A novel extracellular drug conjugate significantly inhibits head and neck squamous cell carcinoma

Mini-Review: Can the Metastatic Cascade Be Inhibited by Targeting CD147/EMMPRIN to Prevent Tumor Recurrence?

Solid tumors metastasize very early in their development, and once the metastatic cell is lodged in a remote organ, it can proliferate to generate a metastatic lesion or remain dormant for long periods. Dormant cells represent a real risk for future tumor recurrence, but because they are typically undetectable and insensitive to current modalities of treatment, it is difficult to treat them in time. We describe the metastatic cascade, which is the process that allows tumor cells to detach from the primary tumor, migrate in the tissue, intravasate and extravasate the lymphatics or a blood vessel, adhere to a remote tissue and eventually outgrow. We focus on the critical enabling role of the interactions between tumor cells and immune cells, especially macrophages, in driving the metastatic cascade, and on those stages that can potentially be targeted. In order to prevent the metastatic cascade and tumor recurrence, we would need to target a molecule that is involved in all of the steps of the process, and evidence is brought to suggest that CD147/EMMPRIN is such a protein and that targeting it blocks metastasis and prevents tumor recurrence.

Activation of a G protein-coupled receptor through indirect antibody-mediated tethering of ligands

Antibodies raised against many cell surface proteins, including G protein-coupled receptors, remain important tools for their functional characterization. By linking antibodies to ligands for cell surface proteins, such adducts can be targeted to the surface of a cell type of choice. Site-specific functionalization of full-size antibodies with synthetic moieties remains challenging. Here we present new approaches in which single domain antibodies (known as VHHs or nanobodies) that target either cell surface proteins or conventional antibodies are used to indirectly deliver ligands for GPCRs to their sites of action. The combination of high yield production of nanobodies, facile site-specific functionalization, and compatibility with commercially available mouse and rabbit antibodies should enable wide application of this approach.

The use of antibodies to target membrane receptors enables specific and potent activation. But antibodies with appropriate specificity can be lacking. We present methods for targeting receptors without target-specific antibodies.

Strategies for targeting cell surface proteins using multivalent conjugates and chemical biology

Proper function of receptors on the cell surface is essential for homeostasis. Compounds that target cell surface receptors to address dysregulation have proven exceptionally successful as therapeutic agents; however, the development of compounds with the desired specificity for receptors, cells, and tissues of choice has proven difficult in some cases. The use of compounds that can engage more than one binding site at the cell surface offers a path toward improving biological specificity or pharmacological properties. In this chapter we summarize historical context for the development of such bivalent compounds. We focus on developments in chemical methods and biological engineering to provide bivalent compounds in which the high affinity and specificity of antibodies are leveraged to create multifunctional conjugates with new and useful properties. The development of methods to meld biological macromolecules with synthetic compounds will facilitate modulation of receptor biology in ways not previously possible.

Therapeutic Potential of Antibody-Drug Conjugate-Based Therapy in Head and Neck Cancer: A Systematic Review

BACKGROUND

Antibody-drug conjugates (ADCs) are designed to deliver potent cytotoxic agents into tumor tissues. During the last two decades, a plethora of ADCs have been successfully developed and used for several indications, including hematologic and solid tumors. In this work, we systematically reviewed the progress in ADC development for the treatment of HNC.

METHODS

This review was registered in PROSPERO database. A comprehensive search was conducted following PRISMA guidelines and using PubMed, Scopus and Web of Science database.

RESULTS

In total, 19 studies were included. Due to the significant heterogeneity of the outcome measures, meta-analysis was not performed, and data were summarized in tables. HNC results are poorly represented in the cohorts of completed clinical trials; published data are mostly focused on safety evaluation rather than efficacy of ADCs.

CONCLUSIONS

Although several novel agents against a wide range of different antigens were investigated, showing promising results at a preclinical level, most of the targets reported in this review are not specific for HNC; hence, the development of ADCs tailored for the HNC phenotype could open up new therapeutic perspectives. Moreover, the results from the present systematic review call attention to how limited is the application of current clinical trials in HNC.

Knockdown of lncRNA BLACAT1 enhances radiosensitivity of head and neck squamous cell carcinoma cells by regulating PSEN1

OBJECTIVE

This work focused on the function role and underlying mechanism of BLACAT1 in regulating the radiosensitivity of head and neck squamous cell carcinoma (HNSCC) cells via PSEN1.

METHODS

BLACAT1 and PSEN1 expression in HNSCC tissues and cells were measured by qRT-PCR. Kaplan-Meier method and Spearman's correlation analysis determined the prognostic roles and association of BLCAT1 and PSEN1 in HNSCC. The impacts of BLACAT1 and PSEN1, alone and in combination, on radiosensitivity of HNSCC cells were separately assessed through CCK-8, colony formation, flow cytometry, western blot and γH2AX foci staining assays.

RESULTS

Our study disclosed that BLACAT1 and PSEN1 were both in association with poor prognosis and radioresistance of HNSCC cells. BLACAT1 knockdown improved the radiosensitivity of HNSCC cells by changing cellular activities containing repressed cell viability, accelerated cell apoptosis, induced cell cycle arrest, and stimulated DNA damage response. Further, we found that PSEN1 was positively correlated with BLACAT1. Rescue assays confirmed that BLACAT1 regulated the radiosensitivity of HNSCC cells by modulating PSEN1.

CONCLUSION

We revealed that BLACAT1 knockdown enhanced radioresistance of HNSCC cells via regulating PSEN1, exposing the probable target role of BLACAT1 in HNSCC.

ADVANCES IN KNOWLEDGE

This was the first time that the pivotal role of BLACAT1 was investigated in HNSCC, which provided a novel therapeutic direction for HNSCC patients.

CD147 and Cyclooxygenase Expression in Feline Oral Squamous Cell Carcinoma

Feline oral squamous cell carcinoma (OSCC) is a highly invasive form of cancer in cats. In human OSCC, cluster of differentiation 147 (CD147) contributes to inflammation and tumor invasiveness. CD147 is a potential therapeutic target, but the expression of CD147 in feline OSCC has not been examined. Immunohistochemistry was used to determine if cyclooxygenase 2 (COX-2) and CD147 expression in feline OSCC biopsies was coordinated. Tumor cells were more likely to express COX-2 (22/43 cases or 51%) compared to stroma (8/43 or 19%) and adjacent oral epithelium (9/31 cases or 29%) (p < 0.05). CD147 was also more likely to occur in tumor cells compared to stroma and adjacent mucosa, with 21/43 (49%) of cases having >50% tumor cells with mild or moderate CD147 expression, compared to 9/28 (32%) in adjacent epithelium and only 5/43 (12%) in adjacent stroma (p < 0.05). In feline OSCC cell lines (SCCF1, SCCF2, and SCCF3), CD147 gene expression was more consistently expressed compared to COX-2, which was 60-fold higher in SCCF2 cells compared to SCCF1 cells (p < 0.05). CD147 expression did not correlate with COX-2 expression and prostaglandin E2 (PGE2) secretion, indicating that they may be independently regulated. CD147 potentially represents a novel therapeutic target for the treatment of feline OSCC and further study of CD147 is warranted.

Structure-guided Discovery of Dual-recognition Chemibodies

Small molecules and antibodies each have advantages and limitations as therapeutics. Here, we present for the first time to our knowledge, the structure-guided design of “chemibodies” as small molecule-antibody hybrids that offer dual recognition of a single target by both a small molecule and an antibody, using DPP-IV enzyme as a proof of concept study. Biochemical characterization demonstrates that the chemibodies present superior DPP-IV inhibition compared to either small molecule or antibody component alone. We validated our design by successfully solving a co-crystal structure of a chemibody in complex with DPP-IV, confirming specific binding of the small molecule portion at the interior catalytic site and the Fab portion at the protein surface. The discovery of chemibodies presents considerable potential for novel therapeutics that harness the power of both small molecule and antibody modalities to achieve superior specificity, potency, and pharmacokinetic properties.

The altered glucose metabolism in tumor and a tumor acidic microenvironment associated with extracellular matrix metalloproteinase inducer and monocarboxylate transporters

Extracellular matrix metalloproteinase inducer, also knowns as cluster of differentiation 147 (CD147) or basigin, is a widely distributed cell surface glycoprotein that is involved in numerous physiological and pathological functions, especially in tumor invasion and metastasis. Monocarboxylate transporters (MCTs) catalyze the proton-linked transport of monocarboxylates such as L-lactate across the plasma membrane to preserve the intracellular pH and maintain cell homeostasis. As a chaperone to some MCT isoforms, CD147 overexpression significantly contributes to the metabolic transformation of tumor. This overexpression is characterized by accelerated aerobic glycolysis and lactate efflux, and it eventually provides the tumor cells with a metabolic advantage and an invasive phenotype in the acidic tumor microenvironment. This review highlights the roles of CD147 and MCTs in tumor cell metabolism and the associated molecular mechanisms. The regulation of CD147 and MCTs may prove to be with a therapeutic potential for tumors through the metabolic modification of the tumor microenvironment.

Adenovirotherapy Delivering Cytokine and Checkpoint Inhibitor Augments CAR T Cells against Metastatic Head and Neck Cancer

In solid tumors, chimeric antigen receptor (CAR)-modified T cells must overcome the challenges of the immunosuppressive tumor microenvironment. We hypothesized that pre-treating tumors with our binary oncolytic adenovirus (CAd), which produces local oncolysis and expresses immunostimulatory molecules, would enhance the antitumor activity of HER2-specific CAR T cells, which alone are insufficient to cure solid tumors. We tested multiple cytokines in conjunction with PD-L1-blocking antibody and found that Ad-derived IL-12p70 prevents the loss of HER2.CAR-expressing T cells at the tumor site. Accordingly, we created a construct encoding the PD-L1-blocking antibody and IL-12p70 (CAd12_PDL1). In head and neck squamous cell carcinoma (HNSCC) xenograft models, combining local treatment with CAd12_PDL1 and systemic HER2.CAR T cell infusion improved survival to >100 days compared with approximately 25 days with either approach alone. This combination also controlled both primary and metastasized tumors in an orthotopic model of HNSCC. Overall, our data show that CAd12_PDL1 augments the anti-tumor effects of HER2.CAR T cells, thus controlling the growth of both primary and metastasized tumors.

Targeting CD147 for T to NK Lineage Reprogramming and Tumor Therapy

CD147 is highly expressed on the surface of numerous tumor cells to promote invasion and metastasis. Targeting these cells with CD147-specific antibodies has been validated as an effective approach for lung and liver cancer therapy. In the immune system, CD147 is recognized as a co-stimulatory receptor and impacts the outcome of thymic selection. Using T cell-specific deletion, we showed here that in thymus CD147 is indispensable for the stable αβ T cell lineage commitment: loss of CD147 biases both multipotent DN (double negative) and fully committed DP (double positive) cells into innate NK-like lineages. Mechanistically, CD147 deficiency results in impaired Wnt signaling and expression of BCL11b, a master transcription factor in determining T cell identity. In addition, functional blocking of CD147 by antibody phenocopies genetic deletion to enrich NK-like cells in the periphery. Furthermore, using a melanoma model and orthotopic liver cancer transplants, we showed that the augmentation of NK-like cells strongly associates with resistance against tumor growth upon CD147 suppression. Therefore, besides its original function in tumorigenesis, CD147 is also an effective surface target for immune modulation in tumor therapy.

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DN, DP cells were reprogrammed into innate NK-like cells after thymic CD147 deleted

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Loss of CD147 results in impaired Bcl11b expression and T-lineages development, which can be rescued by Wnt3a stimulation.

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CD147 is an vital target for immune modulation via NK-like cells in tumor therapy.

Tumor therapy is a difficult task and many methods have been used. Among them, tumor immunotherapy is a focus in the field and has made great progress. In this study, we found CD147 is an vital target for immune modulation via NK-like cells in tumor therapy, which means CD147 antibody may be through regulating immune cells to achieve tumor therapy. Although CD147 antibody has been used for liver cancer, making clear the mechanism of CD147 antibody mediated tumor therapy may be benefit for guiding clinical treatment.

Influence of Sugar Amine Regiochemistry on Digitoxigenin Neoglycoside Anticancer Activity

The synthesis of a set of digitoxigenin neogluco/xylosides and corresponding study of their anticancer SAR revealed sugar amine regiochemistry has a dramatic effect upon activity. Specifically, this study noted sugar 3-amino followed by 4-amino-substitution to be most advantageous where the solvent accessibility of the appended amine within neoglycoside-Na(+),K(+)-ATPase docked models correlated with increased anticancer potency. This study presents a preliminary model for potential further warhead optimization in the context of antibody-directed steroidal glycosides and extends the demonstrated compatibility of aminosugars in the context of neoglycosylation.

Antibody Drug Conjugates: Application of Quantitative Pharmacology in Modality Design and Target Selection

Antibody drug conjugates (ADCs) are a multi-component modality comprising of an antibody targeting a cell-specific antigen, a potent drug/payload, and a linker that can be processed within cellular compartments to release payload upon internalization. Numerous ADCs are being evaluated in both research and clinical settings within the academic and pharmaceutical industry due to their ability to selectively deliver potent payloads. Hence, there is a clear need to incorporate quantitative approaches during early stages of drug development for effective modality design and target selection. In this review, we describe a quantitative approach and framework for evaluation of the interplay between drug- and systems-dependent properties (i.e., target expression, density, localization, turnover, and affinity) in order to deliver a sufficient amount of a potent payload into the relevant target cells. As discussed, theoretical approaches with particular considerations given to various key properties for the target and modality suggest that delivery of the payload into particular effect cells to be more sensitive to antigen concentrations for targets with slow turnover rates as compared to those with faster internalization rates. Further assessments also suggest that increasing doses beyond the threshold of the target capacity (a function of target internalization and expression) may not impact the maximum amount of payload delivered to the intended effect cells. This article will explore the important application of quantitative sciences in selection of the target and design of ADC modalities.

Emerging formats for next-generation antibody drug conjugates

INTRODUCTION

Antibody drug conjugates now make up a significant fraction of biopharma's oncology pipeline due to great advances in the understanding of the three key components and how they should be optimised together. With this clinical success comes innovation to produce new enabling technologies that can deliver more effective antibody-drug conjugates (ADCs) with a larger therapeutic index.

AREAS COVERED

There are many reviews that discuss the various strategies for ADCs design but the last 5 years or so have witnessed the emergence of a number of different antibody formats compete with the standard whole immunoglobulin. Using published research, patent applications and conference disclosures, the authors review the many antibody and antibody-like formats, discussing innovations in protein engineering and how these new formats impact on the conjugation strategy and ultimately the performance. The alternative chemistries that are now available offer new linkages, stability profiles, drug:antibody ratio, pharmacokinetics and efficacy. The different sizes being considered promise to address issues, such as tumour penetration, circulatory half-life and side-effects.

EXPERT OPINION

ADCs are at the beginning of the next stage in their evolution and as these newer formats are developed and examined in the clinic, we will discover if the predicted features have a clinical benefit. From the commercial activity, it is envisaged that smaller or fragment-based ADCs will expand oncological applications.

Pheophorbide-a conjugates with cancer-targeting moieties for targeted photodynamic cancer therapy

Pheophorbide-a, a non-selective photosensitizer, was conjugated with cancer-targeting moieties, such as folic acid, the CRGDLASLC peptide, the cRGDfK peptide and leuprorelin, for the purpose of targeted photodynamic cancer therapy. The cellular uptake of pheophorbide-a conjugates in cancer cells overexpressing the corresponding receptors of the targeting moieties was largely enhanced compared with that in the receptor-negative cells. In the study of in vitro photodynamic activity and selectivity of pheophorbide-a conjugates in the receptor-positive and receptor-negative cells, a pheophorbide-a conjugate, (14) with an αvβ6 ligand (CRGDLASLC) exhibited the highest selectivity in the positive FaDu cells. Targeted PDT with 14 induced cell death through apoptosis and morphological apoptosis-like characteristics. These results suggest that pheophorbide-a conjugate 14 could be utilized in selective photodynamic therapy for oral cancers primarily expressing the αvβ6 receptor.

The biological function and clinical utilization of CD147 in human diseases: a review of the current scientific literature

CD147 or EMMPRIN is a member of the immunoglobulin superfamily in humans. It is widely expressed in human tumors and plays a central role in the progression of many cancers by stimulating the secretion of matrix metalloproteinases (MMPs) and cytokines. CD147 regulates cell proliferation, apoptosis, and tumor cell migration, metastasis and differentiation, especially under hypoxic conditions. CD147 is also important to many organ systems. This review will provide a detailed overview of the discovery, characterization, molecular structure, diverse biological functions and regulatory mechanisms of CD147 in human physiological and pathological processes. In particular, recent studies have demonstrated the potential application of CD147 not only as a phenotypic marker of activated regulatory T cells but also as a potential diagnostic marker for early-stage disease. Moreover, CD147 is recognized as an effective therapeutic target for hepatocellular carcinoma (HCC) and other cancers, and exciting clinical progress has been made in HCC treatment using CD147-directed monoclonal antibodies.

Neoglycosylation and neoglycorandomization: Enabling tools for the discovery of novel glycosylated bioactive probes and early stage leads

This review focuses upon the development, scope, and utility of the highly versatile chemoselective alkoxyamine-based 'neoglycosylation' reaction first described by Peri and Dumy. The fundamentals of neoglycosylation and the subsequent development of a 'neoglycorandomization' platform to afford differentially-glycosylated libraries of plant-based natural products, microbial-based natural products, and small molecule-based drugs for drug discovery applications are discussed.

Prostate cancer relevant antigens and enzymes for targeted drug delivery

Chemotherapy is one of the most widely used approaches in combating advanced prostate cancer, but its therapeutic efficacy is usually insufficient due to poor specificity and associated toxicity. Lack of targeted delivery to prostate cancer cells is also the primary obstacles in achieving feasible therapeutic effect of other promising agents including peptide, protein, and nucleic acid. Consequently, there remains a critical need for strategies to increase the selectivity of anti-prostate cancer agents. This review will focus on various prostate cancer-relevant antigens and enzymes that could be exploited for prostate cancer targeted drug delivery. Among various targeting strategies, active targeting is the most advanced approach to specifically deliver drugs to their designated cancer cells. In this approach, drug carriers are modified with targeting ligands that can specifically bind to prostate cancer-specific antigens. Moreover, there are several specific enzymes in the tumor microenvironment of prostate cancer that can be exploited for stimulus-responsive drug delivery systems. These systems can specifically release the active drug in the tumor microenvironment of prostate cancer, leading to enhanced tumor penetration efficiency.

EMMPRIN expression in oral squamous cell carcinomas: correlation with tumor proliferation and patient survival

The aim of our study was to explore the clinicopathological and prognostic significance of extracellular matrix metalloproteinase inducer (EMMPRIN) expression in oral squamous cell carcinomas (OSCC), and its relation with the proliferative tumor status of OSCC. We examined EMMPRIN and Ki-67 proteins expression by immunohistochemistry in 74 cases with OSCC. Statistical analysis was conducted to examine their clinicopathological and prognostic significance in OSCC. EMMPRIN membrane expression was observed in all cases, with both membrane and cytoplasmic tumor expression in 61 cases (82.4%). EMMPRIN overexpression was observed in 56 cases (75.7%). Moderately or poorly differentiated tumors showed EMMPRIN overexpression more frequently than well-differentiated tumors (P = 0.002). Overexpression of EMMPRIN was correlated with high Ki-67 expression (P = 0.004). In the multivariate analysis, EMMPRIN overexpression reveals an adverse independent prognostic value for cancer-specific survival (CSS) (P = 0.034). Our results reveal that EMMPRIN protein is overexpressed in more than two-thirds of OSCC cases, especially in high proliferative and less differentiated tumors. The independent value of EMMPRIN overexpression in CSS suggests that this protein could be used as an important biological prognostic marker for patients with OSCC. Moreover, the high expression of EMMPRIN makes it a possible therapeutic target in OSCC patients.

Antagonistic role of natural compounds in mTOR-mediated metabolic reprogramming

Cells reprogram their metabolism very early during carcinogenesis; this event is critical for the establishment of other cancer hallmarks. Many oncogenes and tumor suppressor genes control metabolism by interplaying with the existing nutrient-sensing intracellular pathways. Mammalian target of rapamycin, mTOR, is emerging as a collector and sorter of a metabolic network controlling upstream and downstream modulation of these same genes. Natural compounds represent a source of anti-cancer molecules with chemopreventive and therapeutic properties. This review describes selected pathways and genes orchestrating the metabolic reprogramming and discusses the potential of natural compounds to target oncogenic metabolic aberrations.