Department of Gastroenterology, Central Clinical School, Monash University, Melbourne, VIC, Australia.
Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-City, Osaka, Japan.
Commun Biol. 2023 Nov 24;6(1):1191. doi: 10.1038/s42003-023-05562-y.
Circulating tumor cells (CTCs) play an important role in metastasis and recurrence. However, which cells comprise the complex tumor lineages in recurrence and are key in metastasis are unknown in colorectal cancer (CRC). CRC with high expression of POU5F1 has a poor prognosis with a high incidence of liver metastatic recurrence. We aim to reveal the key cells promoting metastasis and identify treatment-resistant lineages with established EGFP-expressing organoids in two-dimensional culture (2DOs) under the POU5F1 promotor. POU5F1-expressing cells are highly present in relapsed clinical patients' blood as CTCs. Sorted POU5F1-expressing cells from 2DOs have cancer stem cell abilities and abundantly form liver metastases in vivo. Single-cell RNA sequencing of 2DOs identifies heterogeneous populations derived from POU5F1-expressing cells and the Wnt signaling pathway is enriched in POU5F1-expressing cells. Characteristic high expression of CTLA4 is observed in POU5F1-expressing cells and immunocytochemistry confirms the co-expression of POU5F1 and CTLA4. Demethylation in some CpG islands at the transcriptional start sites of POU5F1 and CTLA4 is observed. The Wnt/β-catenin pathway inhibitor, XAV939, prevents the adhesion and survival of POU5F1-expressing cells in vitro. Early administration of XAV939 also completely inhibits liver metastasis induced by POU5F1-positive cells.
循环肿瘤细胞 (CTCs) 在转移和复发中起着重要作用。然而，在结直肠癌 (CRC) 中，哪些细胞构成了复发中的复杂肿瘤谱系，哪些是转移的关键，目前尚不清楚。POU5F1 高表达的 CRC 预后不良，肝转移复发率高。我们旨在揭示促进转移的关键细胞，并在 POU5F1 启动子下的二维培养 (2DO) 中用已建立的 EGFP 表达类器官鉴定耐药谱系。POU5F1 表达细胞在复发的临床患者血液中作为 CTCs 高度存在。从 2DOs 中分选的 POU5F1 表达细胞具有癌症干细胞能力，并在体内大量形成肝转移。2DOs 的单细胞 RNA 测序鉴定了源自 POU5F1 表达细胞的异质群体，Wnt 信号通路在 POU5F1 表达细胞中富集。在 POU5F1 表达细胞中观察到 CTLA4 的特征性高表达，免疫细胞化学证实了 POU5F1 和 CTLA4 的共表达。在 POU5F1 和 CTLA4 的转录起始位点的一些 CpG 岛观察到去甲基化。Wnt/β-catenin 通路抑制剂 XAV939 可防止 POU5F1 表达细胞在体外的黏附和存活。早期给予 XAV939 也可完全抑制 POU5F1 阳性细胞诱导的肝转移。
