抗血管形成靶向药物的研究进展

肿瘤的生长和转移离不开肿瘤新生血管,这使得抗血管形成治疗成为肿瘤治疗的重要途径之一。血管内皮生长因子及其受体是抗肿瘤治疗的重要靶点之一。本文主要介绍了近年来抗血管形成治疗的一些最新药物研究成果——包括针对血管内皮生长因子的单克隆抗体——贝伐;针对血管内皮生长因子受体的酪氨酸激酶抑制剂——舒尼替尼、索拉非尼等;以及血管内皮生长因子受体的单克隆抗体IMC-1C11等。     

Future options ofanti-angiogenic cancer therapy

In human patients, drugs that block tumor vessel growth are widely used to treat a variety of cancer types. Many rigorous phase 3 clinical trials have demonstrated signiifcant survival beneifts; however, the addition of an anti-angio-genic component to conventional therapeutic modalities has generally produced modest survival beneifts for cancer patients. Currently, it is unclear why these clinically available drugs targeting the same angiogenic pathways produce dissimilar effects in preclinical models and human patients. In this article, we discuss possible mechanisms of various anti-angiogenic drugs and the future development of optimized treatment regimens.     

Molecular insight of regorafenib treatment for colorectal cancer

Regorafenib is a multi-targeting kinase inhibitor approved for the treatment of metastatic colorectal cancer patients in refractory to standard chemotherapy. Similarly to sorafenib, this agent was originally developed as a RAF1 inhibitor. However, the kinase inhibitory profile is distinct from sorafenib. A broad-spectrum of kinase inhibition induces wide-range drug sensitivity, irrespective of mutation status of major oncogenes. This agent’s main therapeutic effects are anti-angiogenesis and the remodeling of tumor microenvironment through several mechanisms of action. The dual blockade of VEGF receptors and TIE2 can lead to both additive anti-angiogenesis effects and the suggestive unique regulation of vessel stability. Additionally, it inhibits molecular escape pathways to VEGF inhibition (e.g., FGF, PIGF, and PDGF signaling), enabling its continuous antiangiogenic effect even in tumors resistant to VEGF inhibitors. Furthermore, regorafenib has the important effect of enhancing anti-tumor immunity via macrophage modulation. Based on this concept, clinical trials have been recently launched for the development of a combination strategy with immune checkpoint inhibitors. Contrary to regorafenib induced clinical benefits and advances in the novel strategy, currently no predictive biomarkers have been identified. In the present review, we revisit and summarize regorafenib’s unique mechanisms of action. The review could highlight molecular insights and provide some perspective for the search of predictive biomarkers used in metastatic colorectal cancer patients treated with regorafenib.     

Inhibition of blood vessel formation by a chondrocyte-derived extracellular matrix

In this study, the chondrocyte-derived extracellular matrix (CECM) was evaluated for its activity to inhibit vessel invasion in vitro and in vivo. Human umbilical vein endothelial cells (HUVECs) and rabbit chondrocytes were plated on a bio-membrane made of CECM or human amniotic membrane (HAM). The adhesion, proliferation, and tube formation activity of HUVECs and chondrocytes were examined. The CECM and HAM powders were then mixed individually in Matrigel and injected subcutaneously into nude mice to examine vessel invasion in vivo after 1 week. Finally, a rabbit model of corneal neovascularization (NV) was induced by 3-point sutures in the upper cornea, and CECM and HAM membranes were implanted onto the corneal surface at day 5 after suture injury. The rabbits were sacrificed at 7 days after transplantation and the histopathological analysis was performed. The adhesion and proliferation of HUVECs were more efficient on the HAM than on the CECM membrane. However, chondrocytes on each membrane showed an opposite result being more efficient on the CECM membrane. The vessel invasion in vivo also occurred more deeply and intensively in Matrigel containing HAM than in the one containing CECM. In the rabbit NV model, CECM efficiently inhibited the neovessels formation and histological remodeling in the injured cornea. In summary, our findings suggest that CECM, an integral cartilage ECM composite, shows an inhibitory effect on vessel invasion both in vitro and in vivo, and could be a useful tool in a variety of biological and therapeutic applications including the prevention of neovascularization after cornea injury.     

Local and systemic delivery of VEGF siRNA using polyelectrolyte complex micelles for effective treatment of cancer

For efficient cancer therapy, small interfering RNA (siRNA) should be stably and efficiently delivered into the target tissue and readily taken up by cancer cells. To address these needs, a polyelectrolyte complex (PEC) micelle-based siRNA delivery system was developed for anti-angiogenic gene therapy. The interaction between poly(ethylene glycol) (PEG)-conjugated vascular endothelial growth factor siRNA (VEGF siRNA–PEG) and polyethylenimine (PEI) led to the spontaneous formation of nanoscale polyelectrolyte complex micelles (VEGF siRNA–PEG/PEI PEC micelles), having a characteristic siRNA/PEI PEC inner core with a surrounding PEG shell layer. Intravenous as well as intratumoral administration of the PEC micelles significantly inhibited VEGF expression at the tumor tissue and suppressed tumor growth in an animal tumor model without showing any detectable inflammatory responses in mice. Upon examination of the PEC micelle distribution and in vivo optical imaging following intravenously injection, enhanced accumulation of the PEC micelles was also observed in the tumor region. This study demonstrates the feasibility of using PEC micelles as a potential carrier for therapeutic siRNAs in local and systemic treatment of cancer.     

阿帕替尼联合放化疗治疗晚期头颈部鳞癌的前瞻性研究

目的 研究旨在探索阿帕替尼联合放化疗治疗晚期头颈部鳞癌的有效性和安全性。方法 37例患者在同步放化疗期间口服阿帕替尼250mg/d,直到放疗结束、经影像学评估为完全缓解、不可接受的不良反应或死亡。在所有具有完整基线和安全性数据的患者中评估基线特征、客观反应率(ORR)和不良反应事件。使用Kaplan-Meier法计算无进展生存(PFS)和总生存(OS)率,Cox模型进行预后影响因素分析。结果 ORR为85%(95%CI为72%~98%),中位PFS为17.9个月,2年OS率为62%(95%CI为48%~80%)。近期疗效为无效(HR=0.035,95%CI为0.02~0.652,P=0.025)是OS较差的独立影响险因素,近期疗效为无效(HR=0.104,95%CI为0.017~0.633,P=0.014)和淋巴细胞减少(HR=17.539,95%CI为2.040~150.779,P=0.009)是PFS较差的独立影响因素。常见不良反应(>60%)为淋巴细胞减少症(76%)、白细胞减少症(68%)和放射性黏膜损伤(65%)。最常见的治疗相关3级不良事件是淋巴细胞减少症(49%)。结论 阿帕替尼联合放化疗对头颈部鳞癌具有显著的抗肿瘤活性,不良反应可控。对于晚期患者,近期疗效和淋巴细胞减少可能是阿帕替尼联合放化疗疗效的预测因子。     

复方苦参注射液对小鼠移植性S180肉瘤血管形成抑制作用

[目的]探讨复方苦参注射液对肿瘤血管形成的抑制作用。[方法]通过建立小鼠肿瘤模型,运用免疫组化方法,观察复方苦参注射液对小鼠移植性S180肉瘤血管形成抑制作用。[结果]小鼠腹腔注射复方苦参注射液0.3,0.6g/kg,连续8d后瘤体较对照组分别减小25%,36%;瘤体微血管密度较对照组分别减小32%,40%。[结论]复方苦参注射液能够抑制肿瘤的生长,具有抑制肿瘤血管形成的作用。     

Gene therapy in pancreatic cancer

Pancreatic cancer(PC) is a highly lethal disease and notoriously difficult to treat. Only a small proportion of PC patients are eligible for surgical resection, whilst conventional chemoradiotherapy only has a modest effect with substantial toxicity. Gene therapy has become a new widely investigated therapeutic approach for PC.This article reviews the basic rationale, gene delivery methods, therapeutic targets and developments of laboratory research and clinical trials in gene therapy of PC by searching the literature published in English using the PubMed database and analyzing clinical trials registered on the Gene Therapy Clinical Trials Worldwide website(http://www. wiley.co.uk/genmed/ clinical). Viral vectors are main gene delivery tools in gene therapy of cancer, and especially, oncolytic virus shows brighter prospect due to its tumor-targeting property.Efficient therapeutic targets for gene therapy include tumor suppressor gene p53, mutant oncogene K-ras,anti-angiogenesis gene VEGFR, suicide gene HSK-TK,cytosine deaminase and cytochrome p450, multiple cytokine genes and so on. Combining different targets or combination strategies with traditional chemoradiother-apy may be a more effective approach to improve the efficacy of cancer gene therapy. Cancer gene therapy is not yet applied in clinical practice, but basic and clinical studies have demonstrated its safety and clinical benefits. Gene therapy will be a new and promising field for the treatment of PC.     

长春瑞滨联合西妥昔单抗抑制血管生成作用的实验研究

目的 探讨长春瑞滨联合西妥昔单抗对体内外血管生成的抑制作用.方法 以人肺腺癌细胞株A549为对照,采用四甲基偶氮唑蓝(MTT)法,观察长春瑞滨联合西妥昔单抗对人脐静脉内皮细胞(HUVEC)增殖能力的影响;应用Transwell小室模型、体外小管形成实验及流式细胞术,分别观察长春瑞滨联合西妥昔单抗对HUVEC迁移、小管形成及细胞凋亡的影响;应用鸡胚绒毛尿囊膜(CAM)模型,观察药物对体内CAM血管生成的抑制作用.结果 0.1、0.4和0.8 ng/ml长春瑞滨对HUVEC增殖的抑制率分别为25.8%、39.2%和54.0%,0.25 μg/ml西妥昔单抗对HUVEC增殖的抑制率为19.7%.0.1 ng/ml长春瑞滨+0.25 μg/ml西妥昔单抗和0.4 ng/ml长春瑞滨+0.25 μg/ml西妥昔单抗对HUVEC增殖的抑制率分别为29.5%和46.4%,联合用药有次加作用;0.8 ng/ml长春瑞滨+0.25 μg/ml西妥昔单抗对HUVEC增殖的抑制率为64.6%,联合用药有协同作用.0.1、0.4和0.8 ng/ml长春瑞滨分别联合0.25 μg/ml西妥昔单抗具有抑制HUVEC迁移的作用,抗HUVEC迁移率分别为51.9%、68.2%和95.0%,联合应用有协同作用.0.1 ng/ml长春瑞滨+0.25 μg/ml西妥昔单抗或0.4 ng/ml长春瑞滨+0.25 μg/ml西妥昔单抗对抑制HUVEC小管形成有次加或协同作用,抗HUVEC小管形成率分别为38.8%和57.7%;0.8 ng/ml长春瑞滨+0.25 μg/ml西妥昔单抗对抑制HUVEC小管形成有协同作用,抗HUVEC小管形成率为78.9%.0.8 ng/ml长春瑞滨+0.25 μg/ml西妥昔单抗诱导HUVEC的凋亡率为59.9%,有协同作用.长春瑞滨联合西妥昔单抗具有协同抑制CAM血管生成的作用.结论 小剂量长春瑞滨和西妥昔单抗在体内外具有抗血管生成作用,联合用药具有次加或协同作用.     

OPN b and c Isoforms Doubtless Veto Anti-angiogenesis Effects of Curcumin in Combination with Conventional AML Regiment

Osteopontin (OPN) is an extracellular structural protein that is secreted by osteoblasts and hematopoietic cells. It suppresses the proliferation of hematopoietic stem and also plays an important role in promoting survival and drug resistance in leukemic stem cells (LSCs). Since the role of OPN isoforms in AML angiogenesis are remaining controversial, in the present study, we aimed to evaluate whether curcumin (CUR), as a known natural component with anti-angiogenesis effects, in a combination of AML conventional regiment has the potency to preclude induced anti-angiogenesis effects of OPN isoforms or not? Leukemia cells were treated with different concentration of CUR and AML conventional drugs alone and/or in combination with together to find effective doses and IC50 values. Percentages of apoptotic cells were evaluated by Annexin/PI staining and mRNA levels of OPN isoforms and AKT/ VEGF-A and VEGF-C/ STAT3/ β-catenin/ CXCR4/ IL-6/ KDR gene expression were investigated by Real Time-PCR method. Moreover, to confirm OPN gene expression data, we investigated the effect of simvastatin and OPN siRNA as an OPN inhibitor on the cell proliferation and induction of apoptosis in the indicated cell lines. Our data display that Ara-c (2μM and 1μM in KG-1 and U937 cell lines respectively), CUR (40μM in both cell lines), and also their combination significantly increased the percentage of apoptotic cells. Moreover, the mRNA level of OPN isoforms were down regulated in the KG-1and U937 cell lines treated with Ara-c while, upregulated in KG-1and U937 cell lines treated with CUR and its combination. Our results suggest that despite anti-angiogenesis effects of CUR, AML cells probably evade from anti-angiogenesis effects of CUR via induction of OPN b and c isoform and related molecular pathways.