Department of Minimally Invasive Gynecologic Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100006, China.
Department of Urology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China.
Biomed Res Int. 2021 Feb 27;2021:8868700. doi: 10.1155/2021/8868700. eCollection 2021.
Several theories on the origin of adenomyosis (ADS) have been proposed, of which the most widely accepted is the fundamental pathogenic role of uterine eutopic endometrium. Emerging evidence suggests that circular RNAs participate in the multiple tumorgenesis. The vital importance of circular RNA PVT1 (circPVT1) in the pathological progress like malignancies has been well documented. Nevertheless, its underlying correlation with ADS remains elusive yet. The purpose of this study was to investigate the expression pattern, regulatory effect, and internal mechanism of circPVT1 in ADS. qRT-PCR was performed to detect the relative mRNA expression of circPVT1, miR-145, and Talin1 in ADS endometrial tissue and cells. The protein level of Talin1 was measured by Western blot and immunochemistry. Immunofluorescence was used to identify the primary endometrial epithelial and stromal cells. circPVT1 knockdown in vitro was achieved by transfecting with specific lentivirus vector CCK-8, and colony formation assays were utilized to assess cell proliferation; meanwhile, the transwell assay was employed for evaluating cell invasion ability. By conducting bioinformatics, dual-luciferase reporter assay, or RNA immunoprecipitation (RIP) experiment, the interaction between miR-145 and circPVT1 or Talin1 was verified. Rescue experiments further determined the regulatory effect of circPVT1/miR-145/Talin1 axis. We found both circPVT1 and Talin1 were markedly upregulated in ADS endometrial tissue and cells, whereas miR-145 was decreased. Elevated expression of circPVT1 was closely related to the severity of dysmenorrhea, menorrhagia, and uterine enlargement of patients with ADS. Knockdown of circPVT1 inhibited adenomyotic epithelial and stromal cell proliferation and invasion. Further mechanistic experiments revealed that circPVT1 negatively regulated miR-145 through serving as a molecular sponge. And the facilitating effect of circPVT1 was partially reversed by miR-145. Talin1 was demonstrated to be a down target of miR-145 and indirectly affected by circPVT1. Our findings unveiled that enhanced circPVT1 may be involved in the pathogenesis of ADS via stimulating endometrial cell proliferation and invasion. The establishment of circPVT1/miR-145/Talin1 pathway might present a novel therapeutic insight for ADS.
几种关于子宫腺肌病（ADS）的起源理论已经提出，其中最广泛接受的是子宫内异位内膜的基本致病作用。新出现的证据表明，环状 RNA 参与了多种肿瘤发生。环状 RNA PVT1（circPVT1）在恶性肿瘤等病理进展中的重要作用已经得到充分证实。然而，其与 ADS 的潜在相关性仍然难以捉摸。本研究旨在探讨 circPVT1 在 ADS 中的表达模式、调节作用和内在机制。qRT-PCR 用于检测 ADS 子宫内膜组织和细胞中 circPVT1、miR-145 和 Talin1 的相对 mRNA 表达。Western blot 和免疫组化法测定 Talin1 蛋白水平。免疫荧光法用于鉴定原发性子宫内膜上皮细胞和基质细胞。体外通过转染特异性慢病毒载体 CCK-8 实现 circPVT1 敲低，CCK-8 法测定细胞增殖，Transwell 法测定细胞侵袭能力。通过生物信息学、双荧光素酶报告基因检测或 RNA 免疫沉淀（RIP）实验验证 miR-145 与 circPVT1 或 Talin1 之间的相互作用。挽救实验进一步确定了 circPVT1/miR-145/Talin1 轴的调节作用。我们发现 ADS 子宫内膜组织和细胞中 circPVT1 和 Talin1 明显上调，而 miR-145 下调。circPVT1 的高表达与 ADS 患者痛经、月经过多和子宫增大的严重程度密切相关。circPVT1 敲低抑制了腺肌病上皮细胞和基质细胞的增殖和侵袭。进一步的机制实验表明，circPVT1 通过作为分子海绵负调控 miR-145。circPVT1 的促进作用部分被 miR-145 逆转。Talin1 是 miR-145 的下游靶标，并受 circPVT1 的间接影响。我们的研究结果表明，增强的 circPVT1 可能通过刺激子宫内膜细胞增殖和侵袭参与 ADS 的发病机制。circPVT1/miR-145/Talin1 通路的建立可能为 ADS 提供新的治疗思路。
