Department of Medical Biochemistry, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan.
EMBO J. 2023 Jul 17;42(14):e112614. doi: 10.15252/embj.2022112614. Epub 2023 Apr 25.
Tumor-initiating cells are major drivers of chemoresistance and attractive targets for cancer therapy, however, their identity in human pancreatic ductal adenocarcinoma (PDAC) and the key molecules underlying their traits remain poorly understood. Here, we show that a cellular subpopulation with partial epithelial-mesenchymal transition (EMT)-like signature marked by high expression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) is the origin of heterogeneous tumor cells in PDAC. We demonstrate that ROR1 depletion suppresses tumor growth, recurrence after chemotherapy, and metastasis. Mechanistically, ROR1 induces the expression of Aurora kinase B (AURKB) by activating E2F through c-Myc to enhance PDAC proliferation. Furthermore, epigenomic analyses reveal that ROR1 is transcriptionally dependent on YAP/BRD4 binding at the enhancer region, and targeting this pathway reduces ROR1 expression and prevents PDAC growth. Collectively, our findings reveal a critical role for ROR1high cells as tumor-initiating cells and the functional importance of ROR1 in PDAC progression, thereby highlighting its therapeutic targetability.
肿瘤起始细胞是化疗耐药的主要驱动因素,也是癌症治疗的有吸引力的靶点,然而,它们在人类胰腺导管腺癌 (PDAC) 中的身份以及它们特征背后的关键分子仍知之甚少。在这里,我们表明,具有部分上皮-间充质转化 (EMT) 样特征的细胞亚群,其特征是高表达受体酪氨酸激酶样孤儿受体 1 (ROR1),是 PDAC 中异质性肿瘤细胞的起源。我们证明 ROR1 的耗竭可抑制肿瘤生长、化疗后复发和转移。在机制上,ROR1 通过 c-Myc 激活 E2F 诱导 Aurora 激酶 B (AURKB) 的表达,从而增强 PDAC 的增殖。此外,表观基因组分析表明,ROR1 的转录依赖于 YAP/BRD4 在增强子区域的结合,靶向该途径可降低 ROR1 的表达并阻止 PDAC 的生长。总的来说,我们的研究结果揭示了 ROR1high 细胞作为肿瘤起始细胞的关键作用,以及 ROR1 在 PDAC 进展中的功能重要性,从而突出了其治疗靶点的可靶向性。