肿瘤细胞从原发灶脱离是肝细胞癌(HCC)转移的早期事件,其中细胞粘附分子起着重要作用。机械拥挤的作用越来越引起人们的关注。先前的研究发现,过度拥挤可以诱导活细胞挤压以维持上皮细胞稳态,通常,活的挤压细胞最终会通过称为“失巢”的过程死亡,提示肿瘤细胞对失巢凋亡具有抗性,可能会通过细胞挤出引发原发肿瘤的转移。我们已经证明跨膜粘附分子血管心外膜物质(BVES)抑制是HCC转移的早期事件。然而,其抑制是否与肝癌细胞挤压有关,特别是在肝癌转移中,仍然未知。本研究旨在探讨BVES在肿瘤细胞挤压在肝癌转移中的作用,以及潜在的机制。
通过硅胶室观察到细胞挤出,培养皿倒置,和三维细胞培养模型。聚合酶链反应,西方印迹,免疫组织化学,免疫荧光,免疫共沉淀,和RhoA活性测定用于探索BVES调节细胞挤压的潜在机制。建立了原位异种移植模型,以研究BVES和细胞挤出在体内HCC转移中的作用。
在HCC细胞和组织中观察到肿瘤细胞挤出。BVES在HCC和挤压肿瘤细胞中的表达均降低。BVES过表达导致体外和体内HCC细胞挤出减少。此外,我们的数据显示,BVES与ZO-1和GEFT共同定位,调节ZO-1的表达和定位,和GEFT分布,从而调节RhoA活性。
本研究表明,肝癌中BVES下调增强了肿瘤细胞的挤压,从而促进HCC转移,这有助于更全面地了解肿瘤转移,并为开发新的HCC治疗策略提供了线索。视频摘要。
Tumor cells detachment from primary lesions is an early event for hepatocellular carcinoma (HCC) metastasis, in which cell adhesion molecules play an important role. The role of mechanical crowding has attracted increasing attention. Previous studies have found that overcrowding can induce live cells extrusion to maintain epithelial cell homeostasis, and normally, live extruded cells eventually die through a process termed anoikis, suggesting the potential of tumor cells resistant to anoikis might initiate metastasis from primary tumors by cell extrusion. We have demonstrated transmembrane adhesion molecule blood vessel epicardial substance (
BVES) suppression as an early event in HCC metastasis. However, whether its suppression is involved in HCC cell extrusion, especially in HCC metastasis, remains unknown. This study aims to investigate the role of
BVES in tumor cells extrusion in HCC metastasis, as well as the underlying mechanisms.
Cells extrusion was observed by silicone chamber, petri dish inversion, and three-dimensional cell culture model. Polymerase chain reaction, western blotting, immunohistochemistry, immunofluorescence, co-immunoprecipitation, and RhoA activity assays were used to explore the underlying mechanisms of cell extrusion regulated by BVES. An orthotopic xenograft model was established to investigate the effects of
BVES and cell extrusion in HCC metastasis in vivo.
Tumor cell extrusion was observed in HCC cells and tissues.
BVES expression was decreased both in HCC and extruded tumor cells.
BVES overexpression led to the decrease in HCC cells extrusion in vitro and in vivo. Moreover, our data showed that BVES co-localized with ZO-1 and GEFT, regulating ZO-1 expression and localization, and GEFT distribution, thus modulating RhoA activity.
The present study revealed that BVES downregulation in HCC enhanced tumor cells extrusion, thus promoting HCC metastasis, which contributed to a more comprehensive understanding of tumor metastasis, and provided clues for developing novel HCC therapy strategies. Video abstract.