Introduction: Cancer is one of the main causes of morbidity and mortality worldwide. Angiogenesis is general hallmark in the tumor growth and metastasis of cancers. Accordingly, therapies targeting angiogenesis and tumor vasculature (TV), such as vascular endothelial growth factor (VEGF)-targeted agents (like Bevacizumab which remains the only VEGF-targeted agent approved by the US Food and Drug Administration), are considered as the first-line treatment strategies for patients with metastatic cancers. Heterogeneity in primary tumor and related metastases however, similar to other anticancer therapies, demands precision and personalized therapeutic approaches for targeting TV, while lack of selectivity/specificity might impede their ‘‘systemic administration, too The tumor-associated endothelial cells (TAECs) are major cell type involved in tumor angiogenesis. The overexpression of vascular endothelial growth factor receptor-2 (VEGFR2 or KDR) in TAECs makes them a potent candidate for targeted therapy against cancer.
Methods: Several VEGFR2-targeted lentiviral vectors (LVs) pseudotyped with chimeric sindbis virus E2 glycoprotein (cSVE2s) were constructed. To this end, either sequence of a VEGFR2-specific nanobody (3VGR19) or its natural ligand (VEGF121) was inserted into the binding site of sindbis virus E2 glycoprotein (as fusogenic molecule). In addition, the corresponding LVs were constructed employing two transductional strategies, so called “chimeric” or “two molecules” strategies. For in silico modeling, FASTA sequence formats of cSVE2s were submitted to I-TASSER server. Other methods were based on regular protocols.
Results: In silico modeling data suggested that the inserted targeting motifs were exposed in the context of cSVE2s. Western blot analysis of LVs indicated the incorporation of cSVE2s into viral particles. Capture ELISA demonstrated the specificity/functionality of the incorporated cSVE2s. Transduction of 293/KDR (expressing VEGFR2) or 293T cells (negative control) by constructed LVs followed by fluorescent microscopy and flow cytometric analyses indicated selective transduction of 293/KDR cells (30 %) by both targeting motifs compared to 293T control cells (1–2 %).
Conclusions: These results implied similar targeting properties of VEGFR2-specific nanobody compared to the VEGF121 and still superior outcomes for two-molecule strategy and indicated the potential for transductional targeting of tumor vasculature by the nanobody displaying LVs which might be used as a carrier for precise/personalized delivery of Anti-TV therapeutics.
Personalized therapies (cancer, immunology, infectious diseases, clinical case studies, et
