Addition of low-dose tumor necrosis factor-alpha to systemic treatment with STEALTH liposomal doxorubicin (Doxil) improved anti-tumor activity in osteosarcoma-bearing rats

Multi-omics analysis reveals the panoramic picture of necroptosis-related regulators in pan-cancer

Background: Unlike apoptosis, necroptosis is a tightly regulated form of programmed cell death (PCD) that occurs in a caspase-independent manner and is mainly triggered by receptor-interacting serine/threonine-protein kinases RIPK1 and RIPK3 and the RIPK3 substrate mixed-lineage kinase domain-like protein (MLKL). A growing body of evidence has documented that necroptosis, as a novel therapeutic strategy to overcome apoptosis resistance, has potential pro- or anti-tumoral effects in tumorigenesis, metastasis, and immunosurveillance. However, comprehensive multi-omics studies on regulators of necroptosis from a pan-cancer perspective are lacking.

Methods: In the present study, a pan-cancer multi-omics analysis of necroptosis-related regulators was performed by integrating over 10,000 multi-dimensional cancer genomic data across 33 cancer types from TCGA, 481 small-molecule drug response data from CTRP, and normal tissue data from GTEx. Pan-cancer pathway-level analyses of necroptosis were conducted by gene set variation analysis (GSVA), including differential expression, clinical relevance, immune cell infiltration, and regulation of cancer-related pathways.

Results: Genomic alterations and abnormal epigenetic modifications were associated with dysregulated gene expression levels of necroptosis-related regulators. Changes in the gene expression levels of necroptosis-related regulators significantly influenced cancer progression, intratumoral heterogeneity, alterations in the immunological condition, and regulation of cancer marker-related pathways. These changes, in turn, caused differences in potential drug sensitivity and the prognosis of patients.

Conclusion: Necroptosis-related regulators are expected to become novel biomarkers of prognosis and provide a fresh perspective on cancer diagnosis and treatment.

Development of Natural-Based Bone Cement for a Controlled Doxorubicin-Drug Release

Osteosarcoma (OS) accounts for 60% of all global bone cancer diagnoses. Intravenous administration of Doxorubicin Hydrochloride (DOXO) is the current form of OS treatment, however, systemic delivery has been linked to the onset of DOXO induced cardiomyopathy. Biomaterials including calcium phosphate cements (CPCs) and nanoparticles (NPs) have been tested as localized drug delivery scaffolds for OS cells. However, the tumor microenvironment is critical in cancer progression, with mesenchymal stem cells (MSCs) thought to promote OS metastasis and drug resistance. The extent of MSC assisted survival of OS cells in response to DOXO delivered by CPCs is unknown. In this study, we aimed at investigating the effect of DOXO release from a new formulation of calcium phosphate-based bone cement on the viability of OS cells cocultured with hMSC in vitro. NPs made of PLGA were loaded with DOXO and incorporated in the formulated bone cement to achieve local drug release. The inclusion of PLGA-DOXO NPs into CPCs was also proven to increase the levels of cytotoxicity of U2OS cells in mono- and coculture after 24 and 72 h. Our results demonstrate that a more effective localized DOXO delivery can be achieved via the use of CPCs loaded with PLGA-DOXO NPs compared to CPCs loaded with DOXO, by an observed reduction in metabolic activity of U2OS cells in indirect coculture with hMSCs. The presence of hMSCs offer a degree of DOXO resistance in U2OS cells cultured on PLGA-DOXO NP bone cements. The consideration of the tumor microenvironment via the indirect inclusion of hMSCs in this study can act as a starting point for future direct coculture and in vivo investigations.

Hyperthermia and smart drug delivery systems for solid tumor therapy

Chemotherapy is a cornerstone of cancer therapy. Irrespective of the administered drug, it is crucial that adequate drug amounts reach all cancer cells. To achieve this, drugs first need to be absorbed, then enter the blood circulation, diffuse into the tumor interstitial space and finally reach the tumor cells. Next to chemoresistance, one of the most important factors for effective chemotherapy is adequate tumor drug uptake and penetration. Unfortunately, most chemotherapeutic agents do not have favorable properties. These compounds are cleared rapidly, distribute throughout all tissues in the body, with only low tumor drug uptake that is heterogeneously distributed within the tumor. Moreover, the typical microenvironment of solid cancers provides additional hurdles for drug delivery, such as heterogeneous vascular density and perfusion, high interstitial fluid pressure, and abundant stroma. The hope was that nanotechnology will solve most, if not all, of these drug delivery barriers. However, in spite of advances and decades of nanoparticle development, results are unsatisfactory. One promising recent development are nanoparticles which can be steered, and release content triggered by internal or external signals. Here we discuss these so-called smart drug delivery systems in cancer therapy with emphasis on mild hyperthermia as a trigger signal for drug delivery.

Liposomes targeted to MHC-restricted antigen improve drug delivery and antimelanoma response

Purpose

Melanoma is the most aggressive form of skin cancer. Chemotherapy at a late stage fails due to low accumulation in tumors, indicating the need for targeted therapy.

Materials and methods

To increase drug uptake by tumor cells, we have targeted doxorubicin-containing liposomes using a T-cell receptor (TCR)-like antibody (scFv G8 and Hyb3) directed against melanoma antigen A1 (MAGE-A1) presented by human leukocyte antigen A1 (M1/A1). With the use of flow cytometry and confocal microscopy, we have tested our formulation in vitro. In vivo pharmacokinetics was done in tumor-free nu/nu mice, while biodistribution and efficacy study was done in nu/nu mice xenograft.

Results

We demonstrated two to five times higher binding and internalization of these immunoliposomes by M1⁺/A1⁺ melanoma cells in vitro in comparison with nontargeted liposomes. Cytotoxicity assay showed significant tumor cell kill at 10 µM doxorubicin (DXR) for targeted vs nontargeted liposomes. In vivo pharmacokinetics of nontargeted and targeted liposomes were similar, while accumulation of targeted liposomes was 2- to 2.5-fold and 6.6-fold enhanced when compared with nontargeted liposomes and free drug, respectively. Notably, we showed a superior antitumor activity of MAGE-A1-targeted DXR liposomes toward M1⁺/A1⁺ expressing tumors in mice compared with the treatment of M1⁻/A1⁺ tumors. Our results indicate that targeted liposomes showed better cytotoxicity in vitro and pharmacokinetics in vivo.

Conclusion

Liposomes decorated with TCR-mimicking scFv antibodies effectively and selectively target antigen-positive melanoma. We showed that DXR-loaded liposomes coupled to anti-M1/-A1 scFv inflict a significant antitumor response. Targeting tumor cells specifically promotes internalization of drug-containing nanoparticles and may improve drug delivery and ultimately antitumor efficacy. Our data argue that targeting MAGE in A1 context, by nanosized carriers decorated with TCR-like antibodies mimicking scFv, can be used as a theragnostic platform for drug delivery, immunotherapy, and potentially imaging, and diagnosis of melanoma.

Intravital Microscopy of Tumor-associated Vasculature Using Advanced Dorsal Skinfold Window Chambers on Transgenic Fluorescent Mice

Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static information and is often not sufficient for a correct interpretation. Intravital evaluation, in which a process is followed in time, provides extra and often unexpected information. With the creation of transgenic animals expressing cell-specific markers and live cell tracers, improvements to imaging equipment, and the development of several imaging chambers, intravital microscopy has become an important tool to better understand biological processes. This paper describes an experimental design for the investigation of tumor vessel development and of therapeutic effects in a spatial and temporal manner. Using this setup, the stage of vessel development, tip cell and lumen formation, blood flow, extravasation, an established vascular bed, and vascular destruction can be visualized and followed. Furthermore, therapeutic effects, intratumoral fate, and the localization of chemotherapeutic compounds can also be followed.

Using In Vitro Live-cell Imaging to Explore Chemotherapeutics Delivered by Lipid-based Nanoparticles

Conventional imaging techniques can provide detailed information about cellular processes. However, this information is based on static images in an otherwise dynamic system, and successive phases are easily overlooked or misinterpreted. Live-cell imaging and time-lapse microscopy, in which living cells can be followed for hours or even days in a more or less continuous fashion, are therefore very informative. The protocol described here allows for the investigation of the fate of chemotherapeutic nanoparticles after the delivery of doxorubicin (dox) in living cells. Dox is an intercalating agent that must be released from its nanocarrier to become biologically active. In spite of its clinical registration for more than two decades, its uptake, breakdown, and drug release are still not fully understood. This article explores the hypothesis that lipid-based nanoparticles are taken up by the tumor cells and are slowly degraded. Released dox is then translocated to the nucleus. To prevent fixation artifacts, live-cell imaging and time-lapse microscopy, described in this experimental procedure, can be applied.

A diaCEST MRI approach for monitoring liposomal accumulation in tumors

Nanocarrier-based chemotherapy allows preferential delivery of therapeutics to tumors and has been found to improve the efficacy of cancer treatment. However, difficulties in tracking nanocarriers and evaluating their pharmacological fates in patients have limited judicious selection of patients to those who might most benefit from nanotherapeutics. To enable the monitoring of nanocarriers in vivo, we developed MRI-traceable diamagnetic Chemical Exchange Saturation Transfer (diaCEST) liposomes. The diaCEST liposomes were based on the clinical formulation of liposomal doxorubicin (i.e. DOXIL®) and were loaded with barbituric acid (BA), a small, organic, biocompatible diaCEST contrast agent. The optimized diaCEST liposomal formulation with a BA-to-lipid ratio of 25% exhibited 30% contrast enhancement at B1=4.7μT in vitro. The contrast was stable, with ~80% of the initial CEST signal sustained over 8h in vitro. We used the diaCEST liposomes to monitor the response to tumor necrosis factor-alpha (TNF-α), an agent in clinical trials that increases vascular permeability and uptake of nanocarriers into tumors. After systemic administration of diaCEST liposomes to mice bearing CT26 tumors, we found an average diaCEST contrast at the BA frequency (5ppm) of 0.4% at B1=4.7μT while if TNF-α was co-administered the contrast increased to 1.5%. This novel approach provides a non-radioactive, non-metallic, biocompatible, semi-quantitative, and clinically translatable approach to evaluate the tumor targeting of stealth liposomes in vivo, which may enable personalized nanomedicine.

Theranostic immunoliposomes for osteoarthritis

Although there have been substantial advancements in the treatment of inflammatory arthritis, treatments for osteoarthritis (OA) have lagged and currently are primarily palliative until joints become totally dysfunctional and prosthetic replacement is needed. One obstacle for developing a preventive therapy for OA is the lack of good tools for efficiently diagnosing the disease and monitoring its progression during the early stages when the effect of therapeutic drugs or biologics is most likely to be effective. We have developed near infrared immunoliposomes conjugated with type II collagen antibody for diagnosis and treatment of early OA. These immunoliposomes bind to damaged but not normal cartilage. Utilizing these reagents, we can quantitate exposure of type II collagen during cartilage degradation in individual joints in vivo in a guinea pig. Immunoliposomes could be used to determine the effectiveness of therapeutic interventions in small animals as well as vehicles for localized drug delivery to OA chondrocytes.

FROM THE CLINICAL EDITOR

This team of authors have developed near infrared immunoliposomes conjugated with type II collagen antibody for diagnosis and treatment of early OA, with promising results demonstrated in a guinea pig model.

Phase I/II study of the tumour-targeting human monoclonal antibody-cytokine fusion protein L19-TNF in patients with advanced solid tumours

PURPOSE

L19-TNF is an armed antibody that selectively targets human TNF to extra domain B-fibronectin on tumour blood vessels. We performed a phase I/II first-in-man trial with L19-TNF monotherapy in metastatic solid cancer patients to study safety and signs of clinical activity.

METHODS

Six cohorts of patients were treated with increasing (1.3-13 μg/kg) doses of intravenous L19-TNF on day 1, 3, and 5 of repeated 3-weekly cycles, and 12 colorectal cancer patients were treated at 13 μg/kg. PK, antibody formation, changes in lymphocyte subsets, 5-HIAA plasma levels as well as safety and clinical activity were analysed.

RESULTS

Thirty-four patients received at least one L19-TNF dose. The serum half-life of L19-TNF at 13 μg/kg was 33.6 min, and maximum peak serum concentration was 73.14 μg/L. Mild chills, nausea and vomiting but no haemato- or unexpected toxicity were observed. Grade 3 lumbar pain in bone metastasis was the only dose-limiting toxicity found in one patient. Objective tumour responses were not detected. Transient stable disease occurred in 19 of 31 evaluable patients.

CONCLUSIONS

Intravenous L19-TNF on day 1, 3, and 5 of a 3-weekly schedule was safe up to 13 μg/kg, but did not result in objective tumour responses. The maximally tolerated dose (MTD) was not reached, allowing for further dose escalation of L19-TNF possibly in combination with chemotherapy.

Systemic use of tumor necrosis factor alpha as an anticancer agent

Tumor necrosis factor-α (TNF-α) has been discussed as a potential anticancer agent for many years, however initial enthusiasm about its clinical use as a systemic agent was curbed due to significant toxicities and lack of efficacy. Combination of TNF-α with chemotherapy in the setting of hyperthermic isolated limb perfusion (ILP), has provided new insights into a potential therapeutic role of this agent. The therapeutic benefit from TNF-α in ILP is thought to be not only due to its direct anti-proliferative effect, but also due to its ability to increase penetration of the chemotherapeutic agents into the tumor tissue. New concepts for the use of TNF-α as a facilitator rather than as a direct actor are currently being explored with the goal to exploit the ability of this agent to increase drug delivery and to simultaneously reduce systemic toxicity.

This review article provides a comprehensive overview on the published previous experience with systemic TNF-α. Data from 18 phase I and 10 phase II single agent as well as 18 combination therapy studies illustrate previously used treatment and dose schedules, response data as well as the most prominently observed adverse effects. Also discussed, based on recent preclinical data, is a potential future role of systemic TNF-α in combination with liposomal chemotherapy to facilitate increased drug uptake into tumors.

Tumor necrosis factor-mediated interactions between inflammatory response and tumor vascular bed

Solid tumor therapy with chemotherapeutics greatly depends on the efficiency with which drugs are delivered to tumor cells. The typical characteristics of the tumor physiology promote but also appose accumulation of blood-borne agents. The leaky tumor vasculature allows easy passage of drugs. However, the disorganized vasculature causes heterogeneous blood flow, and together with the often-elevated interstitial fluid pressure, this state results in poor intratumoral drug levels and failure of treatment. Manipulation of the tumor vasculature could overcome these barriers and promote drug delivery. Targeting the vasculature has several advantages. The endothelial lining is readily accessible and the first to be encountered after systemic injection. Second, endothelial cells tend to be more stable than tumor cells and thus less likely to develop resistance to therapy. Third, targeting the tumor vasculature can have dual effects: (i) manipulation of the vasculature can enhance concomitant chemotherapy, and (ii) subsequent destruction of the vasculature can help to kill the tumor. In particular, tumor necrosis factor alpha is studied. Its action on solid tumors, both directly through tumor cell killing and destruction of the tumor vasculature and indirectly through manipulation of the tumor physiology, is complex. Understanding the mechanism of TNF and agents with comparable action on solid tumors is an important focus to further develop combination immunotherapy strategies.

Tumor necrosis factor alpha mediates homogeneous distribution of liposomes in murine melanoma that contributes to a better tumor response

Successful treatment of solid tumors with chemotherapeutics requires that adequate levels reach the tumor cells. Tumor vascular normalization has been proposed to enhance drug delivery and improve tumor response to chemotherapy. Differently, augmenting leakage of the tumor-associated vasculature, and as such enhance vascular abnormality, may improve tumor response as well. In the present study, we show that addition of low-dose tumor necrosis factor alpha (TNF) to systemic injections with pegylated long circulating liposomes augmented the tumor accumulation of these liposomes 5- to 6-fold, which strongly correlated with enhanced tumor response. Using intravital microscopy, we could study the liposomal distribution inside the tumor in more detail. Especially 100 nm liposomes effectively extravasate in the surrounding tumor tissue in the presence of TNF and this occurred without any effect on tumor vascular density, branching, and diameter. Next to that, we observed in living animals that tumor cells take up the liposomes intact, followed by intracellular degradation. To our knowledge, this is an unprecedented observation. Taken together, TNF renders more tumor vessels permeable, leading to a more homogeneous distribution of the liposomes throughout the tumor, which is crucial for an optimal tumor response. We conclude that delivery of nanoparticulate drug formulations to solid tumor benefits from augmenting the vascular leakage through vascular manipulation with vasoactive drugs like TNF.

Effective tumor targeted gene transfer using PEGylated adenovirus vector via systemic administration

Conjugation of polyethylene glycol to protein or particles (PEGylation) prolongs their plasma half-lives and promotes their accumulation in tumors due to enhanced permeability and retention (EPR) effect. Although PEGylation of adenovirus vectors (Ads) is an attractive strategy to improve the in vivo kinetics of conventional Ads, the EPR effect of PEGylated Ad (PEG-Ad) had not previously been reported. In this study, we prepared PEG-Ads with PEG at various modification ratios, injected them intravenously into tumor-bearing mice, and determined the blood kinetics, viral distribution, and gene expression patterns, respectively. In addition, we conducted a cancer therapeutic study of PEG-Ad encoding tumor necrosis factor (TNF)-alpha. The plasma half-life of PEG-Ad was longer than that of unmodified-Ad, and accumulation of PEG-Ad in tumor tissue increased as the PEG modification ratio increased. In particular, PEG-Ad with about 90% modification ratio showed higher (35 times) gene expression in tumor and lower (6%) in liver, compared with values for unmodified Ad. Moreover, PEG-Ad encoding TNF-alpha demonstrated not only stronger tumor-suppressive activity but also fewer hepatotoxic side effects compared with unmodified-Ad. PEGylation of Ad achieved tumor targeting through the EPR effect, and these attributes suggest that systemic injection of PEG-Ad has great potential as an anti-tumor treatment.

Direct evidence for rapid and selective induction of tumor neovascular permeability by tumor necrosis factor and a novel derivative, colloidal gold bound tumor necrosis factor

Tumor necrosis factor (TNF) causes regression of advanced cancers when used in isolation perfusion with melphalan; evidence suggests these effects are mediated via selective yet uncharacterized actions on tumor neovasculature. A novel derivative, colloidal gold bound TNF (cAu-TNF) has been shown to have similar antitumor effects as native TNF with less systemic toxicity in mice. These studies were done to determine their effects on tumor neovasculature, using in vivo video microscopy. Female C57BL/6 mice bearing 20 mm(2) MC38 or LLC tumors that are TNF sensitive and resistant tumors, respectively, had dorsal skinfold chambers implanted. The rate of interstitial accumulation of Texas red fluorescently labeled albumin in tumor and normal vasculature was measured after intravenous TNF, cAu-TNF or PBS. Changes in interstitial fluorescent intensity over time were quantified as a reflection of alterations in vascular permeability. MC38 bearing mice treated with TNF or cAu-TNF demonstrated a rapid, selective and significant increase in tracer accumulation in areas of neovasculature compared to those of normal vasculature. Experiments in LLC tumor bearing mice showed similar results. Monoclonal antibody against tissue factor partially abrogated the effects of TNF on MC38 neovasculature. These data provide direct evidence that TNF and cAu-TNF selectively and rapidly alter permeability in tumor neovasculature; a phenomenon that may be exploited to enhance selective delivery of chemotherapeutics to tumor.