS.