Intrahepatic cholangiocarcinoma (iCCA) is a subtype of CCA and has a high mortality rate and a relatively poor prognosis. However, studies focusing on increased cell motility and loss of epithelial integrity during iCCA progression remain relatively scarce. We collected seven fresh tumor samples from four patients to perform RNA sequencing (RNA-seq) and assay for transposase-accessible chromatin using sequencing (ATAC-seq) to determine the transcriptome profile and chromatin accessibility of iCCA. The increased expression of cell cycle regulators, including PLK1 and its substrate MISP, was identified. Ninety-one iCCA patients were used to validate the clinical significance of PLK1 and MISP. The upregulation of PLK1 and MISP was determined in iCCA tissues. Increased expression of PLK1 and MISP was significantly correlated with tumor number, N stage, and lymphatic invasion in an iCCA cohort. Knockdown of PLK1 or MISP reduced trans-lymphatic endothelial migration and wound healing and affected focal adhesions in vitro. In cell‒cell junctions, MISP localized to adherens junctions and suppressed E-cadherin dimerization. PLK1 disrupted adherens junctions in a myosin-dependent manner. Furthermore, PLK1 and MISP promoted cell proliferation in vitro and tumorigenesis in vivo. In iCCA, PLK1 and MISP promote aggressiveness by increasing lymphatic invasion, tumor growth, and motility through the repression of E-cadherin adherens junctions.

肝内胆管癌（iCCA）是CCA的一个亚型，死亡率较高，预后较差。然而，针对 iCCA 进展过程中细胞运动性增加和上皮完整性丧失的研究仍然相对较少。我们从 4 名患者那里收集了 7 份新鲜肿瘤样本，进行 RNA 测序 (RNA-seq)，并使用测序 (ATAC-seq) 检测转座酶可及染色质，以确定 iCCA 的转录组谱和染色质可及性。细胞周期调节因子（包括 PLK1 及其底物 MISP）的表达增加已被确定。使用 91 名 iCCA 患者来验证 PLK1 和 MISP 的临床意义。在 iCCA 组织中确定了 PLK1 和 MISP 的上调。在 iCCA 队列中，PLK1 和 MISP 表达的增加与肿瘤数量、N 分期和淋巴侵袭显着相关。PLK1 或 MISP 的敲低可减少跨淋巴内皮迁移和伤口愈合，并影响体外粘着斑。在细胞-细胞连接中，MISP 定位于粘附连接并抑制 E-钙粘蛋白二聚化。PLK1 以肌球蛋白依赖性方式破坏粘附连接。此外，PLK1和MISP在体外促进细胞增殖，在体内促进肿瘤发生。在 iCCA 中，PLK1 和 MISP 通过抑制 E-钙粘蛋白粘附连接来增加淋巴侵袭、肿瘤生长和运动，从而促进侵袭性。