舒尼替尼治疗早产儿视网膜病变动物模型的研究

目的观察玻璃体腔内注射不同剂量舒尼替尼(Sunitinib)对视网膜新生血管是否具有抑制作用,及其抑制效果是否呈剂量依赖性。方法 高浓度氧气诱导Wistar鼠仔建立早产儿视网膜病变动物模型。鼠龄7d的鼠仔108只,随机分为6组(A:空气对照组、B:高氧对照组、C:高氧+PBS组、D:高氧+5μg舒尼替尼组、E:高氧+25μg舒尼替尼组、F:高氧+125μg舒尼替尼组)。当鼠仔脱氧时,C、D、E、F组分别玻璃体腔内注射单纯无菌PBS缓冲液和相应剂量的舒尼替尼。视网膜铺片(ADP酶法)观察视网膜血管形态、病理切片计数突破视网膜内界膜的新生血管内皮细胞核数目及RT-PCR检测VEGFR2mRNA的含量。结果 视网膜铺片结果显示:A组视网膜血管从视盘发出向四周放射状均匀分布,周边血管形态正常。B组视网膜血管在持续高氧环境中收缩闭塞,在相对缺氧环境中迂曲扩张并形成大量新生血管。舒尼替尼治疗后新生血管有不同程度的减少,抑制效果随着剂量增加而明显。视网膜新生血管内皮细胞核计数:A组为2.650±0.875,B组31.450±0.686,C组31.600±0.681,D组26.450±1.099,E组21.250±1.070,F组12.550±0.999,A与B组间差异有统计学意义(P<0.05),B与C组间差异无统计学意义(P>0.05),C、D、E、F各组间比较差异均有统计学意义(均为P<0.05)。RT-PCR结果示:A组VEGFR2mRNA的表达维持在一个较低水平。持续高氧环境下VEGFR2mRNA表达显著下降,而相对缺氧环境下其表达显著增加。舒尼替尼治疗组其表达不同程度降低,降低效果随剂量的增加而明显。A、B组17d时VEGFR2mRNA表达差异有统计学意义(P<0.05),B、C2组于17d时VEGFR2mRNA表达差异无统计学意义(P>0.05),C、D、E、F组于17d时VEGFR2mRNA的表达各组间比较差异均具有统计学意义(均为P<0.05)。结论 舒尼替尼能抑制视网膜新生血管的生成,且抑制效果呈剂量依赖性。     

血管生长因子受体3(VEGFR3)在胎盘的细胞定位及其在ART安全性研究中的意义

目的:探讨血管生长因子受体3(vascular endothelial growth factor 3,VEGFR3)在ART妊娠胎盘组织中的差异表达及其安全性研究中的意义。方法:收集11例自然妊娠(对照组)和10例ART妊娠(ART组)的单胎足月妊娠选择性剖宫产分娩的胎盘组织,分析比较组间的临床资料;并应用免疫组织化学技术和实时荧光定量PCR技术,观察VEGFR3在胎盘组织的细胞定位,比较VEGFR3在ART和对照组胎盘组织中的差异表达。结果:VEGFR3在胎盘组织中定位于胎盘绒毛合体滋养层细胞胞质。与对照组相比,VEGFR3细胞定位一致,ART妊娠的胎盘组织中VEGFR3 mRNA表达水平有上升趋势,但无统计学差异(P>0.05)。结论:ART妊娠的胎盘组织中VEGFR3细胞定位和表达水平未见明显变化。     

Purinergic regulation of vascular endothelial growth factor signaling in angiogenesis

P2Y purine nucleotide receptors (P2YRs) promote endothelial cell tubulogenesis through breast cancer cell-secreted nucleoside diphosphate kinase (NDPK). We tested the hypothesis that activated P2Y₁ receptors transactivate vascular endothelial growth factor receptor (VEGFR-2) in angiogenic signaling. P2Y₁R stimulation (10 μM 2-methyl-thio-ATP (2MS-ATP)) of angiogenesis is suppressed by the VEGFR-2 tyrosine kinase inhibitor, SU1498 (1 μM). Phosphorylation of VEGFR-2 by 0.0262 or 2.62 nM VEGF was comparable with 0.01 or 10 μM 2MS-ATP stimulation of the P2Y₁R. 2MS-ATP, and VEGF stimulation increased tyrosine phosphorylation at tyr1175. 2MS-ATP (0.1–10 μM) also stimulated EC tubulogenesis in a dose-dependent manner. The addition of sub-maximal VEGF (70 pM) in the presence of increasing concentrations of 2MS-ATP yielded additive effects at 2MS-ATP concentrations <3 μM, whereas producing saturated and less than additive effects at ⩾3 μM. We propose that the VEGF receptor can be activated in the absence of VEGF, and that the P2YR–VEGFR2 interaction and resulting signal transduction is a critical determinant of vascular homoeostasis and tumour-mediated angiogenesis.     

Liposomal honokiol inhibits VEGF‐D‐induced lymphangiogenesis and metastasis in xenograft tumor model

Lymph nodes metastasis of tumor could be a crucial early step in the metastatic process. Induction of tumor lymphangiogenesis by vascular endothelial growth factor‐D may play an important role in promoting tumor metastasis to regional lymph nodes and these processes can be inhibited by inactivation of the VEGFR‐3 signaling pathway. Honokiol has been reported to possess potent antiangiogenesis and antitumor properties in several cell lines and xenograft tumor models. However, its role in tumor‐associated lymphangiogenesis and lymphatic metastasis remains unclear. Here, we established lymph node metastasis models by injecting overexpressing VEGF‐D Lewis lung carcinoma cells into C57BL/6 mice to explore the effect of honokiol on tumor‐associated lymphangiogenesis and related lymph node metastasis. The underlying mechanisms were systematically investigated in vitro and in vivo. In in vivo study, liposomal honokiol significantly inhibited the tumor‐associated lymphangiogenesis and metastasis in Lewis lung carcinoma model. A remarkable delay of tumor growth and prolonged life span were also observed. In in vitro study, honokiol inhibited VEGF‐D‐induced survival, proliferation and tube‐formation of both human umbilical vein endothelial cells (HUVECs) and lymphatic vascular endothelial cells (HLECs). Western blotting analysis showed that liposomal honokiol‐inhibited Akt and MAPK phosphorylation in 2 endothelial cells, and downregulated expressions of VEGFR‐2 of human vascular endothelial cells and VEGFR‐3 of lymphatic endothelial cells. Thus, we identified for the first time that honokiol provided therapeutic benefit not only by direct effects on tumor cells and antiangiogenesis but also by inhibiting lymphangiogenesis and metastasis via the VEGFR‐3 pathway. The present findings may be of importance to investigate the molecular mechanisms underlying the spread of cancer via the lymphatics and explore the therapeutical strategy of honokiol on antilymphangiogenesis and antimetastasis. © 2008 Wiley‐Liss, Inc.     

VEGFR1和MDR1在胃癌中的表达及意义

目的:探讨VEGFR1和MDR1在胃癌中的表达及意义.方法:采用免疫组化SP法检测VEGFR1和MDR1在胃癌中的表达及与分化程度的关系;比较VEGFR1和MDR1在胃癌中的表达相关性.结果:VEGFR1在高、中、低度分化胃癌的表达率依次为15/53(28%)、19/43(44%)、37/54(68%); 在低分化胃癌组织中的表达明显高于高分化和中分化胃癌组织(P＜0.05).MDR1在高、中、低度分化胃癌的表达率依次为18/53(34%)、21/43(48%)、41/54(76%); 在低分化胃癌组织中的表达明显高于高分化和中分化胃癌组织 (P＜0.05).结论:VEGFR1和MDR1在胃癌中的表达具有一致性,可能在胃癌的多药耐药中扮演重要角色.     

Celastrol inhibits the growth of human glioma xenografts in nude mice through suppressing VEGFR expression

Celastrol, a compound purified from Tripterygium wilfordii whose preparations have been used for clinical treatment for rheumatoid arthritis, has been demonstrated to have antiangiogenic activity, and be inhibitory against mice tumor growth by a few recent studies. However, whether its antiangiogenic activity plays a role in the celastrol-mediated suppression of tumor growth and the molecular basis of anti-tumor activity are poorly understood. In this study, we found that celastrol inhibited the growth of human glioma xenografts in mice, which concurred with the suppression of angiogenesis. Interestingly, while celastrol had no effect on either the expression of VEGF or its mRNA levels, celastrol treatment lowered the expression levels of its receptors (VEGFR-1 and VEGFR-2) and their mRNA levels. These findings suggest that celastrol have potential to be used as an antiangiogenesis drug through its role in suppressing VEGF receptors expression that might consequently reduce the signal transduction between VEGF and VEGFR.     

SU11248 (sunitinib) sensitizes pancreatic cancer to the cytotoxic effects of ionizing radiation

PURPOSE: SU11248 (sunitinib) is a small-molecule tyrosine kinase inhibitor which targets VEGFR and PDGFR isoforms. In the present study, the effects of SU11248 and ionizing radiation on pancreatic cancer were studied. METHODS AND MATERIALS: For in vitro studies human pancreatic adenocarcinoma cells lines were treated with 1 microM SU11248 1 h before irradiation. Western blot analysis was used to determine the effect of SU11248 on radiation-induced signal transduction. To determine if SU11248 sensitized pancreatic cancer to the cytotoxic effects of ionizing radiation, a clonogenic survival assay was performed using 0-6 Gy. For in vivo assays, CAPAN-1 cells were injected into the hind limb of nude mice for tumor volume and proliferation studies. RESULTS: SU11248 attenuated radiation-induced phosphorylation of Akt and ERK at 0, 5, 15, and 30 min. Furthermore, SU11248 significantly reduced clonogenic survival after treatment with radiation (p < 0.05). In vivo studies revealed that SU11248 and radiation delayed tumor growth by 6 and 10 days, respectively, whereas combined treatment delayed tumor growth by 30 days. Combined treatment with SU11248 and radiation further attenuated Brdu incorporation by 75% (p = 0.001) compared to control. CONCLUSIONS: SU11248 (sunitinib) sensitized pancreatic cancer to the cytotoxic effects of radiation. This compound is promising for future clinical trials with chemoradiation in pancreatic cancer.     

冻干法制备VEGFR2靶向超声微泡体外寻靶及显影实验

目的 采用冻干法制备血管内皮生长因子受体2（VEGFR2）靶向超声造影剂,并评价其体外寻靶能力及超声显影效果。方法 冻干法制备生物素化微泡,将链霉亲和素及VEGFR2单克隆抗体依次连接至生物素化微泡,构建VEGFR2靶向超声微泡。采用免疫荧光染色法验证链霉亲和素及大鼠抗小鼠VEGFR2单克隆抗体与微泡的结合情况。观察及检测VEGFR2靶向超声微泡的形态、大小及分布。体外培养人脐静脉内皮细胞(HUVEC)至对数期,分3组,分别为非靶向超声微泡组（加入非靶向微泡1×107个）、抗体预饱和+VEGFR2靶向微泡组（加入过量的VEGFR2抗体孵育后,再加入VEGFR2靶向超声微泡1×107个）及VEGFR2靶向超声微泡组（加入VEGFR2靶向超声微泡1×107个）,比较各组微泡与细胞的结合情况。采用自制体外循环装置并采集超声图像,检测VEGFR2靶向超声微泡体外显影能力。结果 通过免疫荧光染色法的验证,链霉亲和素及大鼠抗小鼠VEGFR2单克隆抗体可与生物素化微泡结合构建VEGFR2靶向超声微泡。VEGFR2靶向微泡光学显微镜下呈圆形,大小一致且分布均匀,平均直径为（1.31±0.93） μm。显微镜下见非靶向微泡组HUVEC周围可见少量微泡结构,抗体预饱和+VEGFR2靶向超声微泡组HUVEC周围几乎无微泡结构,VEGFR2靶向超声微泡组HUVEC周围可见较多微泡结构存在。在超声增强模式下自制微泡显影效果良好,随造影时间延长无明显衰减。结论 冻干法可制备VEGFR2靶向超声造影剂,在体外实验中具有良好的寻靶能力且超声辐照下可显影。     

卡瑞利珠单抗,一种人源化抗PD-1 IgG4亚型单克隆抗体在临床前研究中表现出优异的抗肿瘤活性以及良好的安全性

卡瑞利珠单抗是一种人源化的抗PD-1单克隆抗体.在体外与人和食蟹猴PD-1蛋白具有纳摩尔级别的高亲和力,但不结合鼠源PD-1蛋白.它在体外有效阻断PD-1/PD-L1信号通路的同时还可以激活T细胞.卡瑞利珠单抗与PD-1独特的结合表位同PD-1和PD-L1结合表位有部分的重叠,证明了卡瑞利珠单抗对PD-1/PD-L1具...