Tumor-Associated Disialylated Glycosphingolipid Antigen-Revealing Antibodies Found in Melanoma Patients' Immunoglobulin Repertoire Suggest a Two-Direction Regulation Mechanism Between Immune B Cells and the Tumor

PMAIP1-mediated glucose metabolism and its impact on the tumor microenvironment in breast cancer: Integration of multi-omics analysis and experimental validation

BACKGROUND

Glucose metabolism in breast cancer has a potential effect on tumor progression and is related to the immune microenvironment. Thus, this study aimed to develop a glucose metabolism-tumor microenvironment score to provide new perspectives on breast cancer treatment.

METHOD

Data were acquired from the Gene Expression Omnibus and UCSC Xena databases, and glucose-metabolism-related genes were acquired from the Gene Set Enrichment Analysis database. Genes with significant prognostic value were identified, and immune infiltration analysis was conducted, and a prognostic model was constructed based on the results of these analyses. The results were validated by in vitro experiments with MCF-7 and MCF-10A cell lines, including expression validation, functional experiments, and bulk sequencing. Single-cell analysis was also conducted to explore the role of specific cell clusters in breast cancer, and Bayes deconvolution was used to further investigate the associations between cell clusters and tumor phenotypes of breast cancer.

RESULTS

Four significant prognostic genes (PMAIP1, PGK1, SIRT7, and SORBS1) were identified, and, through immune infiltration analysis, a combined prognostic model based on glucose metabolism and immune infiltration was established. The model was used to classify clinical subtypes of breast cancer, and PMAIP1 was identified as a potential critical gene related to glucose metabolism in breast cancer. Single-cell analysis and Bayes deconvolution jointly confirmed the protective role of the PMAIP1+ luminal cell cluster.

Immune Repertoires in Various Dermatologic and Autoimmune Diseases

The immune repertoire (IR) is a term that defines the combined unique genetic rearrangements of antigen receptors expressed by B and T lymphocytes. The IR determines the ability of the immune system to identify and respond to foreign antigens while preserving tolerance to host antigens. When immune tolerance is disrupted, development of autoimmune diseases can occur due to the attack of self-antigens. Recent technical advances in immune profiling allowed identification of common patterns and shared antigen-binding sequences unique to diverse array of diseases. However, there is no current literature to date evaluates IR findings in autoimmune and skin inflammatory conditions. In this review, we provide an overview of the past and current research findings of IR in various autoimmune and dermatologic conditions. Enriching our understanding of IRs in these conditions is critical for understanding the pathophysiology behind autoimmune skin disease onset and progression. Furthermore, understanding B-cell and T-cell IR will help devise therapeutic treatments in the hopes of restoring immune tolerance and preventing disease onset and progression.

Bioactive sphingolipids as emerging targets for signal transduction in cancer development

Sphingolipids, crucial components of cellular membranes, play a vital role in maintaining cellular structure and signaling integrity. Disruptions in sphingolipid metabolism are increasingly implicated in cancer development. Key bioactive sphingolipids, such as ceramides, sphingosine-1-phosphate (S1P), ceramide-1-phosphate (C1P), and glycosphingolipids, profoundly impact tumor biology. They influence the behavior of tumor cells, stromal cells, and immune cells, affecting tumor aggressiveness, angiogenesis, immune modulation, and extracellular matrix remodeling. Furthermore, abnormal expression of sphingolipids and their metabolizing enzymes modulates the secretion of tumor-derived extracellular vesicles (TDEs), which are key players in creating an immunosuppressive tumor microenvironment, remodeling the extracellular matrix, and facilitating oncogenic signaling within in situ tumors and distant pre-metastatic niches (PMNs). Understanding the role of sphingolipids in the biogenesis of tumor-derived extracellular vesicles (TDEs) and their bioactive contents can pave the way for new biomarkers in cancer diagnosis and prognosis, ultimately enhancing comprehensive tumor treatment strategies.

Smaller size packs a stronger punch - Recent advances in small antibody fragments targeting tumour-associated carbohydrate antigens

Attached to proteins, lipids, or forming long, complex chains, glycans represent the most versatile post-translational modification in nature and surround all human cells. Unique glycan structures are monitored by the immune system and differentiate self from non-self and healthy from malignant cells. Aberrant glycosylations, termed tumour-associated carbohydrate antigens (TACAs), are a hallmark of cancer and are correlated with all aspects of cancer biology. Therefore, TACAs represent attractive targets for monoclonal antibodies for cancer diagnosis and therapy. However, due to the thick and dense glycocalyx as well as the tumour micro-environment, conventional antibodies often suffer from restricted access and limited effectiveness in vivo. To overcome this issue, many small antibody fragments have come forth, showing similar affinity with better efficiency than their full-length counterparts. Here we review small antibody fragments against specific glycans on tumour cells and highlight their advantages over conventional antibodies.

CDC25C is a prognostic biomarker and correlated with mitochondrial homeostasis in pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PAAD) is a common digestive tract malignant tumor with an extremely poor prognosis. The survival and prognosis may significantly improve if it is diagnosed early. Therefore, identifying biomarkers for early diagnosis is still considered a great clinical challenge in PAAD. Cell Division Cycle 25C (CDC25C), a cardinal cell cycle regulatory protein, directly mediates the G2/M phase and is intimately implicated in tumor development. In the current study, we aim to explore the possible functions of CDC25C and determine the potential role of CDC25C in the early diagnosis and prognosis of PAAD. Expression analysis indicated that CDC25C was overexpressed in PAAD . In addition, survival analysis revealed a strong correlation between the enhanced expression of CDC25C and poor survival in PAAD. Furthermore, pathway analysis showed that CDC25C is related to TP53 signaling pathways, glutathione metabolism, and glycolysis. Mechanically, our in vitro experiments verified that CDC25C was capable of promoting cell viability and proliferation. CDC25C inhibition increases the accumulation of ROS, inhibits mitochondrial respiration, suppresses glycolysis metabolism and reduces GSH levels. To summarize, CDC25C may be involved in energy metabolism by maintaining mitochondrial homeostasis. Our results suggested that CDC25C is a potential biological marker and promising therapeutic target of PAAD.

A B-cell or a key player? The different roles of B-cells and antibodies in melanoma

The B‐cell system plays an important role in the melanoma immune response; however, consensus has yet to be reached in many facets. Here, we comprehensively review human studies only, due to fundamental differences in the humoral response with animal models. Tumour‐infiltrating B‐cells are associated with contradictory prognostic values, reflecting a lack of agreement between studies on cell subset classification and differences in the markers used, particularly the common use of a single marker not differentiating multiple subsets. Tertiary lymphoid structures (TLS) organise T‐cells and B‐cells within tumours to generate a local anti‐tumour response and TLS presence associates with improved survival in response to immune checkpoint blockade, in late‐stage disease. Autoantibody production is increased in melanoma patients and has been proposed as biomarkers for diagnosis, prognosis and treatment/toxicity response; however, no consistent targets are yet identified. The function of antibodies in an anti‐tumour response is determined by its isotype and subclass; IgG₄ is immune‐suppressive and robustly correlate with poor patient survival in melanoma. We conclude that the current B‐cell literature needs careful interpretation based on the methods used and that we need a consensus of markers to define B‐cells and associated lymphoid organs. Furthermore, future studies need to not only examine antibody targets, but also isotypes when considering functional roles.