Efficacy Evaluation of Combination Treatment Using Gemcitabine and Radioimmunotherapy with 90Y-Labeled Fully Human Anti-CD147 Monoclonal Antibody 059-053 in a BxPC-3 Xenograft Mouse Model of Refractory Pancreatic Cancer

CD147: an integral and potential molecule to abrogate hallmarks of cancer

CD147 also known as EMMPRIN, basigin, and HAb18G, is a single-chain type I transmembrane protein shown to be overexpressed in aggressive human cancers of CNS, head and neck, breasts, lungs, gastrointestinal, genitourinary, skin, hematological, and musculoskeletal. In these malignancies, the molecule is integral to the diverse but complimentary hallmarks of cancer: it is pivotal in cancerous proliferative signaling, growth propagation, cellular survival, replicative immortality, angiogenesis, metabolic reprogramming, immune evasion, invasion, and metastasis. CD147 also has regulatory functions in cancer-enabling characteristics such as DNA damage response (DDR) and immune evasion. These neoplastic functions of CD147 are executed through numerous and sometimes overlapping molecular pathways: it transduces signals from upstream molecules or ligands such as cyclophilin A (CyPA), CD98, and S100A9; activates a repertoire of downstream molecules and pathways including matrix metalloproteinases (MMPs)-2,3,9, hypoxia-inducible factors (HIF)-1/2α, PI3K/Akt/mTOR/HIF-1α, and ATM/ATR/p53; and also functions as an indispensable chaperone or regulator to monocarboxylate, fatty acid, and amino acid transporters. Interestingly, induced loss of functions to CD147 prevents and reverses the acquired hallmarks of cancer in neoplastic diseases. Silencing of Cd147 also alleviates known resistance to chemoradiotherapy exhibited by malignant tumors like carcinomas of the breast, lung, pancreas, liver, gastric, colon, ovary, cervix, prostate, urinary bladder, glioblastoma, and melanoma. Targeting CD147 antigen in chimeric and induced-chimeric antigen T cell or antibody therapies is also shown to be safer and more effective. Moreover, incorporating anti-CD147 monoclonal antibodies in chemoradiotherapy, oncolytic viral therapy, and oncolytic virus-based-gene therapies increases effectiveness and reduces on and off-target toxicity. This study advocates the expedition and expansion by further exploiting the evidence acquired from the experimental studies that modulate CD147 functions in hallmarks of cancer and cancer-enabling features and strive to translate them into clinical practice to alleviate the emergency and propagation of cancer, as well as the associated clinical and social consequences.

Developments and challenges in neoadjuvant therapy for locally advanced pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a significant public health challenge and is currently the fourth leading cause of cancer-related mortality in developed countries. Despite advances in cancer treatment, the 5-year survival rate for patients with PDAC remains less than 5%. In recent years, neoadjuvant therapy (NAT) has emerged as a promising treatment option for many cancer types, including locally advanced PDAC, with the potential to improve patient outcomes. To analyze the role of NAT in the setting of locally advanced PDAC over the past decade, a systematic literature search was conducted using PubMed and Web of Science. The results suggest that NAT may reduce the local mass size, promote tumor downstaging, and increase the likelihood of resection. These findings are supported by the latest evidence-based medical literature and the clinical experience of our center. Despite the potential benefits of NAT, there are still challenges that need to be addressed. One such challenge is the lack of consensus on the optimal timing and duration of NAT. Improved criteria for patient selection are needed to further identify PDAC patients likely to respond to NAT. In conclusion, NAT has emerged as a promising treatment option for locally advanced PDAC. However, further research is needed to optimize its use and to better understand the role of NAT in the management of this challenging disease. With continued advances in cancer treatment, there is hope of improving the outcomes of patients with PDAC in the future.

In vivo validation of the switch antibody concept: SPECT/CT imaging of the anti-CD137 switch antibody Sta-MB shows high uptake in tumors but low uptake in normal organs in human CD137 knock-in mice

CD137 is an attractive target for cancer immunotherapy, but its expression in normal tissues induces some adverse effects in patients receiving CD137-targeted therapy. To overcome this issue, we developed a switch antibody, STA551, that binds to CD137 only under high ATP concentrations around cells. This study quantified biodistribution of murine switch antibodies in human CD137 knock-in mice to show the viability of the switch antibody concept in vivo. We utilized four antibodies: Sta-MB, Ure-MB, Sta-mIgG1, and KLH-MB. Sta-MB is a switch antibody having the variable region of STA551. The MB is a murine Fc highly binding to murine Fcγ receptor II. Ure-MB has a variable region mimicking the clinically available anti-CD137 agonist antibody urelumab, binding to CD137 regardless of ATP concentration. Sta-mIgG1 has the same variable region as Sta-MB but has the standard murine constant region. KLH-MB binds to keyhole limpet hemocyanin. The four antibodies were radiolabeled with In-111, SPECT/CT imaging was conducted in human CD137 knock-in mice, and the uptake in regions of interest was quantified. 111In-labeled Sta-MB and Sta-mIgG1 showed high uptake in tumors but low uptake in the lymph nodes and spleen in human CD137 knock-in mice. On the other hand, Ure-MB highly accumulated not only in tumors but also in the lymph nodes and spleen. KLH-MB showed low uptake in the tumors, lymph nodes, and spleen. The present study provides evidence that the switch antibody concept works in vivo. Our findings encourage further clinical imaging studies to evaluate the biodistribution of STA551 in patients.

The natural sulfoglycolipid derivative SQAP improves the therapeutic efficacy of tissue factor-targeted radioimmunotherapy in the stroma-rich pancreatic cancer model BxPC-3

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SQAP enhanced tumor uptake and the therapeutic efficacy of radiolabeled anti-tissue factor antibody 1849.

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SQAP allows for a reduction of the dose of the therapeutic agent ⁹⁰Y-labeled 1849 to half.

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SQAP did not affect hematologic parameters, or gastrointestinal and respiratory systems in mice.

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⁹⁰Y-labeled 1849 with SQAP potentially increases exposure of tumors to radiation.

α-Sulfoquinovosylacyl-1,3-propanediol (SQAP) is a semi-synthetic derivative of natural sulfoglycolipid that sensitizes tumors to external-beam radiotherapy. How SQAP affects internal radiotherapy, however, is not known. Here, we investigated the effects of SQAP for radioimmunotherapy (RIT) targeting tissue factor (TF) in a stroma-rich refractory pancreatic cancer mouse model, BxPC-3. A low dose of SQAP (2 mg/kg) increased tumor uptake of the ¹¹¹In-labeled anti-TF antibody 1849, indicating increased tumor perfusion. The addition of SQAP enhanced the growth-inhibitory effect of ⁹⁰Y-labeled 1849 without leading to severe body weight changes, allowing for the dose of ⁹⁰Y-labeled 1849 to be reduced to half that when used alone. Histologic analysis revealed few necrotic and apoptotic cells, but Ki-67–positive proliferating cells and increased vascular formation were detected. These results suggest that the addition of a low dose of SQAP may improve the therapeutic efficacy of TF-targeted RIT by increasing tumor perfusion, even for stroma-rich refractory pancreatic cancer.

Perspectives on metals-based radioimmunotherapy (RIT): moving forward

Radioimmunotherapy (RIT) is FDA-approved for the clinical management of liquid malignancies, however, its use for solid malignancies remains a challenge. The putative benefit of RIT lies in selective targeting of antigens expressed on the tumor surface using monoclonal antibodies, to systemically deliver cytotoxic radionuclides. The past several decades yielded dramatic improvements in the quality, quantity, recent commercial availability of alpha-, beta- and Auger Electron-emitting therapeutic radiometals. Investigators have created new or improved existing bifunctional chelators. These bifunctional chelators bind radiometals and can be coupled to antigen-specific antibodies. In this review, we discuss approaches to develop radiometal-based RITs, including the selection of radiometals, chelators and antibody platforms (i.e. full-length, F(ab')2, Fab, minibodies, diabodies, scFv-Fc and nanobodies). We cite examples of the performance of RIT in the clinic, describe challenges to its implementation, and offer insights to address gaps toward translation.

Therapeutic Application of Monoclonal Antibodies in Pancreatic Cancer: Advances, Challenges and Future Opportunities

Pancreatic cancer remains as one of the most aggressive cancer types. In the absence of reliable biomarkers for its early detection and more effective therapeutic interventions, pancreatic cancer is projected to become the second leading cause of cancer death in the Western world in the next decade. Therefore, it is essential to discover novel therapeutic targets and to develop more effective and pancreatic cancer-specific therapeutic agents. To date, 45 monoclonal antibodies (mAbs) have been approved for the treatment of patients with a wide range of cancers; however, none has yet been approved for pancreatic cancer. In this comprehensive review, we discuss the FDA approved anticancer mAb-based drugs, the results of preclinical studies and clinical trials with mAbs in pancreatic cancer and the factors contributing to the poor response to antibody therapy (e.g. tumour heterogeneity, desmoplastic stroma). MAb technology is an excellent tool for studying the complex biology of pancreatic cancer, to discover novel therapeutic targets and to develop various forms of antibody-based therapeutic agents and companion diagnostic tests for the selection of patients who are more likely to benefit from such therapy. These should result in the approval and routine use of antibody-based agents for the treatment of pancreatic cancer patients in the future.

Proof of Concept Study for Increasing Tenascin-C-Targeted Drug Delivery to Tumors Previously Subjected to Therapy: X-Irradiation Increases Tumor Uptake

Simple Summary

We hypothesized that an agent recognizing a specific factor, which is involved in tissue injury repair, could achieve the goal of delivering an additional antitumor agent to tumors during tissue repair after initial anticancer therapy. To demonstrate our concept, the present study employed tenascin-C (TNC) as a target molecule and radiation as initial therapy. Increased TNC expression was observed in tumors after radiation exposure in a pancreatic cancer mouse model. Of our three anti-TNC antibodies, the antibody 3–6 showed statistically significant higher tumor uptake compared with non-irradiated tumors in the by biodistribution and single-photon emission computed tomography with computed tomography studies. This finding strongly supports our concept. Our proposed therapeutic strategy could result in better outcomes for patients with treatment-refractory cancer.

Abstract

In treatment-refractory cancers, tumor tissues damaged by therapy initiate the repair response; therefore, tumor tissues must be exposed to an additional burden before successful repair. We hypothesized that an agent recognizing a molecule that responds to anticancer treatment-induced tissue injury could deliver an additional antitumor agent including a radionuclide to damaged cancer tissues during repair. We selected the extracellular matrix glycoprotein tenascin-C (TNC) as such a molecule, and three antibodies recognizing human and murine TNC were employed to evaluate X-irradiation-induced changes in TNC uptake by subcutaneous tumors. TNC expression was assessed by immunohistochemical staining of BxPC-3 tumors treated with or without X-irradiation (30 Gy) for 7 days. Antibodies against TNC (3–6, 12–2–7, TDEAR) and a control antibody were radiolabeled with ¹¹¹In and injected into nude mice having BxPC-3 tumors 7 days after X-irradiation, and temporal uptake was monitored for an additional 4 days by biodistribution and single-photon emission computed tomography with computed tomography (SPECT/CT) studies. Intratumoral distribution was analyzed by autoradiography. The immunohistochemical signal for TNC expression was faint in nontreated tumors but increased and expanded with time until day 7 after X-irradiation. Biodistribution studies revealed increased tumor uptake of all three ¹¹¹In-labeled antibodies and the control antibody. However, a statistically significant increase in uptake was evident only for ¹¹¹In-labeled 3–6 (35% injected dose (ID)/g for 30 Gy vs. 15% ID/g for 0 Gy at day 1, p < 0.01), whereas limited changes in ¹¹¹In-labeled TDEAR2, 12–2–27, and control antibody were observed (several % ID/g for 0 and 30 Gy). Serial SPECT/CT imaging with ¹¹¹In-labeled 3–6 or control antibody provided consistent results. Autoradiography revealed noticeably stronger signals in irradiated tumors injected with ¹¹¹In-labeled 3–6 compared with each of the nonirradiated tumors and the control antibody. The signals were observed in TNC-expressing stroma. Markedly increased uptake of ¹¹¹In-labeled 3–6 in irradiated tumors supports our concept that an agent, such as an antibody, that recognizes a molecule involved in tissue injury repair, such as TNC, could enhance drug delivery to tumor tissues that have undergone therapy. The combination of antibody 3–6 coupled to a tumoricidal drug and conventional therapy has the potential to achieve better outcomes for patients with refractory cancer.

Psychological Stress Up-Regulates CD147 Expression Through Beta-Arrestin1/ERK to Promote Proliferation and Invasiveness of Glioma Cells

Psychological stress is closely related to the occurrence and prognosis of various malignant tumors, but the underlying mechanisms are not well studied. CD147 has been reported to be expressed in glioma and other malignant tumors. CD147 not only participates in lactic acid transport, but it also plays an important role in the invasion and metastasis of malignant tumor cells by stimulating the production of numerous matrix metalloproteinases (MMPs) and vascular endothelial growth factor by fibroblasts, and could also act as an autocrine factor stimulating MMPs production in metastatic tumor cells. Here, we found that silencing CD147 in chronically stressed nude mice not only inhibited the proliferation of xenografts but also decreased matrix metalloproteinase-2, 9 expression and lactic acid content in tumor tissues. Furthermore, norepinephrine (NE) was significantly increased in the serum of nude mice in glioma stress model. To determine the underlying cellular mechanism, we added exogenous NE into LN229 and U87 cells to simulate the stress environment in vitro. The invasiveness of the glioma cells was subsequently examined using a Matrigel invasion assay. We demonstrated that knockdown of CD147 inhibited glioma invasiveness and metastasis with norepinephrine stimulation. Luciferase reporter gene experiments further demonstrated that the expression of CD147 is up-regulated primarily by norepinephrine via the β-Adrenalin receptor (βAR)-β-arrestin1-ERK1/2-Sp1 pathway. High expression of CD147 promoted the secretion of MMP-2 and the increment of lactic acid, which accelerated the augmented invasion and metastasis of glioma induced by psychological stress. Taken together, these results suggest that psychological stress promotes glioma proliferation and invasiveness by up-regulating CD147 expression. Thus, CD147 might be a potential target site in the treatment of glioma progression induced by chronic psychological stress.

Pancreatic Adenocarcinoma: Unconventional Approaches for an Unconventional Disease

This review highlights current treatments, limitations, and pitfalls in the management of pancreatic cancer and discusses current research in novel targets and drug development to overcome these clinical challenges. We begin with a review of the clinical landscape of pancreatic cancer, including genetic and environmental risk factors, as well as limitations in disease diagnosis and prevention. We next discuss current treatment paradigms for pancreatic cancer and the shortcomings of targeted therapy in this disease. Targeting major driver mutations in pancreatic cancer, such as dysregulation in the KRAS and TGFβ signaling pathways, have failed to improve survival outcomes compared with nontargeted chemotherapy; thus, we describe new advances in therapy such as Ras-binding pocket inhibitors. We then review next-generation approaches in nanomedicine and drug delivery, focusing on preclinical advancements in novel optical probes, antibodies, small-molecule agents, and nucleic acids to improve surgical outcomes in resectable disease, augment current therapies, expand druggable targets, and minimize morbidity. We conclude by summarizing progress in current research, identifying areas for future exploration in drug development and nanotechnology, and discussing future prospects for management of this disease.

Radioimmunotherapy of Pancreatic Ductal Adenocarcinoma: A Review of the Current Status of Literature

Pancreatic ductal adenocarcinoma (PDAC) has long been associated with low survival rates. A lack of accurate diagnostic tests and limited treatment options contribute to the poor prognosis of PDAC. Radioimmunotherapy using α- or β-emitting radionuclides has been identified as a potential treatment for PDAC. By harnessing the cytotoxicity of α or β particles, radioimmunotherapy may overcome the anatomic and physiological factors which traditionally make PDAC resistant to most conventional treatments. Appropriate selection of target receptors and the development of selective and cytotoxic radioimmunoconjugates are needed to achieve the desired results of radioimmunotherapy. The aim of this review is to examine the growing preclinical and clinical trial evidence regarding the application of α and β radioimmunotherapy for the treatment of PDAC. A systematic search of MEDLINE® and Scopus databases was performed to identify 34 relevant studies conducted on α or β radioimmunotherapy of PDAC. Preclinical results demonstrated α and β radioimmunotherapy provided effective tumour control. Clinical studies were limited to investigating β radioimmunotherapy only. Phase I and II trials observed disease control rates of 11.2%-57.9%, with synergistic effects noted for combination therapies. Further developments and optimisation of treatment regimens are needed to improve the clinical relevance of α and β radioimmunotherapy in PDAC.

Current advances and outlooks in immunotherapy for pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an incurable cancer resistant to traditional treatments, although a limited number of early-stage patients can undergo radical resection. Immunotherapies for the treatment of haematological malignancies as well as solid tumours have been substantially improved over the past decades, and impressive results have been obtained in recent preclinical and clinical trials. However, PDAC is likely the exception because of its unique tumour microenvironment (TME). In this review, we summarize the characteristics of the PDAC TME and focus on the network of various tumour-infiltrating immune cells, outlining the current advances in PDAC immunotherapy and addressing the effect of the PDAC TME on immunotherapy. This review further explores the combinations of different therapies used to enhance antitumour efficacy or reverse immunodeficiencies and describes optimizable immunotherapeutic strategies for PDAC. The concordant combination of various treatments, such as targeting cancer cells and the stroma, reversing suppressive immune reactions and enhancing antitumour reactivity, may be the most promising approach for the treatment of PDAC. Traditional treatments, especially chemotherapy, may also be optimized for individual patients to remodel the immunosuppressive microenvironment for enhanced therapy.

CD147 Is a Promising Target of Tumor Progression and a Prognostic Biomarker

Microenvironment plays a crucial role in tumor development and progression. Cancer cells modulate the tumor microenvironment, which also contribute to resistance to therapy. Identifying biomarkers involved in tumorigenesis and cancer progression represents a great challenge for cancer diagnosis and therapeutic strategy development. CD147 is a glycoprotein involved in the regulation of the tumor microenvironment and cancer progression by several mechanisms—in particular, by the control of glycolysis and also by its well-known ability to induce proteinases leading to matrix degradation, tumor cell invasion, metastasis and angiogenesis. Accumulating evidence has demonstrated the role of CD147 expression in tumor progression and prognosis, suggesting it as a relevant tumor biomarker for cancer diagnosis and prognosis, as well as validating its potential as a promising therapeutic target in cancers.

Update on current pancreatic treatments: from molecular pathways to treatment

Pancreatic cancer is still diagnosed at a late stage although we have novel diagnostic tools. Pancreatic cancer chemotherapy treatment resistance is observed and therefore novel treatments are in need. Anti-cancer stem cell therapy, combination of chemotherapy and/or radiotherapy with immunotherapy, proteins/enzymes and gene therapy are currently under evaluation. Targeted treatment with tyrosine kinase inhibitors is also administered and novel inhibitors are also under evaluation. In the current review we present recent data from our search within the year 2018.

Therapeutic anti-CD147 antibody sensitizes cells to chemoradiotherapy via targeting pancreatic cancer stem cells

We have previously demonstrated that anti-CD44s H4C4 or liposomal-delivered STAT3 inhibitor FLLL32 sensitized pancreatic cancer cells to radiotherapy through the elimination or inhibition of cancer stem cells (CSCs) and that HAb18G/CD147 promoted STAT3-mediated pancreatic tumor development by forming a signaling complex with CD44s. In this paper, we therefore explored whether anti-CD147 HAb18IgG sensitized pancreatic cancer cells to chemoradiotherapy via the targeting of CSCs. We tested the influence of HAb18IgG on the sensitivity of pancreatic cancer cells to chemoradiotherapy by clonogenic and MTT assays and on pancreatic CSCs by colony and sphere formation assays, flow cytometry, quantitative real-time RT-PCR (qRT-PCR) and stem cell transcription factors PCR array analysis. Changes in CD147 signaling were examined by immunoblot and reporter assays. We found that HAb18IgG sensitized pancreatic cancer cells to chemoradiotherapy by dose-dependently decreasing colony and sphere formation. Furthermore, HAb18IgG reduced the pancreatic CSC subpopulation and the expression of stem cell transcription factors OCT4, SOX2 and NANOG. Mechanistically, HAb18IgG inhibited CSCs by blocking CD44s-pSTAT3 signaling. The present findings indicated the promising therapeutic role of anti-CD147 HAb18IgG in suppressing pancreatic tumor initiation and overcoming post-chemoradiotherapy recurrence through the direct targeting of CSCs.

A novel human monoclonal Trop2-IgG antibody inhibits ovarian cancer growth in vitro and in vivo

Trop2 is a tumor-related antigen closely related to the development of a variety of tumors and has been identified as a promising target for cancer immunotherapy. In this study, a Trop2-IgG antibody was constructed by a eukaryotic expression system based on our previously constructed Trop2-Fab antibody. SDS-PAGE, cell ELISA, affinity assays, fluorescence staining and FACS analyses were performed to characterize Trop2-IgG. Then, CCK-8, wound healing, Transwell and annexin V-PI assays were employed to evaluate the tumor inhibitory effects of Trop2-IgG on OC in vitro, while tumor-bearing mice were constructed to examine the tumor inhibitory effects of Trop2-IgG on OC in vivo. Trop2-IgG was successfully constructed by a eukaryotic expression system and maintained recognition characteristics to Trop2 antigen. In vitro, Trop2-IgG could inhibited tumor cell growth, migration, and invasion compared to those of control cells and induced tumor cell apoptosis. In vivo, Trop2-IgG exerted critical tumor inhibitory effects in OC xenografts. Our data suggest that the use of Trop2-IgG provides a potential therapeutic strategy for the immunotherapy of Trop2-expressing OC.