Department of Obstetrics and Gynecology, University of Florida, Gainesville, FL 32610-0294, USA.
Endocr Relat Cancer. 2012 Jul 22;19(4):541-56. doi: 10.1530/ERC-12-0007. Print 2012 Aug.
MicroRNA-200c (miR-200c) through repression of specific target genes has been associated with cellular transition, tumorigenesis, and tissue fibrosis. We explored the expression and functional aspects of miR-200c in genesis of leiomyomas (LYO), benign uterine tumors with fibrotic characteristic. Using LYO and matched myometrium (MYO; n=76) from untreated and from patients exposed to hormonal therapies (GNRH agonist (GNRHa), Depo-Provera, and oral contraceptives), we found that miR-200c was expressed at significantly lower levels (P<0.05) in LYO as compared with MYO. These levels were lower in LYO from African Americans as compared with Caucasians, patients experiencing abnormal uterine bleeding and those exposed to GNRHa therapy. Gain-of-function of miR-200c in isolated leiomyoma smooth muscle cells (LSMCs), myometrial smooth muscle cells (MSMCs), and leiomyosarcoma cell line (SKLM-S1) repressed ZEB1/ZEB2 mRNAs and proteins, with concurrent increase in E-cadherin (CDH1) and reduction in vimentin expression, phenotypic alteration, and inhibition of MSMC and LSMC proliferations. We further validated TIMP2, FBLN5, and VEGFA as direct targets of miR-200c through interaction with their respective 3' UTRs, and other genes as determined by microarray analysis. At tissue levels, LYO expressed lower levels of TIMP2 and FBLN5 mRNAs but increased protein expressions, which to some extent altered due to hormonal exposure. Given the regulatory functions of ZEBs, VEGFA, FBLN5, and TIMP2 on cellular activities that promote cellular transition, angiogenesis, and matrix remodeling, we concluded that altered expression of miR-200c may have a significant impact on the outcome of LYO growth, maintenance of their mesenchymal and fibrotic characteristics, and possibly their associated symptoms.
微小 RNA-200c（miR-200c）通过抑制特定靶基因与细胞转化、肿瘤发生和组织纤维化有关。我们探讨了 miR-200c 在子宫肌瘤（LYO）发生中的表达和功能，LYO 是一种具有纤维化特征的良性子宫肿瘤。使用未经处理和接受激素治疗（促性腺激素释放激素激动剂（GNRHa）、Depo-Provera 和口服避孕药）的 LYO 和匹配的子宫肌层（MYO；n=76），我们发现 miR-200c 在 LYO 中的表达水平明显较低（P<0.05）与 MYO 相比。与白种人相比，非裔美国人的 LYO 中 miR-200c 的表达水平更低，异常子宫出血的患者和接受 GNRHa 治疗的患者也是如此。在分离的子宫肌瘤平滑肌细胞（LSMCs）、子宫平滑肌细胞（MSMCs）和 leiomyosarcoma 细胞系（SKLM-S1）中过表达 miR-200c 可抑制 ZEB1/ZEB2 mRNA 和蛋白质的表达，同时增加 E-钙粘蛋白（CDH1）的表达并降低波形蛋白的表达，导致表型改变，并抑制 MSMC 和 LSMC 的增殖。我们进一步通过与各自的 3'UTR 相互作用验证了 TIMP2、FBLN5 和 VEGFA 是 miR-200c 的直接靶标，并通过微阵列分析确定了其他基因。在组织水平上，LYO 表达较低水平的 TIMP2 和 FBLN5 mRNA，但蛋白质表达增加，这在一定程度上由于激素暴露而改变。鉴于 ZEBs、VEGFA、FBLN5 和 TIMP2 对促进细胞转化、血管生成和基质重塑的细胞活性的调节功能，我们得出结论，miR-200c 的表达改变可能对 LYO 生长、维持其间充质和纤维化特征以及可能与其相关症状产生重大影响。
