Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, and Department of Obstetrics and Gynecology at Harbor-UCLA Medical Center, Torrance, California.
Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, and Department of Obstetrics and Gynecology at Harbor-UCLA Medical Center, Torrance, California.
Fertil Steril. 2021 Jan;115(1):238-247. doi: 10.1016/j.fertnstert.2020.07.024. Epub 2020 Oct 15.
To determine the expression and functional roles of a long noncoding RNA (lncRNA) X-inactive specific transcript (XIST) in leiomyoma.
Experimental study.
Academic research laboratory.
PATIENT(S): Women undergoing hysterectomy for leiomyoma.
INTERVENTION(S): Overexpression and underexpression of XIST; blockade of specific protein 1 (SP1).
MAIN OUTCOME MEASURE(S): Expression of XIST in leiomyoma and its effects on microRNA 29c (miR-29c), miR-200c, and their targets.
RESULT(S): Leiomyoma expressed statistically significantly more XIST as compared with matched myometrium, independent of race/ethnicity and menstrual cycle phase. By use of a three-dimensional spheroid culture system, we found reduced XIST levels in leiomyoma smooth muscle cells (LSMC) after treatment with 17β-estradiol, progesterone, and their combination. The expression of XIST was down-regulated by treatment with the SP1-inhibitor mithramycin A and SP1 small interfering RNA. Knockdown of XIST resulted in inhibition of cell proliferation, up-regulation of miR-29c and miR-200c, and a concomitant inhibition of the target genes of these miRNAs, namely collagen type I (COL1A1), collagen type III (COL3A1), and fibronectin (FN1). By contrast, overexpression of XIST in myometrium smooth muscle cells repressed miR-29c and miR-200c, and induced COL1A1, COL3A1, and FN1 levels. By use of RNA immunoprecipitation analysis we confirmed XIST has sponge activity over miR-29c and miR-200c, which is more pronounced in leiomyoma as compared with myometrium.
CONCLUSION(S): Our data demonstrate that increased expression of XIST in leiomyoma results in reduced expression of miR-29c and miR-200c with a consequent up-regulation of the genes targeted by these microRNAs including COL1A1, COL3A1, and FN1, which play key roles in extracellular matrix accumulation associated with fibroids.
确定长非编码 RNA（lncRNA）X 失活特异性转录物（XIST）在子宫肌瘤中的表达和功能作用。
实验研究。
学术研究实验室。
因子宫肌瘤接受子宫切除术的女性。
XIST 的过表达和低表达；特异性蛋白 1（SP1）的阻断。
子宫肌瘤中 XIST 的表达及其对 microRNA 29c（miR-29c）、miR-200c 及其靶标的影响。
与匹配的子宫肌层相比，子宫肌瘤表达的 XIST 统计学上显著增加，而与种族/民族和月经周期阶段无关。通过使用三维球体培养系统，我们发现子宫肌瘤平滑肌细胞（LSMC）在 17β-雌二醇、孕酮及其组合处理后 XIST 水平降低。XIST 的表达通过 SP1 抑制剂米托蒽醌 A 和 SP1 小干扰 RNA 的处理而下调。XIST 的敲低导致细胞增殖抑制、miR-29c 和 miR-200c 的上调，以及这些 miRNA 的靶基因即胶原 I 型（COL1A1）、胶原 III 型（COL3A1）和纤连蛋白（FN1）的抑制。相比之下，在子宫肌层平滑肌细胞中过表达 XIST 抑制了 miR-29c 和 miR-200c，并诱导了 COL1A1、COL3A1 和 FN1 水平。通过 RNA 免疫沉淀分析，我们证实 XIST 对 miR-29c 和 miR-200c 具有海绵活性，在子宫肌瘤中比在子宫肌层中更为明显。
我们的数据表明，子宫肌瘤中 XIST 的表达增加导致 miR-29c 和 miR-200c 的表达降低，从而导致这些 microRNA 靶向的基因包括 COL1A1、COL3A1 和 FN1 的上调，这些基因在与纤维瘤相关的细胞外基质积累中发挥关键作用。
