去甲斑蝥素对人乳腺癌血管生成的抑制作用

背景与目的:去甲斑蝥素(norcantharidin,NCTD)具有抑瘤作用,本文研究它对血管生成的作用,以及对人乳腺癌MCF-7细胞鸡胚绒毛尿囊膜(chorioallantoci membrane,CAM)移植肿瘤血管生成的影响。方法:①建立鸡胚绒毛尿囊膜模型,将明胶海绵载体置于两条前卵黄静脉间血管的CAM上,将不同剂量的NCTD加在载体上,以生理盐水对照,观察记录载体周围血管分支点数,计算血管生成抑制率。②建立人乳腺癌MCF-7细胞鸡胚移植模型。给予不同剂量的NCTD20μl[72、36、18μg/(胚.d)],以生理盐水对照,计算血管生成抑制率。结果:NCTD对以明胶海绵为载体的鸡胚绒毛尿囊膜血管生成具抑制作用,72、36、18、9μg NCTD组血管生成抑制率分别为77.7%、62.9%、50.6%及33.0%,并且呈剂量依赖性。移植肿瘤可诱发血管生成,NCTD能明显抑制MCF-7鸡胚移植肿瘤血管生成,72、36、18μg NCTD对移植瘤诱导的血管抑制率分别为66.2%、39.3%和22.8%。结论:NCTD能明显抑制鸡胚绒毛尿囊膜新生血管的生成,同时能抑制人乳腺癌MCF-7细胞鸡胚移植肿瘤的血管生成。其抗肿瘤作用与抑制肿瘤血管生成有关。     

抑制VEGF表达的锤头状核酶系统

目的:建立和评估抑制血管内皮生长因子(VEGF)表达的锤头状核酶(hammerhead ribozyme)技术系统.方法:对VEGF121基因RNA序列进行二级结构分析,选择靶点;设计并构建针对VEGF的分泌肽RNA的可表达锤头状核酶(14)载体系统和VEGF-荧光色素酶融合基因报告质粒;通过试管内切割实验等方法评估核酶对于试管内转录得到的VEGF RNA切割特异性和效率;通过瞬时共转染实验和稳定转染实验评估核酶在细胞内对于VEGF RNA的切割效率.结果:设计和构建了对VEGF RNA二级结构水平上的暴露区( 8, 36和 71位点:核酶1,3和4)和非暴露区( 17位点:核酶2)4个锤头状核酶(14)的两套质粒;试管内切割检测表明,针对 8, 36和 71位点的核酶(1,3和4)可以有效地在试管内对VEGFRNA进行特异性切割,使其水平分别降至对照的61.7%,27.6%和44.8%(荧光色素酶活性)或66.3%,27.0%和30.0%(蛋白质水平);将核酶表达质粒与VEGF-LUC模板质粒瞬时共转染人SMMC-7721肝癌细胞,核酶1,3和4 VEGF-LUC水平分别降低到对照的81.4%,56.6%和69.1%;稳定表达针对VEGF的核酶1,3或4的SMMC-7721细胞株中,内源性VEGF RNA的水平降至对照水平的5%以下.对照未转染的、转染空载体的和转染了核酶2( 17)的SMMC-7721细胞.结论:分别针对VEGF 8, 36和 71位点锤头状核酶可有效地抑制VEGF的RNA水平.     

乐伐替尼治疗恶性肿瘤的研究进展

乐伐替尼是一种口服的多靶点酪氨酸激酶受体抑制剂,用于放射性碘难治性分化型甲状腺癌的单药治疗以及与依维莫司联合治疗晚期肾细胞癌。近年越来越多的临床数据展示出了该药在未来抗肿瘤治疗中的巨大潜力。本文将对其作用机制、研究历程、临床试验以及最新研究进展进行综述,以求使读者能够更全面地了解和认识乐伐替尼并且为我国的临床实践提供建议。     

Kinetics of tumor size and peritumoral brain edema before,during, and after systemic therapy in recurrent WHO grade II or III meningioma

Background

The efficacy of systemic antineoplastic therapy on recurrent World Health Organization (WHO) grades II and III meningiomas is unclear.

Methods

We performed a retrospective multicenter analysis of serial cranial MRI in patients with recurrent WHO II and III meningiomas treated with antineoplastic systemic therapies. Growth rates for tumor volume and diameter, as well as change rates for edema size, were calculated for all lesions.

Results

We identified a total of 34 patients (23 atypical, 11 anaplastic meningiomas) with a total of 57 meningioma lesions who had been treated at 6 European institutions. Systemic therapies included bevacizumab, cytotoxic chemotherapy, somatostatin analogues, and tyrosine kinase inhibitors. Overall, tumor growth rates decreased during systemic therapy by 51% for tumor diameter and 14% for tumor volume growth rates compared with the period before initiation of systemic therapy. The most pronounced decrease in meningioma growth rates during systemic therapy was evident in patients treated with bevacizumab, with a reduction of 80% in diameter and 59% in volume growth. Furthermore, a decrease in size of peritumoral edema after initiation of systemic therapy was exclusively observed in patients treated with bevacizumab (−107%).

Conclusions

Our data indicate that systemic therapy may inhibit growth of recurrent WHO grades II and III meningiomas to some extent. In our small cohort, bevacizumab had the most pronounced inhibitory effect on tumor growth, as well as some anti-edematous activity. Prospective studies are needed to better define the role of medical therapies in this tumor type.     

蟾毒灵抑制血管生成作用的初步观察

目的明确抗肿瘤中药提取物蟾毒灵有无抗血管生成的活性,并检测其量效关系。方法采用MTT法测定蟾毒灵对人脐静脉内皮细胞ECV304生长的抑制作用,计算IC50,观察其量效、时效关系;并以鸡胚绒毛尿囊膜为模型观察蟾毒灵在体内组织器官水平对血管生成的影响。结果蟾毒灵对ECV304细胞的生长有抑制作用,且呈浓度和时间的依赖性。24、48、72hIC50分别为1.104、0.355、0.0905μg/mL。鸡胚绒毛尿囊膜实验表明蟾毒灵可显著抑制血管生成的作用,并呈浓度依赖性。结论蟾毒灵具有明确的抑制血管内皮细胞增殖、抗血管生成的作用。     

桑黄多糖抗肿瘤机制研究进展

综述桑黄多糖的抗肿瘤机制及研究进展。桑黄多糖的抗肿瘤机制主要表现在免疫调节、抗血管生成、抗氧化三方面；桑黄多糖与环磷酰胺联合用药能够增强疗效,降低副作用。     

片仔癀体外抗肿瘤作用研究

目的 研究片仔癀对体外肿瘤细胞增殖的影响,以及对鸡胚尿囊膜血管生成的抑制作用。方法 采用MTT法检测片仔癀对体外培养肿瘤细胞（肝癌SMMC-7721细胞、胃癌SGC-7901细胞、宫颈癌HeLa细胞）的抗肿瘤作用;以鸡胚尿囊膜血管生成（CAM）实验,研究片仔癀对新生血管生成的抑制作用。结果 片仔癀在0.2～1.0 mg/mL对各肿瘤细胞的增殖有显著抑制作用,1.0 mg/mL片仔癀对肝癌细胞增殖抑制率达到81.55%;片仔癀在0.1～1 000 μg/mL对鸡胚尿囊膜血管生成有显著抑制作用,给药鸡胚的新生血管数减少,血管变细,其中10 μg/mL抑制率最高,一级血管抑制率为61.1%,二级血管抑制率为59.1%。结论 在实验给药浓度下,片仔癀对受试肿瘤细胞的增殖具有较强抑制作用,对鸡胚尿囊膜血管生成有显著抑制作用。     

Tumstatin对兔耳增生性瘢痕的抑制作用

目的 探讨肿瘤抑素(Tumstatin)对兔耳瘢痕组织生长情况的影响.方法 建立兔耳增生性瘢痕模型,用Tumstatin对兔耳腹侧建立的增生性瘢痕模型通过在体局部注射进行干预,随机设立Tumstatin治疗组、Tumstatin预防治疗组、曲安奈德对照组、生理盐水对照组;停止药物注射21天后各组同时于每只兔的双侧对称部位取材瘢痕组织,每一取材瘢痕组织均分成同样大小的四等份,分别进行组织形态学观察、CD34免疫组化方法测定血管密度的变化、观察血管内皮细胞与成纤维细胞凋亡的变化情况.结果 Tumstatin预防治疗组和Tumstatin治疗组中,新生毛细血管密度、内皮细胞活性以及成纤维细胞数量都较曲安奈德和生理盐水对照组明显降低,差异有统计学意义(P<0.05).结论 Tumstatin能够较曲安奈德更明显地抑制增生性瘢痕的生长,为Tumstatin用于防治增生性瘢痕的可行性提供了初步的理论依据.     

YL529, a novel,orally available multikinase inhibitor,potently inhibits angiogenesis and tumour growth in preclinical models

Background and Purpose

Targeted chemotherapy using small-molecule inhibitors of angiogenesis and proliferation is a promising strategy for cancer therapy.

Experimental Approach

YL529 was developed via computer-aided drug design, de novo synthesis and high-throughput screening. The biochemical, pharmacodynamic and toxicological profiles of YL529 were investigated using kinase and cell viability assays, a mouse tumour cell-containing alginate bead model, a zebrafish angiogenesis model and several human tumour xenograft models in athymic mice.

Key Results

In vitro, YL529 selectively inhibited the activities of VEGFR2/VEGFR3 and serine/threonine kinase RAF kinase. YL529 inhibited VEGF₁₆₅-induced phosphorylation of VEGFR2, as well as the proliferation, migration, invasion and tube formation of human umbilical vascular endothelial cells. It also significantly blocked vascular formation and angiogenesis in the zebrafish model. Moreover, YL529 strongly attenuated the proliferation of A549 cells by disrupting the RAF/mitogen-activated protein (MAP) or extracellular signal-regulated kinase (Erk) kinase (MEK) kinase kinase/MAPK pathway. Oral administration of YL529 (37.5–150 mg⁻¹·kg⁻¹·day⁻¹) to nude mice bearing established tumour xenografts significantly prevented the growth (60–80%) of A549, SPC-A1, A375, OS-RC-2 and HCT116 tumours without detectable toxicity. YL529 markedly reduced microvessel density and increased tumour cell apoptosis in the tumours formed in mice inoculated with the lung cancer cells, SPC-A1 and A549, and the colon carcinoma cells, HCT116.

Conclusions and Implications

YL529, an orally active multikinase inhibitor, shows therapeutic potential for solid tumours, and warrants further investigation as a possible anticancer agent.