Inflammation is a key contributor to both the initiation and progression of tumors, and it can be triggered by genetic instability within tumors, as well as by lifestyle and dietary factors. The inflammatory response plays a critical role in the genetic and epigenetic reprogramming of tumor cells, as well as in the cells that comprise the tumor microenvironment. Cells in the microenvironment acquire a phenotype that promotes immune evasion, progression, and metastasis. We will review the mechanisms and pathways involved in the interaction between tumors, inflammation, and nutrition, the limitations of current therapies, and discuss potential future therapeutic approaches.

Oxidative phosphorylation and glycolysis are the main ATP-generating pathways in cell metabolism. The balance between these two pathways is frequently altered to carry out cell-specific activities in response to stimuli involving activation, proliferation, or differentiation. Despite being a useful tool for researching metabolic profiles in real time in relatively small numbers of cancer cells, the main Agilent Seahorse XF Pro Analyzer (Agilent Technologies, Santa Clara, CA, USA) guideline is currently not fully detailed in the distinction between suspensions vs. adherent cancer cells. This article provides step-by-step protocols for profiling metabolic fluxes in suspension vs. adherent cancer cells via Seahorse technology, including adjustments for normalisation of data on the basis of the number of viable cells or the total protein content. Owing to the adaptations of plates, reagents, cell count, and protein quantification, it is possible to (i) analyse both adherent and suspension cells with a single instrument; (ii) conduct all experiments in 96-well plates, thus using fewer cells, media, and reagents; (iii) determine the effect of a drug or compound directly on cell metabolism; (iv) normalise data on the basis of the number of viable cells or the total protein content via a spectrophotometer; and (v) achieve notable savings in cost and time.

Background/Objectives: Breast cancer is the most frequently diagnosed malignancy among women and is characterized by marked heterogeneity in treatment response. Metabolic reprogramming, particularly enhanced de novo lipogenesis, represents a hallmark of cancer progression and a promising therapeutic target. Firsocostat, a selective allosteric inhibitor of acetyl-CoA carboxylase (ACC), has previously been investigated in metabolic diseases but has never been evaluated in breast cancer models. This study aimed to assess the antitumor effects of firsocostat on breast cancer cell lines. Methods: We investigated the cytotoxic and metabolic effects of firsocostat in four breast cancer cell lines—MCF7 (luminal A HR⁺), SK-BR-3 (HER2-positive), MDA-MB-231 (triple-negative), and HCC1937 (triple-negative, BRCA1-mutated)—together with the non-tumorigenic MCF-10A line. Dose- and time-dependent responses were evaluated using phase-contrast microscopy for morphological evaluation, Trypan Blue exclusion assays, and MTS-based viability assays. Results: Firsocostat significantly reduced cell viability across all breast cancer subtypes in a concentration- and time-dependent manner, with IC₅₀ values ranging from 80 to 93 µM. In contrast, non-tumorigenic MCF-10A cells were less affected, indicating a selective cytotoxic effect toward malignant cells. Conclusions: Firsocostat exerts robust cytotoxic effects in breast cancer models, identifying it as a promising metabolism-targeting therapeutic candidate capable of selectively impairing breast cancer cell survival by disrupting fatty acid biosynthesis. These results indicate that firsocostat could represent a viable candidate as a metabolic-based therapeutic approach for breast cancer. Given its established clinical safety profile in metabolic diseases, firsocostat warrants further preclinical investigation and supports further mechanistic and preclinical evaluation.