Development of a recombinant anti-VEGFR2-EPCAM bispecific antibody to improve antiangiogenic efficiency

Transient intracellular expression of PD-L1 and VEGFR2 bispecific nanobody in cancer cells inspires long-term T cell activation and infiltration to combat tumor and inhibit cancer metastasis

BACKGROUND

PD-L1, an immune checkpoint inhibitor, and VEGFR2, essential for cancer metastasis, play pivotal roles in tumorigenesis. However, their miniature bispecific intracellular nanobodies for combining check-point blockade and anti-metastasis anticancer therapy remain underexplored.

METHODS

The intrabodies were developed using gene cloning technology. Specificity of the intrabodies was testified using Western blot, co-immunoprecipitation (co-IP) analysis, antibody competitive binding assay, flow cytometry analysis, etc. Checkpoint blockade was demonstrated using antibody-antigen competitive binding assay. Cancer cell migration was determined using scratch assay. Combined anti-cancer therapeutic efficacy of FAP1V2 was determined in vivo of mice models. The PD-1hi immune cells, TCR βhi and CD25hi T-cells were analyzed by flow cytometry, and cancer cell metastasis was performed using immune-fluorescence analysis on lung and liver tissues. Transcriptome analysis was performed to explore signaling pathways associated with the enhanced anticancer efficiency.

RESULTS

Bispecific intrabody FAP1V2 fused with antibody VH regions, was successfully developed and verified with its ability to target and block human and mouse PD-L1 and VEGFR2, inhibiting cancer cell binding to PD-1 and reducing their migratory capacity. Compared to the other treatment, two-rounds of transient FAP1V2 expression in LLC cells in experimental mice models achieved remarkable tumor inhibition, which brought about complete immune inhibition on growth of secondary-round of LLC tumor in 1/6 of the tested mice, inspired long-term activation of TCR βhi T cells and increased their infiltration to tumors, inhibited the emergence of PD-1hi immune cells, indicating prevented T cell depletion. The elevated CD25 expression also supported the success in enhancing immune response reported by elevated T cell activity in spleen. Transcriptome analysis identified critical intracellular pathways regulated by the concurrent blockade of PD-L1 and VEGFR2.

CONCLUSION

PD-L1 and VEGFR2- bispecific VH intracellular nanobody was highly biocompatible and showed the potential for combined anti-cancer therapy through long-term immune activation mediated by PD-L1/PD-1 checkpoint blockade and anti-metastasis mediated by VEGFR2 blockade.

Emerging immunologic approaches as cancer anti-angiogenic therapies

Targeting tumor angiogenesis, the formation of new blood vessels supporting cancer growth and spread, has been an intense focus for therapy development. However, benefits from anti-angiogenic drugs like bevacizumab have been limited by resistance stemming from activation of compensatory pathways. Recent immunotherapy advances have sparked interest in novel immunologic approaches that can induce more durable vascular pruning and overcome limitations of existing angiogenesis inhibitors. This review comprehensively examines these emerging strategies, including modulating tumor-associated macrophages, therapeutic cancer vaccines, engineered nanobodies and T cells, anti-angiogenic cytokines/chemokines, and immunomodulatory drugs like thalidomide analogs. For each approach, the molecular mechanisms, preclinical/clinical data, and potential advantages over conventional drugs are discussed. Innovative therapeutic platforms like nanoparticle delivery systems are explored. Moreover, the importance of combining agents with distinct mechanisms to prevent resistance is evaluated. As tumors hijack angiogenesis for growth, harnessing the immune system's specificity to disrupt this process represents a promising anti-cancer strategy covered by this review.

Endocannabinoids and related compounds as modulators of angiogenesis: Concepts and clinical significance

Vasculogenesis (the process of differentiation of angioblasts toward endothelial cells and de novo formation of crude vascular networks) and angiogenesis (the process of harmonized sprouting and dispersal of new capillaries from previously existing ones) are two fundamentally complementary processes, obligatory for maintaining physiological functioning of vascular system. In clinical practice, however, the later one is of more importance as it guarantees correct embryonic nourishment, accelerates wound healing processes, prevents uncontrolled cell growth and tumorigenesis, contributes in supplying nutritional demand following occlusion of coronary vessels and is in direct relation with development of diabetic retinopathy. Hence, discovery of novel molecules capable of modulating angiogenic events are of great clinical importance. Recent studies have demonstrated multiple angio-regulatory activities for endocannabinoid system modulators and endocannabinoid-like molecules, as well as their metabolizing enzymes. Hence, in present article, we reviewed the regulatory roles of these molecules on angiogenesis and described molecular mechanisms underlying them.

Understanding the versatile roles and applications of EpCAM in cancers: from bench to bedside

Epithelial cell adhesion molecule (EpCAM) functions not only in physiological processes but also participates in the development and progression of cancer. In recent decades, extensive efforts have been made to decipher the role of EpCAM in cancers. Great advances have been achieved in elucidating its structure, molecular functions, pathophysiological mechanisms, and clinical applications. Beyond its well-recognized role as a biomarker of cancer stem cells (CSCs) or circulating tumor cells (CTCs), EpCAM exhibits novel and promising value in targeted therapy. At the same time, the roles of EpCAM in cancer progression are found to be highly context-dependent and even contradictory in some cases. The versatile functional modules of EpCAM and its communication with other signaling pathways complicate the study of this molecule. In this review, we start from the structure of EpCAM and focus on communication with other signaling pathways. The impacts on the biology of cancers and the up-to-date clinical applications of EpCAM are also introduced and summarized, aiming to shed light on the translational prospects of EpCAM.

Anti-cancer therapeutic strategies based on HGF/MET, EpCAM, and tumor-stromal cross talk

As an intelligent disease, tumors apply several pathways to evade the immune system. It can use alternative routes to bypass intracellular signaling pathways, such as nuclear factor-κB (NF-κB), Wnt, and mitogen-activated protein (MAP)/phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR). Therefore, these mechanisms lead to therapeutic resistance in cancer. Also, these pathways play important roles in the proliferation, survival, migration, and invasion of cells. In most cancers, these signaling pathways are overactivated, caused by mutation, overexpression, etc. Since numerous molecules share these signaling pathways, the identification of key molecules is crucial to achieve favorable consequences in cancer therapy. One of the key molecules is the mesenchymal-epithelial transition factor (MET; c-Met) and its ligand hepatocyte growth factor (HGF). Another molecule is the epithelial cell adhesion molecule (EpCAM), which its binding is hemophilic. Although both of them are involved in many physiologic processes (especially in embryonic stages), in some cancers, they are overexpressed on epithelial cells. Since they share intracellular pathways, targeting them simultaneously may inhibit substitute pathways that tumor uses to evade the immune system and resistant to therapeutic agents.

Recent progress in antibody-based therapeutics for triple-negative breast cancer

INTRODUCTION

Triple-negative breast cancer (TNBC) is a subtype of severely aggressive breast cancer that lacks the expression of oestrogen receptor (ER), progesterone receptor and human epidermal growth factor receptor 2 (HER2) and is highly metastatic and related to a poor prognosis. Current standard treatments are still limited to systemic chemotherapy, radiotherapy, and surgical resection. More effective treatments are urgently needed.

AREAS COVERED

The immunogenicity of TNBC has provided opportunities for the development of targeted immunotherapy. In this review, we focus on the recent development in antibody-based drug modalities, including angiogenesis inhibitors, immune checkpoint inhibitors, antibody-drug conjugates, immunoconjugates, T cell-redirecting bispecific antibodies and CAR-T cells, and their mechanisms of action in TNBC.

EXPERT OPINION

At present, the treatment of TNBC is still a major challenge that needs to be addressed. Novel immunotherapies are promising opportunities for improving the management of this aggressive disease.

Chemerin Effect on the Endometrial Proteome of the Domestic Pig during Implantation Obtained by LC-MS/MS Analysis

Chemerin (CHEM) is a hormone mainly expressed in adipocytes involved in the regulation of energy homeostasis and inflammatory response. CHEM expression has been demonstrated in the structures of the porcine hypothalamic-pituitary-gonadal axis, as well as in the uterus, trophoblasts and conceptuses of pigs. In this study, we performed high-throughput proteomic analyses (liquid chromatography with tandem mass spectrometry, LC-MS/MS) to examine the influence of CHEM (400 ng/mL) on differentially regulated proteins (DRPs) in the porcine endometrial tissue explants during implantation (15 to 16 days of gestation). Among all 352 DRPs, 164 were up-regulated and 188 were down-regulated in CHEM-treated group. DRPs were assigned to 47 gene ontology (GO) terms (p-adjusted < 0.05). Validation of four DRPs (IFIT5, TGFβ1, ACO1 and PGRMC1) by Western blot analysis confirmed the veracity and accuracy of the LC-MS/MS method used in the present study. We suggest that CHEM, by modulating various protein expressions, takes part in the endometrial cell proliferation, migration and invasion at the time of implantation. It also regulates the endometrial immune response, sensitivity to P4 and the formation of new blood vessels. Additionally, CHEM appears to be an important factor involved in endothelial cell dysfunction during the pathogenesis of preeclampsia. The identification of a large number of DRPs under the influence of CHEM provides a valuable resource for understanding the molecular mechanisms of this hormone action during implantation, which is a prerequisite for better control of pig reproduction.

Comparison of mucin-1 in human breast cancer and canine mammary gland tumor: a review study

Mucin-1 (MUC-1) is a transmembrane glycoprotein, which bears many similarities between dogs and humans. Since the existence of animal models is essential to understand the significant factors involved in breast cancer mechanisms, canine mammary tumors (CMTs) could be used as a spontaneously occurring tumor model for human studies. Accordingly, this review assessed the comparison of canine and human MUC-1 based on their diagnostic and therapeutic aspects and showed how comparative oncology approaches could provide insights into translating pre-clinical trials from human to veterinary oncology and vice versa which could benefit both humans and dogs.

Cellular stress response to extremely low-frequency electromagnetic fields (ELF-EMF): An explanation for controversial effects of ELF-EMF on apoptosis

Impaired apoptosis is one of the hallmarks of cancer, and almost all of the non‐surgical approaches of eradicating tumour cells somehow promote induction of apoptosis. Indeed, numerous studies have stated that non‐ionizing non‐thermal extremely low‐frequency magnetic fields (ELF‐MF) can modulate the induction of apoptosis in exposed cells; however, much controversy exists in observations. When cells are exposed to ELF‐EMF alone, very low or no statistically significant changes in apoptosis are observed. Contrarily, exposure to ELF‐EMF in the presence of a co‐stressor, including a chemotherapeutic agent or ionizing radiation, can either potentiate or inhibit apoptotic effects of the co‐stressor. In our idea, the main point neglected in interpreting these discrepancies is “the cellular stress responses” of cells following ELF‐EMF exposure and its interplay with apoptosis. The main purpose of the current review was to outline the triangle of ELF‐EMF, the cellular stress response of cells and apoptosis and to interpret and unify discrepancies in results based on it. Therefore, initially, we will describe studies performed on identifying the effect of ELF‐EMF on induction/inhibition of apoptosis and enumerate proposed pathways through which ELF‐EMF exposure may affect apoptosis; then, we will explain cellular stress response and cues for its induction in response to ELF‐EMF exposure; and finally, we will explain why such controversies have been observed by different investigators.