Discovery of a linear peptide for improving tumor targeting of gene products and treatment of distal tumors by IL-12 gene therapy

Tumor-Homing Peptides as Crucial Component of Magnetic-Based Delivery Systems: Recent Developments and Pharmacoeconomical Perspective

According to data from the World Health Organization (WHO), cancer is considered to be one of the leading causes of death worldwide, and new therapeutic approaches, especially improved novel cancer treatment regimens, are in high demand. Considering that many chemotherapeutic drugs tend to have poor pharmacokinetic profiles, including rapid clearance and limited on-site accumulation, a combined approach with tumor-homing peptide (THP)-functionalized magnetic nanoparticles could lead to remarkable improvements. This is confirmed by an increasing number of papers in this field, showing that the on-target peptide functionalization of magnetic nanoparticles improves their penetration properties and ensures tumor-specific binding, which results in an increased clinical response. This review aims to highlight the potential applications of THPs in combination with magnetic carriers across various fields, including a pharmacoeconomic perspective.

Cell membrane-anchored and tumor-targeted IL-12 T-cell therapy destroys cancer-associated fibroblasts and disrupts extracellular matrix in heterogenous osteosarcoma xenograft models

BACKGROUND

The extracellular matrix (ECM) and cancer-associated fibroblasts (CAFs) play major roles in tumor progression, metastasis, and the poor response of many solid tumors to immunotherapy. CAF-targeted chimeric antigen receptor-T cell therapy cannot infiltrate ECM-rich tumors such as osteosarcoma.

METHOD

In this study, we used RNA sequencing to assess whether the recently invented membrane-anchored and tumor-targeted IL-12-armed (attIL12) T cells, which bind cell-surface vimentin (CSV) on tumor cells, could destroy CAFs to disrupt the ECM. We established an in vitro model of the interaction between osteosarcoma CAFs and attIL12-T cells to uncover the underlying mechanism by which attIL12-T cells penetrate stroma-enriched osteosarcoma tumors.

RESULTS

RNA sequencing demonstrated that attIL12-T cell treatment altered ECM-related gene expression. Immunohistochemistry staining revealed disruption or elimination of high-density CAFs and ECM in osteosarcoma xenograft tumors following attIL12-T cell treatment, and CAF/ECM density was inversely correlated with T-cell infiltration. Other IL12-armed T cells, such as wild-type IL-12-targeted or tumor-targeted IL-12-T cells, did not disrupt the ECM because this effect depended on the engagement between CSV on the tumor cell and its ligand on the attIL12-T cells. Mechanistic studies found that attIL12-T cell treatment elevated IFNγ production on interacting with CSV+ tumor cells, suppressing transforming growth factor beta secretion and in turn upregulating FAS-mediated CAF apoptosis. CAF destruction reshaped the tumor stroma to favor T-cell infiltration and tumor inhibition.

CONCLUSIONS

This study unveiled a novel therapy-attIL12-T cells-for targeting CAFs/ECM. These findings are highly relevant to humans because CAFs are abundant in human osteosarcoma.

Extracellular vimentin as a versatile immune suppressive protein in cancer

The interest in finding new targets in the tumor microenvironment for anti-cancer therapy has increased rapidly over the years. More specifically, the tumor-associated blood vessels are a promising target. We recently found that the intermediate filament protein vimentin is externalized by endothelial cells of the tumor vasculature. Extracellular vimentin was shown to sustain angiogenesis by mimicking VEGF and supporting cell migration, as well as endothelial cell anergy, the unresponsiveness of the endothelium to proinflammatory cytokines. The latter hampers immune cell infiltration and subsequently provides escape from tumor immunity. Other studies showed that extracellular vimentin plays a role in sustained systemic and local inflammation. Here we will review the reported roles of extracellular vimentin with a particular emphasis on its involvement in the interactions between immune cells and the endothelium in the tumor microenvironment. To this end, we discuss the different ways by which extracellular vimentin modulates the immune system. Moreover, we review how this protein can alter immune cell-vessel wall adhesion by altering the expression of adhesion proteins, attenuating immune cell infiltration into the tumor parenchyma. Finally, we discuss how vimentin-targeting therapy can reverse endothelial cell anergy and promote immune infiltration, supporting anti-tumor immunity.

Vimentin-targeted radiopeptide 99m Tc-HYNIC-(tricine/EDDA)-VNTANST: a promising drug for pulmonary fibrosis imaging

OBJECTIVE

Idiopathic pulmonary fibrosis (IPF) is a fatal disease characterized by the accumulation of extracellular matrix. Because there is no effective treatment for advanced IPF to date, its early diagnosis can be critical. Vimentin is a cytoplasmic intermediate filament that is significantly up-regulated at the surface of fibrotic foci with a crucial role in fibrotic morphological changes.

METHODS

In the present study, VNTANST sequence as a known vimentin-targeting peptide was conjugated to hydrazinonicotinic acid (HYNIC) and labeled with 99m Tc. The stability test in saline and human plasma and log P determination were performed. Next, the biodistribution study and single photon emission computed tomography (SPECT) integrated with computed tomography (CT) scanning were performed in healthy and bleomycin-induced fibrosis mice models.

RESULTS

The 99m Tc-HYNIC-(tricine/EDDA)-VNTANST showed a hydrophilic nature (log P  = -2.20 ± 0.38) and high radiochemical purity > 97% and specific activity (336 Ci/mmol). The radiopeptide was approximately 93% and 86% intact in saline and human plasma within 6 h, respectively. The radiopeptide was substantially accumulated in the pulmonary fibrotic lesions (test vs. control = 4.08 ± 0.08% injected dose per gram (ID/g) vs. 0.36 ± 0.01% ID/g at 90 min postinjection). SPECT-CT images in fibrosis-bearing mice also indicated the fibrotic foci and kidneys.

CONCLUSION

Because there is no available drug for the treatment of advanced pulmonary fibrosis, early diagnosis is the only chance. The 99m Tc-HYNIC-(tricine/EDDA)-VNTANST could be a potential tracer for SPECT imaging of pulmonary fibrosis.

Membrane-Anchored and Tumor-Targeted IL12 (attIL12)-PBMC Therapy for Osteosarcoma

PURPOSE

Chimeric antigen receptor (CAR) T-cell therapy has shown great promise for treating hematologic malignancies but requires a long duration of T-cell expansion, is associated with severe toxicity, and has limited efficacy for treating solid tumors. We designed experiments to address those challenges.

EXPERIMENTAL DESIGN

We generated a cell membrane-anchored and tumor-targeted IL12 (attIL12) to arm peripheral blood mononuclear cells (PBMC) instead of T cells to omit the expansion phase for required CAR T cells.

RESULTS

This IL12-based attIL12-PBMC therapy showed significant antitumor efficacy in both heterogeneous osteosarcoma patient-derived xenograft tumors and metastatic osteosarcoma tumors with no observable toxic effects. Mechanistically, attIL12-PBMC treatment resulted in tumor-restricted antitumor cytokine release and accumulation of attIL12-PBMCs in tumors. It also induced terminal differentiation of osteosarcoma cells into bone-like cells to impede tumor growth.

CONCLUSIONS

In summary, attIL12-PBMC therapy is safe and effective against osteosarcoma. Our goal is to move this treatment into a clinical trial. Owing to the convenience of the attIL12-PBMC production process, we believe it will be feasible.

Cell membrane-anchored and tumor-targeted IL-12 (attIL12)-T cell therapy for eliminating large and heterogeneous solid tumors

BACKGROUND

Adoptive T-cell transfer has become an attractive therapeutic approach for hematological malignancies but shows poor activity against large and heterogeneous solid tumors. Interleukin-12 (IL-12) exhibits potent antitumor efficacy against solid tumors, but its clinical application has been stalled because of toxicity. Here, we aimed to develop a safe approach to IL-12 T-cell therapy for eliminating large solid tumors.

METHODS

We generated a cell membrane-anchored IL-12 (aIL12), a tumor-targeted IL-12 (ttIL12), and a cell membrane-anchored and ttIL-12 (attIL12) and a cell membrane-anchored and tumor-targeted ttIL-12 (attIL12) armed T cells, chimeric antigen receptor-T cells, and T cell receptor-T (TCR-T) cells with each. We compared the safety and efficacy of these armed T cells in treating osteosarcoma patient-derived xenograft tumors and mouse melanoma tumors after intravenous infusions of the armed T cells.

RESULTS

attIL12-T cell infusion showed remarkable antitumor efficacy in human and mouse large solid tumor models. Mechanistically, attIL12-T cells targeted tumor cells expressing cell-surface vimentin, enriching effector T cell and interferon γ production in tumors, which in turn stimulates dendritic cell maturation for activating secondary T-cell responses and tumor antigen spreading. Both attIL12- and aIL12-T-cell transfer eliminated peripheral cytokine release and the associated toxic effects.

CONCLUSIONS

This novel approach sheds light on the safe application of IL-12-based T-cell therapy for large and heterogeneous solid tumors.

Binding-Induced Fibrillogenesis Peptides Recognize and Block Intracellular Vimentin Skeletonization against Breast Cancer

Life is recognized as a sophisticated self-assembling material system. Cancer involves the overexpression and improper self-assembly of proteins, such as cytoskeleton protein vimentin, an emerging target related to tumor metastasis. Herein, we design a binding-induced fibrillogenesis (BIF) peptide that in situ forms fibrous networks, blocking the improper self-assembly of vimentin against cancer. The BIF peptide can bind to vimentin and subsequently perform fibrillogenesis to form fibers on vimentin. The resultant peptide fibrous network blocks vimentin skeletonization and inhibits the migration and invasion of tumor cells. In mouse models of tumor metastasis, the volume of tumor and the number of lung metastases are markedly decreased. Moreover, the efficacy of BIF peptide (5 mg/kg) is much higher than small molecular antimetastasis drug withaferin A (5 mg/kg) as a standard, indicating that the BIF peptide shows advantages over small molecular inhibitors in blocking the intracellular protein self-assembly.

Cell surface vimentin-positive circulating tumor cell-based relapse prediction in a long-term longitudinal study of postremission neuroblastoma patients

Neuroblastoma (NB) is a deadly childhood disease that carries a 50% chance of relapse for anyone in remission and similar level of 5-year survival. We investigated the value of our proprietary approach-cell surface vimentin (CSV) positive circulating tumor cells (CTC) to monitor treatment response and predict relapse in NB patients under remission in a Phase II long-term preventative clinical trial. We longitudinally analyzed peripheral blood samples from 93 patients for 27 cycles (~25 months) and discovered that the presence of CSV⁺ CTCs in the first two sequential samples (baseline, cycle 4 [month 3-4]) was a significant indicator of earlier relapse. We observed strong correlation between relapse-free survival (RFS) and lack of CSV⁺ CTCs in first 4 cycles of therapy (95%). There was sensitivity reaching 100% in predicting RFS in patients who had neither CSV⁺ CTCs nor MycN amplification. Of note, the low number of CSV⁺ CTCs seems equivalent to low tumor load because the prevention therapy difluoromethylornithine yields faster reduction of relapse risk when none or only 1-2 CSV⁺ CTCs (every 6 mL) are present in the blood samples compared to >3 CSV⁺ CTCs. To the best of our knowledge, this is the first study that directly observes CTCs in under remission NB patients for relapse prediction and the first to gather sequential CSV⁺ CTC data in any study in a long-term longitudinal manner.

Discovery of Cell-Surface Vimentin (CSV) as a Sarcoma Target and Development of CSV-Targeted IL12 Immune Therapy

This chapter discusses a novel target of osteosarcoma (OS), cell-surface vimentin (CSV), and a novel generation of interleukin-12 (IL12), CSV-targeted IL12, for treating OS tumor metastasis. Vimentin is a known intracellular structural protein for mesenchymal cells but is also documented in tumor cells. Our recent study definitively revealed that vimentin can be translocated to the surface of very aggressive tumor cells, such as metastatic cells. This CSV property allows investigators to capture circulating tumor cells (CTCs) across any type of tumor, including OS. CTCs are known as the seeds of metastasis; therefore, targeting these cells using CSV is a logical approach for use in a metastatic OS setting. Interestingly, we found that the peptide VNTANST can bind to CSV when fused to the p40 subunit encoding the DNA of IL12. Systemic delivery of this CSV-targeted IL12 immune therapy inhibited OS metastasis and relapse in a mouse tumor model as detailed in this chapter. This CSV-targeted delivery of IL12 also reduced toxicity of IL12. In summary, this chapter details a novel approach for safe IL12 immune therapy via targeting CSV.

Tumor-targeted IL-12 combined with tumor resection yields a survival-favorable immune profile

BACKGROUND

Although accumulated evidence provides a strong scientific premise for using immune profiles to predict survival in patients with cancer, a universal immune profile across tumor types is still lacking, and how to achieve a survival-associated immune profile remains to be evaluated.

METHODS

We analyzed datasets from The Cancer Genome Atlas to identify an immune profile associated with prolonged overall survival in multiple tumor types and tested the efficacy of tumor cell-surface vimentin-targeted interleukin 12 (ttIL-12) in inducing that immune profile and prolonging survival in both mouse and patient-derived xenograft tumor models.

RESULTS

We identified an immune profile (IFNγHiCD8HiFOXP3LowCD33Low) associated with prolonged overall survival across several human tumor types. ttIL-12 in combination with surgical resection of the primary tumor transformed tumors to this immune profile. Intriguingly, this immune profile transformation led to inhibition of metastasis and to prolonged survival in both mouse and patient-derived xenograft malignant models. Wild-type IL-12 combined with surgery was significantly less effective. In the IL-12-sensitive C3H mouse strain, in fact, wild-type IL-12 and surgery resulted in shorter overall survival than in mice treated with control pDNA; this surprising result is believed to be attributable to IL-12 toxicity, which was absent in the mice treated with ttIL-12. The ttIL-12-induced immune profile associated with longer overall survival was also associated with a greater accumulation of CD8+ T cells and reduced infiltration of regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. The underlying mechanism for this transformation by ttIL-12 treatment was induction of expression of CXCL9 and reduction of expression of CXCL2 and CCL22 in tumors.

CONCLUSIONS

ttIL-12 when combined with surgery led to conversion to the IFNγHiCD8HiFOXP3LowCD33Low immune profile, eliminated relapse and metastasis, and prolonged overall survival.

Vimentin Diversity in Health and Disease

Vimentin is a protein that has been linked to a large variety of pathophysiological conditions, including cataracts, Crohn's disease, rheumatoid arthritis, HIV and cancer. Vimentin has also been shown to regulate a wide spectrum of basic cellular functions. In cells, vimentin assembles into a network of filaments that spans the cytoplasm. It can also be found in smaller, non-filamentous forms that can localise both within cells and within the extracellular microenvironment. The vimentin structure can be altered by subunit exchange, cleavage into different sizes, re-annealing, post-translational modifications and interacting proteins. Together with the observation that different domains of vimentin might have evolved under different selection pressures that defined distinct biological functions for different parts of the protein, the many diverse variants of vimentin might be the cause of its functional diversity. A number of review articles have focussed on the biology and medical aspects of intermediate filament proteins without particular commitment to vimentin, and other reviews have focussed on intermediate filaments in an in vitro context. In contrast, the present review focusses almost exclusively on vimentin, and covers both ex vivo and in vivo data from tissue culture and from living organisms, including a summary of the many phenotypes of vimentin knockout animals. Our aim is to provide a comprehensive overview of the current understanding of the many diverse aspects of vimentin, from biochemical, mechanical, cellular, systems biology and medical perspectives.

Cell surface vimentin-targeted monoclonal antibody 86C increases sensitivity to temozolomide in glioma stem cells

Glioblastoma multiforme (GBM) is the most prevalent and aggressive brain tumor. The current standard therapy, which includes radiation and chemotherapy, is frequently ineffective partially because of drug resistance and poor penetration of the blood-brain barrier. Reducing resistance and increasing sensitivity to chemotherapy may improve outcomes. Glioma stem cells (GSCs) are a source of relapse and chemoresistance in GBM; sensitization of GSCs to temozoliomide (TMZ), the primary chemotherapeutic agent used to treat GBM, is therefore integral for therapeutic efficacy. We previously discovered a unique tumor-specific target, cell surface vimentin (CSV), on patient-derived GSCs. In this study, we found that the anti-CSV monoclonal antibody 86C efficiently increased GSC sensitivity to TMZ. The combination TMZ+86C induced significantly greater antitumor effects than TMZ alone in eight of 12 GSC lines. TMZ+86C-sensitive GSCs had higher CSV expression overall and faster CSV resurfacing among CSV^- GSCs compared with TMZ+86C-resistant GSCs. Finally, TMZ+86C increased apoptosis of tumor cells and prolonged survival compared with either drug alone in GBM mouse models. The combination of TMZ+86C represents a promising strategy to reverse GSC chemoresistance.

Discovery of cell surface vimentin targeting mAb for direct disruption of GBM tumor initiating cells

Intracellular vimentin overexpression has been associated with epithelial–mesenchymal transition, metastasis, invasion, and proliferation, but cell surface vimentin (CSV) is less understood. Furthermore, it remains unknown whether CSV can serve as a therapeutic target in CSV-expressing tumor cells. We found that CSV was present on glioblastoma multiforme (GBM) cancer stem cells and that CSV expression was associated with spheroid formation in those cells. A newly developed monoclonal antibody against CSV, 86C, specifically and significantly induced apoptosis and inhibited spheroid formation in GBM cells in vitro. The addition of 86C to GBM cells in vitro also led to rapid internalization of vimentin and decreased GBM cell viability. These findings were associated with an increase in caspase-3 activity, indicating activation of apoptosis. Finally, treatment with 86C inhibited GBM progression in vivo. In conclusion, CSV-expressing GBM cells have properties of tumor initiating cells, and targeting CSV with the monoclonal antibody 86C is a promising approach in the treatment of GBM.

Sarcoma-Targeting Peptide-Decorated Polypeptide Nanogel Intracellularly Delivers Shikonin for Upregulated Osteosarcoma Necroptosis and Diminished Pulmonary Metastasis

Purpose: Osteosarcoma is the most common primary bone cancer and is notorious for pulmonary metastasis, representing a major threat to pediatric patients. An effective drug targeting osteosarcoma and its lung metastasis is urgently needed.

Design: In this study, a sarcoma-targeting peptide-decorated disulfide-crosslinked polypeptide nanogel (STP-NG) was exploited for enhanced intracellular delivery of shikonin (SHK), an extract of a medicinal herb, to inhibit osteosarcoma progression with minimal systemic toxicity.

Results: The targeted, loaded nanogel, STP-NG/SHK, killed osteosarcoma cells by inducing RIP1- and RIP3-dependent necroptosis in vitro. Necroptosis is a novel cell death form that could be well adapted as an efficient antitumor strategy, the main obstacle of which is its high toxicity. After intravenous injection, STP-NG/SHK efficiently suppressed tumor growth and reduced pulmonary metastasis, offering greater tumor necrosis and higher RIP1 and RIP3 upregulation compared to free SHK or untargeted NG/SHK in vivo. Additionally, the treatment with NG/SHK or STP-NG/SHK showed minimal toxicity to normal organs, suggesting low systemic toxicity compared to free SHK. Conclusion: The STP-guided intracellular drug delivery system using the necroptosis mechanism showed profound anti-osteosarcoma activity, especially eliminated lung metastasis in vivo. This drug formulation may have great potential for treatment of osteosarcoma.

Influence of fluorine substituents on the properties of phenylboronic compounds

Rapid development of research on the chemistry of boronic acids is connected with their applications in organic synthesis, analytical chemistry, materials’ chemistry, biology and medicine. In many applications Lewis acidity of boron atoms plays an important role. Special group of arylboronic acids are fluoro-substituted compounds, in which the electron withdrawing character of fluorine atoms influences their properties. The present paper deals with fluoro-substituted boronic acids and their derivatives: esters, benzoxaboroles and boroxines. Properties of these compounds, i.e. acidity, hydrolytic stability, structures in crystals and in solution as well as spectroscopic properties are discussed. In the next part examples of important applications are given.

Nano-biomimetic carriers are implicated in mechanistic evaluation of intracellular gene delivery

Several tissue specific non-viral carriers have been developed for gene delivery purposes. However, the inability to escape endosomes, undermines the efficacy of these carriers. Researchers inspired by HIV and influenza virus, have randomly used Gp41 and H5WYG fusogenic peptides in several gene delivery systems without any rational preference. Here for the first time, we have genetically engineered two Nano-biomimetic carriers composed of either HWYG (HNH) or Gp41 (GNH) that precisely provide identical conditions for the study and evaluation of these fusogenic peptides. The luciferase assay demonstrated a two-fold higher transfection efficiency of HNH compared to GNH. These nanocarriers also displayed equivalent properties in terms of DNA binding ability and DNA protection against serum nucleases and formed similar nanoparticles in terms of surface charge and size. Interestingly, hemolysis and cellular analysis demonstrated both of nanoparticles internalized into cells in similar rate and escaped from endosome with different efficiency. Furthermore, the structural analysis revealed the mechanisms responsible for the superior endosomal escaping capability of H5WYG. In conclusion, this study describes the rationale for using H5WYG peptide to deliver nucleic acids and suggests that using nano-biomimetic carriers to screen different endosomal release peptides, improves gene delivery significantly.

Secreted Reporters for Monitoring Multiple Promoter Function

Secreted reporter proteins are reliable modalities for monitoring of different biological processes, which can be measured longitudinally in conditioned medium of cultured cells or body fluids such as blood and urine, ex vivo. In this chapter, we will explore established secreted reporters and their applications and limitations for monitoring of promoter function. We will also describe both cell-based and blood-based assays for detecting three commonly used reporters: secreted alkaline phosphatase (SEAP ), Gaussia luciferase (Gluc), and Vargula luciferase (Vluc).

Gene therapy approaches against cancer using in vivo and ex vivo gene transfer of interleukin-12

IL-12 is an immunostimulatory cytokine with strong antitumor properties. Systemic administration of IL-12 in cancer patients led to severe toxic effects, prompting the development of gene therapy vectors able to express this cytokine locally in tumors. Both nonviral and viral vectors have demonstrated a high antitumor efficacy in preclinical tumor models. Some of these vectors, including DNA electroporation, adenovirus and ex vivo transduced dendritic cells, were tested in patients, showing low toxicity and moderate antitumor efficacy. IL-12 activity can be potentiated by molecules with immunostimulatory, antiangiogenic or cytotoxic activity. These combination therapies are of clinical interest because they could lower the threshold for IL-12 efficacy, increasing the therapeutic potential of gene therapy and preventing the toxicity mediated by this cytokine.

Targeting activated hepatic stellate cells (aHSCs) for liver fibrosis imaging

Following injurious stimuli, quiescent hepatic stellate cells (qHSCs) transdifferentiate into activated HSCs (aHSCs). aHSCs play pivotal roles in the onset and progression of liver fibrosis. Therefore, molecular imaging of aHSCs in liver fibrosis will facilitate early diagnosis, prognosis prediction, and instruction and evaluation of aHSC-targeted treatment. To date, several receptors, such as integrin αvβ3, mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF-IIR), collagen type VI receptor (CVIR), platelet-derived growth factor receptor-β (PDGFR-β), vimentin, and desmin, have been identified as biomarkers of aHSCs. Corresponding ligands to these receptors have also been developed. This review will discuss strategies for developing aHSC-targeted imaging in liver fibrosis.

Safety and efficacy of tumor-targeted interleukin 12 gene therapy in treated and non-treated, metastatic lesions

The ability to control the immune system to actively attack tumor tissues will be a marvelous weapon to combat the persistent attack of cancer. Unfortunately, safe and effective methods to gain this control are not yet available as cancer therapies. To overcome the impediments to this control, tumor-targeted (tt) Interleukin 12 (IL-12) plasmid DNA can be safely delivered to accessible tumors, and these treatments can induce antitumor immune responses in both the treated and untreated tumors. Here, electroporationmediated ttIL-12 pDNA treatments are shown to be safe and well tolerated in a dose escalation study in canines bearing naturally-occurring neoplasms. The final patient in the dose-escalation study received up to 3,800 μg pDNA distributed among five separate squamous cell carcinoma tumors in doses equivalent to those administered in a Phase I trial with wildtype IL-12 pDNA. Not a single severe adverse event occurred in any patient at any of the five dose levels, and only minor, transient changes were noted in any tested parameter. Clinical response analysis and immune marker mRNA detection of treated and non-treated lesions suggest that ttIL-12 pDNA treatments in only a few tumors can elicit antitumor immune responses in the treated lesions as well as distant metastatic lesions. These observations and results demonstrate that ttIL-12 pDNA can be safely administered at clinical levels, and these treatments can affect both treated and nontreated, metastatic lesions.

Safe and effective treatment of spontaneous neoplasms with interleukin 12 electro-chemo-gene therapy

Electroporation improves the anti-tumour efficacy of chemotherapeutic and gene therapies. Combining electroporation-mediated chemotherapeutics with interleukin 12 (IL-12) plasmid DNA produces a strong yet safe anti-tumour effect for treating primary and refractory tumours. A previously published report demonstrated the efficacy of a single cycle of IL-12 plasmid DNA and bleomycin in canines, and, similarly, this study further demonstrates the safety and efficacy of repeated cycles of chemotherapy plus IL-12 gene therapy for long-term management of aggressive tumours. Thirteen canine patients were enrolled in this study and received multiple cycles of electro-chemo-gene therapy (ECGT) with IL-12 pDNA and either bleomycin or gemcitabine. ECGT treatments are very effective for inducing tumour regression via an antitumour immune response in all tested histotypes except for sarcomas, and these treatments can quickly eradicate or debulk large squamous cell carcinomas. The versatility of ECGT allows for response-based modifications which can overcome treatment resistance for affecting refractory lesions. Importantly, not a single severe adverse event was noted even in animals receiving the highest doses of chemotherapeutics and IL12 pDNA over multiple treatment cycles. This report highlights the safety, efficacy and versatility of this treatment strategy. The data reveal the importance of inducing a strong anti-tumour response for successfully affecting not only the treated tumours, but also non-treated metastatic tumours. ECGT with IL12 pDNA plus chemotherapy is an effective strategy for treating multiple types of spontaneous cancers including large, refractory and multiple tumour burdens.

Epithelial-mesenchymal transitioned circulating tumor cells capture for detecting tumor progression

PURPOSE

This study aimed to detect cell-surface vimentin (CSV) on the surface of epithelial-mesenchymal transitioned (EMT) circulating tumor cells (CTC) from blood of patients with epithelial cancers.

EXPERIMENTAL DESIGN

In this study, 101 patients undergoing postsurgery adjuvant chemotherapy for metastatic colon cancer were recruited. EMT CTCs were detected from blood of patients using the 84-1 monoclonal antibody against CSV as a marker. EMT CTCs isolated were characterized further using EMT-specific markers, fluorescent in situ hybridization, and single-cell mutation analysis.

RESULTS

Using the 84-1 antibody, we detected CSV exclusively on EMT CTCs from a variety of tumor types but not in the surrounding normal cells in the blood. The antibody exhibited very high specificity and sensitivity toward different epithelial cancer cells. With this antibody, we detected and enumerated EMT CTCs from patients. From our observations, we defined a cutoff of <5 or ≥5 EMT CTCs as the optimal threshold with respect to therapeutic response using ROC curves. Using this defined threshold, the presence of ≥5 EMT CTCs was associated with progressive disease, whereas patients with <5 EMT CTCs showed therapeutic response.

CONCLUSION

Taken together, the number of EMT CTCs detected correlated with the therapeutic outcome of the disease. These results establish CSV as a universal marker for EMT CTCs from a wide variety of tumor types and thus provide the foundation for emerging CTC detection technologies and for studying the molecular regulation of these EMT CTCs.

IL-30 (IL27p28) attenuates liver fibrosis through inducing NKG2D-rae1 interaction between NKT and activated hepatic stellate cells in mice

Chronic hepatic diseases, such as cirrhosis, hepatocellular carcinoma, and virus-mediated immunopathogenic infections, affect billions of people worldwide. These diseases commonly initiate with fibrosis. Owing to the various side effects of antifibrotic therapy and the difficulty of diagnosing asymptomatic patients, suitable medication remains a major concern. To overcome this drawback, the use of cytokine-based sustained therapy might be a suitable alternative with minimal side effects. Here, we studied the therapeutic efficacy and potential mechanisms of interleukin (IL)-30 as antifibrosis therapy in murine liver fibrosis models. CCl4 or 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) 0.1% (wt/wt) Purina 5015 Chow (LabDiet, St. Louis, MO) was fed for 3 weeks to induce liver fibrosis. Either control vector (pCtr) or pIL30 was injected hydrodynamically once per week. A significant decrease in collagen deposition and reduced expression of alpha-smooth muscle actin (α-SMA) protein indicated that IL-30-based gene therapy dramatically reduced bridging fibrosis that was induced by CCl4 or DDC. Immunophenotyping and knockout studies showed that IL-30 recruits natural-killer-like T (NKT) cells to the liver to remove activated hepatic stellate cells (HSCs) significantly and ameliorate liver fibrosis. Both flow cytometric and antibody-mediated neutralization studies showed that liver NKT cells up-regulate the natural killer group 2, member D (NKG2D) ligand and bind with the NKG2D ligand, retinoic acid early inducible 1 (Rae1), and positively activated HSCs to ameliorate liver fibrosis. Furthermore, adoptive transfer of liver NKT cells in T-cell-deficient mice showed reduction of fibrosis upon IL-30 administration.

CONCLUSIONS

Highly target-specific liver NKT cells selectively remove activated HSCs through an NKG2D-Rae1 interaction to ameliorate liver fibrosis after IL-30 treatment.

Specific protein markers for stem cell cross-talk with neighboring cells in the environment

A stem cell interacts with the neighboring cells in its environment. To maintain a living organism's metabolism, either cell-cell or cell-environment interactions may be significant. Usually, these cells communicate with each other through biological signaling by interactive behaviors of primary proteins or complementary chemicals. The signaling intermediates offer the stem cell's functionality on its metabolism. With the rapid advent of omics technologies, various specific markers by which stem cells cooperate with their surroundings have been discovered and established. In this article, we review several stem cell markers used to communicate with either cancer or immune cells in the human body.

Combination of interleukin-12 gene therapy, metronomic cyclophosphamide and DNA cancer vaccination directs all arms of the immune system towards tumor eradication

In this work a combination therapy that acts upon the immune suppressive, the innate and specific arms of the immune system is proposed. This combination therapy, which consists of intratumoral interleukin-12 (IL-12) gene therapy, human tyrosinase (hTyr) DNA vaccination and metronomic cyclophosphamide (CPX), was evaluated in a B16-F10 mouse model. The following groups were compared: (1) no treatment, (2) control vector, (3) intratumoral IL-12 gene therapy, (4) intratumoral IL-12 gene therapy+metronomic CPX, (5) intratumoral IL-12 gene therapy+metronomic CPX+hTyr DNA vaccination. Next to clinical efficacy and safety, we characterized acute effects of IL-12 and anti-tumor immune response after a second tumor challenge. All treatment groups showed increased survival and higher cure rates than control groups. Survival of non-cured mice was increased when metronomic CPX was combined with IL-12 gene therapy. Furthermore, mice that received metronomic CPX had significantly lower percentages of regulatory T cells. Addition of the hTyr DNA vaccine increased cure rate and resulted in increased survival compared to other treatment groups. We also demonstrated that the manifest necrosis within days after IL-12 gene therapy is at least partly due to IL-12 mediated activation of NK cells. All cured mice were resistant to a second challenge. A humoral memory response against the tumor cells was observed in all groups that received IL-12 gene therapy, while a cellular memory response was observed only in the vaccinated mice. In conclusion, every component of this combination treatment contributed a unique immunologic trait with associated clinical benefits.

Molecular mechanisms of oncogene-induced inflammation and inflammation-sustained oncogene activation in gastrointestinal tumors: an under-appreciated symbiotic relationship

Inflammation plays an integral part in tumor initiation. Specifically, patients with colitis, pancreatitis, or hepatitis have an increased susceptibility to cancer. The activation, mutation, and overexpression of oncogenes have been well documented in cell proliferation and transformation. Recently, oncogenes were found to also regulate the inflammatory milieu in tumors. Similarly, the inflammatory milieu can promote oncogene activation. In this review, we summarize advances of the symbiotic relationship oncogene activation and inflammation in gastrointestinal tumors such as colorectal, hepatic, and pancreatic tumors. NF-κB and STAT3 are the two most common pathways that are deregulated via these oncogenes. Understanding these interactions may yield effective therapeutic strategies for tumor prevention and treatment.

Universal marker and detection tool for human sarcoma circulating tumor cells

To date, no specific marker exists for the detection of circulating tumor cells (CTC) from different types of sarcomas, though tools are available for detection of CTCs in peripheral blood of patients with cancer for epithelial cancers. Here, we report cell-surface vimentin (CSV) as an exclusive marker on sarcoma CTC regardless of the tissue origin of the sarcoma as detected by a novel monoclonal antibody. Utilizing CSV as a probe, we isolated and enumerated sarcoma CTCs with high sensitivity and specificity from the blood of patients bearing different types of sarcoma, validating their phenotype by single cell genomic amplification, mutation detection, and FISH. Our results establish the first universal and specific CTC marker described for enumerating CTCs from different types of sarcoma, thereby providing a key prognosis tool to monitor cancer metastasis and relapse.

Intricacies for posttranslational tumor-targeted cytokine gene therapy

The safest and most effective cytokine therapies require the favorable accumulation of the cytokine in the tumor environment. While direct treatment into the neoplasm is ideal, systemic tumor-targeted therapies will be more feasible. Electroporation-mediated transfection of cytokine plasmid DNA including a tumor-targeting peptide-encoding sequence is one method for obtaining a tumor-targeted cytokine produced by the tumor-bearing patient's tissues. Here, the impact on efficacy of the location of targeting peptide, choice of targeting peptide, tumor histotype, and cytokine utilization are studied in multiple syngeneic murine tumor models. Within the same tumor model, the location of the targeting peptide could either improve or reduce the antitumor effect of interleukin (IL)12 gene treatments, yet in other tumor models the tumor-targeted IL12 plasmid DNAs were equally effective regardless of the peptide location. Similarly, the same targeting peptide that enhances IL12 therapies in one model fails to improve the effect of either IL15 or PF4 for inhibiting tumor growth in the same model. These interesting and sometimes contrasting results highlight both the efficacy and personalization of tumor-targeted cytokine gene therapies while exposing important aspects of these same therapies which must be considered before progressing into approved treatment options.

Multiplex blood reporters for simultaneous monitoring of cellular processes

Reporters secreted into the conditioned medium of cells in culture or into blood in vivo have shown to be useful tools for simple and noninvasive monitoring of biological processes in real-time. Here, we characterize the naturally secreted Vargula luciferase as a secreted blood reporter and show that this reporter can be multiplexed with the secreted Gaussia luciferase and alkaline phosphatase for simultaneous monitoring of three different cellular processes in the same biological system. We applied this system to monitor the response of three different subsets of glioma cells to a clinically relevant chemotherapeutic agent in the same well in culture or animal in vivo. This system could be extended to any field to detect multiple processes in the same biological system and is amenable for high-throughput screening to find drugs that affect multiple cellular populations/phenomena simultaneously.

Enhanced aqueous Suzuki-Miyaura coupling allows site-specific polypeptide 18F-labeling

The excesses of reagents used in protein chemistry are often incompatible with the reduced or even inverse stoichiometries used for efficient radiolabeling. Analysis and screening of aqueous Pd(0) ligand systems has revealed the importance of a guanidine core and the discovery of 1,1-dimethylguanidine as an enhanced ligand for aqueous Suzuki–Miyaura cross-coupling. This novel Pd catalyst system has now allowed the labeling of small molecules, peptides, and proteins with the fluorine-18 prosthetic [¹⁸F]4-fluorophenylboronic acid. These findings now enable site-specific protein ¹⁸F-labeling under biologically compatible conditions using a metal-triggered reaction.

Targeted delivery of paclitaxel to EphA2-expressing cancer cells

PURPOSE

YSA is an EphA2-targeting peptide that effectively delivers anticancer agents to prostate cancer tumors. Here, we report on how we increased the drug-like properties of this delivery system.

EXPERIMENTAL DESIGN

By introducing non-natural amino acids, we have designed two new EphA2 targeting peptides: YNH, where norleucine and homoserine replace the two methionine residues of YSA, and dYNH, where a D-tyrosine replaces the L-tyrosine at the first position of the YNH peptide. We describe the details of the synthesis of YNH and dYNH paclitaxel conjugates (YNH-PTX and dYNH-PTX) and their characterization in cells and in vivo.

RESULTS

dYNH-PTX showed improved stability in mouse serum and significantly reduced tumor size in a prostate cancer xenograft model and also reduced tumor vasculature in a syngeneic orthotopic allograft mouse model of renal cancer compared with vehicle or paclitaxel treatments.

CONCLUSION

This study reveals that targeting EphA2 with dYNH drug conjugates could represent an effective way to deliver anticancer agents to a variety of tumor types.

Intraosseous inoculation of tumor cells into bone marrow promotes distant metastatic tumor development: A novel tool for mechanistic and therapeutic studies

Bone marrow-derived cells have a potent impact on the formation and progression of tumor metastasis. This study demonstrates that bone marrow directly promotes metastasis to distant sites from tumor cells residing in the bone marrow in multiple types of tumors and multiple mouse strains. The bone marrow environment requires less tumor cells for inducing distant metastasis and overcomes the inhibition of metastasis resulting from engineering the tumor cells with reporter genes. This discovery provides an effective approach to generate spontaneous-like metastatic tumor models which will satisfy the urgent need for studying metastasis biology and discovering novel therapeutics.

Dynamic behaviors of vimentin induced by interaction with GlcNAc molecules

The cytoskeleton protein vimentin is dramatically altered following pathological events such as fibrosis and tumorigenesis. Vimentin binds to multivalent N-acetylglucosamine (GlcNAc) molecules at the cell surface and interacts with O-linked β-GlcNAc proteins. Moreover, dying cells can be engulfed by neighboring cells through surface interactions between vimentin and many O-GlcNAc proteins in cell debris. Here, we show that vimentin was altered by its interaction with GlcNAc-bearing molecules such as GlcNAc-bearing polymers. The interaction with GlcNAc-bearing polymers promoted the cell surface recruitment of vimentin followed by the phosphorylation of vimentin serine 71 and the increase in tetrameric vimentin disassembled from vimentin filaments in HeLa cells. Moreover, it was found that GlcNAc-bearing polymers and O-GlcNAc proteins from dying cells promoted vimentin expression and cell migration in the Madin-Darby canine kidney and Michigan Cancer Foundation-7 cells. These results suggest that interactions between surface vimentin and GlcNAc molecules, including the O-GlcNAc proteins from dying cells, may play a pivotal role in vimentin expression and the migration of cancer cells. We propose new mechanisms of vimentin expression in cancer cells.

Novel targeted system to deliver chemotherapeutic drugs to EphA2-expressing cancer cells

The efficacy of anticancer drugs is often limited by their systemic toxicities and adverse side effects. We report that the EphA2 receptor is overexpressed preferentially in several human cancer cell lines compared to normal tissues and that an EphA2 targeting peptide (YSAYPDSVPMMS) can be effective in delivering anticancer agents to such tumors. Hence, we report on the synthesis and characterizations of a novel EphA2-targeting agent conjugated with the chemotherapeutic drug paclitaxel. We found that the peptide-drug conjugate is dramatically more effective than paclitaxel alone at inhibiting tumor growth in a prostate cancer xenograft model, delivering significantly higher levels of drug to the tumor site. We believe these studies open the way to the development of a new class of therapeutic compounds that exploit the EphA2 receptor for drug delivery to cancer cells.

Local delivery of interleukin-12 using T cells targeting VEGF receptor-2 eradicates multiple vascularized tumors in mice

PURPOSE

We investigated the feasibility of delivering the proinflammatory cytokine interleukin (IL)-12 into tumor using T cells genetically engineered to express a chimeric antigen receptor (CAR) against the VEGF receptor-2 (VEGFR-2).

EXPERIMENTAL DESIGN

Two different strains of mice bearing five different established subcutaneous tumors were treated with syngeneic T cells cotransduced with an anti-VEGFR-2 CAR and a constitutively expressed single-chain murine IL-12 or an inducible IL-12 gene after host lymphodepletion. Tumor regression, survival of mice, and persistence of the transferred cells were evaluated.

RESULTS

Adoptive transfer of syngeneic T cells cotransduced with an anti-VEGFR-2 CAR and a constitutively expressing single-chain IL-12 resulted in the regression of five different established tumors of different histologies without the need for IL-2 administration. T cells transduced with either anti-VEGFR-2 CAR or single-chain IL-12 alone did not alter the tumor growth indicating that both of them had to be expressed in the same cell to mediate tumor regression. Anti-VEGFR-2 CAR and IL-12-cotransduced T cells infiltrated the tumors, expanded, and persisted for prolonged periods. The antitumor effect did not require the presence of host T and B cells but was dependent on host IL-12R-expressing cells. The anti-VEGFR-2 CAR changed the immunosuppressive tumor environment by altering/reducing both the systemic and the intratumoral CD11b(+)Gr1(+) myeloid suppressor cell subsets that expressed VEGFR-2.

CONCLUSIONS

These results suggest that targeted delivery of IL-12 into the tumor environment with T cells redirected against VEGFR-2 is a promising approach for treating patients with a variety of solid tumor types.

Secreted blood reporters: insights and applications

Secreted reporters detected in body fluids (blood, serum or urine) have shown to be simple and useful tools for ex vivo real-time monitoring of in vivo biological processes. Here we explore the most commonly used secreted blood reporters in experimental animals: secreted alkaline phosphatase, soluble marker peptides derived from human carcinoembryonic antigen and human chorionic gonadotropin, as well as Gaussia luciferase. We also comment on other recently discovered secreted luciferases and their potential use as blood reporters for multiplexing applications.