Optimal combination of antiangiogenic therapy for hepatocellular carcinoma

The success of sorafenib in prolonging survival of patients with hepatocellular carcinoma (HCC) makes therapeutic inhibition of angiogenesis a component of treatment for HCC. To enhance therapeutic efficacy, overcome drug resistance and reduce toxicity, combination of antiangiogenic agents with chemotherapy, radiotherapy or other targeted agents were evaluated. Nevertheless, the use of antiangiogenic therapy remains suboptimal regarding dosage, schedule and duration of therapy. The issue is further complicated by combination antiangiogenesis to other cytotoxic or biologic agents. There is no way to determine which patients are most likely respond to a given form of antiangiogenic therapy. Activation of alternative pathways associated with disease progression in patients undergoing antiangiogenic therapy has also been recognized. There is increasing importance in identifying, validating and standardizing potential response biomarkers for antiangiogenesis therapy for HCC patients. In this review, biomarkers for antiangiogenesis therapy including systemic, circulating, tissue and imaging ones are summarized. The strength and deficit of circulating and imaging biomarkers were further demonstrated by a series of studies in HCC patients receiving radiotherapy with or without thalidomide.     

An in vivo role for Trypanosoma cruzi calreticulin in antiangiogenesis

Angiogenesis leads to neovascularization from existing blood vessels. It is associated with tumor growth and metastasis and is regulated by pro- and antiangiogenic molecules, some of them currently under clinical trials for cancer treatment. During the last few years we have cloned, sequenced and expressed a Trypanosoma cruzi calreticulin gene (TcCRT). Its product, TcCRT, a 45 kDa protein, is more than 50% identical to human CRT (HuCRT). TcCRT, present on the surface of trypomastigotes, binds both C1q and mannan binding lectin and inhibits the classical activation pathway of human complement. Since TcCRT is highly homologous to a functional antiangiogenic fragment from HuCRT (aa 120–180), recombinant (r) and native (n) TcCRT were tested in their antiangiogenic effects, in the chick embryonic chorioallantoid membrane (CAM) assay. Both proteins mediated highly significant antiangiogenic effects in the in vivo CAM assay. This effect was further substantiated in experiments showing that the plasmid construct pSecTag/TcCRT also displayed significant antiangiogenic properties, as compared to the empty vector. Most likely, the fact that antiangiogenic substances act preferentially on growing neoplasic tissues, but not on already established tumors, is due to their effects on emerging blood vessels. The results shown here indicate that TcCRT, like its human counterpart, has antiangiogenic properties. These properties may explain, at least partly, the reported antineoplasic effect of experimental T. cruzi infection.     

VEGF反义寡核苷酸抑制大鼠胶质瘤生长的时间与剂量的效应关系

目的在大鼠脑内原位注射反义寡核苷酸观察胶质瘤的生长抑制情况的时间与剂量的效应关系。方法所有大鼠均在立体定向导引下右尾状核区接种1×106C6胶质瘤细胞。不同时间和剂量VEGF反义寡核苷酸均在立体定向导引下原穿刺靶点注射。其中实验Ⅰ组在接种细胞的同时原位注射1000μmol/L的VEGF反义寡核苷酸,而实验Ⅱ组则同时注射2000μmol/L的VEGF反义寡核苷酸。对照Ⅰ组为对照。实验Ⅲ和Ⅳ组在细胞接种后的1和2周各原位注射1次,共2次,每次实验Ⅲ组为1000μmol/L、实验Ⅳ组为2000μmol/L的VEGF反义寡苷核酸。对照Ⅱ组为对照。实验V组仅在接种后2周注射1次2000μmol/L的VEGF反义寡核苷酸,并设对照Ⅲ组为对照。实验3周时处死所有的大鼠,解剖出全脑标本,观察肿瘤的生长情况,测量肿瘤大小。结果实验Ⅰ组的抑瘤率为94.5％,实验Ⅱ组的抑瘤率为100％。实验Ⅲ组的抑瘤率为91.5％,实验Ⅳ组为100％,实验Ⅴ组抑瘤率为87.8％。实验组和对照组的肿瘤体积比较有非常显著的差异。结论 原位应用VEGF反义寡核苷酸能取得很好的抗血管生成的治疗效果,抑瘤效果有明显的浓度依赖性。原位早期使用足量反义核酸能取得更好的效果。     

Antiangiogenic activity of 2-formyl-8-hydroxy-quinolinium chloride

Tumour growth is closely related to the development of new blood vessels to supply oxygen and nutrients to cancer cells. Without the neovascular formation, tumour volumes cannot increase and undergo metastasis. Antiangiogenesis is one of the most promising approaches for antitumour therapy. The exploration of new antiangiogenic agents would be helpful in antitumour therapy. Quinoline is an aromatic nitrogen compound characterized by a double-ring structure which exhibits a benzene ring fused to pyridine at two adjacent carbon atoms. The high stability of quinoline makes it preferable in a variety of therapeutic and pharmaceutical applications, including antitumour treatment. This work is to examine the potential antiangiogenic activity of the synthetic compound 2-Formyl-8-hydroxy-quinolinium chloride. We found that 2-Formyl-8-hydroxy-quinolinium chloride could inhibit the growth of human umbilical vein endothelial cells in vitro. Using the diethylnitrosamine-induced hepatocarcinogenesis model, 2-Formyl-8-hydroxy-quinolinium chloride showed strong antiangiogenic activity. Furthermore, 2-Formyl-8-hydroxy-quinolinium chloride could inhibit the growth of large Hep3B xenografted tumour from the nude mice. We assume that 2-Formyl-8-hydroxy-quinolinium chloride could be a potential antiangiogenic and antitumour agent and it is worthwhile to further study its underlying working mechanism.     

The Potential of Combined Immunotherapy and Antiangiogenesis for the Synergistic Treatment of Advanced NSCLC

Over the past few years, there have been considerable advances in the treatments available to patients with metastatic or locally advanced NSCLC, particularly those who have progressed during first-line treatment. Some of the treatment options available to patients are discussed here, with a focus on checkpoint inhibitor immunotherapies (nivolumab and pembrolizumab) and antiangiogenic agents (bevacizumab, ramucirumab, and nintedanib). It is hypothesized that combining immunotherapy with antiangiogenic treatment may have a synergistic effect and enhance the efficacy of both treatments. In this review, we explore the theory and potential of this novel treatment option for patients with advanced NSCLC. We discuss the growing body of evidence that proangiogenic factors can modulate the immune response (both by reducing T-cell infiltration into the tumor microenvironment and through systemic effects on immune-regulatory cell function), and we examine the preclinical evidence for combining these treatments. Potential challenges are also considered, and we review the preliminary evidence of clinical efficacy and safety with this novel combination in a variety of solid tumor types.     

抗血管生成药物改善肿瘤血供及含氧量的机制探讨和应用展望

肿瘤的生长和转移离不开血管,目前抗血管生成药物已广泛应用于一些恶性肿瘤的临床治疗.其原理为使肿瘤血管退化和再生抑制,从而剥夺肿瘤的氧气和营养供给,达到抑制肿瘤生长和转移的效果.临床上,抗血管生成药物与放、化疗方案联合使用能起到协同抗肿瘤的效果,然而放疗和化疗需要依靠血液来输送氧气和药物,理论上血管退化应当是抑制而非增强放、化疗的效果,这与临床事实相矛盾.随着“血管正常化”理论的提出,越来越多的证据显示抗血管生成药物可以在破坏肿瘤血管之前,先使肿瘤血管的整体生理机能正常化,达到改善肿瘤血供、增加组织含氧量的效果.这对于抗血管生成药物的应用,提出了新的观点和挑战.本文针对抗血管生成药物改善肿瘤血液供应和含氧量的机制、相关研究以及应用展望进行综合论述。     

Judah Folkman,a pioneer in the study of angiogenesis

More than 30 years ago, Judah Folkman found a revolutionary new way to think about cancer. He postulated that in order to survive and grow, tumors require blood vessels, and that by cutting off that blood supply, a cancer could be starved into remission. What began as a revolutionary approach to cancer has evolved into one of the most exciting areas of scientific inquiry today. Over the years, Folkman and a growing team of researchers have isolated the proteins and unraveled the processes that regulate angiogenesis. Meanwhile, a new generation of angiogenesis research has emerged as well, widening the field into new areas of human disease and deepening it to examine the underlying biological processes responsible for those diseases.     

Specific cell targeting with APRPG conjugated PEG–PLGA nanoparticles for treating ovarian cancer

Good biocompatibility, specific tumor targeting, effective drug loading capacity and persistence in the circulation in vivo are imperative prerequisites for the antitumor efficiency of nanoparticles and their further clinical application. In this study, APRPG (Ala-Pro-Arg-Pro-Gly) peptide-modified poly (ethylene glycol)–poly (lactic acid) (PEG–PLA) nanoparticles (NP-APRPG) encapsulating inhibitors of angiogenesis (TNP-470) (TNP-470-NP-APRPG) were fabricated. TNP-470-NP-APRPG was designed to feature maleimide-PEG–PLA and mPEG–PLA as carrier materials, the APRPG peptide for targeting angiogenesis, PEG for prolonging circulation in vivo and PLA for loading TNP-470. TNP-470-NP-APRPG was confirmed to be approximately 130 nm in size with negative ζ-potential (−14.3 mV), narrow distribution (PDI = 0.27) and spherical morphology according to dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses. In addition, X-ray photoelectron spectra (XPS) analyses confirmed 7.73% APRPG grafting on the TNP-470-NP. In vitro, TNP-470-NP-APRPG exhibited effective inhibition of proliferation, migration and tube formation in human umbilical vein endothelial cells (HUVECs). Similar findings were observed for the retardation of tumor growth in SKOV3 ovarian cancer-bearing mice, suggesting the significant inhibition of angiogenesis and antitumor efficiency of TNP-470-NP-APRPG. Moreover, no obvious toxic drug responses were observed. Further evidence obtained from the immunohistochemical examination demonstrated that the tumor growth inhibition was closely correlated with the high rate of apoptosis among endothelial cells and the effective blockade of endothelial cell proliferation. These results demonstrate that NP-APRPG is a promising carrier for delivering TNP-470 to treat ovarian cancer and that this approach has the potential to achieve broad tumor coverage in the clinic.     

沙利度胺抗肿瘤机制及应用进展

沙利度胺（thalidomide）是目前研究广泛的口服抗血管生成和免疫调节剂。通过抑制肿瘤坏死因子（TNF）-α降低血管内皮生成因子（VEGF）表达、抑制环氧合酶（COX）等达到抗肿瘤血管生成、诱导凋亡作用。同时沙利度胺调节多种免疫细胞因子，间接抑制肿瘤细胞。临床试验表明沙利度胺对多种肿瘤治疗有效，是一种有效的化疗药物。目前已开发出多种疗效佳、不良反应小的类似物。