TY - JOUR AB - Circular RNA (circRNA) circ_POLA2 is an oncogene in lung and cervical cancers. However, the role of circ_POLA2 in other types of cancer is unknown. The present study investigated the role of circ_POLA2 in endometrial cancer (EC). The mRNA expression levels of circ_POLA2 and microRNA (miR)‑31 in EC and paired adjacent normal tissues were analyzed using reverse transcription‑quantitative (RT‑qPCR). Overexpression of circ_POLA2 was achieved in the EC cell lines, and its effects on miR‑31 mRNA expression level and methylation were evaluated using RT‑qPCR and methylation‑specific PCR (MSP), respectively. Cell proliferation was assessed using a Cell Counting Kit‑8 assay. The results indicated that circ_POLA2 was highly expressed in EC tissue and inversely correlated with miR‑31 mRNA expression level. MSP analysis showed that circ_POLA2 overexpression increased miR‑31 methylation and RT‑qPCR analysis showed that circ_POLA2 overexpression decreased miR‑31 mRNA expression level. Furthermore, circ_POLA2 overexpression also increased EC cell proliferation, while miR‑31 overexpression decreased cell proliferation. Finally, circ_POLA2 overexpression reduced the effects of miR‑31 overexpression. In conclusion, circ_POLA2 may increase miR‑31 methylation of miR‑31 in EC cells to promote cancer cell proliferation. AD - Department of Gynecology, Beilun District People's Hospital, Ningbo, Zhejiang 315800, P.R. China Department of Neurology, Beilun District People's Hospital, Ningbo, Zhejiang 315800, P.R. China AU - Fang,Xia AU - Wang,Jinhua AU - Chen,Lingying AU - Zhang,Xiaochun DA - 2021/11/01 DO - 10.3892/ol.2021.13023 IS - 5 JO - Oncol Lett KW - circ_POLA2 miR‑31 endometrial cancer methylation proliferation PY - 2021 SN - 1792-1074 1792-1082 SP - 762 ST - circRNA circ_POLA2 increases microRNA‑31 methylation to promote endometrial cancer cell proliferation T2 - Oncology Letters TI - circRNA circ_POLA2 increases microRNA‑31 methylation to promote endometrial cancer cell proliferation UR - https://doi.org/10.3892/ol.2021.13023 VL - 22 ER -