Growth factors, endocrine aspects and hormonal treatment in hepatocellular carcinoma--an overview

Medical Treatment of Hepatocellular Carcinoma: Any Progress?

Background

Hepatocellular carcinoma (HCC) remains one of the most common neoplasms worldwide. Curative treatment options include liver transplantation or resection. Unfortunately, most patients still have unresectable or untransplantable HCC due to disease extension or comorbid factors and are therefore candidate only for palliative treatments.

Methods

In this review we have analyzed the different medical approaches employed in the treatment of HCC in an attempt to better define their roles.

Results

Palliative medical treatments including systemic chemotherapy, immunotherapy or hormonal manipulation rarely influence survival of the patients. Although a high response rate is often reported with new local therapies such as transcatheter arterial embolization, intraarterial chemotherapy or percutaneous ethanol injection, the real impact of these treatment modalities on patient survival remains to be determined.

Conclusion

One way to improve the diagnosis of HCC patients would be an appropriate approach to evaluate new drugs or treatment modalities. To answer all the open questions, further trials, possibly randomized, should be conducted on a substantial number of patients with homogeneous prognostic factors.

Megestrol Acetate in Unresectable Hepatocellular Carcinoma

Aims and background

No consolidated medical treatment has yet been established for unresectable hepatocellular carcinoma (HCC). A possible interference of hormones in the pathogenesis and cellular growth of HCC has been suggested.

Methods

To evaluate the activity and tolerance of progestins in HCC, patients were treated with megestrol acetate orally at a dose of 160 mg daily until progression of disease or grade III-IV toxicity was observed.

Results

Eleven patients entered the study and were assessable for response and side effects. Median duration of treatment was 80 days (range 60-150). No major responses were observed, 4 patients had stabilization of disease for at least 2 months, and 7 had progressive disease. Median time to disease progression was 3 months (range 2-5). Three patients required interruption of treatment because of toxicity (2 patients had worsening of concomitant diabetes and 1 patient had gastric bleeding).

Conclusions

The results of the present study suggest that hormone therapy with megestrol acetate has no significant role in HCC.

Effect of trenbolone acetate plus estradiol on transcriptional regulation of metabolism pathways in bovine liver

The use of anabolic steroids is forbidden for food producing animals in the EU. Owing to the advantages of anabolics for production profitability, illegal application is appealing. Anabolics are known to influence gene expression of several tissues. We focused on the liver because of its important role in nutrient and hormone metabolism. The aim of the present study was to find differentially regulated metabolic pathways, which might be used as treatment biomarkers.

A total of 18 Nguni heifers were allocated equally to a control group and a treatment group and were implanted with Revalor H. Expression of 34 target genes was measured using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR).

Upregulation of androgen receptor and insulin-like growth factor 1 (IGF-1) and downregulation of IGF-2, insulin-like growth factor binding protein 2, steroid hormone binding globulin, insulin receptor α, insulin receptor β, tyrosine aminotransferase, 17β-hydroxy steroid dehydrogenase 2,3-hydroxy-methylglutaryl-coenzym-A-synthase, cathepsin B, hepatocyte growth factor, steroidogenic acute regulatory protein, apolipoprotein 2 and tumor necrosis factor α was demonstrated.

Several biochemical pathways showed different regulations on mRNA level under the influence of trenbolone acetate plus estradiol. The inhibition of nutrient metabolism and protein breakdown seems to support growth processes. IGF-1 plays an important role in growth and development and thus the upregulation of IGF-1 could be responsible for the stimulation of growth in treated animals. The upregulation of IGF-1 could also be revealed as a possible risk factor for the generation of artherosclerotic plaques, which are known as long-term side effects following the use of anabolic steroids. Principal components analysis of RT-qPCR results showed that both groups arrange together and can be clearly separated. Therefore, these might be used as possible biomarkers in bovine liver.

Modification of mRNA expression after treatment with anabolic agents and the usefulness for gene expression-biomarkers

With this feasibility study a first step towards a new monitoring system for hormonal treatments was done. Screening of regulation and function of anabolic sex steroids via modified gene expression of mRNA in various tissues could be a new approach to trace treatments with unknown drugs or newly combined cocktails. In the study, uterus, liver and muscle tissue from 24 cycling heifers were taken after the animals were treated either with Melengestrol Acetate (MGA), Finaplix-H (200 mg Trenbolone Acetate) or Ralgro (36 mg Zeranol) for 56 days. In every treatment group always two heifers were given 1-fold, 3-fold and 10-fold doses of the standard preparation, the control group without any treatment consisted of two animals. The different tissue gene expression profiles were investigated via the candidate gene approach. Totally 57 candidate genes were selected according to their functionality by screening the actual literature and composed to functional groups: angiogenesis, apoptosis, cell cycle, endocrine factors, energy metabolism, inflammatory factors, muscle function, oncogenes, protein metabolism and transcription factors. Gene expression was measured using quantitative real-time RT-PCR (qRT-PCR) technology. From 24 tested candidate genes in the liver, 17 showed a significant regulation. Eight genes were influenced by MGA, 9 by Finaplix-H, and 4 by Ralgro. For the muscle tissue 19 genes were tested with the result that in the neck muscle 11 genes were regulated and in the hind limb muscle 8 genes. In the neck 5 genes were affected by MGA, 6 by Finaplix-H and 3 by Ralgro. Only 2 genes were influenced by MGA in the hind limb muscle. Finaplix-H affected 6 and Ralgro 4 genes. In the uterus 29 target genes were tested and 13 were significantly influenced by the anabolic sex steroids. Under Finaplix-H treatment eight target genes were regulated and Ralgro and MGA showed a significant regulation in four target genes. The highest gene expression changes under anabolic treatment were observed in the uterus. The analyzed genes showed significant regulations but further studies, testing different animal husbandry conditions will be needed to identify meaningful expression patterns for the different tissues. With the investigation of the regulation and possible function of anabolic sex steroids via gene expression, a preparatory work for the development of an expression pattern for drug screening was made.

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.

Sexual functioning in patients with hepatocellular carcinoma

BACKGROUND

The objectives of the current study were to assess the rates of sexual dysfunction in patients with hepatocellular carcinoma (HCC) and compare the rates of sexual morbidity with a sample of patients diagnosed with chronic liver disease (CLD) and the general population. It was expected that patients diagnosed with HCC would have a greater prevalence of sexual dysfunction than those diagnosed with CLD and the general population, respectively. Furthermore, those patients who reported a sexual dysfunction would also have a poorer quality of life (QOL).

METHODS

Twenty-one men diagnosed with HCC and 23 men diagnosed with CLD completed a battery of questionnaires that included the Sexual History Questionnaire and the Functional Assessment of Cancer Therapy-Hepatobiliary.

RESULTS

Results indicated that 41% of patients reported a current sexual problem (29% of HCC patients and 71% of patients with CLD) and 43% met the Diagnostic and Statistical Manual of Mental Disorders-4th edition (DSM-IV) criteria for at least 1 type of sexual dysfunction (25% of patients with HCC and 75% of patients with LD). Of the total sample, 68% reported being diagnosed with a comorbid medical condition or taking a medication that had potential sexual side effects. After eliminating cases with comorbid medical conditions and/or who were taking medications that contributed to sexual morbidity, the rate of sexual problems were found to be similar to that of the general population. Clinically significant differences were found with regard to the QOL. People who were experiencing sexual problems also reported a poorer QOL.

CONCLUSIONS

Although a large percentage of sexual dysfunction may have been secondary to comorbid medical problems and medications, treatment of the sexual dysfunction is still warranted.

Testosterone responsiveness of spleen and liver in female lymphotoxin β receptor-deficient mice resistant to blood-stage malaria

Disrupted signaling through lymphotoxin beta receptor (LTbetaR) results in severe defects of the spleen and even loss of all other secondary lymphoid tissues, making mice susceptible to diverse infectious agents. Surprisingly, however, we find that female LTbetaR-deficient mice are even more resistant to blood stages of Plasmodium chabaudi malaria than wild-type C57BL/6 mice. Higher resistance of LTbetaR-deficient mice correlates with an earlier onset of reticulocytosis, and the period of anemia is shorter. After surviving fulminant parasitemias of about 35%, mice develop long-lasting protective immunity against homologous rechallenge, with both spleen and liver acting as anti-malaria effectors. Testosterone suppresses resistance, i.e. all mice succumb to infections during or shortly after peak parasitemia. At peak parasitemia, testosterone does not essentially affect cellularity and apoptosis in the spleen, but aggravates liver pathology in terms of increased cell swelling, numbers of apoptotic and binucleated cells and reduced serum alkaline phosphatase levels, and conversely, reduces inflammatory lymphocytic infiltrates in the liver. In the spleen, hybridization of cDNA arrays identified only a few testosterone-induced changes in gene expression, in particular upregulation of INFgamma and IFN-regulated genes. By contrast, a much larger number of testosterone-affectable genes was observed in the liver, including genes involved in regulation of the extracellular matrix, in chemokine and cytokine signaling, and in cell cycle control. Collectively, our data suggest that testosterone dysregulates the inflammatory response in spleen and liver during their differentiation to anti-malaria effectors in malaria-resistant female LTbetaR-deficient mice, thus contributing to the testosterone-induced lethal outcome of malaria.

Epidemiology and carcinogenesis of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) shows marked variation worldwide but the magnitude of this tumor is reflected by the occurrence of at least 1 million new cases annually and the uniformly dismal outlook with median survivals of <25 months after resection and <6 months with symptomatic treatment. The strikingly uneven distribution of this tumor parallels the prevalence of hepatitis B infection with rising incidence in western countries attributed to hepatitis C infection. Chronic hepatitis and cirrhosis constitute the major preneoplastic conditions in the majority of HCCs and may be related to other etiologic agents such as environmental chemical carcinogens including nitrites, hydrocarbons, solvents, organochlorine pesticides, and the chemicals in processed foods, cleaning agents, cosmetics and pharmaceuticals, as well as plant toxins such as anatoxins produced by fungi that cause spoilage of grain and food in the tropics. Genetic diseases such as genetic hematochromatosis, Wilson's disease, alpha-1-antitrypsin deficiency, and the inborn errors of metabolism including hereditary tyrosinemia and hepatic porphyria, are known to be associated with HCC. Numerous genetic alterations and the modulation of DNA methylation are recognized in HCC and it is likely that these genetic and epigenetic changes combine with factors involved in chronic hepatocyte destruction and regeneration to result in neoplastic growth and multiple molecular pathways may be involved in the production of subsets of hepatocellular tumors.

In situ hybridization assay of androgen receptor gene in hepatocarcinogenesis

AIM: To determine the correlation between expression of androgen receptor (AR) gene and hepatocarcinogenesis.

METHODS: Male SD rats were used as experimental animals and the animal model of experimental hepatocarcinoma was established by means of 3’-me-DAB administration. Androgen receptor mRNA was detected by a non-radioactive in situ hybridization assay in neoplastic and non-neoplastic liver tissues.

RESULTS: The expression of androgen receptor mRNA was observed only in neoplasticcells and some atypical hyperplastic cells. In the liver tissue of control animal and the remaining normal liver cells adjacent to the carcinoma tissue, no positive signal was seen.

CONCLUSION: Androgen has an important correlation with hepatocarcinogenesis and the expression of androgen receptor gene might be a mark event during hepatocarcinogenesis.

Practical considerations in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents one of the most common neoplasms worldwide. To date, curative treatment options include liver transplantation or resection. Unfortunately, most patients are detected with nonresectable or -transplantable HCC due to disease extension or comorbid factors, and are therefore candidates only for palliative treatments. Palliative medical treatments, including systemic chemotherapy, immunotherapy or hormonal manipulation, have a borderline activity on HCC and cannot be recommended outside clinical trials. A high response rate has been reported with local therapies such as transcatheter arterial embolisation, intra-arterial chemotherapy or percutaneous alcohol (ethanol) injection, but as there is no clear evidence of a survival advantage for these treatment modalities, further investigations are required. Multidisciplinary treatment, including preoperative cytoreduction or postoperative adjuvant therapy, is currently under investigation, with encouraging survival results. HCC patients should be evaluated within clinical trials, possibly randomised and with homogeneous prognostic factors, in order that we may find the answer to all these important questions.

Phase II study of megestrol acetate in the treatment of hepatocellular carcinoma

This is a report of a phase II study of megestrol acetate (160 mg/day, orally) in the treatment of hepatocellular carcinoma (HCC). Forty-six patients with advanced HCC were studied and tumour response, changes in appetite, bodyweight, a feeling of well-being, survival and toxicity were evaluated. Thirty-two patients were able to be evaluated for response; there were no complete responders or partial responders. Twelve patients (38%) had stable disease and seven of these patients had a minor response with a median size reduction in the tumour of 18%. Twenty patients (62%) had progressive disease. Five of 24 (21%) patients had a median reduction in alpha-fetoprotein levels of 59 ng/mL. The overall median survival was 4 months (range 1 week to 27 months). Twenty of 32 (62%) patients had an increased appetite and feeling of well-being. Fourteen of 22 (64%) patients had a median lean bodyweight gain of 5 kg (range 1-14 kg). Toxicities were minimal. Tests for glucocorticoid receptors were performed in 10 patients. Four of five patients who were positive for glucocorticoid receptors in the tumour had a stable disease and all five patients who were negative for glucocorticoid receptors had progressive disease. Megestrol acetate had no significant effect on the tumour in HCC patients. However, megestrol acetate is useful in the palliative management of HCC patients, with improvements in appetite, bodyweight and a feeling of well-being with minimal side effects. Some patients had stable disease, a minor reduction of tumour size and a prolonged survival after megestrol acetate treatment and this response may be related to the presence of glucocorticoid receptors in the HCC tumour.

Inhibition of zinc-induced metallothionein mRNA accumulation by gonadotropin-releasing hormone in human hepatocarcinoma cell line HepG2

Recently we have demonstrated that the human hepatocellular carcinoma-derived cell lines, HepG2 and HuH7, contain gonadotropin-releasing hormone (gonadoliberin) receptors and respond to various molecular forms of gonadoliberin in terms of suppressed proliferation in vitro. This study provides the first demonstration that gonadoliberin inhibits the zinc-induced production of metallothionein mRNA in HepG2 and HuH7 cells. Administration of gonadoliberin agonist (gonadoliberin-A) inhibited the Zn-induced metallothionein mRNA level in a time-related and dose-related manner. The effect of gonadoliberin-A was found to be specific, because concomitant treatment with a gonadoliberin antagonist (gonadoliberin-ANT) blocked gonadoliberin-A inhibition of metallothionein mRNA accumulation. Furthermore, the gonadoliberin-A-induced inhibition of Zn-mediated metallothionein accumulation was found to correlate closely with suppresion of cell proliferation and [3H]thymidine uptake in these cells. It is known that the metal-binding protein metallothionein plays an important role in tumor cell pathobiology and resistance to chemotherapeutic drugs. The present findings may have important implications in the development of an effective chemotherapy for treatment of human liver cancer, in part, by improving the sensitivity of tumor cells through suppression of metallothionein production by gonadoliberin peptides.

Stress influence on development of hepatocellular tumors in transgenic mice overexpressing TGF alpha

We investigated whether stress increases tumorigenesis in male transgenic mice that overexpress the gene encoding human transforming growth factor alpha (TGF alpha). At the age of 10-15 months, these mice begin to develop spontaneous hepatocellular carcinomas at high incidence. The male TGF alpha mice were housed with their siblings (non-stressful environment), housed in social isolation, or housed with aggressive non-siblings (stressful environment). Some animals in each group were exposed once a week to a second stressor (swim stress), beginning at the age of 7 months. Housing with aggressive non-siblings increased neoplastic growth in the male TGF alpha mice: the incidence and multiplicity of liver tumors, and tumor burden were higher in these animals than in the sibling-housed mice. Among the isolated TGF alpha mice, only the tumor burden was increased, when compared with the sibling-housed TGF alpha mice. Swim stress significantly increased the incidence of liver tumors and tumor burden in the sibling-housed TGF alpha mice. Plasma levels of 17 beta-estradiol (E2) that are elevated in the TGF alpha mice, were modestly but significantly higher in the non-sibling housed transgenic mice than in the sibling-housed. Natural killer (NK) cell activity, reduced in these mice, was not affected by housing environment. These data suggest that stress promotes the growth of hepatocellular tumors in the male TGF alpha mice. Whether estrogens are involved in mediating this association remains to be determined.

Opposing behavioural alterations in male and female transgenic TGF alpha mice: association with tumour susceptibility

Psychosocial factors are thought to influence risk and survival from cancer. We have previously studied specific behaviours in transgenic male CD-1 MT42 mice, which overexpress the gene encoding human transforming growth factor alpha (TGF alpha) in multiple tissues, and which develop a high incidence of spontaneous hepatocellular carcinoma. The male TGF alpha mice spent a lengthened time immobile in the swim test, were highly aggressive, had increased plasma levels of 17 beta-estradiol (E2), and reduced natural killer (NK) cell activity. The female transgenic MT42 TGF alpha mice do not develop an increased rate of tumours at any site. We hypothesised that if the alterations in male TGF alpha mice are associated with their development of hepatocellular carcinomas, female TGF alpha should not show these alterations. The data in the present study indicate that female TGF alpha mice display shortened immobility in the swim test, suggesting an improved ability to cope with stress, and appear less aggressive in the resident-intruder test than non-transgenic female CD-1 mice. The female TGF alpha mice also exhibit a 3-fold increase in the plasma levels of E2, and a 3-fold increase in NK cell activity. These findings suggest that the elevated expression of TGF alpha in the transgenic mice is associated with gender-specific behavioural alterations, and the development of spontaneous hepatocellular tumours in the males. Furthermore, TGF alpha alters hormonal and immune parameters similarly in both sexes. It remains to be determined whether the development of hepatocarcinoma in the male TGF alpha animals is associated with an impaired ability to cope with stress and elevated aggressive tendencies and/or whether manipulations leading to an impaired ability to cope with stress will promote tumourigenesis in female TGF alpha mice.

Sex hormone receptors in hepatocellular carcinoma. Is there a rationale for hormonal treatment?

The present study assessed the tumor concentration of receptors for estrogens, progesterone and androgens in a series of Western patients with hepatocellular carcinoma. Receptors for estrogens and for progesterone were determined by enzyme immunoassay, while androgen receptors were determined by receptor binding assay. Receptors for progesterone were always absent. Estrogen receptors were detected in only 4 tumors, while in the remaining specimens estrogen receptor concentration was lower than 5 fmol/mg of protein. The concentration of receptors within the tumor was not related to the presence of receptor in the non-tumoral liver, which contained estrogen receptors in 12 cases, ranging between 5 and 27 fmol/mg of protein. In contrast, 14 of the 26 tumors contained androgen receptors at concentrations ranging between 2 and 211 fmol/mg of protein; these were not related to the characteristics of the underlying liver, which contained androgen receptors in 14 cases. The results suggest that the beneficial effects of tamoxifen on the survival of patients with hepatocellular carcinoma cannot be explained by the action of this drug on estrogen receptors and that anti-androgen therapy may have some benefit in patients with androgen-receptor-positive tumors.

Non-surgical treatment of hepatocarcinoma

Hepatocellular carcinoma (HCC) is one of the most common tumors affecting man. It is the general feeling that only hepatectomy can give a chance for cure. However, less than 20% of patients can be resected, and other treatment modalities are required. Systemic (chemotherapy, hormonotherapy, immunotherapy) and loco-regional (intratumoral injection of alcohol, intra-arterial chemotherapy embolization, internal radiotherapy) approaches have been developed. In view of the small number of patients, tumor and patient heterogeneity, and difficulties in assessing tumor response, the real place of these treatments is difficult to evaluate. A review of the literature suggests that embolization with Gelfoam, even when given without chemotherapy, has an effect on response rate and on survival, and could be considered, at the present time, as the most attractive treatment in non-operable HCC. Chemotherapy seems effective only if combined with embolization. When administered alone by the systemic or the intra-arterial hepatic route, no clinically significant activity can be found. Unexpectedly, Lipiodol by itself seems inactive, and the co-administration of chemotherapy does not improve activity. Other approaches such as intratumoral injection of alcohol, immunotherapy, hormonotherapy, and radioimmunotherapy are still experimental, and well-designed studies are needed to identify their role.

Alterations in behavior, steroid hormones and natural killer cell activity in male transgenic TGF alpha mice

The expression of transforming growth factor alpha (TGF alpha) is widely distributed throughout many normal and neoplastic tissues, but its physiological significance remains unclear. We have utilized male transgenic mice overexpressing the gene encoding human TGF alpha in multiple tissues to further identify those functions which are influenced by this protein. Male TGF alpha mice develop hepatocellular carcinoma at the age of 10-15 months. At the age of 2-3 months these mice, compared to age matched CD-1 controls, spent significantly longer times immobile in Porsolt's swim test, a model of stress and depressive behavior, and exhibiting aggressive behavior in the resident-intruder test. In contrast, the transgenic TGF alpha mice did not differ from the controls in either the plusmaze test of anxiety, or in their voluntary alcohol intake. Significantly, the TGF alpha mice exhibited a 25% lower Natural Killer (NK) cell activity and a four-fold increase in the plasma levels of 17-beta-estradiol (E2) than the controls. No significant changes in plasma testosterone or corticosterone levels were noted. The results indicate that transgenic male mice overexpressing TGF alpha exhibit behaviors characteristic of both an impaired ability to cope with stress and an increased aggressivity. The TGF alpha mice also show reduced NK cell activity and increased plasma estradiol concentrations. The present data suggest that TGF alpha may be important in influencing behavioral, immunological and hormonal systems prior to the onset of tumors. It remains to be determined whether hepatocarcinoma is associated with the direct proliferative and transforming effects of TGF alpha and/or indirect effects mediated through immune, hormonal and behavioral mechanisms.

Advances in neoplastic disease of the liver and biliary tract

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