LncRNA TMPO-AS1 suppresses the maturation of miR-335-5p to participate in polycystic ovary syndrome

BACKGROUND: TMPO-AS1 is a recently characterized oncogenic lncRNA in ovarian cancer. Its role in other ovary diseases is unknown. This study explored its role in polycystic ovary syndrome (PCOS). METHODS: Follicular fluid was extracted from both PCOS patients and controls. The levels of TMPO-AS1 and mature and premature miR-335-5p were analyzed by RT-qPCR. The role of TMPO-AS1 in regulating miR-355-5p maturation in granulosa-like tumor (KGN) cells was analyzed by overexpression experiments. The interaction between TMPO-AS1 and premature miR-335-5p was analyzed by RNA pull-down assay. The subcellular location of TMPO-AS1 in KGN cells was analyzed by nuclear fractionation assay. The role of TMPO-AS1 and miR-335-5p in KGN cell proliferation was analyzed by BrdU assay. RESULTS: TMPO-AS1 was increased in PCOS, while mature miR-355-5p was decreased in PCOS. TMPO-AS1 overexpression decreased mature miR-355-5p level but increased premature miR-355-5p. TMPO-AS1 was localized in both nucleus and cytoplasm. TMPO-AS1 directly interacted with premature miR-355-5p in KGN cells. TMPO-AS1 increased KGN cell proliferation while miR-355-5p decreased cell proliferation. The co-transfection assay showed that TMPO-AS1 reduced the suppressive effects of miR-355-5p on cell proliferation. CONCLUSIONS: TMPO-AS1 might suppress miR-335-5p maturation to participate in PCOS.