ICAM-1介导的肿瘤相关内皮细胞与血小板相互作用在肝癌射频消融后残留癌进展中的作用机制

Residual tumor progression in hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) is an important prognostic risk factor. Our previous study demonstrated that Tumor associated endothelial cells after insufficient thermal ablation exhibited enhanced function, platelets were activated in HCC patient after RFA, the expression of ICAM-1 was increased in TAECs after insufficient thermal ablation, and TAECs after insufficient thermal ablation promoted the activation of the platelets. So we hypothesized that ICAM-1 may mediate the process that TAECs after insufficient thermal ablation promotes the activation of platelets, which enhances the HCC-cell transendothelial migration and further promotes the progression of residual tumor. The present study was designed to verify the hypothesis by the following steps. Based on the model of TAECs after insufficient thermal ablation, we down- or up-regulate the expression of ICAM-1, the morphologe and activation of platelet, the ability of adhesion and aggregation of platelet, invasion, proliferation, transendothelial migration, growth and metastasis of HCC cells are investigated. We also establish the model of residual HCC after RFA using ICAM-1(-/-) mice, which are treated anti-platelet drugs or antibody, and the growth and metastasis of residual tumor are investigated. If the hypothesis is verified, the mechanism of progression of HCC after RFA would be revealed and provide the theoretical basis for RFA combination anti-platelet therapy in order to prevent the progression of residual HCC.

肝细胞癌（HCC）射频消融（RFA）后残留癌进展是影响疗效的主要因素。前期发现，肿瘤相关内皮细胞（TAECs）不完全热消融后功能增强；HCC患者RFA后体内血小板激活；TAECs不完全热消融后ICAM-1表达增加并促进血小板激活。因此提出：ICAM-1可介导TAECs不完全热消融后促血小板激活，增加HCC细胞跨内皮细胞转移，进而促进残留癌进展。本研究拟在TAECs不完全热消融模型基础上，敲低/过表达其ICAM-1表达，与血小板和HCC细胞作用，观察血小板形态、激活、聚集和粘附、HCC细胞侵袭、增殖、跨内皮细胞转移和体内生长和转移，并利用ICAM-1（-/-）小鼠建立肝癌不完全RFA后残留癌模型，给予抗血小板药物或抗体后观察残留癌局部生长和肺转移。该假说如获证实，将为揭示HCC 不完全热消融后残留癌进展的机制提供新的研究点，为HCC RFA联合抗血小板治疗预防残留癌进展提供新的理论。

背景：肝细胞癌（HCC）射频消融（RFA）后局部复发病灶侵袭能力增强并且倾向于转移。血管完整性和血小板参与了肿瘤转移。内皮细胞和血小板相互作用是否诱导了HCC不完全RFA后血管通透性增强仍然不明。.方法：收取HCC病人RFA前后的血小板。分离肿瘤相关内皮细胞（TAECs）。扫描电镜观察TAECs和血小板之间的相互作用。血小板激活和聚集实验用于观察血小板功能。体内外血管渗透性实验观察肿瘤血管渗漏情况。Western blot、免疫共沉淀和免疫荧光实验用于观察蛋白表达。异位、原位和转移肿瘤模型用于观察肿瘤生长和转移。ICAM敲除小鼠用于观察ICAM-1对于肿瘤血管渗漏的影响。.结果：HCC病人RFA后血液中CD62P阳性血小板数量和血浆中sP-selectin水平较RFA前明显升高。TAECs不完全RFA后能够激活血小板。在血小板存在的状况下，TAECs不完全热消融后内皮通透性增加。异位移植瘤不完全RFA后肿瘤血管通透性增加。血小板通过VE-cadherin促进不完全RFA诱导的血管通透性增加。TAECs不完全RFA后ICAM-1表达上调导致了血小板激活和聚集。ICAM-1介导了血小板和不完全RFA诱导的内皮通透性增加。同时，Ezrin参与了ICAM-1介导的VE-cadherin表达。血小板删除和抑制ICAM-1抑制了HCC不完全RFA后肿瘤生长和转移。ICAM-/-小鼠异位移植瘤不完全RFA后肿瘤血管通透性明显降低。.结论：HCC不完全RFA后血小板激活。TAECs中ICAM-1可通过Ezrin/VE-cadherin通路促进了不完全RFA后血小板激活和肿瘤血管通透性增加。为抗血小板治疗联合射频消融治疗HCC奠定了理论基础。