Isolation and characterization of nanobodies against epithelial cell adhesion molecule as novel theranostic agents for cancer therapy

Nanobodies targeting the tumor microenvironment and their formulation as nanomedicines

Among the emerging strategies for cancer theranostics, nanomedicines offer significant promise in advancing both patients' diagnosis and treatment. In combination with nanobodies, nanomedicines can potentially enhance the precision and efficiency of drug or imaging agent delivery, addressing key limitations of current approaches, such as off-target toxicities. The development of nanomedicines will be further accelerated by the creation of smart nanoparticles, and their integration with immunotherapy. Obviously, the success of nano-immunotherapy will depend on a comprehensive understanding of the tumor microenvironment, including the complex interplay of mechanisms that drive cancer-mediated immunosuppression and immune escape. Hence, effective therapeutic targeting of the tumor microenvironment requires modulation of immune cell function, overcoming resistance mechanisms associated with stromal components or the extracellular matrix, and/or direct elimination of cancer cells. Identifying key molecules involved in cancer progression and drug resistance is, therefore, essential for developing effective therapies and diagnostic tools that can predict patient responses to treatment and monitor therapeutic outcomes. Current nanomedicines are being designed with careful consideration of factors such as the choice of carrier (e.g., biocompatibility, controlled cargo release) and targeting moiety. The unique properties of nanobodies make them an effective engineering tool to target biological molecules with high affinity and specificity. In this review, we focus on the latest applications of nanobodies for targeting various components of the tumor microenvironment for diagnostic and therapeutic purposes. We also explore the main types of nanoparticles used as a carrier for cancer immunotherapies, as well as the strategies for formulating nanoparticle-nanobody conjugates. Finally, we highlight how nanobody-nanoparticle formulations can enhance current nanomedicines.

Encapsulation of anti-VEGF nanobody into niosome nanoparticles: a novel approach to enhance circulation half life and efficacy

This study aimed to encapsulate an anti-VEGF nanobody (Nb) within niosome nanoparticles (NNPs) to enhance its circulation half life. Key parameters such as encapsulation efficiency, stability, Nb release, cytotoxicity, and cell migration inhibition in HUVEC cells were evaluated, along with pharmacokinetic studies in mice. Nb-loaded NNPs (Nb-NNPs) were successfully prepared with an encapsulation efficiency of 78.3 ± 3.2% and demonstrated stability over one month. In vitro assays revealed that Nb-NNPs enhanced cytotoxicity and significantly reduced cell migration in HUVEC cells compared to free Nb (P < 0.05). Pharmacokinetic studies in mice demonstrated a dramatically reduced elimination rate constant (0.025 h-1 vs. 0.843 h-1) and an extended terminal half life (27.721 h vs. 0.822 h), indicating slower clearance and prolonged systemic presence. In conclusion, these findings underscore the potential of Nb-NNPs to provide sustained and potent therapeutic effects, contributing valuable insights for advancing targeted therapeutic strategies.

Discovery of nanobodies: a comprehensive review of their applications and potential over the past five years

Nanobodies (Nbs) are antibody fragments derived from heavy-chain-only IgG antibodies found in the Camelidae family as well as cartilaginous fish. Their unique structural and functional properties, such as their small size, the ability to be engineered for high antigen-binding affinity, stability under extreme conditions, and ease of production, have made them promising tools for diagnostics and therapeutics. This potential was realized in 2018 with the approval of caplacizumab, the world's first Nb-based drug. Currently, Nbs are being investigated in clinical trials for a broad range of treatments, including targeted therapies against PDL1 and Epidermal Growth Factor Receptor (EGFR), cardiovascular diseases, inflammatory conditions, and neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. They are also being studied for their potential for detecting and imaging autoimmune conditions and infectious diseases such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A variety of methods are now available to generate target-specific Nbs quickly and efficiently at low costs, increasing their accessibility. This article examines these diverse applications of Nbs and their promising roles. Only the most recent articles published in the last five years have been used to summarize the most advanced developments in the field.

Development and characterization of nanobody against envenomation by Naja naja oxiana

Snakebites are considered a significant health issue. Current antivenoms contain polyclonal antibodies, which vary in their specificity against different venom components. Development and characterization of next generation antivenoms including nanobodies against Naja naja oxiana was the main aim of this study. Crude venom was injected into the Sephadex G50 filtration gel chromatography column and then toxic fractions were obtained. Then the corresponding fraction was injected into the HPLC column and the toxic peaks were identified. N. naja oxiana venom was injected into a camel and specific nanobodies screening was performed against the toxic peak using phage display technique. The obtained results showed that among the 12 clones obtained, N24 nanobody was capable of neutralizing P1, the most toxic peak obtained from HPLC chromatography. The molecular weight of P1 was measured with a mass spectrometer and was found to be about seven kDa. The results of the neutralization test of crude N. naja oxiana venom with N24 nanobody showed that 250 μg of recombinant nanobody could neutralize the toxic effects of 20 μg equivalent to LD50 × 10 of crude venom in mice. The findings indicate the potential of the developed nanobody to serve as a novel antivenom therapy.

Enhancing the cytotoxicity of immunotoxins by facilitating their dissociation from target receptors under the reducing conditions of the endocytic pathway

Immunotoxins (ITs) are recombinant chimeric proteins that combine a protein toxin with a targeting moiety to facilitate the selective delivery of the toxin to cancer cells. Here, we present a novel strategy to enhance the cytosolic access of ITs by promoting their dissociation from target receptors under the reducing conditions of the endocytic pathway. We engineered monobodySS, a human fibronectin type III domain-based monobody with disulfide bond (SS)-containing paratopes, targeting receptors such as EGFR, EpCAM, Her2, and FAP. MonobodySS exhibited SS-dependent target receptor binding with a significant reduction in binding under reducing conditions. We then created monobodySS-based ITs carrying a 25 kDa fragment of Pseudomonas exotoxin A (PE25), termed monobodySS-PE25. These ITs showed dose-dependent cytotoxicity against target receptor-expressing cancer cells and a wider therapeutic window due to higher efficacy at lower doses compared to controls with SS reduction inhibited. ERSS/28-PE25, with a KD of 28 nM for EGFR, demonstrated superior tumor-killing potency compared to ER/21-PE25, which lacks an SS bond, at equivalent and lower doses. In vivo, ERSS/28-PE25 outperformed ER/21-PE25 in suppressing tumor growth in EGFR-overexpressing xenograft mouse models. This study presents a strategy for developing solid tumor-targeting ITs using SS-containing paratopes to enhance cytosolic delivery and antitumor efficacy.

Applications of the phage display technology in molecular biology, biotechnology and medicine

The phage display technology is based on the presentation of peptide sequences on the surface of virions of bacteriophages. Its development led to creation of sophisticated systems based on the possibility of the presentation of a huge variability of peptides, attached to one of proteins of bacteriophage capsids. The use of such systems allowed for achieving enormous advantages in the processes of selection of bioactive molecules. In fact, the phage display technology has been employed in numerous fields of biotechnology, as diverse as immunological and biomedical applications (in both diagnostics and therapy), the formation of novel materials, and many others. In this paper, contrary to many other review articles which were focussed on either specific display systems or the use of phage display in selected fields, we present a comprehensive overview of various possibilities of applications of this technology. We discuss an usefulness of the phage display technology in various fields of science, medicine and the broad sense of biotechnology. This overview indicates the spread and importance of applications of microbial systems (exemplified by the phage display technology), pointing to the possibility of developing such sophisticated tools when advanced molecular methods are used in microbiological studies, accompanied with understanding of details of structures and functions of microbial entities (bacteriophages in this case).

Advancements in ovarian cancer immunodiagnostics and therapeutics via phage display technology

Ovarian cancer, ranking as the seventh most prevalent malignancy among women globally, faces significant challenges in diagnosis and therapeutic intervention. The difficulties in early detection are amplified by the limitations and inefficacies inherent in current screening methodologies, highlighting a pressing need for more efficacious diagnostic and treatment strategies. Phage display technology emerges as a pivotal innovation in this context, utilizing extensive phage-peptide libraries to identify ligands with specificity for cancer cell markers, thus enabling precision-targeted therapeutic strategies. This technology promises a paradigm shift in ovarian cancer management, concentrating on targeted drug delivery systems to improve treatment accuracy and efficacy while minimizing adverse effects. Through a meticulous review, this paper evaluates the revolutionary potential of phage display in enhancing ovarian cancer therapy, representing a significant advancement in combating this challenging disease. Phage display technology is heralded as an essential instrument for developing effective immunodiagnostic and therapeutic approaches in ovarian cancer, facilitating early detection, precision-targeted medication, and the implementation of customized treatment plans.

Use of Albumin for Drug Delivery as a Diagnostic and Therapeutic Tool

Drug delivery is an important topic that has attracted the attention of researchers in recent years. Albumin nanoparticles play a significant role in drug delivery as a carrier due to their unique characteristics. Albumin is non-toxic, biocompatible, and biodegradable. Its structure is such that it can interact with different drugs, which makes the treatment of the disease faster and also reduces the side effects of the drug. Albumin nanoparticles can be used in the diagnosis and treatment of many diseases, including cancer, diabetes, Alzheimer's, etc. These nanoparticles can connect to some compounds, such as metal nanoparticles, antibodies, folate, etc. and create a powerful nanostructure for drug delivery. In this paper, we aim to investigate albumin nanoparticles in carrier format for drug delivery application. In the beginning, different types of albumin and their preparation methods were discussed, and then albumin nanoparticles were discussed in detail in diagnosing and treating various diseases.

Targeted Delivery of Diphtheria Toxin into VEGFR1/VEGFR2 Overexpressing Cells Induces Anti-angiogenesis Activity

BACKGROUND

Vascular Endothelial Growth Factor Receptors (VEGFR1 and VEGFR2) are tyrosine kinase receptors expressed on endothelial cells and tumor vessels and play an important role in angiogenesis. In this study, three repeats of VEGFR1 and VEGFR2 binding peptide (VGB3) were genetically fused to the truncated diphtheria toxin (TDT), and its in vitro activity was evaluated.

METHODS

The recombinant construct (TDT-triVGB3) was expressed in bacteria cells and purified with nickel affinity chromatography. The binding capacity and affinity of TDT-triVGB3 were evaluated using the enzyme-linked immunosorbent assay. The inhibitory activity of TDT-triVGB3 on viability, migration, and tube formation of human endothelial cells was evaluated using MTT, migration, and tube formation assays.

RESULTS

TDT-triVGB3 selectively detected VEGFR1 and VEGFR2 with high affinity in an enzyme- linked immunosorbent assay and significantly inhibited viability, migration, and tube formation of human endothelial cells.

CONCLUSION

The developed TDT-triVGB3 is potentially a novel agent for targeting VEGFR1/ VEGFR2 over-expressing cancer cells.

Neuropilin-1 Binding Peptide as Fusion to Diphtheria Toxin Induces Apoptosis in Non-small Cell Lung Cancer Cell Line

BACKGROUND

Targeted cancer therapy can be considered as a new strategy to overcome the side effects of current cancer treatments. Neuropilin-1 (NRP-1) is a transmembrane glycoprotein that is expressed in endothelial cells and tumor vessels to stimulate angiogenesis progression. Targeted diphtheria toxin (DT)- based therapeutics are promising tools for cancer treatment. This study aimed to construct a novel NRP-1 binding peptide (as three repeats) (CRGDK) as a fusion to truncated DT (DTA) (DTA-triCRGDK) for targeted delivery of DT into NRP-1 expressing cells.

METHODS

The concept of DTA-triCRGDK was designed, synthesized and cloned into the bacterial host. Expression of DTA-triCRGDK was induced by Isopropyl ß-D-1-thiogalactopyranoside (IPTG) and purification was performed using Ni-NTA chromatography. Biological activity of DTA-triCRGDK was evaluated using MTT, apoptosis, and wound healing assays. In addition, expression levels of apoptotic Bax, Bcl2, and Casp3 genes were determined by Real-time PCR.

RESULTS

Cytotoxicity analysis showed the IC50 values of DTA-triCRGDK for A549 and MRC5 were 0.43 nM and 4.12 nM after 24 h, respectively. Bcl2 expression levels decreased 0.4 and 0.72 fold in A549 and MRC5, respectively. However, Bax and Casp3 expression level increased by 6.75 and 8.19 in A549 and 2.51 and 3.6 in MRC5 cells.

CONCLUSION

Taken together, DTA-triCRGDK is a promising tool for targeted therapy of NRP-1 overexpressing cancer cells.

Targeting of human fibroblast growth factor receptor 2 by a novel specific nanobody

Inhibition of FGFR2 signaling is promising in targeted therapy of FGFR2-related tumors. In this study, anti-FGFR2 nanobodies (Nbs) were isolated through screening of an immune camelid phage display library. Four rounds of biopanning were carried out with commercial human FGFR2 antigen and enrichment was assessed by ELISA and phage titration. The gene of Nb was sub-cloned into the expression vector, and the recombinant vector was transformed into Escherichia coli WK6 cells. The recombinant protein was purified using Ni-NTA affinity chromatography. The anti-FGFR2 Nb (C13) was characterized by SDS-PAGE, western blotting, competitive inhibition ELISA, flow cytometry, MTT, and migration assay. C13 Nb recognized FGFR2 with high specificity and no cross-reactivity was observed with other tested antigens. The affinity of C13 Nb was calculated to be 1.5 × 10-9 M. Results of cytotoxicity showed that C13 Nb (10 µg/ml) inhibited 85% of the proliferation of T-47D cells (p < 0.001). In addition, C13 inhibited the migration of 68% of T-47D toward the source of the growth factor (p < 0.01). The flow cytometry showed that C13 Nb bound to the surface of FGFR2+ cells, T-47D cell line (96%). Results indicate the potential of anti-FGFR2 Nb for targeted therapy of FGFR2-overexpressing tumors after complementary investigations.

Design and Construction of a Synthetic Nanobody Library: Testing Its Potential with a Single Selection Round Strategy

Nanobodies (Nbs) are single domain antibody fragments derived from heavy-chain antibodies found in members of the Camelidae family. They have become a relevant class of biomolecules for many different applications because of several important advantages such as their small size, high solubility and stability, and low production costs. On the other hand, synthetic Nb libraries are emerging as an attractive alternative to animal immunization for the selection of antigen-specific Nbs. Here, we present the design and construction of a new synthetic nanobody library using the phage display technology, following a structure-based approach in which the three hypervariable loops were subjected to position-specific randomization schemes. The constructed library has a clonal diversity of 10⁸ and an amino acid variability that matches the codon distribution set by design at each randomized position. We have explored the capabilities of the new library by selecting nanobodies specific for three antigens: vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF) and the glycoprotein complex (GnGc) of Andes virus. To test the potential of the library to yield a variety of antigen-specific Nbs, we introduced a biopanning strategy consisting of a single selection round using stringent conditions. Using this approach, we obtained several binders for each of the target antigens. The constructed library represents a promising nanobody source for different applications.

A Novel Immunotoxin Targeting Epithelial Cell Adhesion Molecule Using Single Domain Antibody Fused to Diphtheria Toxin

Epithelial Cell Adhesion Molecule (EpCAM) is overexpressed in a variety of cancers such as colon, stomach, pancreas, and prostate adenocarcinomas. Inhibition of EpCAM is considered as a potential target for cancer therapy. In current study, anti-EpCAM immunotoxin (α-EpCAM IT) was developed using genetic fusion of α-EpCAM single domain antibody (nanobody) (α-EpCAM Nb) to truncated form of diphtheria toxin. The expression of recombinant α-EpCAM IT was induced by Isopropyl β-d-1-thiogalactopyranoside (IPTG) and confirmed by SDS-PAGE and western blot. Recombinant α-EpCAM IT was purified from the inclusion bodies and refolded using urea gradient procedure. The cytotoxicity and apoptosis activity of α-EpCAM IT on EpCAM over-expressing (MCF7), low-expressing (HEK293), and no-expressing (HUVEC) cells were evaluated by 3-4,5-Dimethylthiazol-2-yl (MTT) assay and annexin V-FITC-PI assay as well. In addition, anti-tumor activity of α-EpCAM IT was evaluated on nude mice bearing MCF7 tumor cells. Results showed success expression and purification of α-EpCAM IT. The α-EpCAM IT showed time and dose-dependent anti-proliferative activity on MCF-7 cells. However, α-EpCAM IT did not show any anti-proliferative activity on HEK293 and HUVEC cells as well. In addition, the annexin V-FITC-PI assay results showed that α-EpCAM IT significantly increased apoptotic rate in MCF-7 cells with no effect on HEK293 and HUVEC as well. Moreover, α-EpCAM IT significantly reduced tumor size in vivo study. The achieved results indicate the potential of designing α-EpCAM IT as a novel therapeutic for cancer therapy.

Nanobodies in cell-mediated immunotherapy: On the road to fight cancer

The immune system is essential in recognizing and eliminating tumor cells. The unique characteristics of the tumor microenvironment (TME), such as heterogeneity, reduced blood flow, hypoxia, and acidity, can reduce the efficacy of cell-mediated immunity. The primary goal of cancer immunotherapy is to modify the immune cells or the TME to enable the immune system to eliminate malignancies successfully. Nanobodies, known as single-domain antibodies, are light chain-free antibody fragments produced from Camelidae antibodies. The unique properties of nanobodies, including high stability, reduced immunogenicity, enhanced infiltration into the TME of solid tumors and facile genetic engineering have led to their promising application in cell-mediated immunotherapy. They can promote the cancer therapy either directly by bridging between tumor cells and immune cells and by targeting cancer cells using immune cell-bound nanobodies or indirectly by blocking the inhibitory ligands/receptors. The T-cell activation can be engaged through anti-CD3 and anti-4-1BB nanobodies in the bispecific (bispecific T-cell engagers (BiTEs)) and trispecific (trispecific T-cell engager (TriTEs)) manners. Also, nanobodies can be used as natural killer (NK) cell engagers (BiKEs, TriKEs, and TetraKEs) to create an immune synapse between the tumor and NK cells. Nanobodies can redirect immune cells to attack tumor cells through a chimeric antigen receptor (CAR) incorporating a nanobody against the target antigen. Various cancer antigens have been targeted by nanobody-based CAR-T and CAR-NK cells for treating both hematological and solid malignancies. They can also cause the continuation of immune surveillance against tumor cells by stopping inappropriate inhibition of immune checkpoints. Other roles of nanobodies in cell-mediated cancer immunotherapy include reprogramming macrophages to reduce metastasis and angiogenesis, as well as preventing the severe side effects occurring in cell-mediated immunotherapy. Here, we highlight the critical functions of various immune cells, including T cells, NK cells, and macrophages in the TME, and discuss newly developed immunotherapy methods based on the targeted manipulation of immune cells and TME with nanobodies.

Exploration of Specific Nanobodies As Immunological Reagents to Detect Milk Allergen of β-Lactoglobulin without Interference of Hydrolytic Peptides

Milk proteins are widely used for food supplementation, despite the potential risk of food allergy, especially against β-lactoglobulin (BLG), which makes BLG surveillance critical. Possible interaction of detecting antibodies with BLG-derived peptides will result in unprecise inspection. Thus, in this study, it was proposed to generate nanobodies (Nbs) and validate the immunological detection of intact BLG rather than hydrolytic peptides. Nbs were successfully retrieved and characterized with high stability and target specificity. A competitive enzyme-linked immunosorbent assay (cELISA) was developed with a linear range from 39 to 10,000 ng/mL and a detection limit (LOD) of 4.55 ng/mL, with a recovery of 86.30%-95.09% revealed by analysis of spiked samples. Meanwhile, a sandwich ELISA (sELISA) was established with Nb82 and BLG polyclonal antibody (pAb-BLG) providing a linear range from 29.7 to 1250 ng/mL and an LOD of 13.82 ng/mL with a recovery of 87.82%-103.97%. The interaction of selected Nbs with BLG-derived peptides was investigated by Nb structure modeling and BLG docking. No binding on hydrolytic peptides was revealed, confirming the precision of Nb-mediated immunoassays. In summary, this study successfully identified BLG-specific Nbs for immunoassay development and guaranteed the monitoring of intact BLG without interference of hydrolytic peptides, providing experimental evidence that our Nbs recognize intact food allergen.

Investigation of the therapeutic potential of recombinant bispecific bivalent anti-PD-L1/VEGF nanobody in inhibition of angiogenesis

Immunotherapy's using monoclonal antibodies targeting programmed death ligand-1 (PD-L1) on cancer cells as a biomarker of escape from response to immune checkpoint has demonstrated efficacy in treating many solid tumors. In addition, some of the signals, such as vascular endothelial growth factor (VEGF), bind to receptors on the surface of normal endothelial cells and encourage angiogenesis, or the formation and survival of new blood vessels. Due to the special features of nanobodies with high specificity and affinity as a powerful new tool in cancer therapy, here, a recombinant bispecific bivalent anti-PD-L1/VEGF nanobody was constructed and its functionality in inhibition of angiogenesis in vitro was investigated. Results demonstrated that bivalent anti-PD-L1/VEGF nanobody efficiently inhibited HUVEC and A431 cells proliferation and tube formation. In addition, bivalent anti-PD-L1/VEGF nanobody efficiently inhibited angiogenesis in an ex ovo Chick Chorioallantoic Membrane assay. The results indicate for the potential of bivalent anti-PD-L1/VEGF nanobody as a novel promising tool for cancer therapy.

Envafolimab - first PD-1/PD-L1 antibody to be administered by subcutaneous injection for microsatellite instability-high or deficient mismatch repair advanced solid tumors

INTRODUCTION

Programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors mobilize and activate the anti-tumor activity of the immune system by blocking the inhibitory effects of the PD-1/PD-L1 signaling pathway in T cells. Several anti-PD-1 or -PD-L1 monoclonal antibodies have been approved for the treatment of advanced solid tumors. However, most of immune checkpoint inhibitors (ICIs) are administered via intravenous infusion, which is inconvenient and leads to unsatisfactory patient compliance in the treatment process. Therefore, subcutaneous envafolimab is to be a potential treatment modality for advanced solid tumors.

AREA COVERED

A phase I clinical trial showed that the safety and pharmacokinetic profiles of envafolimab were similar to those of other traditional antibodies. Additionally, clinical findings from a phase II trial revealed that envafolimab monotherapy exhibited satisfactory clinical therapeutic effects and no significant adverse events in patients with Microsatellite instability-high/deficient mismatch Repair (MSI-H/dMMR) solid tumors who failed at least one line of prior systemic therapy.

EXPERT OPINION

Subcutaneous envafolimab may serve as a more convenient and acceptable treatment modality than those approved PD-1/PD-L1 inhibitors for patients with an advanced solid tumor, which may revolutionize the modes of immunotherapy in the future.

Effective blocking of neuropilin-1activity using oligoclonal nanobodies targeting different epitopes

Neuropilin-1 (NRP-1) is a non-tyrosine kinase receptor and when overexpressed, leads to angiogenesis. High expression of NRP-1 has been observed in various cancers. Unique characteristic of nanobodies (small size, high affinity and stability, and ease production) make them potential therapeutic tools. Oligoclonal nanobodies which detect multiple functional epitopes on the target antigen could be potential tools for inhibition of cancer resistance problems due to escape variant of tumor cells. In this study, oligoclonal anti-NRP-1 nanobodies were selected from camel immune library and their binding activities as well as in vitro functionality were evaluated. Anti-NRP-1 nanobodies were expressed in an Escherichia coli host, and purified using nickel affinity chromatography. The effect of each individual and oligoclonal nanobodies on human endothelial cells were evaluated by MTT, Tube formation, and migration assay as well. Results showed that oligoclonal anti-NRP-1 nanobodies detected different epitopes of NRP-1 antigen and inhibited in vitro angiogenesis of human endothelial cells better than each individual nanobody. Results indicate promising oligoclonal anti-NRP-1 nanobodies for inhibition of angiogenesis.

Routine flow cytometry approach for the evaluation of solid tumor neoplasms and immune cells in minimally invasive samples

BACKGROUND

Multidimensional flow cytometry (MFC) is routinely used for the diagnosis and follow-up of hematolymphoid neoplasms but its contribution to the identification of non-hematolymphoid malignant tumors is limited.

METHODS

The presence of non-hematolymphoid cells in clinical samples obtained via minimally invasive methods was ascertained by using a panel of monoclonal antibodies previously developed in our laboratory comprising a mixture of antibodies: CD9-PacB/CD45-OC515/CD57-FITC/CD56-PE/CD3-PerCP-Cy5.5/CD117-PE-Cy7/CD326-APC/CD81-APC-C750. Histopathological studies were performed using standard techniques.

RESULTS

164 specimens of different origins were included. Malignancy was finally confirmed in 142 (86.5%), while 22 non neoplastic samples were identified. The most frequent diagnosis was small cell lung carcinoma (SCLC) (50%). High sensitivity (S = 98.6%) was reached combining MFC and conventional pathology. Individual markers differed according to the cellular origin of the neoplasm, with neuroendocrine tumors showing a unique immunophenotypic profile (CD56+ CD326+ CD117-/+ and variable tetraspanins expression). Principal component analysis efficiently distinguished SCLC from other tumor samples. In immune cell populations, differences between reactive and malignant biopsies were found in different cell compartments, especially in B cells and Plasma cells. Differences also emerged in the percentage of CD4+ CD8- T cells, CD4-CD8+ T cells and NK cells and these were dependent on the origin of the tumor cells.

CONCLUSIONS

These results support the use of MFC as a rapid and valuable technique to detect non-hematolymphoid tumoral cells in clinical specimens, providing an initial orientation to complement hystopathological studies and allow a more precise diagnosis, especially in neuroendocrine neoplasms. The impact of different immune cell patterns warrants further research.

Targeted therapy of angiogenesis using anti-VEGFR2 and anti-NRP-1 nanobodies

PURPOSE

Targeted therapy in cancer researches is a promising approach that can resolve drawbacks of systematic therapeutics. Nanobodies are potent therapeutics due to their high specificity and affinity to the target.

METHODS

In this study, we evaluated the effect of the combination of anti-vascular endothelial growth factor receptor 2 (anti-VEGFR2) and anti-neuropilin-1 (anti-NRP1) nanobodies both in vitro (MTT, and tube formation assay) and in vivo (chick chorioallantoic membrane (CAM), and Nude mice treatment assay).

RESULTS

Our results showed that the combination of two nanobodies (anti-VEGFR2/NRP-1 nanobodies) significantly inhibited proliferation as well as tube formation of human endothelial cells effective than a single nanobody. In addition, the mixture of both nanobodies inhibited vascularization of chick chorioallantoic membrane ex ovo CAM assay as compared to a single nanobody. Moreover, the mixture of both nanobodies significantly inhibited tumor growth of the mice (tumor volume and weight) higher than individual nanobodies (P < 0.05).

CONCLUSION

Our results offer a promising role of combination therapies in cancer therapy as well as angiogenesis.

Nanobody: A Small Antibody with Big Implications for Tumor Therapeutic Strategy

The development of monoclonal antibody treatments for successful tumor-targeted therapies took several decades. However, the efficacy of antibody-based therapy is still confined and desperately needs further improvement. Nanobodies are the recombinant variable domains of heavy-chain-only antibodies, with many unique properties such as small size (~15kDa), excellent solubility, superior stability, ease of manufacture, quick clearance from blood, and deep tissue penetration, which gain increasing acceptance as therapeutical tools and are considered also as building blocks for chimeric antigen receptors as well as for targeted drug delivery. Thus, one of the promising novel developments that may address the deficiency of monoclonal antibody-based therapies is the utilization of nanobodies. This article provides readers the significant factors that the structural and biochemical properties of nanobodies and the research progress on nanobodies in the fields of tumor treatment, as well as their application prospect.

Inhibition of neovascularisation in human endothelial cells using anti NRP-1 nanobody fused to truncated form of diphtheria toxin as a novel immunotoxin

Neuropilin-1 (NRP-1) regulates a range of physiological and pathological processes, including angiogenesis. Targeting of NRP1 is considered a significant approach in cancer therapy. In the present study, a novel antiNRP1 immunotoxin (αNRP1 IT) was developed by genetic fusion of a single domain (VHH) anti-NRP-1 antibody fragment to a truncated diphtheria toxin. The αNRP1 IT was expressed into bacterial cells as an inclusion body (IB). Expression of αNRP1 IT was confirmed by SDS-PAGE and western blotting. Recombinant αNRP1 IT was purified using nickel affinity chromatography. Toxicity and antiangiogenesis effect of αNRP1 IT was investigated both in vitro and in vivo. Results showed that αNRP1 IT significantly reduced the viability of human umbilical vein endothelial cell line (HUVEC) (p < .05). The αNRP1 IT significantly inhibited tube formation of HUVEC cells (p < .001). Furthermore, αNRP1 IT inhibited angiogenesis in Chick Chorioallantoic Membrane (CAM) Assay. These data suggest the potential of αNRP1 IT as a novel therapeutic in targeted cancer therapy.