Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA.
Developmental Therapeutics Branch, Laboratory of Molecular Pharmacology, CCR, NCI, NIH, Bethesda, Maryland, USA.
Mol Cell Biol. 2020 Oct 13;40(21). doi: 10.1128/MCB.00224-20.
Differentiation status of tumors is correlated with metastatic potential and malignancy. FOXA1 (forkhead box A1) is a transcription factor known to regulate differentiation in certain tissues. Here, we investigate function in human colorectal cancer (CRC). We found that FOXA1 is robustly expressed in the normal human colon but significantly downregulated in colon adenocarcinoma. Applying FOXA1 chromatin immunoprecipitation coupled with deep sequencing and transcriptome analysis upon knockdown in well-differentiated CRC cells and FOXA1 overexpression in poorly differentiated CRC cells, we identified novel protein-coding and lncRNA genes regulated by FOXA1. Among the numerous novel FOXA1 targets we identified, we focused on , a tumor marker and facilitator of cell adhesion. We show that FOXA1 binds to a distal enhancer downstream of and strongly activates its expression. Consistent with these data, we show that FOXA1 inhibits anoikis in CRC cells. Collectively, our results uncover novel protein-coding and noncoding targets of FOXA1 and suggest a vital role of FOXA1 in enhancing expression and anoikis resistance in CRC cells.
肿瘤的分化状态与转移潜能和恶性程度相关。FOXA1(叉头框转录因子 A1)是一种已知能调节特定组织分化的转录因子。在这里,我们研究了 FOXA1 在人结直肠癌(CRC)中的功能。我们发现,FOXA1 在正常的人结肠中强烈表达,但在结肠腺癌中显著下调。在分化良好的 CRC 细胞中进行 FOXA1 染色质免疫沉淀结合深度测序和转录组分析,并在分化不良的 CRC 细胞中进行 FOXA1 过表达后,我们鉴定出了受 FOXA1 调控的新型蛋白编码基因和 lncRNA 基因。在我们鉴定出的众多新型 FOXA1 靶基因中,我们重点关注了 ,它是一种肿瘤标志物和细胞黏附的促进因子。我们表明 FOXA1 与 下游的一个远端增强子结合,并强烈激活其表达。与这些数据一致的是,我们表明 FOXA1 抑制 CRC 细胞的失巢凋亡。总的来说,我们的结果揭示了 FOXA1 的新型蛋白编码和非编码靶基因,并提示 FOXA1 在增强 CRC 细胞中 的表达和抗失巢凋亡方面发挥着重要作用。