Hepatocellular neoplasms after intrahepatic transplantation of ovarian fragments into ovariectomized rats

[Preneoplastic glycogenotic lesions of the liver and kidney : Metabolic and molecular alterations in preneoplastic clear cell lesions of the liver and the kidney in experimental and human carcinogenesis]

AIM

The focus of these five studies was on human clear cell, glycogen-storing lesions of the liver and kidney, which pertain to preneoplastic lesions of hepatocellular carcinoma and renal cell carcinoma in animal models of diabetes-associated carcinogenesis.

MATERIAL AND METHODS

Noncirrhotic hepatic and renal tissue of humans, rats, and mice were analyzed with histology, immunohistochemistry, electron microscopy, and molecular biologic methods.

RESULTS

In humans, clear cell lesions often occur in noncirrhotic liver and renal tissue. They resemble preneoplastic lesions of experimental hepato- and nephrocarcinogenesis regarding glycogen storage, increased proliferative activity, upregulation of glycolysis and de novo lipogenesis (lipogenic phenotype), and activated protooncogenic signaling pathway of AKT/mTOR. In two models of murine hepatocarcinogenesis, the important role of the transcription factor ChREBP as a "metabolic oncogene" was characterized.

CONCLUSION

In these studies, the significance of small glycogen storing parenchymal alterations for carcinogenesis in human noncirrhotic liver and kidney was demonstrated due to their already present metabolic and molecular alterations. Therefore, they have to represent indicator lesions for an increased risk of carcinogenesis. Activation of the protooncogenic pathway AKT/mTOR as well as the transcription factor ChREBP and the manifestation of the lipogenic phenotype are crucial during the processes of carcinogenesis.

The Epidermal Growth Factor Receptor (EGFR) Inhibitor Gefitinib Reduces but Does Not Prevent Tumorigenesis in Chemical and Hormonal Induced Hepatocarcinogenesis Rat Models

Activation of the epidermal growth factor receptor (EGFR) signaling pathway promotes the development of hepatocellular adenoma (HCA) and carcinoma (HCC). The selective EGFR inhibitor Gefitinib was found to prevent hepatocarcinogenesis in rat cirrhotic livers. Thus, Gefitinib might reduce progression of pre-neoplastic liver lesions to HCC. In short- and long-term experiments, administration of N-Nitrosomorpholine (NNM) or intrahepatic transplantation of pancreatic islets in diabetic (PTx), thyroid follicles in thyroidectomized (TTx) and ovarian fragments in ovariectomized (OTx) rats was conducted for the induction of foci of altered hepatocytes (FAH). Gefitinib was administered for two weeks (20 mg/kg) or three and nine months (10 mg/kg). In NNM-treated rats, Gefitinib administration decreased the amount of FAH when compared to controls. The amount of HCA and HCC was decreased, but development was not prevented. Upon all transplantation models, proliferative activity of FAH was lower after administration of Gefitinib in short-term experiments. Nevertheless, the burden of HCA and HCC was not changed in later stages. Thus, EGFR inhibition by Gefitinib diminishes chemical and hormonal also induced hepatocarcinogenesis in the initiation stage in the non-cirrhotic liver. However, progression to malignant hepatocellular tumors was not prevented, indicating only a limited relevance of the EGFR signaling cascade in later stages of hepatocarcinogenesis.

Testosterone-receptor positive hepatocellular carcinoma in a 29-year old bodybuilder with a history of anabolic androgenic steroid abuse: a case report

Background

Continuous use of anabolic androgenic steroid in high-doses is associated with substantial health risks, including hepatocellular adenoma. Malignant transformation from hepatocellular adenoma to hepatocellular carcinoma after anabolic androgenic steroid abuse has been rarely reported. The morphological distinction of adenoma from well-differentiated hepatocellular carcinoma is challenging and requires elaborated imaging techniques and histology.

Case presentation

We report about a 29-year old male professional bodybuilder who presented with mid-epigastric pain at the emergency unit. Ultrasound showed a severe hepatomegaly with multiple lesions. Contrast-enhanced ultrasound revealed a heterogeneous pattern with signs of hepatocellular carcinoma. CT scan of the abdomen confirmed multiple hypervascular lesions and central areas of necrosis without contrast enhancement. Subsequent diagnostics included fine needle aspiration (FNA) of suspicious lesions and mini-laparoscopy to establish the diagnosis of a β-catenin and testosterone-receptor positive hepatocellular carcinoma embedded in multiple adenomas. The patient was subsequently treated by liver transplantation and remains tumor-free 27 month after surgery.

Conclusion

Hepatocellular carcinoma occurring in association with anabolic androgenic steroid abuse should sensitize physicians and especially professional bodybuilders for the harmful use of high doses of steroids.

Development of hepatocellular carcinoma associated with anabolic androgenic steroid abuse in a young bodybuilder: a case report

Introduction. Many different etiological factors are involved in the development of hepatocellular carcinoma (HCC). We report the case of HCC in a 37-year-old male professional bodybuilder with extensive anabolic androgenic (AAS) steroid abuse. Case Presentation. Because of increasing epigastric and abdominal pain, abdominal ultrasound was performed in a 37-year-old male professional bodybuilder. A hyperechoic lesion in the liver was detected in segment VI. The magnetic resonance imaging showed hepatomegaly and confirmed the lesion, which showed features of a hepatocellular adenoma (HCA). Laboratory values were inconspicuous. After laparoscopic segmentectomy the histological examination revealed HCC. Conclusion. While the development of HCA in the liver by chronic intake of AAS is well known, little is known about the association with HCC. The presented case may indicate aetiological association of chronic intake of AAS and the development of HCC.

[Hepatocellular carcinoma in the non-cirrhotic liver]

Of hepatocellular carcinomas (HCC), 15-20% occur in the non-cirrhotic liver. All factors which cause HCC when liver cirrhosis (LC) is present, can also lead to HCC without LC. On the basis of the relative frequency, HCC can be roughly differentiated into 3 groups: 1) HCC, rarely occurring without cirrhosis (e.g. virus hepatitis, alcohol abuse). 2) HCC, frequently occurring without LC (alpha1-antitrypsin deficiency, hemochromatosis, non-alcoholic fatty liver disease). 3) HCC, consistently occurring without LC (glycogen storage disease type 1, consumption of oral contraceptives/anabolic steroids). In groups 1 and 2 the level of hepatocellular toxicity necessary to reach LC is not yet achieved but the carcinogenic effect is already strong enough to induce HCC, possibly owing to the influence of additional carcinogens or host factors. In group 3, the carcinogenic effect is mediated by a long-standing alteration of the hepatocellular metabolism that is of low toxic effect and does not lead to cell death, but is nevertheless carcinogenic. In these cases, the initial formation of hepatocellular adenomas that subsequently transform into HCC is a common finding (adenoma-carcinoma sequence).

Changes in gene expression and assessment of DNA methylation in primary human hepatocytes and HepG2 cells exposed to the environmental contaminants-Hexabromocyclododecane and 17-beta oestradiol

We evaluated the effects of two putative non-genotoxic hepatic carcinogens, hexabromocyclododecane (HBCD) and 17-beta oestradiol (E(2)) on global and CpG promoter DNA methylation in both primary human hepatocytes and hepatocellular carcinoma (HepG2) cells. The mRNA gene expression levels of genes involved particularly in cell cycle were also evaluated and potential correlation with DNA methylation status examined. HBCD at 0.03 and 0.3 ng/mL did not produce statistically significant differences in global genomic methylation. However, E(2) (0.1 ng/mL) significantly lowered global DNA methylation levels in HepG2 cells by approximately 65% (P<0.01). In primary hepatocytes, the promoter regions of N-cym and ERalpha were methylated in both control and treated groups, signifying lack of promoter demethylation by both HBCD and E(2). Furthermore, CpG promoter methylation of RB1 was observed in HepG2 cells but this was unaffected by treatments. The remaining genes (p16, C-myc, H-ras, THRalpha, histone H3, TBK1 and TNFRalpha) were unmethylated in their CpG promoter regions in both test systems. Quantitative RT-PCR showed that HBCD at 0.03 ng/mL up-regulated the expression of N-cym whereas E(2) up-regulated the expression of ERalpha and THRalpha genes in primary hepatocytes. In HepG2 cells, the mRNA gene expression levels of p16, RB1 and N-cym were significantly down regulated by HBCD (0.03 ng/mL) and E(2) (0.1 ng/mL) while HBCD at 0.3 ng/mL, significantly down regulated the expression levels of N-cym, ERalpha and ERbeta genes. Thus, while both HBCD and E(2) may alter the expression of certain genes involved in proliferation, the mechanisms appear unrelated to DNA methylation.

[A 104-week feeding study of genetically modified soybeans in F344 rats]

A chronic feeding study to evaluate the safety of genetically modified glyphosate-tolerant soybeans (GM soybeans) was conducted using F344 DuCrj rats. The rats were fed diet containing GM soybeans or Non-GM soybeans at the concentration of 30% in basal diet. Non-GM soybeans were a closely related strain to the GM soybeans. These two diets were adjusted to an identical nutrient level. In this study, the influence of GM soybeans in rats was compared with that of the Non-GM soybeans, and furthermore, to assess the effect of soybeans themselves, the groups of rats fed GM and Non-GM soybeans were compared with a group fed commercial diet (CE-2). General conditions were observed daily and body weight and food consumption were recorded. At the termination (104 weeks), animals were subjected to hematology, serum biochemistry, and pathological examinations. There were several differences in animal growth, food intake, organ weights and histological findings between the rats fed the GM and/or Non-GM soybeans and the rats fed CE-2. However, body weight and food intake were similar for the rats fed the GM and Non-GM soybeans. Gross necropsy findings, hematological and serum biochemical parameters, and organ weights showed no meaningful difference between rats fed the GM and Non-GM soybeans. In pathological observation, there was neither an increase in incidence nor any specific type of nonneoplastic or neoplastic lesions in the GM soybeans group in each sex. These results indicate that long-term intake of GM soybeans at the level of 30% in diet has no apparent adverse effect in rats.

Revelation of simple and complex liver acini after portal transplantation of pancreatic islets or thyroid follicles in rats

The microarchitecture of the liver is still not completely understood although various concepts of structural liver organization have been proposed. Among them, Rappaport's liver acinus stands out as one of the most accepted models. The correctness of this model, however, has also been doubted, and its applicability is hampered by the fact that the outlines of the liver acinus are disguised and nobody was ever able to give visual evidence by "unmasking" a simple liver acinus from the surrounding liver tissue. After intraportal transplantation of pancreatic islets or thyroid follicles into diabetic or thyroidectomized rats, respectively, the transplants engraft in small portal tracts and morphologically alter the downstream liver tissue due to excessive hormone secretion. Using a combined approach of perfusion fixation, stereomicroscopy, and light microscopy, we demonstrate in this study that these foci of altered liver tissue represent simple and complex liver acini, exactly as described by Rappaport. We present stereomicroscopical and histological examples of all important cut levels of altered simple and complex liver acini, including their topographical relation to the supplying and draining vessels and to the "central vein" liver lobule. Moreover, by computer-aided reconstruction of serial semi-thin sections, we were able to present the first 3-dimensional images of simple and complex liver acini.

CONCLUSION

Our results prove the correctness of Rappaport's acinus model and confirm the simple liver acinus as the principal microcirculatory unit of the liver.