Fatty acid synthase (FASN)

Overview

FASN encodes fatty acid synthase, a key lipogenic enzyme that catalyzes the de novo synthesis of long-chain fatty acids. In normal physiology, FASN contributes to membrane biogenesis, energy storage, and lipid signaling, but its expression is often tightly regulated because excessive lipogenesis can support metabolic dysfunction and disease. As a result, FASN is widely studied as a metabolic node linking nutrient availability, lipid homeostasis, and cellular growth.

In biomedical research, FASN is frequently examined in the context of cancer and metabolic disease because many tumors and lipid-disordered tissues show increased dependence on de novo lipogenesis. Its activity is commonly discussed alongside pathways such as SIRT1/AMPK, SREBP-1c, Peroxisome proliferator-activated receptor gamma (PPARγ), and mTOR, reflecting its position downstream of broader metabolic signaling networks. In recent studies, FASN has been investigated both as a disease-associated biomarker and as a therapeutic target, including in colorectal cancer, hepatocellular carcinoma, and fatty liver-related models.

Recent Publications Summary

Recent publications have continued to position fatty acid synthase (FASN) as a central node in cancer and metabolic disease research, with studies examining both direct inhibition and pathway-level regulation. In colorectal cancer, FASN inhibition was shown to induce DNA damage while impairing the DNA damage response, thereby potentiating chemotherapy-induced double-strand breaks and apoptotic cell death in colon cancer cell lines and patient-derived organoids; mechanistically, this effect involved altered histone acetylation, reduced ATM expression and CHK2 phosphorylation, and diminished recruitment of BRCA1 and ATM to γH2AX foci, supporting synthetic lethality with PARP inhibition 41661672Feb. In hepatocellular carcinoma, metformin was reported to suppress lipid accumulation and proliferation by lowering global m6A methylation through downregulation of METTL3 and upregulation of FTO, with the METTL3/ACC1/FASN axis identified as a key downstream pathway and metformin reducing FASN expression alongside ACC1 42070116May.

Additional studies focused on FASN as a therapeutic target in metabolic liver disease. A novel inhibitor, 84-B10, was shown to directly bind the MAT domain of FASN, inhibit its enzymatic activity, and promote ubiquitination and proteasomal degradation via recruitment of the E3 ligase TRIM28; in mouse primary hepatocytes, this reduced lipid accumulation and mitochondrial dysfunction, and in HFD-fed mice it was evaluated as a treatment for metabolic dysfunction–associated steatotic liver disease 41760780Feb. In a separate NAFLD study, Swertia mussotii improved hepatic steatosis, inflammation, and oxidative stress while activating the SIRT1/AMPK axis, increasing PPAR-γ, and downregulating SREBP-1c and FASN, consistent with suppression of de novo lipogenesis and promotion of fatty acid β-oxidation 42108548May.

FASN was also explored as a drug-design target in anticancer screening efforts. N-aryl oleamide derivatives from Indonesian palm oil were docked against the thioesterase domain of FASN, with epoxidized compounds showing improved binding affinities and one lead, EOA2, interacting with the catalytic triad Ser2308, Asp2338, and His2481; the synthesized compounds were then tested in vitro, where EOA2 showed the strongest cytotoxicity against HeLa cells and selectivity over Vero cells, with molecular dynamics simulations supporting stable binding 42432367Jul. In bladder cancer, an epigenomics-guided multi-omics analysis identified a lipid-metabolic signature with translational utility, and the functional relevance of key lipid metabolic hub genes was confirmed by pharmacological inhibition in bladder cancer cell line models, although the abstract excerpt does not specify the individual hub genes or the exact role of FASN within the final signature 42500328Jul.

What Changes, What Holds

1. FASN inhibition now looks able to weaken DNA repair as well as lipogenesis
NEW DIRECTION Colorectal cancer work extends FASN from a metabolic node and therapeutic target into a factor that can shape genome maintenance, because blocking it was linked to impaired DNA damage response, altered histone acetylation, and reduced recruitment of repair proteins 41661672Feb. That does not overturn the established cancer-metabolism framing, but it adds a mechanistic rationale for combining FASN inhibition with DNA-damaging therapy or PARP inhibition, pending validation beyond cell and organoid models.

2. FASN suppression is being tied to epitranscriptomic control in liver cancer
NEW DIRECTION metformin-associated downregulation of FASN in hepatocellular carcinoma broadens the baseline account by placing FASN within an m6A-linked regulatory axis, not just downstream of canonical lipogenic signaling 42070116May. The established view that FASN supports tumor growth through de novo lipogenesis still stands, but this work suggests its expression may also be governed by METTL3/FTO-mediated RNA methylation, which could matter for how metabolic drugs are interpreted and combined.

3. Direct FASN degradation emerges as a plausible liver-disease strategy
REINFORCES The new inhibitor strengthens the existing therapeutic-target view of FASN in fatty liver disease by showing that direct enzymatic blockade can also drive proteasomal loss of the protein and improve steatotic phenotypes 41760780Feb. Rather than changing what FASN is understood to do, this supports the idea that lowering FASN activity or abundance can reduce hepatic lipid accumulation and mitochondrial stress, while leaving open whether this chemistry will translate cleanly to humans.

4. Natural-product and multi-omics studies keep FASN in the drug-discovery frame
REINFORCES Docking and cytotoxicity work against the thioesterase domain adds another screening example, not a new biological role, and therefore mainly reinforces FASN as a tractable anticancer target 42432367Jul. The bladder-cancer multi-omics analysis similarly supports the broader lipid-metabolic signature concept already present in the Overview, but the paragraph does not establish a specific new function for FASN itself 42500328Jul.

Overview update candidates: FASN may merit mention as a participant in DNA repair vulnerability in colorectal cancer; and as part of an m6A-linked regulatory axis in hepatocellular carcinoma.