Glycogen storage disease I and hepatocellular tumours

Loss of NUMB promotes hepatomegaly and hepatocellular carcinoma through the AKT/glycogen/hippo signaling

Excessive glycogen deposition is a common feature of liver enlargement, liver adenoma, and liver cancer, yet the underlying mechanisms remain poorly understood. In this study, we found that NUMB, a well-known cell fate determinant, is downregulated in glycogen-rich adenomas and hepatocellular carcinoma (HCC). NUMB-deficient livers developed excessive glycogen accumulation and adenoma formation particularly in aged mice. Surprisingly, the Alb-Cre:Trp53loxP/loxP liver displayed no similar defective morphology and function, although p53 is considered an important downstream target of NUMB and closely related to glucose metabolism. Instead, we observed a synergistic interaction between NUMB and p53 in regulating glycogen metabolism in HCC tissues and cell lines. Combined knockout of NUMB and p53 in mice significantly enhances glycogen accumulation and hepatomegaly, particularly when mice are subjected to a high sugar diet (HSD), leading to higher cancer incidence. Mechanistically, NUMB deficiency disrupts the PTEN-PI3K/AKT signaling pathway, promoting glycogen accumulation. Subsequently, successive glycogen deposition triggers hepatomegaly and tumorigenesis via the Hippo signaling pathway. Our results suggest that NUMB plays a crucial role in maintaining the homeostasis of glucose metabolism and suppressing the development of liver tumors associated with glycogen deposition.

Pictorial Review of MRI Findings of Glycogen Storage Disease from Children to Young Adults

Glycogen storage diseases (GSDs) are rare, inherited disorders of glycogen metabolism caused by a deficiency of enzymes or transporters. GSDs involve the liver, kidneys, skeletal muscles, and heart of children and young adults. The complications involving these organs affect the prognosis of patients with GSDs. Magnetic resonance imaging (MRI) is useful for identifying the complications of GSDs and monitoring the response to treatments owing to its ability of tissue characterization and the lack of a need for ionizing radiation. This pictorial review describes the MRI sequences used for GSDs, presents clinical examples, and emphasizes the pivotal role of MRI as an imaging tool in diagnosing complications associated with GSDs. MRI should be performed at least every year in patients with GSDs and hepatic tumors or myocardial scarring. Further MRI sequences that can be used to quantify the severity of GSDs are discussed.

Deciphering the role of hepcidin in iron metabolism and anemia management

One of the most common diseases worldwide is anemia, which is characterized by insufficient erythrocyte production. Numerous complex factors, such as chronic diseases, genetic mutations, and nutritional inadequacies, contribute to this widespread syndrome. This review focuses specifically on anemias caused by defective hepcidin production. Hepcidin, a peptide hormone produced primarily by liver cells, plays a crucial role in regulating iron levels by controlling its absorption. Hepcidin's mechanism of action involves binding to the ferroportin iron transporter, causing its internalization. Disturbances in iron metabolism can have far-reaching consequences, affecting not only the blood but also organs like the liver, kidneys, and brain. Iron homeostasis is crucial for maintaining optimal physiological function. Several blood-based markers are employed to assess iron stores. However, these markers have inherent limitations. Hepcidin, a key regulator of iron metabolism, plays a pivotal role in preventing iron release into the plasma from absorptive enterocytes and macrophages. Elucidating the structure and function of hepcidin is essential for understanding its role in iron homeostasis, which has significant implications for the diagnosis and management of various anemia subtypes. A well-established correlation exists between hepcidin dysregulation and iron deficiency. Despite its potential as a biomarker, the clinical application of hepcidin is hindered by the lack of a commercially available, clinically validated assay. This review aims to provide a comprehensive overview of hepcidin's role in regulating blood iron concentrations and elucidate its implications in the pathogenesis of various anemia subtypes, paving the way for its future applications in research and clinical practice.

Glycogen Storage Disease Type I and Bone: Clinical and Cellular Characterization

Glycogen storage disease (GSD) is the most prevalent inherited disorder of glycogen metabolism for which no causal treatment is available. In recent years, thanks to the improved clinical management, the life expectancy of these patients extended, disclosing previously unidentified adverse conditions in other organs. In this study, we evaluated the clinical bone complications and the cellular responses in 20 patients (aged 14.1 ± 3.4 years) affected by GSD type I. Fragility fractures were reported in 35% of the patients, which were older than unfractured patients. They involved appendicular skeletal segments, while no vertebral deformity was detected. 60% of the patients had a bone mineral density (BMD) "below the expected range for age", and lumbar spine (LS) BMD Z-scores positively correlated with muscle strength. Circulating mineral and bone markers showed reduction in the older subjects, with no increase in the pubertal age. Significant correlations could not be detected between circulating markers and LS BMD Z-scores, except for sclerostin levels, which also correlated with muscle strength. The osteoclasts differentiated from patients' peripheral blood mononuclear cells did not show cell-autonomous alterations. However, circulating osteoclast precursors from healthy individuals cultured in the presence of patients' sera exhibited increased osteoclastogenesis compared to control sera suggesting that GSD type I serum factors could affect osteoclast function in a non-autonomous manner. In contrast, circulating osteoprogenitors were unremarkable.

Glycogen storage diseases: An update

Glycogen storage diseases (GSDs), also referred to as glycogenoses, are inherited metabolic disorders of glycogen metabolism caused by deficiency of enzymes or transporters involved in the synthesis or degradation of glycogen leading to aberrant storage and/or utilization. The overall estimated GSD incidence is 1 case per 20000-43000 live births. There are over 20 types of GSD including the subtypes. This heterogeneous group of rare diseases represents inborn errors of carbohydrate metabolism and are classified based on the deficient enzyme and affected tissues. GSDs primarily affect liver or muscle or both as glycogen is particularly abundant in these tissues. However, besides liver and skeletal muscle, depending on the affected enzyme and its expression in various tissues, multiorgan involvement including heart, kidney and/or brain may be seen. Although GSDs share similar clinical features to some extent, there is a wide spectrum of clinical phenotypes. Currently, the goal of treatment is to maintain glucose homeostasis by dietary management and the use of uncooked cornstarch. In addition to nutritional interventions, pharmacological treatment, physical and supportive therapies, enzyme replacement therapy (ERT) and organ transplantation are other treatment approaches for both disease manifestations and long-term complications. The lack of a specific therapy for GSDs has prompted efforts to develop new treatment strategies like gene therapy. Since early diagnosis and aggressive treatment are related to better prognosis, physicians should be aware of these conditions and include GSDs in the differential diagnosis of patients with relevant manifestations including fasting hypoglycemia, hepatomegaly, hypertransaminasemia, hyperlipidemia, exercise intolerance, muscle cramps/pain, rhabdomyolysis, and muscle weakness. Here, we aim to provide a comprehensive review of GSDs. This review provides general characteristics of all types of GSDs with a focus on those with liver involvement.

Glycogen storage disease in two sisters: A case report

Glycogen storage diseases (GSDs) are rare autosomal disorders that result from defects in glycogen metabolism. There are more than 12 types, each with distinct clinical features. Clinical scenario, biochemical abnormalities are useful for suspicion whereas liver biopsy and enzyme assay provides definite diagnosis. We report a case of two sisters with similar clinical symptoms suggestive of the disease.

Pathogenesis and Current Treatment Strategies of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent liver cancer with high lethality and low five-year survival rates leading to a substantial worldwide burden for healthcare systems. HCC initiation and progression are favored by different etiological risk factors including hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, non-/and alcoholic fatty liver disease (N/AFLD), and tobacco smoking. In molecular pathogenesis, endogenous alteration in genetics (TP53, TERT, CTNNB1, etc.), epigenetics (DNA-methylation, miRNA, lncRNA, etc.), and dysregulation of key signaling pathways (Wnt/β-catenin, JAK/STAT, etc.) strongly contribute to the development of HCC. The multitude and complexity of different pathomechanisms also reflect the difficulties in tailored medical therapy of HCC. Treatment options for HCC are strictly dependent on tumor staging and liver function, which are structured by the updated Barcelona Clinic Liver Cancer classification system. Surgical resection, local ablative techniques, and liver transplantation are valid and curative therapeutic options for early tumor stages. For multifocal and metastatic diseases, systemic therapy is recommended. While Sorafenib had been the standalone HCC first-line therapy for decades, recent developments had led to the approval of new treatment options as first-line as well as second-line treatment. Anti-PD-L1 directed combination therapies either with anti-VEGF directed agents or with anti-CTLA-4 active substances have been implemented as the new treatment standard in the first-line setting. However, data from clinical trials indicate different responses on specific therapeutic regimens depending on the underlying pathogenesis of hepatocellular cancer. Therefore, histopathological examinations have been re-emphasized by current international clinical guidelines in addition to the standardized radiological diagnosis using contrast-enhanced cross-sectional imaging. In this review, we emphasize the current knowledge on molecular pathogenesis of hepatocellular carcinoma. On this occasion, the treatment sequences for early and advanced tumor stages according to the recently updated Barcelona Clinic Liver Cancer classification system and the current algorithm of systemic therapy (first-, second-, and third-line treatment) are summarized. Furthermore, we discuss novel precautional and pre-therapeutic approaches including therapeutic vaccination, adoptive cell transfer, locoregional therapy enhancement, and non-coding RNA-based therapy as promising treatment options. These novel treatments may prolong overall survival rates in regard with quality of life and liver function as mainstay of HCC therapy.

Studies on glycogen storage disease type 1a animal models: a brief perspective

Glycogen storage disease type 1 (GSD1) is a rare hereditary monogenic disease characterized by the disturbed glucose metabolism. The most widespread variant of GSD1 is GSD1a, which is a deficiency of glucose-6-phosphatase-ɑ. Glucose-6-phosphatase-ɑ is expressed only in liver, kidney, and intestine, and these organs are primarily affected by its deficiency, and long-term complications of GSD1a include hepatic tumors and chronic liver disease. This article is a brief overview of existing animal models for GSD1a, from the first mouse model of 1996 to modern CRISPR/Cas9-generated ones. First whole-body murine models demonstrated exact metabolic symptoms of GSD1a, but the animals did not survive weaning. The protocol for glucose treatment allowed prolonged survival of affected animals, but long-term complications, such as hepatic tumorigenesis, could not be investigated. Next, organ-specific knockout models were developed, and most of the metabolic research was performed on liver glucose-6-phosphate-deficient mice. Naturally occuring mutation was also discovered in dogs. All these models are widely used to study GSD1a from metabolic and physiological standpoints and to develop possible treatments involving gene therapy. Research performed using these models helped elucidate the role of glycogen and lipid accumulation, hypoxia, mitochondrial dysfunction, and autophagy impairment in long-term complications of GSD1a, including hepatic tumorigenesis. Recently, gene replacement therapy and genome editing were tested on described models, and some of the developed approaches have reached clinical trials.

The Role of Chronic Liver Diseases in the Emergence and Recurrence of Hepatocellular Carcinoma: An Omics Perspective

Hepatocellular carcinoma (HCC) typically develops from a background of cirrhosis resulting from chronic inflammation. This inflammation is frequently associated with chronic liver diseases (CLD). The advent of next generation sequencing has enabled extensive analyses of molecular aberrations in HCC. However, less attention has been directed to the chronically inflamed background of the liver, prior to HCC emergence and during recurrence following surgery. Hepatocytes within chronically inflamed liver tissues present highly activated inflammatory signaling pathways and accumulation of a complex mutational landscape. In this altered environment, cells may transform in a stepwise manner toward tumorigenesis. Similarly, the chronically inflamed environment which persists after resection may impact the timing of HCC recurrence. Advances in research are allowing an extensive epigenomic, transcriptomic and proteomic characterization of CLD which define the emergence of HCC or its recurrence. The amount of data generated will enable the understanding of oncogenic mechanisms in HCC from the CLD perspective and provide the possibility to identify robust biomarkers or novel therapeutic targets for the treatment of primary and recurrent HCC. Importantly, biomarkers defined by the analysis of CLD tissue may permit the early detection or prevention of HCC emergence and recurrence. In this review, we compile the current omics based evidence of the contribution of CLD tissues to the emergence and recurrence of HCC.

Clinical features of gout in adult patients with type Ia glycogen storage disease: a single-centre retrospective study and a review of literature

Background

This study aimed to explore the clinical features of gout in adult patients with glycogen storage disease type Ia (GSD Ia).

Methods

Ninety-five adult patients with GSD Ia admitted to Peking Union Medical College Hospital were retrospectively analysed. A clinical diagnosis of GSD Ia was confirmed in all patients through gene sequencing. All patients had hyperuricaemia; 31 patients complicated with gout were enrolled, and 64 adult GSD Ia patients with asymptomatic hyperuricaemia were selected as a control group during the same period. Clinical characteristics were analysed and compared between the two groups.

Results

Thirty-one of the 95 patients had complications of gout (median age, 25 years; 11 (35.5%) females). All 31 patients had hepatomegaly, abnormal liver function, fasting hypoglycaemia, hyperuricaemia, hyperlipaemia, and hyperlacticaemia. A protuberant abdomen, growth retardation, recurrent epistaxis, and diarrhoea were the most common clinical manifestations. Among these 31 patients, 10 patients (32.3%) had gout as the presenting manifestation and were diagnosed with GSD Ia at a median time of 5 years (range, 1–14) after the first gout flare. The median age of gout onset was 18 years (range, 10–29). Fifteen of the 31 GSD Ia-related gout patients were complicated with gouty tophi, which has an average incidence time of 2 years after the first gouty flare. The mean value of the maximum serum uric acid (SUA) was 800.5 μmol/L (range, 468–1068). The incidence of gout in adult GSD Ia patients was significantly associated with the initial age of regular treatment with raw corn starch, the proportion of urate-lowering therapy initiated during the asymptomatic hyperuricaemic stage, maximum SUA level, and mean cholesterol level.

Conclusions

Determination of GSD Ia should be performed for young-onset gout patients with an early occurrence of gouty tophi, especially in patients with hepatomegaly, recurrent hypoglycaemia, or growth retardation. Early detection and long-term regulatory management of hyperuricaemia, in addition to early raw corn starch and lifestyle intervention, should be emphasized for GSD Ia patients in order to maintain good metabolic control.

Trial registration

Retrospectively registered.

Glycogen accumulation and phase separation drives liver tumor initiation

Glucose consumption is generally increased in tumor cells to support tumor growth. Interestingly, we report that glycogen accumulation is a key initiating oncogenic event during liver malignant transformation. We found that glucose-6-phosphatase (G6PC) catalyzing the last step of glycogenolysis is frequently downregulated to augment glucose storage in pre-malignant cells. Accumulated glycogen undergoes liquid-liquid phase separation, which results in the assembly of the Laforin-Mst1/2 complex and consequently sequesters Hippo kinases Mst1/2 in glycogen liquid droplets to relieve their inhibition on Yap. Moreover, G6PC or another glycogenolysis enzyme-liver glycogen phosphorylase (PYGL) deficiency in both human and mice results in glycogen storage disease along with liver enlargement and tumorigenesis in a Yap-dependent manner. Consistently, elimination of glycogen accumulation abrogates liver growth and cancer incidence, whereas increasing glycogen storage accelerates tumorigenesis. Thus, we concluded that cancer-initiating cells adapt a glycogen storing mode, which blocks Hippo signaling through glycogen phase separation to augment tumor incidence.

Emerging roles of autophagy in hepatic tumorigenesis and therapeutic strategies in glycogen storage disease type Ia: A review

Glycogen storage disease type Ia (GSD-Ia) is an inherited metabolic disease caused by a deficiency in glucose-6-phosphatase-α (G6Pase-α or G6PC) which plays a critical role in blood glucose homeostasis by catalyzing the hydrolysis of glucose-6-phosphate (G6P) to glucose and phosphate in the terminal step of glycogenolysis and gluconeogenesis. Patients with GSD-Ia manifest life-threatening fasting hypoglycemia along with the excessive accumulation of hepatic glycogen and triglycerides which results in hepatomegaly and a risk of long-term complications such as hepatocellular adenoma and carcinoma (HCA/HCC). The etiology of HCA/HCC development in GSD-Ia, however, is unknown. Recent studies have shown that the livers in model animals of GSD-Ia display impairment of autophagy, a cellular recycling process which is critical for energy metabolism and cellular homeostasis. However, molecular mechanisms of autophagy impairment and its involvement in pathogenesis in GSD-Ia are still under investigation. Here, we summarize the latest advances for signaling pathways implicated in hepatic autophagy impairment and the roles of autophagy in hepatic tumorigenesis in GSD-Ia. In addition, recent evidence has illustrated that autophagy plays an important role in hepatic metabolism and liver-directed gene therapy mediated by recombinant adeno-associated virus (rAAV). Therefore, we highlight the possible role of hepatic autophagy in metabolic control and rAAV-mediated gene therapy for GSD-Ia. In this review, we also provide potential therapeutic strategies for GSD-Ia on the basis of molecular mechanisms underlying hepatic autophagy impairment in GSD-Ia.

Hepatocellular carcinoma (HCC): Epidemiology, etiology and molecular classification

Hepatocellular carcinoma (HCC), the primary malignancy of hepatocytes, is a diagnosis with bleak outcome. According to National Cancer Institute's SEER database, the average five-year survival rate of HCC patients in the US is 19.6% but can be as low as 2.5% for advanced, metastatic disease. When diagnosed at early stages, it is treatable with locoregional treatments including surgical resection, Radio-Frequency Ablation, Trans-Arterial Chemoembolization or liver transplantation. However, HCC is usually diagnosed at advanced stages when the tumor is unresectable, making these treatments ineffective. In such instances, systemic therapy with tyrosine kinase inhibitors (TKIs) becomes the only viable option, even though it benefits only 30% of patients, provides only a modest (~3months) increase in overall survival and causes drug resistance within 6months. HCC, like many other cancers, is highly heterogeneous making a one-size fits all option problematic. The selection of liver transplantation, locoregional treatment, TKIs or immune checkpoint inhibitors as a treatment strategy depends on the disease stage and underlying condition(s). Additionally, patients with similar disease phenotype can have different molecular etiology making treatment responses different. Stratification of patients at the molecular level would facilitate development of the most effective treatment option. With the increase in efficiency and affordability of "omics"-level analysis, considerable effort has been expended in classifying HCC at the molecular, metabolic and immunologic levels. This review examines the results of these efforts and the ways they can be leveraged to develop targeted treatment options for HCC.

Risk Factors, Pathogenesis, and Strategies for Hepatocellular Carcinoma Prevention: Emphasis on Secondary Prevention and Its Translational Challenges

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated mortality globally. Given the limited therapeutic efficacy in advanced HCC, prevention of HCC carcinogenesis could serve as an effective strategy. Patients with chronic fibrosis due to viral or metabolic etiologies are at a high risk of developing HCC. Primary prevention seeks to eliminate cancer predisposing risk factors while tertiary prevention aims to prevent HCC recurrence. Secondary prevention targets patients with baseline chronic liver disease. Various epidemiological and experimental studies have identified candidates for secondary prevention-both etiology-specific and generic prevention strategies-including statins, aspirin, and anti-diabetic drugs. The introduction of multi-cell based omics analysis along with better characterization of the hepatic microenvironment will further facilitate the identification of targets for prevention. In this review, we will summarize HCC risk factors, pathogenesis, and discuss strategies of HCC prevention. We will focus on secondary prevention and also discuss current challenges in translating experimental work into clinical practice.

Hepatocellular adenoma in the paediatric population: Molecular classification and clinical associations

Hepatocellular adenomas (HCAs) represent rare, benign liver tumours occurring predominantly in females taking oral contraceptives. In children, HCAs comprise less than 5% of hepatic tumours and demonstrate association with various conditions. The contemporary classification of HCAs, based on their distinctive genotypes and clinical phenotypes, includes hepatocyte nuclear factor 1 homeobox alpha-inactivated HCAs, beta-catenin-mutated HCAs, inflammatory HCAs, combined beta-catenin-mutated and inflammatory HCAs, sonic hedgehog-activated HCAs, and unclassified HCAs. In children, there is a lack of literature on the characteristics and distribution of HCA subtypes. In this review, we summarized different HCA subtypes and the clinicopathologic spectrum of HCAs in the paediatric population.

Hepatic Resection and Transplant in Glycogen Storage Diseases

Patients with glycogen storage diseases pose unique management challenges to clinicians.These challenges are exacerbated wheneverthey undergo surgery as the basic anomaly in their glycogen storage pathways make them susceptible to organic acidosis, which may in turn complicate their preoperative, intraoperative, and postoperative course. Because of the rarity of these diseases, clinicians may not be aware of the specific management concerns. In the case reported here, a 37-year-old patient with glycogen storage disease type 1 underwentleft hepatectomy for hepatic adenomatosis, which was complicated by intraoperative severe lactic acidosis that was successfully treated. After successful hepatectomy, the patient underwent liver transplant without major lactic acidosis or hemodynamic instability. Early recognition and aggressive management of blood sugar and lactic acidosis in patients with glycogen storage diseases can allow for successful outcomes even when complex surgical procedures are required.

Fenofibrate rapidly decreases hepatic lipid and glycogen storage in neonatal mice with glycogen storage disease type Ia

Glycogen storage disease type Ia (GSD Ia) is caused by autosomal mutations in glucose-6-phosphatase α catalytic subunit (G6PC) and can present with severe hypoglycemia, lactic acidosis and hypertriglyceridemia. In both children and adults with GSD Ia, there is over-accumulation of hepatic glycogen and triglycerides that can lead to steatohepatitis and a risk for hepatocellular adenoma or carcinoma. Here, we examined the effects of the commonly used peroxisomal proliferated activated receptor α agonist, fenofibrate, on liver and kidney autophagy and lipid metabolism in 5-day-old G6pc -/- mice serving as a model of neonatal GSD Ia. Five-day administration of fenofibrate decreased the elevated hepatic and renal triglyceride and hepatic glycogen levels found in control G6pc -/- mice. Fenofibrate also induced autophagy and promoted β-oxidation of fatty acids and stimulated gene expression of acyl-CoA dehydrogenases in the liver. These findings show that fenofibrate can rapidly decrease hepatic glycogen and triglyceride levels and renal triglyceride levels in neonatal G6pc -/- mice. Moreover, since fenofibrate is an FDA-approved drug that has an excellent safety profile, our findings suggest that fenofibrate could be a potential pharmacological therapy for GSD Ia in neonatal and pediatric patients as well as for adults. These findings may also apply to non-alcoholic fatty liver disease, which shares similar pathological and metabolic changes with GSD Ia.

Activation of tumor-promoting pathways implicated in hepatocellular adenoma/carcinoma, a long-term complication of glycogen storage disease type Ia

Hepatocellular adenoma/carcinoma (HCA/HCC) is a long-term complication of the metabolic disorder glycogen storage disease type Ia (GSD-Ia) deficient in glucose-6-phosphatase-α (G6PC or G6Pase-α). We have shown previously that hepatic G6Pase-α deficiency leads to autophagy impairment, mitochondrial dysfunction, enhanced glycolysis, and augmented hexose monophosphate shunt, all of which can contribute to hepatocarcinogenesis. However, the mechanism underlying HCA/HCC development in GSD-Ia remains unclear. We now show that G6Pase-α deficiency-mediated hepatic autophagy impairment leads to sustained accumulation of an autophagy-specific substrate p62 which can activate tumor-promoting pathways including nuclear factor erythroid 2-related factor 2 (Nrf2) and mammalian target of rapamycin complex 1 (mTORC1). Consistently, the HCA/HCC lesions developed in the G6Pase-α-deficient livers display marked accumulation of p62 aggregates and phosphorylated p62 along with activation of Nrf2 and mTORC1 signaling. Furthermore, the HCA/HCC lesions exhibit activation of additional oncogenic pathways, β-catenin and Yes-associated protein (YAP) which is implicated in autophagy impairment. Intriguingly, hepatic levels of glucose-6-phosphate and glycogen which are accumulated in the G6Pase-α-deficient livers were significantly lower in HCC than those in HCA. Conversely, compared to HCA, the HCC lesion display increased expression of many oncogenes and the M2 isoform of pyruvate kinase (PKM2), a glycolytic enzyme critical for aerobic glycolysis and tumorigenesis. Collectively, our data show that hepatic G6Pase-α-deficiency leads to persistent autophagy impairment and activation of multiple tumor-promoting pathways that contribute to HCA/HCC development in GSD-Ia.

Dietary exacerbation of metabolic stress leads to accelerated hepatic carcinogenesis in glycogen storage disease type Ia

BACKGROUND & AIMS

Glycogen storage disease type Ia (GSDIa) is a rare genetic disease associated with glycogen accumulation in hepatocytes and steatosis. With age, most adult patients with GSDIa develop hepatocellular adenomas (HCA), which can progress to hepatocellular carcinomas (HCC). In this study, we characterized metabolic reprogramming and cellular defense alterations during tumorigenesis in the liver of hepatocyte-specific G6pc deficient (L.G6pc^-/-) mice, which develop all the hepatic hallmarks of GSDIa.

METHODS

Liver metabolism and cellular defenses were assessed at pretumoral (four months) and tumoral (nine months) stages in L.G6pc^-/- mice fed a high fat/high sucrose (HF/HS) diet.

RESULTS

In response to HF/HS diet, hepatocarcinogenesis was highly accelerated since 85% of L.G6pc^-/- mice developed multiple hepatic tumors after nine months, with 70% classified as HCA and 30% as HCC. Tumor development was associated with high expression of malignancy markers of HCC, i.e. alpha-fetoprotein, glypican 3 and β-catenin. In addition, L.G6pc^-/- livers exhibited loss of tumor suppressors. Interestingly, L.G6pc^-/- steatosis exhibited a low-inflammatory state and was less pronounced than in wild-type livers. This was associated with an absence of epithelial-mesenchymal transition and fibrosis, while HCA/HCC showed a partial epithelial-mesenchymal transition in the absence of TGF-β1 increase. In HCA/HCC, glycolysis was characterized by a marked expression of PK-M2, decreased mitochondrial OXPHOS and a decrease of pyruvate entry in the mitochondria, confirming a "Warburg-like" phenotype. These metabolic alterations led to a decrease in antioxidant defenses and autophagy and chronic endoplasmic reticulum stress in L.G6pc^-/- livers and tumors. Interestingly, autophagy was reactivated in HCA/HCC.

CONCLUSION

The metabolic remodeling in L.G6pc^-/- liver generates a preneoplastic status and leads to a loss of cellular defenses and tumor suppressors that facilitates tumor development in GSDI.

LAY SUMMARY

Glycogen storage disease type Ia (GSD1a) is a rare metabolic disease characterized by hypoglycemia, steatosis, excessive glycogen accumulation and tumor development in the liver. In this study, we have observed that GSDIa livers reprogram their metabolism in a similar way to cancer cells, which facilitates tumor formation and progression, in the absence of hepatic fibrosis. Moreover, hepatic burden due to overload of glycogen and lipids in the cells leads to a decrease in cellular defenses, such as autophagy, which could further promote tumorigenesis in the case of GSDI.

Computed Tomography and Magnetic Resonance Imaging Features of Primary and Secondary Hepatic Glycogenosis

Glycogen storage disease type I and glycogenic hepatopathy are the most common type of primary and secondary hepatic glycogenosis, with presenting common radiological features of hepatomegaly, hepatic signal, or density change. Beyond that, glycogen storage disease type I shows hepatocellular adenomas or fatty liver, while glycogenic hepatopathy does not.

Pediatric hepatocellular carcinoma

Pediatric hepatocellular carcinoma (HCC) is the second common malignant liver tumor in children after hepatoblastoma. It differs from the adult HCC in the etiological predisposition, biological behavior and lower frequency of cirrhosis. Perinatally acquired hepatitis-B virus, hepatorenal tyrosinemia, progressive familial intrahepatic cholestasis, glycogen storage disease, Alagille’s syndrome and congenital portosystemic shunts are important predisposing factors. Majority of children (87%) are older than 5 years of age. Following mass immunization against hepatitis-B, there has been a drastic fall in the incidence of new cases of pediatric HCC in the Asia-Pacific region. Management is targeted on complete surgical removal either by resection or liver transplantation. There is a trend towards improving survival of children transplanted for HCC beyond Milan criteria. Chemotherapeutic regimens do not offer good results but may be helpful for down-staging of advanced HCC. Surveillance of children with chronic liver diseases with ultrasound and alpha-fetoprotein may be helpful in timely detection, intervention and overall improvement in outcome of HCC.

Hepatocellular Carcinoma: Causes, Mechanism of Progression and Biomarkers

Hepatocellular Carcinoma (HCC) is one of the most common malignant tumours in the world. It is a heterogeneous group of a tumour that vary in risk factor and genetic and epigenetic alteration event. Mortality due to HCC in last fifteen years has increased. Multiple factors including viruses, chemicals, and inborn and acquired metabolic diseases are responsible for its development. HCC is closely associated with hepatitis B virus, and at least in some regions of the world with hepatitis C virus. Liver injury caused by viral factor affects many cellular processes such as cell signalling, apoptosis, transcription, DNA repair which in turn induce important effects on cell survival, growth, transformation and maintenance. Molecular mechanisms of hepatocellular carcinogenesis may vary depending on different factors and this is probably why a large set of mechanisms have been associated with these tumours. Various biomarkers including α-fetoprotein, des-γ-carboxyprothrombin, glypican-3, golgi protein-73, squamous cell carcinoma antigen, circulating miRNAs and altered DNA methylation pattern have shown diagnostic significance. This review article covers up key molecular pathway alterations, biomarkers for diagnosis of HCC, anti-HCC drugs and relevance of key molecule/pathway/receptor as a drug target.

Hepatocyte specific expression of an oncogenic variant of β-catenin results in lethal metabolic dysfunction in mice

Background

Wnt/β-catenin signaling plays a crucial role in embryogenesis, tissue homeostasis, metabolism and malignant transformation of different organs including the liver. Continuous β-catenin signaling due to somatic mutations in exon 3 of the Ctnnb1 gene is associated with different liver diseases including cancer and cholestasis.

Results

Expression of a degradation resistant form of β-catenin in hepatocytes resulted in 100% mortality within 31 days after birth. Ctnnb1^CAhep mice were characterized by reduced body weight, significantly enlarged livers with hepatocellular fat accumulation around central veins and increased hepatic triglyceride content. Proteomics analysis using whole liver tissue revealed significant deregulation of proteins involved in fat, glucose and mitochondrial energy metabolism, which was also reflected in morphological anomalies of hepatocellular mitochondria. Key enzymes involved in transport and synthesis of fatty acids and cholesterol were significantly deregulated in livers of Ctnnb1^CAhep mice. Furthermore, carbohydrate metabolism was substantially disturbed in mutant mice.

Conclusion

Continuous β-catenin signaling in hepatocytes results in premature death due to severe disturbances of liver associated metabolic pathways and mitochondrial dysfunction.

Methods

To investigate the influence of permanent β-catenin signaling on liver biology we analyzed mice with hepatocyte specific expression of a dominant stable form of β-catenin (Ctnnb1^CAhep) and their WT littermates by serum biochemistry, histology, electron microscopy, mRNA profiling and proteomic analysis of the liver.

Clear cell hepatocellular carcinoma: origin, metabolic traits and fate of glycogenotic clear and ground glass cells

Clear cell hepatocellular carcinoma (CCHCC) has hitherto been considered an uncommon, highly differentiated variant of hepatocellular carcinoma (HCC) with a relatively favorable prognosis. CCHCC is composed of mixtures of clear and/or acidophilic ground glass hepatocytes with excessive glycogen and/or fat and shares histology, clinical features and etiology with common HCCs. Studies in animal models of chemical, hormonal and viral hepatocarcinogenesis and observations in patients with chronic liver diseases prone to develop HCC have shown that the majority of HCCs are preceded by, or associated with, focal or diffuse excessive storage of glycogen (glycogenosis) which later may be replaced by fat (lipidosis/steatosis). In ground glass cells, the glycogenosis is accompanied by proliferation of the smooth endoplasmic reticulum, which is closely related to glycogen particles and frequently harbors the hepatitis B surface antigen (HBsAg). From the findings in animal models a sequence of changes has been established, commencing with preneoplastic glycogenotic liver lesions, often containing ground glass cells, and progressing to glycogen-poor neoplasms via various intermediate stages, including glycogenotic/lipidotic clear cell foci, clear cell hepatocellular adenomas (CCHCA) rich in glycogen and/or fat, and CCHCC. A similar process seems to take place in humans, with clear cells frequently persisting in CCHCC and steatohepatitic HCC, which presumably represent intermediate stages in the development rather than particular variants of HCC. During the progression of the preneoplastic lesions, the clear and ground glass cells transform into cells characteristic of common HCC. The sequential cellular changes are associated with metabolic aberrations, which start with an activation of the insulin signaling cascade resulting in pre-neoplastic hepatic glycogenosis. The molecular and metabolic changes underlying the glycogenosis/lipidosis are apparently responsible for the dramatic metabolic shift from gluconeogenesis to the pentose phosphate pathway and Warburg-type glycolysis, which provide precursors and energy for an ever increasing cell proliferation during progression.

Malignant transformation of hepatocellular adenoma with bone marrow metaplasia arising in glycogen storage disease type I: A case report

Malignant transformation of hepatocellular adenoma (HA) is relatively rare and has been reported to be associated with dysregulation of the β-catenin pathway. The presence of bone marrow metaplasia in HA is an uncommon histological characteristic. The current report presents the case of a 46-year-old woman with glycogen storage disease type I (von Gierke's disease) who underwent resection of hepatocellular carcinoma (HCC) arising in a HA with associated bone marrow metaplasia producing three series of hematopoietic cells. The serum level of proteins induced by des-gamma-carboxy prothrombin (DCP) gradually increased as the tumors grew; following hepatic resection, DCP levels returned to normal. Nuclear accumulation of β-catenin was shown in HCC by immunohistochemistry; however, no mutation was detected in exon 3 of β-catenin. To the best of our knowledge, this is the first report of HA with absolute bone marrow metaplasia producing three series of hematopoietic cells. This occurrence suggests that elevated DCP may be an indicator of malignant transformation of HA.

Liver transplantation for pediatric inherited metabolic disorders: Considerations for indications, complications, and perioperative management

LT is an effective therapeutic option for a variety of IEM. This approach can significantly improve the quality of life of patients who suffer from severe disease manifestations and/or life-threatening metabolic decompensations despite medical/dietary management. Due to the significant risks for systemic complications from surgical stressors, careful perioperative management is vital. Even after LT, some disorders require long-term dietary restriction, medical management, and monitoring of metabolites. Successful liver transplant for these complex disorders can be achieved with disease- and patient-specific strategies using a multidisciplinary approach. In this article, we review indications, complications, perioperative management, and long-term follow-up recommendations for IEM that are treatable with LT.

Reappraisal of the Role of Portacaval Shunting in the Growth of Patients With Glycogen Storage Disease Type I in the Era of Liver Transplantation

BACKGROUND

Instead of dietary modification, surgical management is considered for correcting growth retardation, poor metabolic control, and hepatocellular adenoma (HCA) in glycogen storage disease (GSD) type I.

METHODS

The records of 55 GSD type I patients were retrospectively reviewed. Thirty-two patients underwent only dietary management (group D) and 23 underwent surgical management (group S). In group S, 17 underwent portacaval shunting (PCS), 13 underwent liver transplantation (LT; 7 underwent both PCS and LT). Height-for-age and body mass index-for-age Z-scores based on World Health Organization data were used to compare growth patterns before and after surgery. Changes in metabolic abnormalities and HCA after operation were also investigated.

RESULTS

Height-for-age Z-scores for group S were higher by an average of 0.377 compared to that for group D. Metabolic abnormalities often disappeared after LT but improved partially after PCS. De novo HCA was detected in 4 patients (13%) from group D, 12 (100%) who underwent PCS, and none who underwent LT. One case of hepatocellular carcinoma and one of hemorrhage from a HCA were noted in group D. Two cases of hepatocellular carcinoma, 2 of hemorrhage, and 1 of necrosis were noted after PCS.

CONCLUSIONS

Surgery yielded greater growth improvement than dietary management. However, after PCS, metabolic abnormalities remained unresolved, and the de novo HCA rate was high. Portacaval shunting can be used to improve growth in GSD type I patients when LT is not possible, but close observation for metabolic abnormalities and HCA is essential.

Liver tumors in children with metabolic disorders

Hepatic neoplasia is a rare but serious complication of metabolic diseases in children. The risk of developing neoplasia, the age at onset, and the measures to prevent it differ in the various diseases. We review the most common metabolic disorders that are associated with a heightened risk of developing hepatocellular neoplasms, with a special emphasis on reviewing recent advances in the molecular pathogenesis of the disorders and pre-clinical therapeutic options. The cellular and genetic pathways driving carcinogenesis are poorly understood, but best understood in tyrosinemia.

Case of cholangiocellular carcinoma in a patient with glycogen storage disease type Ia

Glycogen storage disease (GSD) type Ia is caused by a deficiency in glucose-6-phosphatase. Long-term complications, including renal disease, gout, osteoporosis and pulmonary hypertension, develop in patients with GSD type Ia. In the second or third decade, 22-75% of GSD type Ia patients develop hepatocellular adenoma (HCA). In some of these patients, the HCA evolves into hepatocellular carcinoma. However, little is known about GSD type Ia patients with HCA who develop cholangiocellular carcinoma (CCC). Here, we report for the first time, a patient with GSD type Ia with HCA, in whom intrahepatic CCC was developed.

Regression of hepatocellular adenomas with strict dietary therapy in patients with glycogen storage disease type I

Hepatocellular adenomas (HCAs) are a common complication in patients with glycogen storage disease type I (GSD I). In this series, we report regression of HCAs in a cohort of patients who achieved metabolic control with strict dietary therapy. A retrospective review of the clinical records for all patients with GSD I was performed at our institution. All available imaging studies were reviewed in patients with reported regression of HCAs in the medical record. The charts of 163 patients with GSD Ia and 42 patients with GSD Ib were reviewed, and HCAs were documented in 47 subjects (43 Ia/4 Ib). After review of all available imaging studies, eight patients met criteria of being followed with both magnetic resonance imaging and ultrasound and were found to show evidence of regression of HCAs. In these individuals, regression of the HCAs occurred once metabolic control was obtained, as determined by decreasing levels of serum triglyceride levels. The average triglyceride level in all patients prior to regression of HCAs was 753 mg/dL (SD ± 293). The average serum triglyceride level in all patients at the time of regression of HCAs was 340 mg/dL (SD ± 164). These findings suggest that strict dietary therapy may cause regression of HCAs. If HCAs are documented in a patient with suboptimal metabolic control, intensive medical therapy may be an alternative to surgical intervention in some individuals.

Identification of differentially expressed microRNAs in human hepatocellular adenoma associated with type I glycogen storage disease: a potential utility as biomarkers

BACKGROUND

It is known that malignant transformation to hepatocellular carcinoma (HCC) occurs at a higher frequency in hepatocellular adenoma (HCA) from type I glycogen storage disease (GSD I) compared to HCA from other etiologies. In this study, we aimed to identify differentially expressed miRNAs in GSD Ia HCA as candidates that could serve as putative biomarkers for detection of GSD Ia HCA and/or risk assessment of malignant transformation.

METHODS

Utilizing massively parallel sequencing, the miRNA profiling was performed for paired adenomas and normal liver tissues from seven GSD Ia patients. Differentially expressed miRNAs were validated in liver tumor tissues, HCC cell lines and serum using quantitative RT-PCR.

RESULTS

miR-34a, miR-34a, miR-224, miR-224, miR-424, miR-452 and miR-455-5p were found to be commonly deregulated in GSD Ia HCA, general population HCA, and HCC cell lines at compatible levels. In comparison with GSD Ia HCA, the upregulation of miR-130b and downregulation of miR-199a-5p, miR-199b-5p, and miR-214 were more significant in HCC cell lines. Furthermore, serum level of miR-130b in GSD Ia patients with HCA was moderately higher than that in either GSD Ia patients without HCA or healthy individuals.

CONCLUSION

We make the first observation of distinct miRNA deregulation in HCA associated with GSD Ia. We also provide evidence that miR-130b could serve as a circulating biomarker for detection of GSD Ia HCA. This work provides prominent candidate miRNAs worth evaluating as biomarkers for monitoring the development and progress of liver tumors in GSD Ia patients in the future.

Benign hepatocellular tumors in children: focal nodular hyperplasia and hepatocellular adenoma

Benign liver tumors are very rare in children. Most focal nodular hyperplasia (FNH) remain sporadic, but predisposing factors exist, as follows: long-term cancer survivor (with an increasing incidence), portal deprivation in congenital or surgical portosystemic shunt. The aspect is atypical on imaging in two-thirds of cases. Biopsy of the tumor and the nontumoral liver is then required. Surgical resection will be discussed in the case of large tumors with or without symptoms. In the case of associated vascular disorder with portal deprivation, restoration of the portal flow will be discussed in the hope of seeing the involution of FNH. HepatoCellular Adenoma (HCA) is frequently associated with predisposing factors such as GSD type I and III, Fanconi anemia especially if androgen therapy is administered, CPSS, and SPSS. Adenomatosis has been reported in germline mutation of HNF1- α . Management will depend on the presence of a predisposing factor and may include metabolic control, androgen therapy withdrawn, or closure of the shunt when appropriate. Surgery is usually performed on large lesions. In the case of adenomatosis or multiple lesions, surgery will be adapted. Close followup is required in all cases.

Glycogenotic hepatocellular carcinoma with glycogen-ground-glass hepatocytes: A heuristically highly relevant phenotype

Glycogenotic hepatocellular carcinoma (HCC) with glycogen-ground-glass hepatocytes has recently been described as an allegedly “novel variant” of HCC, but neither the historical background nor the heuristic relevance of this observation were put in perspective. In the present contribution, the most important findings in animal models and human beings related to the emergence and further evolution of excessively glycogen storing (glycogenotic) hepatocytes with and without ground glass features during neoplastic development have been summarized. Glycogenotic HCCs with glycogen-ground-glass hepatocytes represent highly differentiated neoplasms which contain subpopulations of cells phenotypically resembling those of certain types of preneoplastic hepatic foci and benign hepatocellular neoplasms. It is questionable whether the occurrence of glycogen-ground-glass hepatocytes in a glycogenotic HCC justifies its classification as a specific entity. The typical appearance of ground-glass hepatocytes is due to a hypertrophy of the smooth endoplasmic reticulum, which is usually associated with an excessive storage of glycogen and frequently also with an expression of the hepatitis B surface antigen. Sequential studies in animal models and observations in humans indicate that glycogen-ground-glass hepatocytes are a facultative, integral part of a characteristic cellular sequence commencing with focal hepatic glycogenosis potentially progressing to benign and malignant neoplasms. During this process highly differentiated glycogenotic cells including ground-glass hepatocytes are gradually transformed via various intermediate stages into poorly differentiated glycogen-poor, basophilic (ribosome-rich) cancer cells. Histochemical, microbiochemical, and molecular biochemical studies on focal hepatic glycogenosis and advanced preneoplastic and neoplastic lesions in tissue sections and laser-dissected specimens in rat and mouse models have provided compelling evidence for an early insulinomimetic effect of oncogenic agents, which is followed by a fundamental metabolic switch from gluconeogenesis towards the pentose-phosphate pathway and the Warburg type of glycolysis during progression from preneoplastic hepatic glycogenosis to the highly proliferative malignant phenotype.

Liver biopsy in modern clinical practice: a pediatric point-of-view

Liver biopsy remains the foundation of evaluation and management of liver disease in children, although the role of the liver biopsy is changing with development of alternative methods of diagnosis and advancement of hepatic imaging techniques. The indications for liver biopsy are evolving as current knowledge of etiologies, noninvasive biomarker alternatives, and treatment options in pediatric liver disease are expanding. The procedure can often be complicated in children by technical difficulties, cost, and smaller specimen size. Communication and partnership of clinicians with pathologists experienced in pediatric liver diseases are essential. DNA sequencing, novel imaging modalities, noninvasive biomarkers of fibrosis and apoptosis, proteomics, and genome-wide association studies offer potential alternative methods for evaluation of liver disease in children. This review presents specific indications, considerations, methods, complications, contraindications, and alternatives for pediatric liver biopsy.

Hepatocellular carcinoma and focal nodular hyperplasia of the liver in a glycogen storage disease patient

Glycogen storage disease type Ia (GSD-Ia; also called von Gierke disease) is an autosomal recessive disorder of carbohydrate metabolism caused by glucose-6-phosphatase deficiency. There have been many reports describing hepatic tumors in GSD patients; however, most of these reports were of hepatocellular adenomas, whereas there are only few reports describing focal nodular hyperplasia (FNH) or hepatocellular carcinoma (HCC). We report a case with GSD-Ia who had undergone a partial resection of the liver for FNH at 18 years of age and in whom moderately differentiated HCC had developed. Preoperative imaging studies, including ultrasonography, dynamic computer tomography (CT) and magnetic resonance imaging, revealed benign and malignant features. In particular, fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT revealed the atypical findings that FDG accumulated at high levels in the non-tumorous hepatic parenchyma and low levels in the tumor. Right hemihepatectomy was performed. During the perioperative period, high-dose glucose and sodium bicarbonate were administered to control metabolic acidosis. He had multiple recurrences of HCC at 10 mo after surgery and was followed-up with transcatheter arterial chemoembolization. The tumor was already highly advanced when it was found by chance; therefore, a careful follow-up should be mandatory for GSD-I patients as they are at a high risk for HCC, similar to hepatitis patients.

Primary malignant liver tumors in children

Liver tumors constitute only 1-4% of all solid tumors in children. Two-thirds of these are malignant. The primary malignant tumors are hepatoblastoma (HB), hepatocellular carcinoma (HCC), rhabdomyosarcoma (RMS), angiosarcoma, rhabdoid tumor, undifferentiated sarcoma and other rarer tumors. Of these HB is the commonest. The diagnosis of HB is based on the radiology, elevated levels of α-fetoprotein (αFP) and the histology/cytology. Staging is essential for risk categorization, risk adapted treatment and prognostication. The commonest staging and risk categorization system used today is PRETEXT system that is being used by nearly all multicentre trials (American, European, German, Japanese) in some way. Treatment of HB is multimodal with surgery and chemotherapy being the main modalities. Survival is not possible without complete surgical resection. Majority of tumors are unresectable at presentation but can be made resectable with chemotherapy, giving a resection rate of more than 85%. Cisplatin is the main stay of chemotherapy and is a part of all multidrug protocols. The 3-y overall survival (OS) today stands at 62%-70% but only 25% patients with metastasis get cured. Panhepatic tumors and those with local factors causing unresectability are now dealt with liver transplantation which has also given a survival rate of nearly 85%. The overall management of HB and HCC has evolved over the past 3 decades giving good long term survival rates for HB, though patients with HCC still do poorly. Successive therapeutic trials have focused attention on increasing the efficiency and reducing the toxicity and long term side effects of the treatment. Among the other uncommon tumors the rhabdoid tumor and angiosarcoma are chemoresistant and have a poor outcome while the undifferentiated sarcoma and rhabdomyosarcoma are now showing better response to the currently used chemotherapy combinations.

Hepatocellular adenoma in glycogen storage disorder type I: a clinicopathological and molecular study

AIMS

  Glycogen storage disease type I is a metabolic disorder resulting from deficiency of the glucose-6-phosphate complex. Long-term complications include the development of hepatocellular adenoma (HCA). In this retrospective study, our aim was to reclassify according to geno-phenotypic characteristics nodular lesions identified in hepatectomy specimens of such patients transplanted between 1998 and 2008 at our institution.

METHODS AND RESULTS

  Clinicopathological data of seven consecutive transplanted patients with glycogen storage disease type I were reviewed. Liver nodules were re-examined histologically and by immunohistochemistry. Molecular analysis was performed additionally in a case with specific features. Four patients had multiple tumours. We concluded that 26 of 38 nodules available for study had features of inflammatory hepatocellular adenomas, seven comprised adenomas not otherwise specified and five were found to be focal nodular hyperplasia.

CONCLUSIONS

  Further studies are needed to clarify the pathogenesis of hepatocellular adenomas in glycogen storage disease; in particular to determine whether they share abnormal metabolic pathways with inflammatory adenomas in the general population. Testing for acute phase proteins may be a helpful tool in the early detection of HCA in such patients. Finally, there is a need to further define their risk of malignant transformation, in relation to age and possible cofactors.

Specific alterations of carbohydrate metabolism are associated with hepatocarcinogenesis in mitochondrially impaired mice

Friedreich's ataxia is an inherited neurodegenerative disease caused by the reduced expression of the mitochondrially active protein frataxin. We have previously shown that mice with a hepatocyte-specific frataxin knockout (AlbFxn(-/-)) develop multiple hepatic tumors in later life. In the present study, hepatic carbohydrate metabolism in AlbFxn(-/-) mice at an early and late life stage was analyzed. In young (5-week-old) AlbFxn(-/-) mice hepatic ATP, glucose-6-phosphate and glycogen levels were found to be reduced by ∼74, 80 and 88%, respectively, when compared with control animals. This pronounced ATP, G6P and glycogen depletion in the livers of young mice reverted in older animals: while half of the mice die before 30 weeks of age, the other half reaches 17 months of age and exhibits glycogen, G6P and ATP levels similar to those in age-matched controls. A key event in this respect seems to be the up-regulation of GLUT1, the predominant glucose transporter in fetal liver parenchyma, which became evident in AlbFxn(-/-) mice being 5-12 weeks of age. The most significant histological findings in animals being 17 or 22 months of age were the appearance of multiple clear cell, mixed cell and basophilic foci throughout the liver parenchyma as well as the development of hepatocellular adenomas and carcinomas. The hepatocarcinogenic process in AlbFxn(-/-) mice shows remarkable differences regarding carbohydrate metabolism alterations when compared with all other chemically and virally driven liver cancer models described up to now.