Gene therapy using plasmid DNA-encoded anti-HER2 antibody for cancers that overexpress HER2

In vivo vectorization and delivery systems for gene therapies and RNA-based therapeutics in oncology

Gene and RNA-based therapeutics represent a promising frontier in oncology, enabling targeted modulation of tumor-associated genes and proteins. This review explores the latest advances in payload vectorization and delivery systems developed for in vivo cancer treatments. We discuss viral and non-viral organic particles, including lipid based nanoparticles and polymeric structures, for the effective transport of plasmids, siRNA, and self-amplifying RNA therapeutics. Their physicochemical properties, strategies to overcome intracellular barriers, and innovations in cell-based carriers and engineered extracellular vesicles are highlighted. Moreover, we consider oncolytic viruses, novel viral capsid modifications, and approaches that refine tumor targeting and immunomodulation. Ongoing clinical trials and regulatory frameworks guide future directions and emphasize the need for safe, scalable production. The potential convergence of these systems with combination therapies paves the way toward personalized cancer medicine.

Recent Advances and Prospects of Nucleic Acid Therapeutics for Anti-Cancer Therapy

Nucleic acid therapeutics are promising alternatives to conventional anti-cancer therapy, such as chemotherapy and radiation therapy. While conventional therapies have limitations, such as high side effects, low specificity, and drug resistance, nucleic acid therapeutics work at the gene level to eliminate the cause of the disease. Nucleic acid therapeutics treat diseases in various forms and using different mechanisms, including plasmid DNA (pDNA), small interfering RNA (siRNA), anti-microRNA (anti-miR), microRNA mimics (miRNA mimic), messenger RNA (mRNA), aptamer, catalytic nucleic acid (CNA), and CRISPR cas9 guide RNA (gRNA). In addition, nucleic acids have many advantages as nanomaterials, such as high biocompatibility, design flexibility, low immunogenicity, small size, relatively low price, and easy functionalization. Nucleic acid therapeutics can have a high therapeutic effect by being used in combination with various nucleic acid nanostructures, inorganic nanoparticles, lipid nanoparticles (LNPs), etc. to overcome low physiological stability and cell internalization efficiency. The field of nucleic acid therapeutics has advanced remarkably in recent decades, and as more and more nucleic acid therapeutics have been approved, they have already demonstrated their potential to treat diseases, including cancer. This review paper introduces the current status and recent advances in nucleic acid therapy for anti-cancer treatment and discusses the tasks and prospects ahead.

Efficacy and advantage of immunotherapy for melanoma via intramuscular co-expression of plasmid-encoded PD-1 and CTLA-4 scFvs

Immunotherapy, in the shape of immune checkpoint inhibitors (ICIs), has completely changed the treatment of cancer. However, the increasing expense of treatment and the frequency of immune-related side effects, which are frequently associated with combination antibody therapies and Fc fragment of antibody, have limited the patient's ability to benefit from these treatments. Herein, we presented the therapeutic effects of the plasmid-encoded PD-1 and CTLA-4 scFvs (single-chain variable fragment) for melanoma via an optimized intramuscular gene delivery system. After a single injection, the plasmid-encoded ICI scFv in mouse sera continued to be above 150 ng/mL for 3 weeks and reached peak amounts of 600 ng/mL. Intramuscular delivery of plasmid encoding PD-1 and CTLA-4 scFvs significantly changed the tumor microenvironment, delayed tumor growth, and prolonged survival in melanoma-bearing mice. Furthermore, no significant toxicity was observed, suggesting that this approach could improve the biosafety of ICIs combination therapy. Overall, the expression of ICI scFvs in vivo using intramuscular plasmid delivery could potentially develop into a reliable, affordable, and safe immunotherapy technique, expanding the range of antibody-based gene therapy systems that are available.

Delivery of DNA-Based Therapeutics for Treatment of Chronic Diseases

Gene therapy and its role in the medical field have evolved drastically in recent decades. Studies aim to define DNA-based medicine as well as encourage innovation and the further development of novel approaches. Gene therapy has been established as an alternative approach to treat a variety of diseases. Its range of mechanistic applicability is wide; gene therapy has the capacity to address the symptoms of disease, the body's ability to fight disease, and in some cases has the ability to cure disease, making it a more attractive intervention than some traditional approaches to treatment (i.e., medicine and surgery). Such versatility also suggests gene therapy has the potential to address a greater number of indications than conventional treatments. Many DNA-based therapies have shown promise in clinical trials, and several have been approved for use in humans. Whereas current treatment regimens for chronic disease often require frequent dosing, DNA-based therapies can produce robust and durable expression of therapeutic genes with fewer treatments. This benefit encourages the application of DNA-based gene therapy to manage chronic diseases, an area where improving efficiency of current treatments is urgent. Here, we provide an overview of two DNA-based gene therapies as well as their delivery methods: adeno associated virus (AAV)-based gene therapy and plasmid DNA (pDNA)-based gene therapy. We will focus on how these therapies have already been utilized to improve treatment of chronic disease, as well as how current literature supports the expansion of these therapies to treat additional chronic indications in the future.

Ex vivo dual gene therapy using human adipocytes secreting anti-HER2 antibody on HER2-positive xenograft tumor models

BACKGROUND

Although targeted treatments against human epidermal growth factor receptor 2 (HER2) have improved survival in patients with metastatic HER2-positive breast cancer, long and repeated treatment is time-consuming and costly for patients. To reduce these burdens, we developed ex vivo gene-transduced adipocytes that secrete anti-HER2 antibodies and evaluated their anti-tumor effects.

METHODS

Ceiling culture-derived proliferative adipocytes (ccdPA) secreting anti-HER2 antibody against domain IV receptors: TRA-ccdPA, and domain II receptors: PER-ccdPA, were constructed using a plasmid lentivirus. Delivery of secreted antibody and its specific binding to HER2 breast cancer were evaluated in vitro and in vivo. To optimize antibody production from ccdPA, different conditions of ccdPA implantation were examined. Anti-tumor efficacy was evaluated in HER2-positive-cancer-inoculated nude mice.

RESULTS

Anti-HER2 antibody against domain II was identified in supernatants from PER-ccdPAs. The optimal method to achieve the highest concentration of antibody in mouse sera was injecting differentiated ccdPA cells into the mammary fat pad. Antibody in supernatants from PER-ccdPAs bound to the surface of HER2-positive breast cancer cells similar to pertuzumab. Antibodies in mouse sera were delivered to HER2-positive breast cancer tumors and tumor necrosis was observed microscopically. One-time administration of combined TRA-ccdPAs and PER-ccdPAs produced antibody continuously in mouse sera, and anti-tumor effects were maintained for the duration of this study in xenograft models. Furthermore, combination therapy significantly suppressed tumor growth compared with a single administration.

CONCLUSION

Ex vivo gene-transduced adipocytes might be useful for cell-based gene therapy. This system may be a platform for various antibody therapies.

Expanding the Reach of Monoclonal Antibodies: A Review of Synthetic Nucleic Acid Delivery in Immunotherapy

Harnessing the immune system to combat disease has revolutionized medical treatment. Monoclonal antibodies (mAbs), in particular, have emerged as important immunotherapeutic agents with clinical relevance in treating a wide range of diseases, including allergies, autoimmune diseases, neurodegenerative disorders, cancer, and infectious diseases. These mAbs are developed from naturally occurring antibodies and target specific epitopes of single molecules, minimizing off-target effects. Antibodies can also be designed to target particular pathogens or modulate immune function by activating or suppressing certain pathways. Despite their benefit for patients, the production and administration of monoclonal antibody therapeutics are laborious, costly, and time-consuming. Administration often requires inpatient stays and repeated dosing to maintain therapeutic levels, limiting their use in underserved populations and developing countries. Researchers are developing alternate methods to deliver monoclonal antibodies, including synthetic nucleic acid-based delivery, to overcome these limitations. These methods allow for in vivo production of monoclonal antibodies, which would significantly reduce costs and simplify administration logistics. This review explores new methods for monoclonal antibody delivery, including synthetic nucleic acids, and their potential to increase the accessibility and utility of life-saving treatments for several diseases.

Delivery platforms for broadly neutralizing antibodies

PURPOSE OF REVIEW

Passive administration of broadly neutralizing antibodies (bNAbs) is being evaluated as a therapeutic approach to prevent or treat HIV infections. However, a number of challenges face the widespread implementation of passive transfer for HIV. To reduce the need of recurrent administrations of bNAbs, gene-based delivery approaches have been developed which overcome the limitations of passive transfer.

RECENT FINDINGS

The use of DNA and mRNA for the delivery of bNAbs has made significant progress. DNA-encoded monoclonal antibodies (DMAbs) have shown great promise in animal models of disease and the underlying DNA-based technology is now being tested in vaccine trials for a variety of indications. The COVID-19 pandemic greatly accelerated the development of mRNA-based technology to induce protective immunity. These advances are now being successfully applied to the delivery of monoclonal antibodies using mRNA in animal models. Delivery of bNAbs using viral vectors, primarily adeno-associated virus (AAV), has shown great promise in preclinical animal models and more recently in human studies. Most recently, advances in genome editing techniques have led to engineering of monoclonal antibody expression from B cells. These efforts aim to turn B cells into a source of evolving antibodies that can improve through repeated exposure to the respective antigen.

SUMMARY

The use of these different platforms for antibody delivery has been demonstrated across a wide range of animal models and disease indications, including HIV. Although each approach has unique strengths and weaknesses, additional advances in efficiency of gene delivery and reduced immunogenicity will be necessary to drive widespread implementation of these technologies. Considering the mounting clinical evidence of the potential of bNAbs for HIV treatment and prevention, overcoming the remaining technical challenges for gene-based bNAb delivery represents a relatively straightforward path towards practical interventions against HIV infection.

Plasmid DNA for Therapeutic Applications in Cancer

Recently, the interest in using nucleic acids for therapeutic applications has been increasing. DNA molecules can be manipulated to express a gene of interest for gene therapy applications or vaccine development. Plasmid DNA can be developed to treat different diseases, such as infections and cancer. In most cancers, the immune system is limited or suppressed, allowing cancer cells to grow. DNA vaccination has demonstrated its capacity to stimulate the immune system to fight against cancer cells. Furthermore, plasmids for cancer gene therapy can direct the expression of proteins with different functions, such as enzymes, toxins, and cytotoxic or proapoptotic proteins, to directly kill cancer cells. The progress and promising results reported in animal models in recent years have led to interesting clinical results. These DNA strategies are expected to be approved for cancer treatment in the near future. This review discusses the main strategies, challenges, and future perspectives of using plasmid DNA for cancer treatment.

Gene therapy with B-cell maturation antigen/CD3 bispecific antibody encoding plasmid DNA for treating multiple myeloma

The delivery of bispecific antibodies (BsAbs) targeting B-cell maturation antigen (BCMA) and CD3 using the gene therapy approach is a promising alternative for BsAb administration in patients with multiple myeloma (MM). In the present study, we evaluated the efficacy of this approach using a xenograft model. Tumour growth was significantly delayed in mice treated with single electroporation-enhanced intramuscular injection of plasmid DNA encoding BCMA/CD3 BsAb in contrast to the vehicle control-treated group. Limited toxicity was observed following treatment. This study demonstrates that the gene therapy-based approach for the delivery of BCMA/CD3 BsAb is effective and safe for the treatment of MM.

Induction of tier-2 neutralizing antibodies in mice with a DNA-encoded HIV envelope native like trimer

HIV Envelope (Env) is the main vaccine target for induction of neutralizing antibodies. Stabilizing Env into native-like trimer (NLT) conformations is required for recombinant protein immunogens to induce autologous neutralizing antibodies(nAbs) against difficult to neutralize HIV strains (tier-2) in rabbits and non-human primates. Immunizations of mice with NLTs have generally failed to induce tier-2 nAbs. Here, we show that DNA-encoded NLTs fold properly in vivo and induce autologous tier-2 nAbs in mice. DNA-encoded NLTs also uniquely induce both CD4 + and CD8 + T-cell responses as compared to corresponding protein immunizations. Murine neutralizing antibodies are identified with an advanced sequencing technology. The structure of an Env-Ab (C05) complex, as determined by cryo-EM, identifies a previously undescribed neutralizing Env C3/V5 epitope. Beyond potential functional immunity gains, DNA vaccines permit in vivo folding of structured antigens and provide significant cost and speed advantages for enabling rapid evaluation of new HIV vaccines.

Gene therapy: A promising approach for breast cancer treatment

Breast cancer (BC) is the most prevalent malignancy and the second leading cause of death among women worldwide that is caused by numerous genetic and environmental factors. Hence, effective treatment for this type of cancer requires new therapeutic approaches. The traditional methods for treating this cancer have side effects, therefore so much research have been performed in last decade to find new methods to alleviate these problems. The study of the molecular basis of breast cancer has led to the introduction of gene therapy as an effective therapeutic approach for this cancer. Gene therapy involves sending genetic material through a vector into target cells, which is followed by a correction, addition, or suppression of the gene. In this technique, it is necessary to target tumour cells without affecting normal cells. In addition, clinical trial studies have shown that this approach is less toxic than traditional therapies. This study will review various aspects of breast cancer, gene therapy strategies, limitations, challenges and recent studies in this area.

Anti-HER2 antibody therapy using gene-transduced adipocytes for HER2-positive breast cancer

PURPOSE

Although recent advances in molecular target therapy have improved the survival of breast cancer patients, high cost and frequent hospital visits result in both societal and individual burden. To reduce these problems, it has been proposed to produce antibodies in vivo. Here, we constructed gene-transduced human ceiling culture-derived proliferative adipocytes secreting anti-HER2 antibody (HER2-ccdPAs) and evaluated their ability to secrete antibody and mediate an anti-tumor effect.

METHODS

Plasmid lentivirus was used as a recipient for anti-HER2 antibody cDNA and transduced into human proliferative adipocyte. Secretory antibody expression was evaluated by ELISA and western blot. Specific binding of secretory antibody to HER2 was examined by immunofluorescence analysis. Direct and indirect anti-tumor effects of supernatants from HER2-ccdPAs were evaluated using BT474 (HER2+) and MDA-MB-231 (HER2-) breast cancer cell lines. Additionally, whether adipocyte differentiation affects antibody secretion was investigated using supernatant collected from different cell maturation states.

RESULTS

Anti-HER2 antibody was identified in the supernatant from HER2-ccdPAs and its production increased with the differentiation into mature adipocyte. Antibodies in supernatants from HER2-ccdPAs bound to HER2-positive breast cancer cells similar to trastuzumab. Supernatant from HER2-ccdPAs inhibited the proliferation of BT474 but not MDA-MB-231 cells, and downregulated AKT phosphorylation in BT474 cells compared with controls. Supernatants from HER2-ccdPAs also had an indirect anti-tumor effect on BT474 cells through ADCC. Additionally, Single inoculation of HER2-ccdPAs showed an anti-tumor effect in BT474 xenograft model.

CONCLUSIONS

HER2-ccdPAs might be useful for cell-based gene therapy. This system could be a platform for various antibody therapies.

Concise Review: Functional Roles and Therapeutic Potentials of Long Non-coding RNAs in Cholangiopathies

Long non-coding RNAs (lncRNAs) are RNAs with lengths exceeding 200 nucleotides that are not translated into proteins. It is well-known that small non-coding RNAs, such as microRNAs (miRNAs), regulate gene expression and play an important role in cholangiopathies. Recent studies have demonstrated that lncRNAs may also play a key role in the pathophysiology of cholangiopathies. Patients with cholangiopathies often develop cholangiocarcinoma (CCA), which is cholangiocyte-derived cancer, in the later stage. Cholangiocytes are a primary target of therapies for cholangiopathies and CCA development. Previous studies have demonstrated that expression levels of lncRNAs are altered in the liver of cholangiopathies or CCA tissues. Some lncRNAs regulate gene expression by inhibiting functions of miRNAs leading to diseased liver conditions or CCA progression, suggesting that lncRNAs could be a novel therapeutic target for those disorders. This review summarizes current understandings of functional roles of lncRNAs in cholangiopathies and seek their potentials for novel therapies.

A gene-based anti-angiogenesis therapy as a novel strategy for cancer treatment

Angiogenesis-targeted therapy of cancer is considered a promising strategy for therapeutic management of cancer progression. Over the last two decades, a few anti-angiogenesis monoclonal antibodies (mAbs) blocking VEGF signaling have been developed and approved by the FDA. The most widely used anti-angiogenesis drug is bevacizumab which binds VEGFA and prevents its interaction with VEGF receptor leading to suppression of angiogenesis. Despite the remarkable success in development of angiogenesis inhibitory mAbs, their clinical application is limited by the high-cost of mAbs-based regimen which includes multiple doses of mAbs due to their short biological half-life. Antibody gene therapy is an alternative system of antibody production. In this study, we have developed a gene-based anti-VEGF mAb system which is expected to produce a high concentration of anti-VEGFA mAb upon a single administration in cancer patients. The full-length cDNA bevacizumab light and heavy chains joint with T2A sequence were cloned in pCDH lentivirus vector. The lentiviral particles expressing bevacizumab was produced in HEK-293T cells. Recombinant lentiviral particles containing bevacizumab (rLV-bev) efficiently transduced HEK-293cells and produced functional bevacizumab mAb. Bevacizumab expression in the transduced cell was assessed by qRT-PCR and western blot at both the mRNA and protein level, respectively. The functionality of the recombinant bevacizumab was confirmed using the tube formation assay in the co-culture system of endothelial cells and HT-29cells transduced with rLV-bev viral particles. Our results show that rLV-bev gene therapy can be useful for angiogenesis-targeted therapy of cancer.

Labeling Single Domain Antibody Fragments with Fluorine-18 Using 2,3,5,6-Tetrafluorophenyl 6-[18F]Fluoronicotinate Resulting in High Tumor-to-Kidney Ratios

ImmunoPET agents are being investigated to assess the status of epidermal growth factor receptor 2 (HER2) in breast cancer patients with the goal of selecting those likely to benefit from HER2-targeted therapies and monitoring their progress after these treatments. We have been exploring the use of single domain antibody fragments (sdAbs) labeled with ¹⁸F using residualizing prosthetic agents for this purpose. In this study, we have labeled two sdAbs that bind to different domains on the HER2 receptor, 2Rs15d and 5F7, using 2,3,5,6-tetrafluorophenyl 6-[¹⁸F]fluoronicotinate ([¹⁸F]TFPFN) and evaluated their HER2 targeting properties in vitro and in vivo. The overall decay-corrected radiochemical yield for the synthesis of [¹⁸F]TFPFN-2Rs15d and [¹⁸F]TFPFN-5F7 was 5.7 ± 3.6 and 4.0 ± 2.0%, respectively. The radiochemical purity of labeled sdAbs was >95%, immunoreactive fractions were about 60%, and affinity was in the low nanomolar range. Intracellularly trapped activity from [¹⁸F]TFPFN-2Rs15d and [¹⁸F]TFPFN-5F7 in HER2-expressing SKOV-3 ovarian and BT474M1 breast carcinoma cells were similar to the sdAbs labeled using the previously validated radioiodination residualizing prosthetic agents N-succinimidyl 4-guanidinomethyl-3-[¹²⁵I]iodobenzoate ([¹²⁵I]SGMIB) and N-succinimidyl 3-guanidinomethyl-5-[¹²⁵I]iodobenzoate ( iso-[¹²⁵I]SGMIB). Intracellular activity was about 2-fold higher for radiolabeled 5F7 compared with 2Rs15d for both ¹⁸F and ¹²⁵I. While tumor uptake of both [¹⁸F]TFPFN-2Rs15d and [¹⁸F]TFPFN-5F7 was comparable to those for the coadministered ¹²⁵I-labeled sdAb, renal uptake of the ¹⁸F-labeled sdAbs was substantially lower. In microPET images, the tumor was clearly delineated in SKOV-3 and BT474 xenograft-bearing athymic mice with low levels of background activity in normal tissues, except the bladder. These results indicate that the [¹⁸F]TFPFN prosthetic group could be a valuable reagent for developing sdAb-based immunoPET imaging agents.

An engineered bispecific DNA-encoded IgG antibody protects against Pseudomonas aeruginosa in a pneumonia challenge model

The impact of broad-spectrum antibiotics on antimicrobial resistance and disruption of the beneficial microbiome compels the urgent investigation of bacteria-specific approaches such as antibody-based strategies. Among these, DNA-delivered monoclonal antibodies (DMAbs), produced by muscle cells in vivo, potentially allow the prevention or treatment of bacterial infections circumventing some of the hurdles of protein IgG delivery. Here, we optimize DNA-delivered monoclonal antibodies consisting of two potent human IgG clones, including a non-natural bispecific IgG1 candidate, targeting Pseudomonas aeruginosa. The DNA-delivered monoclonal antibodies exhibit indistinguishable potency compared to bioprocessed IgG and protect against lethal pneumonia in mice. The DNA-delivered monoclonal antibodies decrease bacterial colonization of organs and exhibit enhanced adjunctive activity in combination with antibiotics. These studies support DNA-delivered monoclonal antibodies delivery as a potential strategy to augment the host immune response to prevent serious bacterial infections, and represent a significant advancement toward broader practical delivery of monoclonal antibody immunotherapeutics for additional infectious pathogens.

DNA-delivered monoclonal antibodies (DMAbs) can be produced by muscle cells in vivo, potentially allowing prevention or treatment of infectious diseases. Here, the authors show that two DMAbs targeting Pseudomonas aeruginosa proteins confer protection against lethal pneumonia in mice.

Therapeutic Tumor Control of HER2 DNA Vaccines Is Achieved by an Alteration of Tumor Cells and Tumor Microenvironment by Gemcitabine and Anti-Gr-1 Ab Treatment in a HER2-Expressing Tumor Model

Therapeutic control of tumors is challenging as they tend to alter their biological functions and microenvironment. In a CT26/HER2 tumor model, HER2 DNA vaccines and even anti-PD-L1 Abs failed to display antitumor therapeutic activity while inducing Ag-specific cytotoxic T lymphocyte (CTL) activity. To clarify this contradictory finding, we selected tumor cells (CT26/HER2-1) from one tumor-bearing animal in the therapeutic model. CT26/HER2-1 cells behaved similar to wild-type CT26/HER2 cells in their HER2 expression, immune cell stimulation for IFN-γ production, and antitumor immune sensitivity. A similar finding was obtained with additional CT26/HER2-2, -3, -4, -5, and -6 cells from the therapeutic model, suggesting that a lack of antitumor therapeutic activity of HER2 DNA vaccines might be ascribed to a factor in the tumor microenvironment, but not to an alteration in tumor cell functions. When tumor-bearing mice were depleted of myeloid-derived suppressor cells (MDSCs) by anti-Gr-1 Ab treatment, they displayed HER2 vaccine-mediated antitumor activity, suggesting a role of MDSCs in blocking antitumor activity. Moreover, when tumor-bearing mice were treated with gemcitabine, they displayed HER2 vaccine-mediated antitumor activity, suggesting that cytotoxic drug treatment makes tumor cells susceptible to lysis by CTLs. Thus, these studies show that therapeutic control of HER2 DNA vaccines can be achieved by anti-Gr-1 Ab treatment through MDSC depletion and by gemcitabine treatment through sensitization of tumor cells to CTL-mediated killing in this model. These findings may have implications for achieving therapeutic control of CTL-resistant tumors in cancer therapy.