Department of Obstetrics and Gynaecology, University of Melbourne, RWH Campus, 20 Flemington Rd., Parkville, Victoria 3052, Australia.
Am J Pathol. 2010 Jan;176(1):278-87. doi: 10.2353/ajpath.2010.090187. Epub 2009 Dec 11.
Fetal growth restriction (FGR), a clinically significant pregnancy disorder, is poorly understood at the molecular level. This study investigates idiopathic FGR associated with placental insufficiency. Previously, we showed that the homeobox gene HLX is expressed in placental trophoblast cells and that HLX expression is significantly decreased in human idiopathic FGR. Here, we used the novel approach of identifying downstream targets of HLX in cell culture to detect potentially important genes involved in idiopathic FGR. Downstream targets were revealed by decreasing HLX expression in cultured trophoblast cells with HLX-specific small interfering RNAs to model human idiopathic FGR and comparing these levels with controls using a real-time PCR-based gene profiling system. Changes in candidate HLX target mRNA levels were verified in an independent trophoblast cell line, and candidate target gene expression was assessed in human idiopathic FGR-affected placentae (n = 25) compared with gestation-matched controls (n = 25). The downstream targets RB1 and MYC, cell cycle regulatory genes, showed significantly increased mRNA levels in FGR-affected tissues compared with gestation-matched controls, whereas CCNB1, ELK1, JUN, and CDKN1 showed significantly decreased mRNA levels (n = 25, P < 0.001, t-test). The changes for RB1 and CDKN1C were verified by Western blot analysis in FGR-affected placentae compared with gestation-matched controls (n = 6). We conclude that cell cycle regulatory genes RB1, MYC, CCNB1, ELK1, JUN, and CDKN1C, which control important trophoblast cell functions, are targets of HLX.
胎儿生长受限（FGR）是一种临床意义重大的妊娠疾病，其在分子水平上的机制尚不清楚。本研究探讨了与胎盘功能不全相关的特发性 FGR。先前，我们发现同源盒基因 HLX 在胎盘滋养层细胞中表达，并且在人类特发性 FGR 中 HLX 的表达显著降低。在这里，我们使用鉴定 HLX 在细胞培养物中的下游靶标的新方法，以检测与特发性 FGR 相关的潜在重要基因。通过用 HLX 特异性小干扰 RNA 降低培养的滋养层细胞中的 HLX 表达来模拟人类特发性 FGR，并使用基于实时 PCR 的基因表达谱系统将这些水平与对照进行比较，从而揭示下游靶标。在独立的滋养层细胞系中验证候选 HLX 靶标 mRNA 水平的变化，并在与妊娠相匹配的对照组（n = 25）中评估候选靶基因在特发性 FGR 胎盘组织中的表达（n = 25）。与妊娠相匹配的对照组相比，细胞周期调节基因 RB1 和 MYC 的下游靶标 mRNA 水平在 FGR 组织中显著增加，而 CCNB1、ELK1、JUN 和 CDKN1 的 mRNA 水平显著降低（n = 25，P < 0.001，t 检验）。在 FGR 组织与妊娠相匹配的对照组相比，通过 Western blot 分析验证了 RB1 和 CDKN1C 的变化（n = 6）。我们得出结论，细胞周期调节基因 RB1、MYC、CCNB1、ELK1、JUN 和 CDKN1C 是 HLX 的靶标，它们控制重要的滋养层细胞功能。
