The water-soluble vitamin, vitamin B₁₂, also known as cobalamin, plays a crucial role in cellular metabolism, particularly in DNA synthesis, methylation, and mitochondrial functionality. Its deficiency can lead to hematological and neurological disorders; however, the manifestation of these clinical outcomes is relatively late. It leads to difficulties in the early diagnosis of vitamin B₁₂ deficiency. A prolonged lack of vitamin B₁₂ may have severe consequences including increased morbidity to neurological and cardiovascular diseases. Beyond inadequate dietary intake, vitamin B₁₂ deficiency might be caused by insufficient bioavailability, blood transport disruptions, or impaired cellular uptake and metabolism. Despite nearly 70 years of knowledge since the isolation and characterization of this vitamin, there are still gaps in understanding its metabolic pathways. Thus, this review aims to compile current knowledge about the crucial proteins necessary to efficiently accumulate and process vitamin B₁₂ in humans, presenting these systems as a multi-protein network. The epidemiological consequences, diagnosis, and treatment of vitamin B₁₂ deficiency are also highlighted. We also discuss clinical warnings of vitamin B₁₂ deficiency based on the ongoing test of specific moonlighting proteins engaged in vitamin B₁₂ metabolic pathways.

We discovered that the overexpression of mitochondrial enzyme succinate dehydrogenase (SDHA) is particularly prevalent in ovarian carcinoma and promotes highly metabolically active phenotype. Succinate dehydrogenase deficiency has been previously studied in some rare disorders. However, the role of SDHA upregulation and its impact on ovarian cancer metabolism has never been investigated, emphasizing the need for further research. We investigated the functional consequences of SDHA overexpression in ovarian cancer. Using proteomics approaches and biological assays, we interrogated protein content of metabolic pathways, cell proliferation, anchorage-independent growth, mitochondrial respiration, glycolytic function, and ATP production rates in those cells. Lastly, we performed a drug screening to identify agents specifically targeting the SDHA overexpressing tumor cells. We showed that SDHA overexpressing cells are characterized by enhanced energy metabolism, relying on both glycolysis and oxidative phosphorylation to meet their energy needs. In addition, SDHA-high phenotype was associated with cell vulnerability to glucose and glutamine deprivation, which led to a substantial reduction of ATP yield. We also identified an anti-metabolic compound shikonin with a potent efficacy against SDHA overexpressing ovarian cancer cells. Our data underline the unappreciated role of SDHA in reprogramming of ovarian cancer metabolism, which represents a new opportunity for therapeutic intervention.

The water-soluble vitamin - vitamin B12, also known as cobalamin, plays a crucial role in cellular metabolism, particularly in DNA synthesis, methylation, and mitochondrial functionality. Its de-ficiency can lead to hematological and neurological disorders, however the manifestation of these clinical outcomes is relatively late. It leads to difficulties in its early diagnosis, often resulting in the development of hidden subclinical cobalamin deficiency. Prolonged lack of vitamin B12 con-dition may have severe consequences including increased morbidity to neurological and cardio-vascular diseases. Beyond inadequate dietary intake, vitamin B12 deficiency might be caused by insufficient bioavailability, blood transport disruptions, or impaired cellular uptake and metabo-lism. Despite nearly 70 years of knowledge since its isolation and characterization, there are still gaps in understanding its metabolic pathways. Thus, this review aims to gather current knowledge about the crucial proteins necessary to efficiently process vitamin B12 in humans, presenting it as a multi-protein mediated network. Based on these findings, we also highlight new potential methods for supporting the evaluation of the risk of epidemiological consequences of vitamin B12 deficiency or clinical warnings of increased risk of vitamin B12 deficiency based on already testing targeting specific moonlighting proteins engaged in vitamin B12 metabolic path-ways.

Immunotherapy, particularly effective in tumors with a high mutational burden, is very often administered in combination with chemotherapy. Several tumor types with a high mutational rate include melanoma and non-small cell lung cancer (NSCLC), which are particularly sensitive to immunotherapy. For NSCLC, conventional platinum-based doublet chemotherapy has been extended with drugs targeting signaling pathways (such as the epidermal growth factor receptor) and immune checkpoint inhibitors (ICI) directed against PD-1 and PD-L1. This review highlights the potential role of the membrane antigens CD73 and CD39 in enhancing the efficacy of combined immuno-chemotherapy. These ecto-nucleotidases catalyze the degradation of extracellular ATP to AMP and subsequently to adenosine (Ado), a potent immunosuppressive metabolite that acts through adenosine receptors. Consequently, CD73 and CD39 function as key downregulators of immunogenic signaling. Both CD73 and CD39 are highly expressed not only on tumor cells but also on immune and endothelial cells within the tumor microenvironment. Conventional chemotherapy may further upregulate their expression, contributing to drug resistance and impaired immune responses. To counteract these effects, inhibitors of CD73 and CD39, both monoclonal antibodies and small molecules, are currently under clinical evaluation, with early results indicating potential therapeutic benefit. Although this evidence supports the involvement of CD73 and CD39 in modulating responses to immunotherapy, particularly in combination with chemotherapy, the precise mechanisms underlying these interactions remain unclear. Elucidating these pathways will be critical for optimizing treatment strategies and improving clinical outcomes in malignancies such as NSCLC. This review highlights the critical role of these pathways in optimizing treatment strategies and improving clinical outcomes in malignancies such as NSCLC.

Background: Breast cancer (BC) is the most frequently diagnosed malignancy and the leading cause of cancer-related death in women. Beyond traditional clinical classifications, metabolic reprogramming has emerged as an additional layer of tumor heterogeneity. Fatty acids (FAs), essential for membrane synthesis, energy storage, and signaling, undergo dynamic remodeling in cancer and may reflect disease progression. Objectives: To examine associations between serum FAs profiles and clinical-pathological features of BC, including tumor stage, surrogate subtype, lymph node status, and proliferative activity. Design: A retrospective, cross-sectional study was conducted at a single institution to analyze metabolic signatures in patients with BC stratified by clinical and surrogate characteristics. Methods: Serum FAs composition was analyzed by gas chromatography–mass spectrometry in 110 patients with BC before treatment initiation. Patients were categorized according to tumor stage, BC surrogate subtype, and Ki-67 proliferation index. Group comparisons and correlations were performed using standard parametric/non-parametric tests as appropriate, with Benjamini–Hochberg false discovery rate (FDR) correction across the FAs panel. Results: In categorical comparisons (e.g., tumor stage, Ki-67, lymph node status), some FAs, particularly arachidonic acid (ARA), and selected saturated, branched-chain, and polyunsaturated species, were nominally elevated in more aggressive phenotypes, but none remained significant after FDR correction ( Q = 0.05). Correlation analysis using Ki-67 as a continuous variable revealed modest but consistent positive associations with multiple FAs. Notably, ARA, dihomo-γ-linolenic acid, docosapentaenoic acid, and several branched- and odd-chain species remained significantly correlated with Ki-67 after FDR adjustment. Conclusion: This exploratory study suggests that specific serum FAs are modestly associated with tumor proliferative activity, supporting the concept that aggressive BC phenotypes may involve systemic lipid remodeling. Further prospective studies are needed to validate these findings and assess their potential clinical relevance.