The tumor vessel targeting agent NGR-TNF controls the different stages of the tumorigenic process in transgenic mice by distinct mechanisms

Abstract

NGR-TNF is a vascular targeting agent in advanced clinical development, coupling tumor necrosis factor-a (TNF) with the CNGRCG peptide, which targets a CD13 isoform specifically expressed by angiogenic vessels. Antitumor efficacy of NGR-TNF has been described in different transplantation tumor models. Nevertheless, the mechanism underlying its activity is not fully understood. In the wild type and in the immunodeficient (RAG ¡/¡ ) RIP1-Tag2 models of multistage pancreatic carcinogenesis, we demonstrate that CD13 is highly expressed on endothelial cells of hyperplastic and angiogenic islets, whereas its expression is down regulated in tumors where it partially colocalize with pericytes. In vivo CNGRCG peptides coupled to fluorescent nanoparticles (quantum dots) bind to CD13 and colocalize with anti-CD31, in pancreatic islets. At early stage, low doses of NGR-murine (m)TNF have a direct cytotoxic effect inducing endothelial cell apoptosis, reducing vessel density and eventually inhibiting the development of angiogenic islets. At a later stage, NGRmTNF is able to reduce tumor growth inducing vascular normalization, exclusively when treatment is carried out in the immunocompetent mice. Interestingly, NGR-mTNF-treated tumors from these mice are characterized by CD8 C T cell infiltration. At molecular level, overexpression of genes involved in vessels normalization was detected only in NGRmTNF-treated tumors from immunocompetent mice.These findings identified a new mechanism of action of NGR-mTNF, providing support for the development of new therapeutic strategies combining chemotherapy or active/adoptive immunotherapies to low dose NGR-TNF treatment.

Mechanism of Action of the Tumor Vessel Targeting Agent NGR-hTNF: Role of Both NGR Peptide and hTNF in Cell Binding and Signaling

“…Related to this increase in caspase activation, it was found that viability was significantly reduced in the cells pulsed with NGR-hTNF in comparison with hTNF (Figure 6C), with a significant EC50 reduction ( p < 0.05; 5 experiments). These results are in agreement with the high level of NGR-TNF-mediated apoptosis detected in vivo, as already described in the literature [7,8], and shown in Supplementary Figure S5A. The apoptosis of endothelial cells along tumor vessels was detected in histological sections of CT26 tumor harvested from tumor-bearing mice 24 h after NGR-hTNF administration, but not after hTNF treatment.…”

“…The in vivo effects of NGR-TNF are multiple and include an alteration of the endothelial barrier function, increased tumor permeability [4,5], and immunological effects [6]. It has been demonstrated that NGR-TNF induces apoptosis of tumor and endothelial cells in vivo [7,8], and that it can promote, through the involvement of the immune system, vessel normalization and an immune-supportive microenvironment, which ultimately results in reduced tumor growth [8]. NGR-hTNF has been administered as an anti-cancer drug alone or in combination with chemotherapy, in several clinical studies encompassing tumors of different histological types (reviewed in [9]).…”

“…The second receptor involved in the NGR-hTNF activity is the CD13 isoform selectively expressed on the tumor endothelial cells [8,29,30], that mediate the binding to the CNGRC motif. CD13, also expressed in a few normal tissues, several tumors and myeloid cells [30,31], is a multiple function ectoenzyme with a role in viral binding, antigen presentation, angiogenesis, and in cell adhesion, motility and invasion (reviewed in [32]).…”

Vascular targeting of LIGHT normalizes blood vessels in primary brain cancer and induces intratumoural high endothelial venules

“…In contrast to human GBM, which shows strong vascular CD13 expression [47], blood vessels in our mouse GBM models are CD13-negative by IHC, indicating low expression levels. Similarly, in a model of neuroendocrine pancreatic cancer, CD13 is downregulated during tumour progression, thus making NGR binding to tumour vessels less effective [48]. As cyclic NGR, when conjugated to TNF-α, is therapeutically more active than its linear counterpart, it is also possible that linear NGR, as employed throughout this study, has inferior tumour vessel binding activity [49].…”

Evaluation of Antitumor Activity of Tumor Necrosis Factor Alpha Within the Artificial Virus-Like Particle

“…Наиболее выраженный и стабильный противоопухолевый эффект был отмечен при 5-кратном внутривенном введении препарата в дозе 1 × 10 5 МЕ / мышь с интервалом в 1 день. исследование влияния фактора некроза опухоли α в составе искусственной вирусоподобной частицы на морфологию экспериментальной опухоли Как известно, противоопухолевый эффект ФНО-α реализуется, помимо цитотоксического воздействия на клетки опухоли, посредством 2 основных механизмов: через повреждение кровеносных сосудов опухоли и индукцию противоопухолевого иммунного ответа [15,16]. В связи с этим для уточнения механизмов действия ФНО-α в средстве доставки было проведено исследование морфологии первичной опухоли, состояния кровеносных сосудов и присутствия эффекторных клеток иммунной системы в ткани опухоли после внутривенного введения препарата в сравнении с показателями контрольных животных.…”