Long non-coding RNA BBOX1 antisense RNA 1 increases the apoptosis of granulosa cells in premature ovarian failure by sponging miR-146b

Long non-coding RNA (lncRNA) BBOX1 antisense RNA 1 (BBOX1-AS1) was reported to participate in ovarian cancer, while its role in other ovarian disorders is unclear. We speculated that BBOX1-AS1 could interact with microRNA(miR)-146b, which is involved in premature ovarian failure (POF). This study was therefore carried out to explore its role in POF. In this study, 60 patients with POF and 60 controls were enrolled. The expression of BBOX1-AS1 and miR-146b were analyzed by RT-qPCRs. The direct interaction between miR-146b and the wild type BBOX1-AS1 (BBOX1-AS1-WT) or mutant BBOX1-AS1 (BBOX1-AS1-mut) was explored with RNA-RNA pulldown assay. Subcellular location of BBOX1-AS1 in COV434 granulosa cells was detected by subcellular fractionation. The role of BBOX1-AS1 and miR-146b in the apoptosis of COV434 cells was evaluated by cell apoptosis assay. Overexpression assay was applied to explore the relationship between BBOX1-AS1 and miR-146b. We found that the expression levels of BBOX1-AS1 were increased, while the expression levels of miR-146b were decreased in POF patients. BBOX1-AS1-WT, but not BBOX1-AS1-mut, directly interacted with miR-146b. BBOX1-AS1 was detected in both nucleus and cytoplasm, while they did not affect the expression of each other. BBOX1-AS1 suppressed the role of miR-146b in cell apoptosis. Therefore, BBOX1-AS1 may increase the apoptosis of granulosa cells in POF by sponging miR-146b.