Introduction

AML12 cells, also known as AML-12, AML 12, and Alpha Mouse Liver 12, are a well-established murine hepatocyte cell line widely used in biomedical research. Wu, Merlino, and Fausto established the line in 1994 from the liver of a transgenic mouse overexpressing human transforming growth factor alpha (TGF-α), a potent hepatocyte mitogen. [1] Unlike primary hepatocytes, AML12 cells maintain key differentiated functions — including peroxisome expression and bile canalicular-like structures — across many passages without becoming tumorigenic. This combination of stability and retained hepatocyte phenotype has made them a preferred in vitro platform for investigating lipid metabolism, non-alcoholic fatty liver disease, chemical and drug-induced liver injury, insulin resistance, and hepatocyte apoptosis. Their mouse origin facilitates direct comparison with transgenic and knockout animal models, broadening their translational utility across diverse liver disease research contexts.

Key Takeaways

• AML12 cells are differentiated, non-tumorigenic murine hepatocytes derived from TGF-α transgenic mice. [1]
• They retain hepatocyte-specific features such as peroxisomes, bile canalicular-like structures, and high mRNA levels of liver-specific serum proteins, although expression of some of these declines with extended passaging. [1]
• The line is widely used to model non-alcoholic fatty liver disease, drug-induced liver injury, and lipid metabolism disorders.
• AML12 cells are responsive to key hepatic signals including TGF-β, TNF, insulin, and retinoic acid.
• Their non-transformed status makes them particularly suitable for studying normal hepatocyte physiology and toxicology.
• They are compatible with adenoviral transfection, antisense oligonucleotides, and CRISPR-based gene editing approaches.
• Molecular characterisation has revealed a near-tetraploid, aneuploid karyotype and partial de-differentiation, so AML12 cells should be complemented with primary hepatocytes or in vivo models for endpoints requiring fully mature hepatocyte function. [18]

What is AML12?

AML12 was derived from hepatocytes of a 5-month-old male mouse (CD-1 strain, line MT42) transgenic for human transforming growth factor alpha under the control of the zinc-inducible metallothionein 1 promoter. Wu, Merlino, and Fausto established the line in 1994 and characterised it as a spontaneously immortalised, non-transformed hepatocyte line. [1] The cells carry the Cellosaurus accession CVCL_0140 and are authenticated against an 18-marker murine STR reference profile. The original publication reports a doubling time of 37 hours (36–48 hours according to supplier data), and transcriptomic data from microarray analyses are publicly available. The original study yielded two lines, AML12 and AML14, both of which were maintained for more than 1.5 years and over 80 passages. AML12 retained its hepatocyte identity and remained non-tumorigenic throughout, although mRNA levels for some serum proteins fell progressively with passaging and could be restored by culture in serum-free medium. AML14, by contrast, lost expression of both differentiated markers and transgene mRNA during extended passaging, with hepatocytic traits only partially recoverable. [1]

AML12 Cell Culture Information

Advantages of AML12 Cells

A central advantage of AML12 cells is their retention of a differentiated hepatocyte phenotype over long-term culture. Unlike many hepatoma lines, AML12 cells contain peroxisomes and bile canalicular-like structures, express high mRNA levels of liver-specific serum proteins including albumin, alpha-1-antitrypsin and transferrin, and secrete albumin. [1] They do not grow in soft agar and remain non-tumorigenic in nude mice, confirming that immortalisation occurred without functional malignant transformation. This non-transformed status is critical for studies that require physiologically relevant baseline behaviour, such as investigations of insulin signalling, lipid metabolism, or hepatotoxicity. At the genomic level, however, the line has since been shown to carry substantial chromosomal aberrations, which are discussed under Limitations. [18]

AML12 cells are highly versatile in terms of genetic manipulation. They support adenoviral vector-based gene overexpression, as demonstrated in studies of activin subunits. [2] [3] They also permit stable tetracycline-regulated transgene expression, enabling inducible models of hepatitis B virus X protein activity. [4] Additionally, antisense oligonucleotide delivery has been achieved efficiently, making AML12 cells suitable for RNA-targeting studies, [5] and CRISPR/Cas9-based knockout derivatives have been generated successfully. [21] Their murine origin allows experimental results to be cross-validated directly against transgenic and knockout mouse data, strengthening the in vitro–in vivo translational bridge.

From a practical standpoint, AML12 cells are robustly responsive to a broad range of physiological stimuli. Documented responses include transcriptional activation by retinoic acid, PPARα ligands, TGF-β, TNF, and insulin pathway modulators. [6] [7] This breadth of signal responsiveness makes the line useful across multiple research domains simultaneously, reducing the need to switch platforms between experimental contexts.

Limitations of AML12 Cells

Despite their differentiated phenotype, AML12 cells are not equivalent to primary hepatocytes in every functional respect. A benchmark study comparing AML12, HepG2 and THLE-2 cells for insulin signalling and hepatokine gene expression found that the insulin responsiveness of AML12 cells was impaired when the cells were cultured in the recommended growth medium, but became comparable to HepG2 cells when insulin-deficient medium was used. [8] Insulin receptor protein levels in AML12 were similar to those in HepG2, whereas AML12 showed only low or undetectable transcript levels of several gluconeogenic enzymes and hepatokines. The authors concluded that, with regard to gluconeogenesis and hepatokine expression, HepG2 cells appeared closer to the in vivo situation despite their tumorigenic origin. Medium composition and the abundance of key signalling proteins should therefore be considered carefully when AML12 cells are used to model insulin resistance.

The murine origin of AML12 cells also introduces inherent species-related differences from human hepatocytes. Drug metabolism pathways, lipid handling, and certain inflammatory responses differ between mouse and human liver cells. Results obtained in AML12 cells therefore require careful evaluation before extrapolation to human physiology, particularly in drug development contexts where species-specific cytochrome P450 activity may confound findings.

The transgenic background of the source animal — TGF-α overexpression — may additionally influence baseline gene expression patterns and growth factor signalling. Studies focused on TGF family member biology should account for this context when interpreting data.

An integrated cytogenetic and transcriptomic characterisation published in 2026 further defines the boundaries of the model. Multicolour FISH and multicolour banding revealed a complex, near-tetraploid and highly aneuploid karyotype (81<4n>) with recurrent structural rearrangements, including del(X)(A3)×2, a dicentric dic(X;17), del(17)(D1)×2 and a derivative chromosome der(3)t(2;3), together with multiple whole-chromosome gains and losses; both Y chromosomes have been lost despite the male origin of the line. [18] When the resulting copy number imbalances were mapped onto orthologous human cytobands, 57.5–68 % overlapped with alterations recurrently reported in human hepatocellular carcinoma. RNA sequencing in the same study confirmed a clear hepatocyte lineage programme but also documented partial de-differentiation: albumin expression was modest, urea cycle and gluconeogenic enzymes such as Cps1, Otc, Pck1 and G6pc were low to absent, and key bile acid- and drug-metabolising cytochromes including Cyp7a1 and the Cyp3a family were barely detectable, alongside induction of ductular and progenitor markers. Being non-tumorigenic in the functional sense therefore does not mean being genomically stable. For endpoints that require mature xenobiotic metabolism, nitrogen handling or bile acid synthesis, the authors recommend complementing AML12 with primary hepatocytes, organoids or in vivo models. The study also identified two related clones whose relative proportions may drift with passage number and culture conditions, reinforcing the case for low-passage master stocks, limited passage windows, and regular authentication against the established STR reference profile. [18]

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Applications

Apoptosis and Cell Death Signalling

AML12 cells have been extensively used to investigate hepatocyte apoptosis triggered by cytokines and growth factors. Pierce and colleagues demonstrated that AML12 cells, like hepatocytes in vivo, are not sensitive to TNF alone but undergo apoptosis when TNF is combined with a low dose of actinomycin D. [9] Their work revealed that TNF-induced apoptosis in AML12 cells involves disruption of redox homeostasis, with loss of NAD(P)H and glutathione preceding mitochondrial damage, cytochrome C release and caspase activation. Injury was largely governed by cellular glutathione content, and the antioxidant alpha-lipoic acid prevented mitochondrial damage and apoptosis entirely. These findings established AML12 cells as a tractable model for the oxidative mechanisms underlying TNF-mediated hepatocyte injury.

TGF-β1 is another key inducer of hepatocyte apoptosis studied in this model. Liao and colleagues showed that AML12 cells exhibit classic apoptotic features — chromatin condensation, nuclear disintegration, and DNA fragmentation — upon TGF-β1 treatment, and that this process was completely blocked by cycloheximide, implicating active protein synthesis in the cell death pathway. [10] Dooley and colleagues further used primary hepatocyte outgrowths and AML12 cells together to characterise TGF-β-induced epithelial-to-mesenchymal transition, showing that Smad7 overexpression in hepatocytes attenuated TGF-β-mediated fibrogenesis and protected against liver damage. [11]

Activin subunit biology has also been characterised in AML12 cells. Wada and colleagues found that overexpression of the activin βC subunit promoted AML12 cell proliferation and survival, whereas βE subunit overexpression reduced proliferation and triggered apoptosis under low-serum conditions. [2] [3] Together, these studies underscore the value of AML12 cells for dissecting the competing pro-survival and pro-apoptotic signals that govern hepatocyte fate in inflammatory and fibrotic liver disease.

Lipid Metabolism and PPAR Signalling

The PPARα pathway is a central regulator of hepatic lipid metabolism, and AML12 cells have proven especially useful for studying its modulation by pharmacological agents. Clemenz and colleagues used AML12 cells to show that the angiotensin type 1 receptor blocker telmisartan acts as a partial PPARα agonist: it induced the PPARα target gene acyl-CoA synthetase long-chain family member 1 (ACSL1) in murine AML12 cells and carnitine palmitoyl transferase 1A (CPT1A) in human HepG2 cells, providing a molecular basis for its clinically observed triglyceride-lowering effects. [7] In mice with diet-induced obesity, telmisartan increased hepatic ACSL1 and CPT1A expression and markedly reduced hepatic and serum triglycerides. Similarly, Huang and colleagues showed that fenofibrate, a PPARα ligand, increased hepatic low-density lipoprotein receptor expression in AML12 cells and restored LDL binding capacity, with results confirmed in vivo. [12]

Aldose reductase (AR) has emerged as an unexpected regulator of PPARα activity in hepatocytes. Qiu and colleagues demonstrated in AML12 cells that AR overexpression strongly suppressed PPARα activity and downregulated fatty acid oxidation genes, effects attenuated by the selective AR inhibitor zopolrestat. [13] AR overexpression also elevated phosphorylated PPARα and ERK1/2, and suppression of PPARα activity was reversed by ERK1/2 inhibition — linking the polyol pathway to lipid homeostasis through kinase-dependent mechanisms. These findings illustrate how AML12 cells can reveal unexpected crosstalk between metabolic and signalling pathways relevant to non-alcoholic fatty liver disease and diabetic liver complications.

Nicotinamide-N-methyltransferase (NNMT) is another enzyme studied in AML12 cells in the context of hepatic lipid regulation. RNAi-mediated knockdown of Nnmt in AML12 cells caused accumulation of S-adenosyl-methionine (SAM) and S-adenosyl-homocysteine and a reduction in 1-methylnicotinamide (MNAM), accompanied by down-regulation of lipogenic genes such as Srebf1 and a measurable decrease in total neutral lipids — linking one-carbon metabolism to hepatic lipogenesis. [19] Separately, the endoplasmic reticulum protein TXNDC5 was identified as an interaction partner of PRDX6 and HSPA9 in AML12 cells; TXNDC5 deficiency reduced PRDX6 and HSPA9 protein levels and significantly decreased lipid peroxidation, reduced glutathione and iPLA2 activity. [20] Building on the same model, squalene loaded into PLGA nanoparticles protected AML12 cells against oxidative and endoplasmic reticulum stress in a TXNDC5-dependent manner, with rapid and efficient cellular uptake observed at 30 µM — findings relevant to future therapeutic strategies for fatty liver disease. [21]

Insulin Signalling and Metabolic Disease

AML12 cells have been deployed as an in vitro tool for interrogating insulin signalling and its pathological disruption. Butler and colleagues used AML12 cells to validate an antisense oligonucleotide strategy targeting PTEN, a lipid phosphatase that negatively regulates the PI3K pathway. Transfection of PTEN antisense oligonucleotides into AML12 cells reduced PTEN mRNA and protein levels and increased insulin-stimulated Akt phosphorylation, providing mechanistic proof of concept before systemic administration in db/db and ob/ob mice normalised blood glucose concentrations. [14] This study illustrated the value of AML12 cells as a first-pass screening platform for metabolic interventions targeting insulin resistance.

The benchmarking study by Sefried and colleagues directly assessed the suitability of AML12 cells for insulin signalling and hepatokine gene expression research. [8] Comparing AML12 with HepG2 and THLE-2 cells, the authors found that acute insulin responsiveness in AML12 depended strongly on the composition of the culture medium, and that AML12 cells expressed only low or undetectable levels of several gluconeogenic and hepatokine transcripts. PPARδ-dependent gene regulation was comparable between AML12 and HepG2, but only HepG2 cells reproduced the cAMP-mediated regulation of hepatic gluconeogenesis. The authors concluded that, for these particular endpoints, HepG2 cells resembled the in vivo situation more closely despite their tumorigenic origin — a key consideration when selecting a model for insulin resistance or type 2 diabetes research.

Tomatine has been evaluated for its capacity to improve glucose metabolism and mitochondrial respiration in high-glucose-induced insulin-resistant AML12 and HepG2 cells. [22] Tomatine dose-dependently increased glucose consumption, restored expression of the glucose transporter Glut2 and of gluconeogenesis-related genes, activated AMPK phosphorylation and up-regulated PGC1α, and improved oxygen consumption rate, ATP production and mitochondrial oxidative phosphorylation complex proteins. Both genetic and pharmacological inhibition of AMPK abolished these benefits, confirming the central role of the pathway and positioning AML12 cells as a useful platform for screening natural compounds with anti-diabetic potential. These findings reinforce the line's relevance to the study of lipid metabolism, insulin resistance, and fatty liver disease mechanisms.

Hepatocellular Carcinoma and Viral Hepatitis Research

The non-transformed status of AML12 cells makes them an ideal control or parental line in hepatocellular carcinoma (HCC) research. Lee and colleagues engineered tetracycline-regulated hepatitis B virus X protein (pX)-expressing derivatives of AML12 cells to create models of pX-mediated transformation. [4] By comparing the differentiated, transforming subline (3pX-1) with the de-differentiated, non-transforming subline (4pX-1), the authors defined distinct cell cycle alterations linked to sustained Ras-Raf-MAPK versus JNK pathway activation, demonstrating how AML12 parental cells can serve as a controlled background for dissecting oncogenic signalling.

Plant-derived anticancer agents have also been evaluated in hepatocyte contexts using AML12 cells. Choedon and colleagues tested fractions of dried latex from Calotropis procera against the hepatoma line Huh-7, the non-hepatoma line COS-1, and non-transformed AML12 hepatocytes. The methanolic extract and its fraction 8 induced extensive cell death and DNA fragmentation in Huh-7 and COS-1 cells, while AML12 cells were spared; in parallel, oral administration of the dried latex fully protected X15-myc transgenic mice against hepatocarcinogenesis. [15] Such selectivity assays, using AML12 cells as a non-malignant hepatocyte reference, are a common strategy for identifying candidate compounds with preferential toxicity to tumour cells over normal liver parenchyma.

Retinoic acid (RA) signalling, which is implicated in HCC suppression, has been comprehensively mapped in AML12 cells using cDNA microarray analysis of 39,000 murine genes. Mamoon and colleagues identified 15 genes upregulated and 3 downregulated at least twofold after 3 hours of all-trans RA treatment, with 26 upregulated and 48 downregulated after 24 hours. [6] A follow-up study by Ventura-Holman and colleagues used microarray analysis of AML12 cells stably transfected with v-erbA — an oncoprotein known to exert a dominant-negative effect on retinoic acid receptors — to identify which RA-responsive genes are affected by v-erbA, as well as genes regulated by v-erbA at the level of basal transcription, several of which are implicated in carcinogenesis. [16]

Oxidative Stress and Ischemia-Reperfusion Injury

Ischemia-reperfusion (I/R) injury represents a major clinical challenge in liver surgery and transplantation, and AML12 cells have been used to model the underlying oxidative mechanisms. Haga and colleagues demonstrated that AML12 cells placed under hypoxia/reoxygenation conditions rapidly developed oxidative stress, with many cells undergoing apoptosis. [17] Knockdown of the p66 isoform of ShcA (p66shc) by RNAi markedly decreased cellular oxidative stress and H/R-induced apoptosis and conferred resistance to hydrogen peroxide. The protection was attributable to enhanced ROS scavenging rather than to inhibition of ROS generation: the antioxidant proteins MnSOD and Ref-1 and the anti-apoptotic Bcl-xL were up-regulated while pro-apoptotic FLICE was down-regulated, whereas catalase expression remained unchanged. These findings identified p66shc as a potential therapeutic target in liver I/R injury.

Antisense oligonucleotide technology has been characterised in AML12 cells in the context of Fas-mediated cell death. Thonberg and colleagues compared six phosphorothioate oligonucleotides targeting Fas mRNA in AML12 cells, revealing that four significantly reduced mRNA levels and that one produced a stable 3′-mRNA cleavage fragment mapping to the antisense-complementary sequence. [5] This study highlighted AML12 cells as a suitable model for evaluating antisense efficiency and for investigating the mechanics of RNase H-mediated RNA degradation in liver cells.

Comprehensive cytogenetic and transcriptomic profiling has confirmed that AML12 cells maintain a clear hepatocyte lineage programme, with robust expression of Hnf4a, Foxa2 and Prox1, nuclear HNF4α protein, and an absence of the lineage-defining markers of hepatic stellate cells, cholangiocytes and Kupffer cells. [18] The same dataset, however, revealed a pronounced stress- and progenitor-associated transcriptional signature, including very high Spp1/osteopontin, Ccl2 and Plscr1 expression together with ductular markers such as Krt19, Sox9, Hnf1b and Jag1. This injury-adapted, progenitor-like baseline makes AML12 a practical model for hepatocyte-intrinsic stress, inflammatory signalling and epithelial plasticity, provided that the baseline state is taken into account when interpreting results in oxidative stress and toxicological studies.

Conclusion

AML12 cells remain one of the most widely used murine hepatocyte models in liver research, offering a unique balance of differentiated hepatocyte function and long-term in vitro stability. Established by Wu, Merlino, and Fausto in 1994, [1] the line has since supported research across non-alcoholic fatty liver disease, drug-induced liver injury, lipid metabolism, insulin resistance, apoptosis, hepatocellular carcinoma, and ischemia-reperfusion injury. The benchmark study by Sefried and colleagues delineated the boundaries of their insulin signalling capacity and showed that, for gluconeogenic and hepatokine endpoints, HepG2 cells may in fact be the closer model. [8] More recent cytogenetic and transcriptomic profiling has documented a near-tetraploid, aneuploid karyotype and partial de-differentiation, arguing for complementary validation in primary hepatocytes, organoids or in vivo models wherever fully mature hepatocyte function is required. [18] Used with those caveats in mind — whether for PPARα pharmacology, viral hepatitis modelling, or oxidative stress investigation — AML12 cells provide a reliable, well-characterised platform for hypothesis-driven liver biology. To order AML12 cells or enquire about specifications, visit cytion.com.

Key Publications

1. Wu JC, Merlino G, Fausto N (1994) Establishment and characterization of differentiated, nontransformed hepatocyte cell lines derived from mice transgenic for transforming growth factor alpha. Proceedings of the National Academy of Sciences of the United States of America. PMID: 7904757
2. Wada W, Maeshima A, Zhang YQ (2004) Assessment of the function of the betaC-subunit of activin in cultured hepatocytes. American journal of physiology. Endocrinology and metabolism. PMID: 15039147
3. Wada W, Medina JJ, Kuwano H (2005) Comparison of the function of the beta(C) and beta(E) subunits of activin in AML12 hepatocytes. Endocrine journal. PMID: 15863943
4. Lee S, Tarn C, Wang WH (2002) Hepatitis B virus X protein differentially regulates cell cycle progression in X-transforming versus nontransforming hepatocyte (AML12) cell lines. The Journal of biological chemistry. PMID: 11756437
5. Thonberg H, Dahlgren C, Wahlestedt C (2004) Antisense-induced Fas mRNA degradation produces site-specific stable 3'-mRNA fragment by exonuclease cleavage at the complementary sequence. Oligonucleotides. PMID: 15625917
6. Mamoon A, Ventura-Holman T, Maher JF (2008) Retinoic acid responsive genes in the murine hepatocyte cell line AML 12. Gene. PMID: 18006250
7. Clemenz M, Frost N, Schupp M (2008) Liver-specific peroxisome proliferator-activated receptor alpha target gene regulation by the angiotensin type 1 receptor blocker telmisartan. Diabetes. PMID: 18184928
8. Sefried S, Häring HU, Weigert C (2018) Suitability of hepatocyte cell lines HepG2, AML12 and THLE-2 for investigation of insulin signalling and hepatokine gene expression. Open biology. PMID: 30355754
9. Pierce RH, Campbell JS, Stephenson AB (2000) Disruption of redox homeostasis in tumor necrosis factor-induced apoptosis in a murine hepatocyte cell line. The American journal of pathology. PMID: 10880392
10. Liao JH, Zhou BH, Chai MQ (2001) Cycloheximide blocks TGF-beta1-induced apoptosis in murine hepatocytes. Acta pharmacologica Sinica. PMID: 11741524
11. Dooley S, Hamzavi J, Ciuclan L (2008) Hepatocyte-specific Smad7 expression attenuates TGF-beta-mediated fibrogenesis and protects against liver damage. Gastroenterology. PMID: 18602923
12. Huang Z, Zhou X, Nicholson AC (2008) Activation of peroxisome proliferator-activated receptor-alpha in mice induces expression of the hepatic low-density lipoprotein receptor. British journal of pharmacology. PMID: 18852694
13. Qiu L, Wu X, Chau JF (2008) Aldose reductase regulates hepatic peroxisome proliferator-activated receptor alpha phosphorylation and activity to impact lipid homeostasis. The Journal of biological chemistry. PMID: 18445591
14. Butler M, McKay RA, Popoff IJ (2002) Specific inhibition of PTEN expression reverses hyperglycemia in diabetic mice. Diabetes. PMID: 11916922
15. Choedon T, Mathan G, Arya S (2006) Anticancer and cytotoxic properties of the latex of Calotropis procera in a transgenic mouse model of hepatocellular carcinoma. World journal of gastroenterology. PMID: 16688796
16. Ventura-Holman T, Mamoon A, Subauste JS (2008) Modulation of expression of RA-regulated genes by the oncoprotein v-erbA. Gene. PMID: 18775481
17. Haga S, Terui K, Fukai M (2008) Preventing hypoxia/reoxygenation damage to hepatocytes by p66(shc) ablation: up-regulation of anti-oxidant and anti-apoptotic proteins. Journal of hepatology. PMID: 18191273
18. Asar DY, Kankel S, Keller DT (2026) Comprehensive Cytogenetic and Genomic Profiling of the Murine AML12 (Alpha Mouse Liver 12) Hepatocyte Cell Line. Cells. PMID: 41827824
19. Yoda M, Mizuno R, Izumi Y (2023) Nicotinamide-N-methyltransferase regulates lipid metabolism via SAM and 1-methylnicotinamide in the AML12 hepatocyte cell line. Journal of biochemistry. PMID: 37014628
20. Bidooki SH, Sánchez-Marco J, Martínez-Beamonte R (2023) Endoplasmic reticulum protein TXNDC5 interacts with PRDX6 and HSPA9 to regulate glutathione metabolism and lipid peroxidation in the hepatic AML12 cell line. International journal of molecular sciences. PMID: 38138960
21. Bidooki SH, Alejo T, Sánchez-Marco J (2022) Squalene loaded nanoparticles effectively protect hepatic AML12 cell lines against oxidative and endoplasmic reticulum stress in a TXNDC5-dependent way. Antioxidants. PMID: 35326231
22. Lee YG, Kim D (2025) Tomatine improves glucose metabolism and mitochondrial respiration in insulin-resistant hepatocyte cell lines AML12 and HepG2 via an AMP-activated protein kinase-dependent pathway. Cells. PMID: 40072058