PFKFB3抑制剂对肺癌的放疗增敏作用及其在放射性肺损伤中的作用和机制研究

Our previous study and a host of studies showed that the antiangiogenic agents induced normalization of tumor vasculature, which was the important mechanism of the antiangiogenic agents improving treatment outcome of radiotherapy. Our previous clinical revealed that the combination of the antiangiogenic agents with chemoradiotherapy in patients with lung cancer showed promising survival benefits. Recent studies show that endothelial cells rely on glycolysis for ATP production, and that the key glycolytic regulator 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) regulates angiogenesis, which makes PFKFB3 a new target in anti-angiogenesis therapy.PFKFB3 inhibitor can also inhibit the proliferation of tumor cell. Moreover, PFKFB3 inhibitor showed therapeutic benefit in bleomycin-induced and transforming growth factor-beta1-induced lung fibrosis in mice. However, the effects of PFKFB3 inhibitor on tumor vascular and its outcomes when in combination with radiation therapy remains unknown. Our previous study showed that during PFKFB3 inhibitor could also induce vessel normalization in lung cancer. We next hypothesized that PFKFB3 inhibitor could induce vascular normalization and inhibit the proliferation of tumor cell, which could finally enhance anticancer therapies of radiotherapy. Accordingly, the aim of the project is to investigate the anti-tumor growth effects of PFKFB3 inhibitor combined with radiotherapy, and the role of PFKFB3 inhibitor in preventing radiation-induced lung injury. In summary, we will explore the expression of PFKFB3 in human lung tissues and its clinical correlation with radiotherapy. The present study focus on the effects and the potential mechanisms of PFKFB3 inhibitor on tumor vascular normalization in a xenografted model of lung cancer. We aimed to elucidate the "normalizing time window" induced by PFKFB3 inhibitor, and examined the anti-tumor effects of radiotherapy delivered during or out the "time window". Also, we will explore the role of PFKFB3 inhibitor in preventing radiation-induced lung injury. These results are of translational importance because the clinical benefits of PFKFB3 inhibitor might be increased by more precise treatment scheduling to ensure that radiation is given during periods of peak radiosensitivity.

我们前期基础研究表明：诱导肿瘤血管正常化是抗血管生成药物增强放疗抗肿瘤作用的重要机制。我们的临床试验也表明：抗血管生成药物与放化疗联合应用，使肺癌患者有明显的生存获益。最新研究发现糖酵解酶PFKFB3在血管生成过程中起到重要的作用，是抗血管生成治疗的新靶点。PFKFB3抑制剂也能抑制肿瘤细胞的增殖，还能预防药物诱导的肺纤维化。PFKFB3抑制剂与放疗的联合作用未见报道。我们的预实验表明PFKFB3抑制剂可诱导裸鼠肺癌移植瘤血管正常化。我们推测PFKFB3抑制剂能通过使肺癌血管正常化和抑制肺癌细胞的增殖的双重作用，能更好地提高放射治疗对肺癌的治疗效果，还可能对放射性肺损伤有一定的保护作用。本项目拟探讨：PFKFB3抑制剂促进肺癌血管正常化的作用和机制，及其联合放疗对肺癌的最佳治疗模式，PFKFB3抑制剂对放射性肺损伤的作用及其机制，旨在为肺癌治疗提供新的药物及为临床应用提供科学依据。

研究背景: PFKFB3在血管生成过程中起到重要的作用，是一个抗血管生成治疗的新靶点。然而，PFKFB3抑制剂对肿瘤血管的作用及机制目前尚不清楚。本研究的目标是探讨抑制PFKFB3对肿瘤细胞和肿瘤血管正常化的作用及机制，为PFKFB3抑制剂联合放疗提供科学依据及理论基础。.材料方法：本研究采用免疫组化分析肺癌、乳腺癌病人PFKFB3表达水平，结合临床资料将其与疗效进行相关性分析。本研究建立慢病毒构建与转染、肿瘤体外培养体系、裸鼠种植瘤模型，利用X线局部照射建立肿瘤放疗模型，采用免疫组化、免疫荧光技术检测、血管生成、采用定量PCR、蛋白免疫印迹技术。.结果：肺癌组织中PFKFB3的表达水平较正常组织明显升高，与患者的生存率存在负相关。乳腺癌组织中PFKFB3表达水平高，PFKFB3高表达的患者的预后更差。慢病毒抑制PFKFB3的表达后，肿瘤细胞的增殖明显受到抑制；肿瘤细胞的细胞周期阻滞在G1期；并且肿瘤的迁移、侵袭也明显受到了抑制。PFKFB3可促进血管生成，而抑制PFKFB3可抑制肿瘤的血管生成。抑制PFKFB3可抑制肿瘤的生长。PFKFB3抑制剂可诱导肺癌的肿瘤血管正常化，与放射治疗联合可提高疗效。.结论：PFKFB3抑制剂对肿瘤血管正常化和抑制肿瘤细胞的双重作用，能增强放疗治疗肿瘤的敏感性，为PFKFB3抑制剂与放疗联合治疗提供依据。