Long survival of patients with metastatic clear cell renal cell carcinoma. Results of real life study of 344 patients

The treatment landscape in metastatic renal cell carcinoma has changed fundamentally over the last decade by the development of antiangiogenic agents, mammalian target of rapamycin inhibitors and immunotherapy. Outside of the context of a clinical trial, the treatments are used sequentially. We describe results under real-life conditions of a sequential treatment strategy, before the era of immunotherapy. All patients were treated according to their prognostic score (either Memorial Sloan Kettering Cancer Center or International Metastatic Renal Cell Carcinoma Database Consortium) for advanced renal cell carcinoma. A treatment strategy involving 1 to 4 lines was determined including a rechallenge criterion for the repeat use of a treatment class. Three hundred forty-four patients were included over 3 years. Overall survival was 57 months in patients with good or intermediate prognosis and 19 months in patients with poor prognosis. In the former group, the proportions of patients treated with 2 to 4 treatment lines were 70%, 38% and 16%, respectively. The best objective response rates for lines 1 to 4 were 46%, 36%, 16% and 17%, respectively. Grade III/IV toxicity did not appear to be cumulative. The recommended strategy was followed in 68% of patients. A large proportion of patients with good or intermediate prognosis who progress after two lines of treatment still have a performance status good enough to receive a systemic treatment, which justifies such a strategy. Overall survival of patients with good and intermediate prognosis was long, suggesting a benefit from the applied approach. These results might be used as selection criterion for the treatment of patients in the era of immune checkpoint inhibitors.     

血管内皮生长因子165b抑制肿瘤血管生成的研究进展

研究认为血管内皮生长因子（vascular endothelial growth factor,VEGF）基因差异剪接后能够产生促进血管生成的VEGFxxx和抑制血管生成的VEGFxxxb。在VEGFxxxb家族中,VEGF165b在功能上具有代表性地位,表现出明显的抑制VEGF165所介导的血管生成作用。由于VEGF165b具有机体自然产生、不具有免疫原性的优势,有望通过强制高表达、外源性给予重组蛋白或促进VEGF外显子8b选择性剪接抑制肿瘤血管生成,从而用于肿瘤的治疗。     

重组人色素上皮衍生因子显著抑制血管内皮细胞增殖

目的通过原核表达,获得具有生物活性的人重组色素上皮衍生因子(PEDF).方法将PEDF基因构建到GST原核表达系统中,经过表达纯化,获得重组蛋白,采用Westem b1ot和质谱分析确证该重组蛋白,采用MTT法检测所获得的重组蛋白对人脐静脉内皮细胞增殖的抑制活性.结果获得了相对分子质量为46 000的重组人PEDF重组蛋白,该蛋白可显著抑制血管内皮细胞增殖.结论成功地经过原核表达获得了具有血管生成抑制活性的重组人色素上皮衍生因子.     

鸡tie-2受体胞外片段重组蛋白的制备及其抗血管生成作用的研究

目的　设法调控血管的生长发育 ,从而达到治疗疾病的目的。方法　用 PCR方法从既往构建含鸡 tie- 2受体胞外段基因的表达质粒中扩增目的片段 ,构建 p QE质粒原核表达载体并诱导目的蛋白的表达 ;将目的蛋白进一步纯化、复性并免疫小鼠 ,获得抗血清 ,用 EL ISA和 Western印迹检测抗血清中抗体的存在 ;分离纯化抗体 ,用流式细胞仪体外观察其对血管内皮细胞生长情况的影响用体内藻酸盐包裹肿瘤细胞实验和肿瘤内微血管 CD31免疫组化观察其对血管生成情况的影响。结果　经酶切分析及测序鉴定表明获得了鸡 tie- 2受体胞外目的片段的p QE原核表达载体 ,且高效表达目的蛋白 ,其免疫小鼠可产生抗重组蛋白的抗体 ;体外细胞培养结果显示免疫后产生的抗体明显的诱导血管内皮细胞凋亡 ;藻酸盐包裹实验表明此抗体能显著降低肿瘤新生血管的形成 ;CD31微血管计数显示此抗体能明显减少肿瘤内微血管数。结论　用原核表达的方法成功制备了鸡 tie- 2受体胞外片段 (配体结构域 )的蛋白疫苗 ,且此疫苗能明显产生抗血管生成作用。     

Anti-angiogeneic Target Therapy for Cancer with Vaccine Based on the Recombinant Chicken FGFR-1 in Tumor-bearing Mice

To explore the anti-tumor effect of immunotherapy with recombinant protein vaccine based on FGFR-1 of chicken (cFR-1) in a mouse Meth A fibrosarcoma model, tumor volume and sur- vival rate of the mice were observed at a 3-day interval. Microvessel density (MVD) was detected by immunohistochemistry. Auto-antibodies against self-FGFR-1 were detected by Western blotting and ELISA, respectively. The anti-FGFR-1 antibody-producing B cells (APBCs) were detected by enzyme-linked immunospot (ELISPOT) assay. Eighteen days after inoculation of tumor cells, the tumor volume was significantly smaller in cFR-1-immunized group than in mouse FGFR-1 (mFR-1) immunized group and normal saline (NS) control group (P<0.05), and the survival time was signifi- cantly longer in cFR-1-immunized group than in the control groups (P<0.01). MVD was significantly lower in cFR-1-immunized group than in mFR-1-immunized group and NS group (16.8 ±5.6 vs 64.6±1.8 and 59.6±8.7, P<0.01). Antibodies against self-FGFR-1 were found in mFR-1-immunized group, the major antibody subclasses were IgG1 and IgG2b. Compared with the two control groups, the numbers of APBCs in cFR-1-immunized group were significantly increased (P<0.01) These re- sults demonstrated that the cFR-1-related anti-angiogenesis protein vaccine could induce the produc- tion of auto-antibodies against self-FGFR-1, which futher inhibit angiogenesis and growth of solid tumor.     

腺相关病毒介导的HGFK1对大鼠肝细胞癌的治疗作用研究

背景与目的:肝细胞痛是一种有高度新生血管的肝脏恶性肿瘤,进展期肝细胞癌的预后很差,目前缺乏有效的治疗.近来有报道肝细胞生长因子的Kringle 1结构域(HGFK1)基因具有很强的抑制新生血管的作用.本研究探讨肝细胞生长因子Kringle 1结构域(HGFK1)基因对原发性肝细胞癌的治疗作用及其机制.方法:构建携带有HGFK1基因的腺相关病毒载体(rAAV-HGFK1),建立大鼠原发性肝细胞癌模型,以rAAV-HGFK1进行治疗,继而观察大鼠原发性肝癌模型的生存时间、肿瘤生长情况、肿瘤内血管密度以及转移情况.结果:在大鼠肝脏内注射6×105个大鼠肝细胞癌细胞株McA-RH7777后,第10天全部成瘤.通过向瘤内和门静脉内注射rAAV-HGFK1导入HGFK1基因可以明显延长荷肝细胞癌大鼠的生存时间,对照组生存时间为30 d,而治疗组的生存时间为49 d.在对照的PBS注射组和AAV-EGFP注射组,肝脏和腹腔内转移的发生率都是100%;而肺转移的发生率则分别为100%和83%.而治疗组都没有转移,且腹水的发生率才只有33%.组织学证实AAV-HGFK1对肿瘤的作用则具体表现为肿瘤生长的受到抑制、肿瘤内血管密度的减少、以及发生肝内、肺、腹膜等转移机率的下降.HGFK1表现出了明显的抗血管生成及抑制肿瘤细胞生长作用.在大鼠体内的毒性实验未发现明显毒性.结论:HGFK1能通过抗血管生成作用达到抑制肝细胞癌原发灶及转移灶的效果,显著延长荷瘤大鼠的生存时间,没有发现明显的毒性,为临床抗肿瘤治疗提供了一个潜在的新靶点.     

Anti-sphingosine-1-phosphate monoclonal antibodies inhibit angiogenesis and sub-retinal fibrosis in a murine model of laser-induced choroidal neovascularization

The efficacy of novel monoclonal antibodies that neutralize the pro-angiogenic mediator, sphingosine-1-phosphate (S1P), were tested using in vitro and in vivo angiogenesis models, including choroidal neovascularization (CNV) induced by laser disruption of Bruch's membrane. S1P receptor levels in human brain choroid plexus endothelial cells (CPEC), human lung microvascular endothelial cells, human retinal vascular endothelial cells, and circulating endothelial progenitor cells were examined by semi-quantitative PCR. The ability of murine or humanized anti-S1P monoclonal antibodies (mAbs) to inhibit S1P-mediated microvessel tube formation by CPEC on Matrigel was evaluated and capillary density in subcutaneous growth factor-loaded Matrigel plugs was determined following anti-S1P treatment. S1P promoted in vitro capillary tube formation in CPEC consistent with the presence of cognate S1P_1-5 receptor expression by these cells and the S1P antibody induced a dose-dependent reduction in microvessel tube formation. In a murine model of laser-induced rupture of Bruch's membrane, S1P was detected in posterior cups of mice receiving laser injury, but not in uninjured controls. Intravitreous injection of anti-S1P mAbs dramatically inhibited CNV formation and sub-retinal collagen deposition in all treatment groups (p < 0.05 compared to controls), thereby identifying S1P as a previously unrecognized mediator of angiogenesis and subretinal fibrosis in this model. These findings suggest that neutralizing S1P with anti-S1P mAbs may be a novel method of treating patients with exudative age-related macular degeneration by reducing angiogenesis and sub-retinal fibrosis, which are responsible for visual acuity loss in this disease.     

The endogenous anti-angiogenic VEGF isoform, VEGF165b inhibits human tumour growth in mice

Vascular endothelial growth factor-A is widely regarded as the principal stimulator of angiogenesis required for tumour growth. VEGF is generated as multiple isoforms of two families, the pro-angiogenic family generated by proximal splice site selection in the terminal exon, termed VEGFxxx, and the anti-angiogenic family formed by distal splice site selection in the terminal exon, termed VEGFxxxb, where xxx is the amino acid number. The most studied isoforms, VEGF165 and VEGF165b have been shown to be present in tumour and normal tissues respectively. VEGF165b has been shown to inhibit VEGF- and hypoxia-induced angiogenesis, and VEGF-induced cell migration and proliferation in vitro. Here we show that overexpression of VEGF165b by tumour cells inhibits the growth of prostate carcinoma, Ewing's sarcoma and renal cell carcinoma in xenografted mouse tumour models. Moreover, VEGF165b overexpression inhibited tumour cell-mediated migration and proliferation of endothelial cells. These data show that overexpression of VEGF165b can inhibit growth of multiple tumour types in vivo indicating that VEGF165b has potential as an anti-angiogenic, anti-tumour strategy in a number of different tumour types, either by control of VEGF165b expression by regulation of splicing, overexpression of VEGF165b, or therapeutic delivery of VEGF165b to tumours.     

VEGF and Delta-Notch: interacting signalling pathways in tumour angiogenesis

Tumour angiogenesis has become an important target for antitumour therapy, with most current therapies aimed at blocking the VEGF pathway. However, not all tumours are responsive to VEGF blockers, and some tumours that are responsive initially may become resistant during the course of treatment, thus there is a need to explore other angiogenesis signalling pathways. Recently, the Delta-Notch pathway, and particularly the ligand Delta-like 4 (Dll4), was identified as a new target in tumour angiogenesis. An important feature in angiogenesis is the manifold ways in which the VEGF and Delta-Notch pathways interact. The emerging picture is that the VEGF pathway acts as a potent upstream activating stimulus for angiogenesis, whereas Delta-Notch helps to guide cell fate decisions that appropriately shape the activation. Here we review the two signalling pathways and what is currently known about the ways in which they interact during tumour angiogenesis.     

Perspectives of Cellular and Molecular Neurosurgery

Therapeutic efforts for human glial tumors have over the past years been redirected towards a compartmental treatment concept. The diffusely infiltrative nature of the disease calls for therapeutic agents to reach single cells far beyond the focus of attention which present therapies like surgery and radiation are able to treat. Specific drug discovery approaches which seek to define targets which are specific for gliomas have generated therapeutic options which allow for a highly selective development of new reagents. Combined with new modalities for compartmental drug delivery, systemic complications might be reduced and advantage taken of a compartmental specificity of a target which otherwise in the context of systemic application would not be as specific or burdened with side effects. From the present status of therapeutic developments in neuro-oncology it can be expected that a sufficient number of drug targets emerge which can be exploited by means of interstitial or intracavitary delivery, which are not neurotoxic and which may even be imaged in their action with the new metabolic imaging modalities. Convection enhanced delivery, conditionally replicating oncolytic viruses and motile, genetically engineered neural stem cells all seem to fulfill the distribution requirements which an effective therapeutic for gliomas will need to overcome the very limited efficacy which surgery, conventional chemotherapy and radiation have to offer. Whereas the genomics based discovery approaches are not specific for neuro-oncology, the development of delivery strategies is highly specific for the central nervous system, thus creating a unique set of organ and disease specific therapies.