Serum CEACAM1 Elevation Correlates with Melanoma Progression and Failure to Respond to Adoptive Cell Transfer Immunotherapy

The role of carcinoembryonic antigen-related cell adhesion molecule 1 in cancer

The Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), also known as CD66a, is a member of the immunoglobulin superfamily. CEACAM1 was shown to be a prognostic marker in patients suffering from cancer. In this review, we summarize pre-clinical and clinical evidence linking CEACAM1 to tumorigenicity and cancer progression. Furthermore, we discuss potential CEACAM1-based mechanisms that may affect cancer biology.

NETosis as an oncologic therapeutic target: a mini review

Neutrophil Extracellular Traps (NETs) are a key form of pro-inflammatory cell death of neutrophils characterized by the extrusion of extracellular webs of DNA containing bactericidal killing enzymes. NETosis is heavily implicated as a key driver of host damage in autoimmune diseases where injurious release of proinflammatory enzymes damage surrounding tissue and releases 70 known autoantigens. Recent evidence shows that both neutrophils and NETosis have a role to play in carcinogenesis, both indirectly through triggering DNA damage through inflammation, and directly contributing to a pro-tumorigenic tumor microenvironment. In this mini-review, we summarize the current knowledge of the various mechanisms of interaction and influence between neutrophils, with particular attention to NETosis, and cancer cells. We will also highlight the potential avenues thus far explored where we can intercept these processes, with the aim of identifying promising prospective targets in cancer treatment to be explored in further studies.

Neutrophil Extracellular Traps in Cancer Therapy Resistance

Neutrophils and their products are increasingly recognized to have a key influence on cancer progression and response to therapy. Their involvement has been shown in nearly every aspect of cancer pathophysiology with growing evidence now supporting their role in resistance to a variety of cancer therapies. Recently, the role of neutrophils in cancer progression and therapy resistance has been further complicated with the discovery of neutrophil extracellular traps (NETs). NETs are web-like structures of chromatin decorated with a variety of microbicidal proteins. They are released by neutrophils in a process called NETosis. NET-dependent mechanisms of cancer pathology are beginning to be appreciated, particularly with respect to tumor response to chemo-, immuno-, and radiation therapy. Several studies support the functional role of NETs in cancer therapy resistance, involving T-cell exhaustion, drug detoxification, angiogenesis, the epithelial-to-mesenchymal transition, and extracellular matrix remodeling mechanisms, among others. Given this, new and promising data suggests NETs provide a microenvironment conducive to limited therapeutic response across a variety of neoplasms. As such, this paper aims to give a comprehensive overview of evidence on NETs in cancer therapy resistance with a focus on clinical applicability.

Antibody-Based Targeted Interventions for the Diagnosis and Treatment of Skin Cancers

BACKGROUND

Cutaneous malignancies most commonly arise from skin epidermal cells. These cancers may rapidly progress from benign to a metastatic phase. Surgical resection represents the gold standard therapeutic treatment of non-metastatic skin cancer while chemo- and/or radiotherapy are often used against metastatic tumors. However, these therapeutic treatments are limited by the development of resistance and toxic side effects, resulting from the passive accumulation of cytotoxic drugs within healthy cells.

OBJECTIVE

This review aims to elucidate how the use of monoclonal Antibodies (mAbs) targeting specific Tumor Associated Antigens (TAAs) is paving the way to improved treatment. These mAbs are used as therapeutic or diagnostic carriers that can specifically deliver cytotoxic molecules, fluorophores or radiolabels to cancer cells that overexpress specific target antigens.

RESULTS

mAbs raised against TAAs are widely in use for e.g. differential diagnosis, prognosis and therapy of skin cancers. Antibody-Drug Conjugates (ADCs) particularly show remarkable potential. The safest ADCs reported to date use non-toxic photo-activatable Photosensitizers (PSs), allowing targeted Photodynamic Therapy (PDT) resulting in targeted delivery of PS into cancer cells and selective killing after light activation without harming the normal cell population. The use of near-infrared-emitting PSs enables both diagnostic and therapeutic applications upon light activation at the specific wavelengths.

CONCLUSION

Antibody-based approaches are presenting an array of opportunities to complement and improve current methods employed for skin cancer diagnosis and treatment.

Comparative analysis of CEACAM1 expression in thin melanomas with and without regression

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a key molecule in several intracellular and intercellular signaling pathways, with multiple functional and structural roles. CEACAM1 expression in melanoma is often described in the invading part of the tumor and has been associated with increased melanoma cells invasion and migration. We studied CEACAM1 expression in regressing versus non-regressing thin melanomas, knowing that phenomenon of regression represents a valuable model for understanding tumor immunity. In melanoma, through homophilic interactions, CEACAM1 inhibits natural killer cell activity, inhibits effector functions of tumor infiltrating lymphocytes, such as cytotoxicity and interferon-γ release. We present a retrospective study including 53 consecutive cases of thin melanoma, 21 with regression and 32 without regression. Comparative analysis of CEACAM1 expression in regressed and non-regressed areas from melanomas with regression and in non-regressed melanomas was performed. We used three different clones of CEACAM1: AA 1-428, extracellular domain, rabbit; AA 1-428, mouse, clone 8B6E2F4; and AA 1-468, full length, mouse, clone 2F6. All three clones had similar reactivity. We identified membrane positivity of tumor cells in non-regressed melanomas and in non-regressed areas in melanomas with regression. Remaining tumor cells in regressed areas were mostly negative for CEACAM1. In non-regressed lesions, there was a stronger positivity of CEACAM1 in the deep invasive front. In thin melanomas, CEACAM1 overexpression is related with invasiveness, suggesting that CEACAM1-positive melanomas are more aggressive. Also, in areas of regression tumor cells lose CEACAM1 expression, probably correlated with the presence of natural killer cells.

On the Dual Role of Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 (CEACAM1) in Human Malignancies

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a glycoprotein belonging to the carcinoembryonic antigen (CEA) family that is expressed on a wide variety of cells and holds a complex role in inflammation through its alternate splicing and generation of various isoforms, mediating intricate mechanisms of modulation and dysregulation. Initially regarded as a tumor suppressor as its expression shows considerable downregulation within the epithelia in the early phases of many solid cancers, CEACAM1 has been linked lately to the progression of malignancy and metastatic spread as various papers point to its role in tumor progression, angiogenesis, and invasion. We reviewed the literature and discussed the various expression patterns of CEACAM1 in different types of tumors, describing its structure and general biologic functions and emphasizing the most significant findings that link this molecule to poor prognosis. The importance of understanding the role of CEACAM1 in cell transformation stands not only in this adhesion molecule's value as a prognostic factor but also in its promising premise as a potential new molecular target that could be exploited as a specific cancer therapy.

Regulation of CEACAM1 Protein Expression by the Transcription Factor ETS-1 in BRAF-Mutant Human Metastatic Melanoma Cells

BRAF becomes constitutively activated in 50% to 70% of melanoma cases. CEACAM1 has a dual role in melanoma, including facilitation of cell proliferation and suppression of infiltrating lymphocytes, which are consistent with its value as a marker for poor prognosis in melanoma patients. Here we show that BRAF^V600E melanoma cells treated with BRAF and MEK inhibitors (MAPKi) downregulate CEACAM1 mRNA and protein expression in a dose- and exposure time–dependent manners. Indeed, there is a significant correlation between the presence of BRAF^V600E and CEACAM1 expression in melanoma specimens obtained from 45 patients. Vemurafenib-resistant cell systems reactivate the MAPK pathway and restore basal CEACAM1 mRNA and protein levels. These combined results suggest transcriptional regulation. Indeed, luciferase reporting assays show that CEACAM1 promoter (CEACAM1p) activity is significantly reduced by MAPKi. Importantly, we show that the MAPK-driven CEACAM1p activity is mediated by ETS1, a major transcription factor and downstream effector of the MAPK pathway. Phosphorylation mutant ETS1^T38A shows a dominant negative effect over CEACAM1 expression. The data are consistent with independent RNAseq data from serial biopsies of melanoma patients treated with BRAF inhibitors, which demonstrate similar CEACAM1 downregulation. Finally, we show that CEACAM1 downregulation by MAPKi renders the cells more sensitive to T-cell activation. These results provide a new view on a potential immunological mechanism of action of MAPKi in melanoma, as well as on the aggressive phenotype observed in drug-resistant cells.

CEACAM1 as a multi-purpose target for cancer immunotherapy

CEACAM1 is an extensively studied cell surface molecule with established functions in multiple cancer types, as well as in various compartments of the immune system. Due to its multi-faceted role as a recently appreciated immune checkpoint inhibitor and tumor marker, CEACAM1 is an attractive target for cancer immunotherapy. Herein, we highlight CEACAM1's function in various immune compartments and cancer types, including in the context of metastatic disease. This review outlines CEACAM1's role as a therapeutic target for cancer treatment in light of these properties.