Cytoskeleton and Cell Plasticity Lab, Life Sciences Research Unit-FSTC, University of Luxembourg, Luxembourg.
Oncogene. 2010 Aug 5;29(31):4436-48. doi: 10.1038/onc.2010.181. Epub 2010 Jun 14.
Epithelial to mesenchymal transition (EMT) is a key step toward metastasis. MCF7 breast cancer cells conditionally expressing the EMT master regulator SNAI1 were used to identify early expressed microRNAs (miRNAs) and their targets that may contribute to the EMT process. Potential targets of miRNAs were identified by matching lists of in silico predicted targets and of inversely expressed mRNAs. MiRNAs were ranked based on the number of predicted hits, highlighting miR-661, a miRNA with so far no reported role in EMT. MiR-661 was found required for efficient invasion of breast cancer cells by destabilizing two of its predicted mRNA targets, the cell-cell adhesion protein Nectin-1 and the lipid transferase StarD10, resulting, in turn, in the downregulation of epithelial markers. Reexpression of Nectin-1 or StarD10 lacking the 3'-untranslated region counteracted SNAI1-induced invasion. Importantly, analysis of public transcriptomic data from a cohort of 295 well-characterized breast tumor specimen revealed that expression of StarD10 is highly associated with markers of luminal subtypes whereas its loss negatively correlated with the EMT-related, basal-like subtype. Collectively, our non-a priori approach revealed a nonpredicted link between SNAI1-triggered EMT and the down-regulation of Nectin-1 and StarD10 through the up-regulation of miR-661, which may contribute to the invasion of breast cancer cells and poor disease outcome.
上皮间质转化(EMT)是转移的关键步骤。MCF7 乳腺癌细胞条件性表达 EMT 主调控因子 SNAI1,用于鉴定可能有助于 EMT 过程的早期表达的 microRNAs(miRNAs)及其靶标。通过匹配计算机预测靶标和反义表达 mRNA 的列表来鉴定 miRNA 的潜在靶标。根据预测命中的数量对 miRNA 进行排序,突出显示 miR-661,这是一种 miRNA,迄今为止在 EMT 中没有报道过作用。miR-661 通过使两个预测的 mRNA 靶标,细胞间粘附蛋白 Nectin-1 和脂质转移酶 StarD10 的稳定性降低,从而有效地破坏了乳腺癌细胞的侵袭性,从而导致上皮标志物的下调。Nectin-1 或缺少 3'-非翻译区的 StarD10 的重新表达可逆转 SNAI1 诱导的侵袭。重要的是,对 295 个特征明确的乳腺癌肿瘤标本的公共转录组数据的分析表明,StarD10 的表达与腔型标志物高度相关,而其缺失与 EMT 相关的基底样型负相关。总之,我们的非先验方法揭示了 SNAI1 触发的 EMT 与 Nectin-1 和 StarD10 的下调之间的非预测性联系,这可能有助于乳腺癌细胞的侵袭和不良的疾病结局。