PFKFB3诱导血管拟态在VEGF靶向治疗口腔鳞癌中的机制研究

Cancer cell vasculogenic mimicry(VM) is an important part of tumor vascular network formation, is one of the causes of resistance to antiangiogenic therapy. We found that (PNAS, 2015) VEGF monoclonal antibody could inhibit tumor angiogenesis, but it had obvious chronergy and transient effect, and whether it had impact on cancer VM is not clear. Our previous study found that the key molecules of VM, HIF-1 alpha and major glycolytic enzyme PFKFB3 highly expressioned in oral squamous cell carcinoma(OSCC). The specific inhibition of PFKFB3 expression could inhibit VM related molecules MMP9, VEGFR2, VEGFR1. Therefore, we hypothesize that cancer cells through glycolysis regulation of VM may be the main reason for anti-angiogenesis drug resistance; targeting PFKFB3 inhibits VM, would effectively overcome the resistance of the anti-VEGF therapy. Therefore, the aim of this project is to clarify the effect of anti-angiogenesis on tumor cell VM in OSCC; to uncover the potential mechanism of PFKFB3-mediated glycolysis induces VM; to make explorations into the effectiveness of combined anti-PFKFB3 and anti-angiogenesis treatment. This study is expected to provide an experimental basis for the inhibition of vascular network formation of malignant tumors, and provide a new way for the treatment of OSCC.

癌细胞血管拟态是肿瘤血管网络构建的重要部分，是抗血管生成治疗抵抗的原因之一。我们研究发现（PNAS，2015），VEGF单抗能抑制肿瘤微血管形成，但存在明显时效性，且对癌细胞血管拟态的影响并不明确。我们前期研究发现，促血管拟态关键分子HIF-1α和糖酵解酶PFKFB3在口腔鳞癌中高表达，特异性抑制PFKFB3，能下调血管拟态相关分子MMP9、VEGFR2、VEGFR1的表达。因此我们推测，癌细胞通过糖酵解调控血管拟态生成是抗VEGF耐药的主要原因；以PFKFB3为靶标，抑制血管拟态发生，将有效克服抗VEGF治疗的耐受。为此，本项目拟在口腔鳞癌模型上明确抗VEGF治疗对癌细胞血管拟态的影响，阐明PFKFB3通过糖酵解调控血管拟态的分子机制，探讨在口腔鳞癌抗血管治疗过程中联合抑制VEGF/PFKFB3的有效性。本研究有望为丰富抑制恶性肿瘤血管网络构建提供实验基础，为口腔鳞癌的治疗提供新思路。

口腔鳞癌是多种促血管生成因子刺激参与，存在高度异常血管化的恶性肿瘤之一，传统的抗血管生成治疗可暂时性抑制肿瘤生长，而产生的治疗抵抗会导致治疗失败。血管拟态是异常血管结构的重要组成部分，近来许多研究报告了血管拟态参与了抗血管生成治疗抵抗产生。本研究发现在口腔鳞癌中，抗血管生成治疗进一步导致肿瘤内低氧环境，促进肿瘤细胞糖酵解水平异常，导致了血管拟态生成以出现肿瘤再次失控生长。糖酵解关键酶PFKFB3特异性抑制剂3PO可减少贝伐珠单抗诱导的血管拟态生成，进而增加了抗血管生成治疗的效果。3PO通过诱导血管拟态关键分子HIF-1α,VE-cadherin,MMPs和VEGFR2的表达水平下降，并降低口腔鳞癌细胞迁移能力以抑制血管拟态生成。研究通过敲低PFKFB3证实，该方案可通过影响血管拟态关键分子表达和抑制口腔鳞癌细胞迁移、侵袭从而减少血管拟态生成。我们的研究结果表明，靶向糖代谢可抑制肿瘤血管拟态形成增加抗血管治疗的效应，为临床联合靶向糖代谢和抗血管生成对口腔鳞癌治疗的新模式提供了实验基础。