Active uptake of testosterone by androgen receptors of hepatocellular carcinoma in humans

EASL Clinical Practice Guidelines on nutrition in chronic liver disease

A frequent complication in liver cirrhosis is malnutrition, which is associated with the progression of liver failure, and with a higher rate of complications including infections, hepatic encephalopathy and ascites. In recent years, the rising prevalence of obesity has led to an increase in the number of cirrhosis cases related to non-alcoholic steatohepatitis. Malnutrition, obesity and sarcopenic obesity may worsen the prognosis of patients with liver cirrhosis and lower their survival. Nutritional monitoring and intervention is therefore crucial in chronic liver disease. These Clinical Practice Guidelines review the present knowledge in the field of nutrition in chronic liver disease and promote further research on this topic. Screening, assessment and principles of nutritional management are examined, with recommendations provided in specific settings such as hepatic encephalopathy, cirrhotic patients with bone disease, patients undergoing liver surgery or transplantation and critically ill cirrhotic patients.

The androgen receptor as an emerging target in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the male-dominant liver diseases with poor prognosis, although treatments for HCC have been progressing in the past decades. Androgen receptor (AR) is a member of the nuclear receptor superfamily. Previous studies reported that AR was expressed in human HCC and non-HCC tissues. AR is activated both ligand-dependently and ligand-independently. The latter is associated with a mitogen-activated protein kinase–, v-akt murine thymoma viral oncogene homolog 1–, or signal-transducer and activator of transcription–signaling pathway, which has been implicated in the development of HCC. It has been reported that more than 200 RNA expression levels are altered by androgen treatment. In the liver, androgen-responsive genes are cytochrome P450s, transforming growth factor β, vascular endothelial growth factor, and glucose-regulated protein 78 kDa, which are also associated with human hepatocarcinogenesis. Recent studies also revealed that AR plays a role in cell migration and metastasis. It is possible that cross-talk among AR-signaling, endoplasmic reticulum stress, and innate immune response is important for human hepatocarcinogenesis and HCC development. This review shows that AR could play a potential role in human HCC and represent one of the important target molecules for the treatment of HCC.

The expression of estrogen receptors in hepatocellular carcinoma in Korean patients

Expression of estrogen receptors (ER)-alpha and -beta, as well as androgen receptor (AR), in hepatocellular carcinoma (HCC) is thought to be correlated with prognosis, survival, and male prevalence of HCC. These hypotheses are based on investigations of European patients; however the expression patterns of these receptors in Asian patients are largely unknown. In this study, we collected liver carcinoma and peritumor tissues from 32 patients (9 females and 23 males) in South Korea. The expression of ERs and ARs was studied using RT-PCR. Wild-type ER-alpha and AR were expressed in all of the samples investigated, and their expression was independent of the causal virus or patient sex. Expression of the ER-alpha variant was independent of sex (100% female vs. 91.3% male) and HCV and HBV status (91.3% vs. 100%). Wild-type ER-beta was expressed more often in HCV patients than in HBV patients (95.7% vs. 44.4%; p < 0.05). In conclusion, the stronger ER-alpha variant expression in HCC tissues implies that this variant has an important role in HCC development. However, at least in Korean patients, expression of the ER-alpha variant (vER-alpha) is not related to male HCC prevalence. In addition, the predominant expression of ER-beta in HCV patients suggests that it plays an important role in HCV-induced liver disease.

Methylation of neutral endopeptidase 24.11 promoter in rat hepatocellular carcinoma

Neutral endopeptidase 24.11 (NEP), a cell-surface enzyme expressed by epithelial cells that cleaves and inactivates biologically active small peptides, is downregulated in various cancers. NEP is encoded by a gene that contains a CpG island in the promoter region, whose hypermethylation appears related to decreased expression. Altered expression of NEP has also been reported in human hepatocellular carcinoma (HCC), suggesting its possible role in hepatocarcinogenesis. To elucidate the status of NEP in HCC, methylation in the promoter region of the gene that encodes NEP in male Fischer 344 rats with HCC, induced by a choline-deficient, l-amino acid-defined diet, was investigated by methylation-specific polymerase chain reaction, combined bisulfite restriction analysis, and bisulfite genomic sequencing. These analyses together showed the promoter to be frequently methylated in HCC in contrast to its unmethylated status in normal liver, the degree of methylation being inversely related to the level of mRNA expression evaluated by reverse transcription-polymerase chain reaction (P = 0.031). In two rat liver cell lines, RLC-16 and RLC-27, the promoter was heavily methylated and NEP mRNA expression was negative. However, administration of 5-aza-2'-deoxycytidine caused NEP expression, suggesting that methylation of CpG is a factor regulating transcriptional expression. Together with the data from microarray analyses performed previously using the same animal model, the current results suggest that reduced expression of NEP or other ectopeptidases could impact on molecules involved in signal-transducing systems, including G-protein coupled receptors, via modified turnover of extracellularly active small peptides.

COX-2 - a target for preventing hepatic carcinoma?

Hepatocellular carcinoma (HCC) is one of the most common reasons for malignancy-related death in Africa and Asia and is still recognised as the leading cancer in men in Taiwan. Despite enthusiastic efforts in early diagnosis, aggressive surgical treatment and application of additional nonoperative modalities, its prognosis is still dismal. This emphasises the necessity to develop new measures and strategies for its prevention. Inducible cyclooxygenease 2 (COX-2) is an immediate-early (IE) response gene and extensive studies conducted over the past few years have recognised its overexpression in several carcinomas and thus its implication in carcinogenesis. Recent studies have suggested that overexpression of COX-2 might be one of the leading factors in hepatic carcinogenesis. COX-2 can induce angiogenesis via vascular endothelial growth factor (VEGF) and prostaglandin production and can also inhibit apoptosis by inducing the antiapoptotic factor Bcl-2 as well as activating antiapoptotic signalling through Akt/PKB. Therefore, the use of selective inhibitors for the downregulation of COX-2 activity might be a target for preventing hepatic carcinoma development.

Hepatocellular carcinoma in primary biliary cirrhosis: similar incidence to that in hepatitis C virus-related cirrhosis

OBJECTIVES

The prevalence of hepatocellular carcinoma (HCC) in primary biliary cirrhosis (PBC) is not well established, as some reports suggest a low risk, whereas others indicate that HCC may be no less frequent than in other types of cirrhosis.

METHODS

We compared the incidence of HCC in a series of 140 patients with PBC (five men, 135 women, mean age 54 +/- 1.6 yr) followed-up for a mean of period of 5.6 +/- 0.4 yr with a group of patients with cirrhosis related to hepatitis C virus (HCV) who were matched for age, sex, and follow-up period. In all patients, HCC was prospectively screened by clinical, laboratory, and ultrasound procedures.

RESULTS

Five patients with PBC (3.6%) developed HCC. All were in stage IV of the disease. The incidence of HCC in the 45 patients with late stages of the disease (III or IV) was 11.1%, similar to that found in patients with HCV-related cirrhosis, which was 15.0%. The relative risk for HCC in late stages of PBC was of 0.812 (95% CI, 0.229-2.883) with respect to HCV-related cirrhosis. The probability for developing HCC was significantly higher in patients with HCV-related cirrhosis than in PBC patients overall (p = 0.001), but was similar in patients with HCV-related cirrhosis and in patients with PBC in stages III and IV (p = ns).

CONCLUSION

The risk for HCC in patients with late stages of PBC is similar to that in patients with HCV-related cirrhosis.

Sex and androgenic steroid receptor expression in hepatic adenomas

Sex hormones and anabolic-androgenic steroids are implicated in the development and progression of hepatic adenomas (HA). We studied the expression of their receptors in HA and adjacent liver. Archival tissue sections of 27 HA (16 resections, four needle biopsies, seven aspirations) from 18 patients, and the adjacent liver, were immunostained with monoclonal antibody to estrogen receptor (ER, 1/80) (Dako, Carpinteria, CA), progesterone receptor (PR, 1/50) (BioGenex, San Ramon, CA), and androgen receptor (AR, 1/80) (BioGenex). An avidin-biotin complex technique was used with microwave antigen retrieval. Nuclear expression was assessed as 1+ to 3+ intensity, with semiquantitation of the percentage of nuclei immunopositive. Five percent or more nuclei immunopositive was regarded as positive. The 18 patients included 16 females of 34 years mean age (range, 16 to 49) with an available history of oral contraceptives in five; the two men were 24 and 30 years, with no history of androgenic steroids. ER, PR, and AR were present in seven (26%) (1+/-2+ intensity, 5% to 10% of nuclei) of HA, seven (26%) (1+/-2+ intensity, 5% to 30% of nuclei) and nine (33%) (1+/-3+ intensity, 5% to 80% of nuclei), respectively. In the adjacent liver in 11 cases, there were one (9%) ER, (2+ intensity, 5% of nuclei), four (36%) PR (1+/-2+ intensity, 5% to 20% of nuclei), and two (18%) AR (2+/-3+ intensity, 10% of nuclei). Receptors are present and may mediate the action of sex hormones or androgenic steroids on HA and adjacent liver, but in less than one third of patients. This may have therapeutic implications.

Effects of testosterone suppression on serum levels of hepatitis B surface antigen and HBV-DNA in men

AIMS/BACKGROUND

There is epidemiological evidence that progression of hepatitis B virus (HBV)-induced liver disease is adversely influenced by male gender. Furthermore, in male transgenic mice, HBsAg levels increase after puberty, resulting in 4- to 10-fold higher HBsAg levels than in female transgenic mice. Castration reduces HBsAg levels by 90-95%, while substitution of testosterone to castrated animals rapidly increases HBsAg concentrations. We hypothesized that suppression of endogenous testosterone levels may have similar effects on HBsAg serum levels in men, as observed in male mice.

METHODS

To test our hypothesis, we studied the influence of reversible testosterone suppression by the LHRH-analog triptorelin on serum concentrations of HBsAg and HBV-DNA. Eight male patients, who were chronically infected with HBV, were studied in a prospective interventional study.

RESULTS

Triptorelin decreased serum testosterone levels to castration levels for several weeks. However, this reversible testosterone suppression had no effect on HBsAg or HBV-DNA serum concentrations (p > 0.05).

CONCLUSIONS

Suppression of endogenous testosterone levels had no effect on HBsAg levels in men, which points to a different regulation of HBsAg expression in men compared with transgenic mice.

Endocrine treatment of hepatocellular carcinoma. Any evidence of benefit?

In the past 20 years, a number of studies have investigated the relationship between sex hormones and liver cancer. Experimental studies indicate that a dynamic process, with sequential modifications in the pattern of sex hormones in the serum and of sex hormone receptors in the liver, occurs progressively during hepatocarcinogenesis. Overall, it seems that both androgens and oestrogens may enhance liver carcinogenesis, while androgens may also support the growth of established liver tumours. Unfortunately, clinical studies of endocrine treatment of hepatocellular carcinoma (HCC) have not adequately tested the suggestions from biological studies. So far, no clinical trial has been performed to test the efficacy of endocrine manipulation for the chemoprevention of HCC in cirrhotic patients nor in preventing relapse after radical resection of primary HCC. Anti-oestrogens have been the most studied agents for the endocrine treatment of established HCC, although the rationale that supports their use is weaker than for anti-androgens. Studies with anti-androgens have produced prevalently negative results, due to either a lack of activity or excessive toxicity. The use of chemical castration, which theoretically could enhance the activity of antihormonal compounds, yielded no benefit at all. In summary, there is, as yet, no definitive evidence that endocrine treatment favourably affects the outcome of patients with HCC.

Better survival in female patients with hepatocellular carcinoma. Possible causes from a pathologic approach

BACKGROUND

Hepatocellular carcinoma is notably more prevalent in men than in women.

METHODS

To examine the sex-related characteristics of patients with primary hepatocellular carcinoma, 35 women were compared with 243 men, both groups having undergone surgical resection of the tumor.

RESULTS

Women had a lower incidence of tumor recurrence, with median disease free survival of 19.5 months compared with 4.5 months for men (P < 0.001). Women also had more favorable actuarial survival than men [36.5 months for women compared with 12.4 months for men (P = 0.002)]. Women had a significantly higher incidence (80%) of tumor encapsulation than men (45%) (P < 0.001). Furthermore, the tumors in women were frequently less invasive in terms of lower incidence of tumor microsatellites, liver invasion, and positive histologic margin. Tumor microsatellite formation was present with 16% of tumors in women, compared with 60% for men (P < 0.0001). Liver invasion was found in 37% of tumors in women and 61% in men (P = 0.03). Only 6% of tumors in women had a positive histologic margin, compared to 24% in men (P = 0.04). There was no statistical significance in the incidence of cirrhosis in the nontumorous liver, hepatitis B surface antigen positivity, mean age, or tumor size, between women and men.

CONCLUSIONS

Women who had hepatocellular carcinoma and hepatic resection had better survival rates and a lower rate of tumor recurrence than male patients. The better prognosis in women with hepatocellular carcinoma appeared to be related to the pathobiologic characteristics of the tumor (i.e., frequent encapsulation and lower tumor invasiveness).

Detection of human androgen receptor mRNA in hepatocellular carcinoma by in situ hybridisation

Recent evidence suggests that anti-androgen therapy may be useful in patients with androgen receptor (AR)-positive hepatocellular carcinomas (HCC), as determined by a steroid binding assay. To evaluate the AR expression of HCC, in both histological and cytological material, we developed a non-radioisotopic in situ hybridisation (NISH) assay specific for the human AR mRNA. A synthetic oligonucleotide complementary to positions 661-695 of the human AR coding sequence was end-labelled with digoxigenin-dUTP and revealed by an alkaline phosphatase-conjugated anti-digoxigenin antibody. We analysed 22 formalin-fixed, paraffin-embedded HCC, obtained at surgery, together with the corresponding non-neoplastic liver tissues (19 cases). In six cases, cell blocks obtained by fine-needle aspiration (FNA) prior to surgery were also available. Positive controls included seminal vesicles and prostate tissues. Sixteen HCCs (73%) expressed a variable amount of AR mRNA, with the proportion of positive cells ranging from very few to more than 90%. Normal hepatocytes were stained weakly and focally in eight cases (42%). Appropriate controls, inclusive of immunohistochemical detection of the AR protein in selected cases, established the specificity of the assay. Data obtained on FNA specimens were predictive of the results on histologic material. However, in two cases the NISH assay was negative on the cytological specimen but stained rare hepatocytes within the surgically resected tumor. In conclusion, NISH is a novel procedure for rapid and specific assessment of the expression of AR in HCC tissue. Its clinical significance, in terms of predictivity of response to anti-androgen treatment, needs to be assessed in large correlative studies.

Aromatase activity in human hepatocellular carcinoma. Relationship with the degree of histologic differentiation

Human hepatocellular carcinomas (HCC) were examined aromatase activity, an enzyme that converts androgen into estrogen. Such activity was detected in all 13 specimens of HCC (mean activity, 120 fmol/30 min/mg microsomal protein). The activity tended to be lower in the HCC tissue than in the surrounding liver tissue (mean activity, 230 fmol/30 min/mg microsomal protein), although it was higher in the HCC tissue from three of eight patients with Edmondson's Grade 2 disease. This relationship was not found in the five with Grade 3 disease. On the whole, aromatase activity was significantly higher in specimens from patients with Edmondson's Grade 2 tumors than in the less differentiated Grade 3 type (P < 0.05). These observations suggested that aromatase activity was present in human HCC and was related to the degree of histologic differentiation.

Hepatitis B virus infection and primary hepatocellular carcinoma

For many years, epidemiological studies have demonstrated a strong link between chronic hepatitis B virus (HBV) infection and the development of primary hepatocellular carcinoma (PHC). Other hepatocarcinogens such as hepatitis C virus and aflatoxin also contribute to hepatocarcinogenesis either in conjunction with HBV infection or alone. Cellular and molecular biological studies are providing explanations for the HBV-PHC relationship, and models are now being formulated to further test the relative importance of various factors such as viral DNA integration, activation of oncogenes, genetic instability, loss of tumor suppressor genes, and trans-activating properties of HBV to the pathogenesis of PHC. Further research will probably define more than a single mechanism whereby chronic HBV infection results in PHC.

Evidence of sex difference in DNA synthesis in hepatocellular carcinoma

To clarify sex differences in DNA synthesis in hepatocellular carcinoma (HCC), bromodeoxyuridine labeling indices (BrdU LI) of HCC cells included in tumor biopsy specimens from 12 consecutive male patients and from 5 consecutive female patients all with liver cirrhosis and HCC were examined using an in vitro labeling technique. The mean BrdU LI +/- SE of HCC from male patients (7.7 +/- 0.8%) was significantly (P less than 0.05) higher than that from female patients (4.4 +/- 1.0%). While 7 of the 12 male HCC patients belonged to the high DNA synthesis group (BrdU LI greater than or equal to 7.0%), none of the 5 female HCC patients showed high DNA synthesis (P less than 0.05). We conclude that DNA synthesis in HCC was higher in males than in females.

Androgen receptor in hepatocellular carcinoma as a prognostic factor after hepatic resection

Androgen receptors (AR) in the cytosol of hepatocellular carcinoma (HCC) were assayed in 45 unselected patients in whom radical hepatic resection was performed. Thirty-one patients had detectable amounts of ARs in tumors, ranging from 2.3 to 82.6 fmol/mg protein with the dissociation constants (Kd) of 4.1 - 30.9 x 10(-10) M. The receptor was not found in the remaining 14 cases. AR negative HCCs were significantly more common among women and nonalcoholic patients. Otherwise, there were no significant difference in the clinicopathologic background between patients with AR positive HCCs and those with AR negative tumors. Three patients died of liver failure in the former group, whereas two died in the latter; one patient died of liver failure and the other died of pneumonia (results were not statistically significant). Excluding those five operative deaths, the recurrence rates were 67.9% in the group of patients with AR positive HCCs and 33.3% in the group of patients with AR negative tumors (0.1 less than p less than 0.05). The 5-year survival rate was significantly better (p less than 0.05) in patients with AR negative HCCs (62.2%) than in those with the positive tumors (17.3%). In light of the current results and previous experimental works by others, it is likely that testosterones enhance the growth and invasiveness of human HCC, which is mediated by AR in the tumor.

Androgen and estrogen receptors in hepatocellular carcinoma and the surrounding liver in women

Androgen receptors (AR) and estrogen receptors (ER) were consecutively assayed for hepatocellular carcinoma (HCC) and the surrounding liver was removed surgically from 19 female patients. Patient age ranged from 43 to 79 years, with an average of 61 +/- 9 years. All patients had underlying liver disease (liver cirrhosis in 16, liver fibrosis in two, and chronic hepatitis in one). Seven (37%) of 19 HCC had AR ranging from 2.3 to 82.6 fmol/mg of cytosol protein. The AR titer was higher in the HCC than in the liver in these cases. Three cases also had ER. ER existed in seven (37%) tumors (range, 2.4 to 25.6 fmol/mg of protein). AR and ER were detected in 11 (65%) and ten (58%) of 17 nonneoplastic liver tissues, respectively. Serum alpha-fetoprotein (AFP) level, hepatitis B virus markers, or histopathologic types of HCC had no correlation with the presence or absence of AR or ER and their titers. Also, there was no correlation between the AR and ER positivities. Further studies are mandatory to determine the genuine role of sex hormone receptors in the development and growth of HCC in humans.

Response to cyproterone acetate treatment in primary hepatocellular carcinoma is related to fall in free 5 alpha-dihydrotestosterone

The male preponderance in cirrhotic patients with primary hepatocellular carcinoma (HCC) and the presence of androgen receptors in tumour tissue suggest possible benefit from anti-androgenic therapy. Twenty-five cirrhotic patients with irresectable HCC (23 male) were treated with cyproterone acetate (CPA) 300 mg daily. Hepatic ultrasound, alpha-fetoprotein and total and free sex steroid levels were monitored. Five patients had an objective response to therapy with a median duration of 8 weeks and survival in excess of 29 weeks. Median survival for all patients was 14 weeks. Apart from transient paranoia in two cases, side-effects were minimal. Total androgen levels (measured in 13 patients) had fallen significantly at 10 weeks, but free 5 alpha-dihydrotestosterone (DHT) which had fallen by 4.8 pM (median) in five responders, had risen by 5.05 pM in eight non-responders: P less than 0.025. The apparent correlation of response with reduction in free DHT suggests that hormonal manipulation may be effective in HCC if free DHT is reliably reduced. This has been achieved in other conditions by the combination of CPA with low dose oestrogen or with LHRH agonists.

Estrogen receptors and androgen receptors in the mammalian liver

An estrogen receptor and an androgen receptor are present in the mammalian liver. In the liver of the rat, the estrogen receptor concentration increases markedly at puberty and this change correlates with enhanced estrogen stimulation of plasma renin substrate synthesis. High doses of estrogen are required for nuclear binding in liver when compared to doses for the uterus. The high dose requirement appears to be predominantly due to extensive metabolism in the hepatocyte of the estrogen to inactive derivatives. Furthermore, estradiol is much weaker than ethinyl estradiol for promoting nuclear binding in the liver. This is due to extremely rapid and extensive metabolism of estradiol. In human liver the concentration of estrogen receptor is low. An androgen receptor is present in high concentration in rabbit liver and is located predominantly in the nucleus after androgen administration. High concentrations of a putative androgen receptor are also present in human liver cytosol. Preliminary studies indicate that synthetic progestins can attach to the human liver androgen receptor. To date, a progesterone receptor has not been found in the mammalian liver. Thus, it appears that extensive steroid metabolism in liver preferentially diminishes sex steroid interaction with liver receptors and that androgen receptors may mediate progestin effects in liver. These observations provide a scientific basis for improved safety of oral contraceptives. Lowering the estrogen and progestin doses in oral contraceptives will decrease the major side-effects, which are liver mediated, and still maintain the desired effects at the hypothalamic-pituitary axis and uterus. Furthermore, it is likely that by selecting which estrogen, progestin or androgen is administered as well as by utilizing a parenteral route of administration that sex steroid effects on the liver could be minimized.