Vascular endothelial cells (VECs) are an integral component of the inner lining of blood vessels, and their functions are essential for the proper functioning of the vascular system. The tight junctions formed by VECs act as a significant barrier to the intravasation and extravasation of tumor cells (TCs). In addition to that, the proliferation, activation, and migration of VECs play a vital role in the growth of new blood vessels, a process known as tumor angiogenesis, which is closely related to the malignant progression of tumors. However, during tumor progression, VECs undergo endothelial-to-mesenchymal transition (EndMT), which further promotes tumor progression. Furthermore, VECs act as the first line of defense against effector immune cells and help prevent immune cells from infiltrating into tumor tissues. VECs also secrete various cytokines that can contribute to regulating the stemness of tumor stem cells. Thus, it has been increasingly recognized that dysfunction of VECs is one of the key driving forces behind tumor metastasis, and therapeutic strategies targeting VECs have the potential to be an effective means of antitumor therapy. This review aims to present a comprehensive overview of the role and mechanisms of VECs in regulating tumor progression and metastasis, providing insights into the possibilities for the development of novel antitumor therapies that target VECs.

血管内皮细胞（VEC）是血管内壁的组成部分，其功能对于血管系统的正常运作至关重要。VEC 形成的紧密连接是肿瘤细胞 (TC) 内渗和外渗的重要屏障。除此之外，VEC的增殖、激活和迁移在新血管的生长中起着至关重要的作用，这一过程被称为肿瘤血管生成，与肿瘤的恶性进展密切相关。然而，在肿瘤进展过程中，VEC 会经历内皮间质转化 (EndMT)，进一步促进肿瘤进展。此外，VEC 作为效应免疫细胞的第一道防线，有助于防止免疫细胞渗入肿瘤组织。VEC 还分泌多种细胞因子，有助于调节肿瘤干细胞的干性。因此，人们越来越认识到VEC功能障碍是肿瘤转移的关键驱动力之一，针对VEC的治疗策略有可能成为抗肿瘤治疗的有效手段。本综述旨在全面概述 VEC 在调节肿瘤进展和转移中的作用和机制，为开发针对 VEC 的新型抗肿瘤疗法的可能性提供见解。