Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experimental and clinical evidence indicates that estrogens have a relevant role in the pathogenesis of cancer of hormone-sensitive organs. Estrogen receptors (ERs) are present in liver cells. Normal liver expresses almost exclusively wild-type ERs derived from the full-length transcript of the gene. During progression of liver disease to hepatocellular carcinoma, variant forms of ERs have been demonstrated that greatly influence the course of the disease and the possibility of palliative treatment. Peritumoral cirrhotic tissue of patients with hepatocellular carcinoma, especially males, expresses a variant form of ER (vER) with an exon 5 deletion. In hepatocellular carcinoma, vER largely predominates and sometimes becomes the only form expressed. That the occurrence of vER alone is limited almost exclusively to males suggests that it could be one of the molecular events that eventually lead to the preferential development of hepatocellular carcinoma in males. In addition, the presence of vER appears most frequently in patients infected with the hepatitis B virus. The growth rate of hepatocellular carcinoma in patients with vER is also significantly higher than that in patients with tumors expressing wtER.
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PMID:Hepatocellular carcinoma: role of estrogen receptors in the liver. 1209 26

Phytoestrogens are plant substances that are similar to 17-beta-estradiol and produce estrogenic effects. A protective role in the development of breast and prostate cancer has been hypothesized. Estrogen receptors and their variant forms play a significant role in the pathogenesis of hepatocellular carcinoma (HCC); therefore weak estrogenic substances in the diet may play a role in its development. To investigate the role of phytoestrogens in HCC an investigation of dietary intake of these substances has been performed. Cases, patients at first diagnosis of cirrhosis or HCC were chosen. Questionnaire was built up using indications from previously published papers, extending the registration of details of the diet to reconstruct intake of nutrients for the last year. Interviews were always performed by the same dietician. Quantities determined with the help of photos of servings. Data were analyzed with Winfood database completed with data regarding content in phytoestrogens of food, beverages and seasonings. So far 92 cirrhotic patients and 32 HCCs have been interviewed. No significant difference was registered among the two groups regarding total caloric intake or single nutrients (lipids, carbohydrates, proteins). A significant lower intake of genistein was evidenced in patients at first diagnosis of HCC in comparison with cirrhotics; no significant difference was found in daidzein intake. Lignans intake was strictly related with wine intake; intake was significantly lower in cases only when wine was taken into account otherwise it was similar. Results can be summarized as follows: (1) there are no clear-cut differences (both qualitative or quantitative) between cirrhotics and HCC patients in the overall daily caloric intake while; (2) definite differences exist in the intake of some of the phytoestrogens (genistein, SEC, MAT); (3) differences between cases and controls in SEC and MAT are mainly attributable to lower alcohol intake in cases while; (4) significantly lower genistein intake in HCC only seems due to personal preferences of patients. In conclusion, these differences that we have evidenced in the diet in regard to estrogen-like substances may be relevant in modulating the risk of developing HCC in cirrhotic patients.
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PMID:Phytoestrogens and liver disease. 1216 Oct 5

The potential for temperature to influence estrogen-mediated responses in poikilothermic animals suggested that temperature may be an important variable to consider when using an estrogen-responsive reporter gene in a rainbow trout cell line to test chemicals for estrogenic activity. Rainbow trout hepatoma cells (RTH 149) incubated at 11 or 18 degrees C were cotransfected with an estrogen-responsive luciferase reporter plasmid and a plasmid containing a constitutively expressed rainbow trout estrogen receptor. The RTH-149 cells were then exposed to estradiol, with samples collected at 24-h intervals. The 72-h effective concentration for 50% maximal response (EC50) for estrogen-responsive luciferase activity at 11 degrees C was 3.8 x 10(-9) M and 7.4 x 10(-10) M at 18 degrees C. The efficacy of estradiol was lower at 11 degrees C. The maximal response to estradiol in cells at 11 degrees C was generally two- to threefold greater than controls (mean = 2.6-fold), whereas the maximal response at 18 degrees C was three- to fourfold greater than controls (mean = 3.2-fold). Ethinylestradiol, a strong estrogen receptor agonist, was similar to estradiol in potency (relative potency = 0.8) and efficacy at the two temperatures. The EC50 of the weak estrogen receptor agonist 4-tert-pentylphenol was 7.6 x 10(-7) M at 11 degrees C and 6.9 x 10(-7) M at 18 degrees C; its potency relative to 17beta-estradiol was not significantly different at the two temperatures, 0.00036 and 0.00054 at 11 degrees C and 18 degrees C, respectively. The estrogen-responsive reporter gene activity produced by 10(-8) M estradiol was completely inhibited by the two estrogen hormone receptor antagonists, ZM 189,154 and ICI 182,780, at 10(-6) M concentration of either antagonist. Although there may be slight differences in responses between the two temperatures tested here, this assay can be used to effectively determine the relative estrogenic activity of chemicals within the physiological temperature range of rainbow trout.
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PMID:Induction of an estrogen-responsive reporter gene in rainbow trout hepatoma cells (RTH 149) at 11 or 18 degrees C. 1268 23

Hepatocellular carcinoma (HCC) is more prevalent in men than in women. Estrogen may play some role in the development of HCC. We conducted a multicenter case-control study to evaluate the effects of reproductive factors on HCC risk, and to assess whether the association between each factor and HCC differs between hepatitis B surface antigen (HBsAg)-positive and -negative women, in which hepatitis C virus (HCV) is the major cause of HCC. The study included 218 women with HCC and 729 control women selected from nonbiological and first-degree female relatives of patients with HCC. The risk of HCC was inversely related to the number of full-term pregnancies (FTP) (P(trend) =.0216) and age at natural menopause (P(trend) =.0251 among women aged 45-55 without prior surgical menopause). Oophorectomy at age <or=50 during premenopausal years was also a risk factor (multivariate-adjusted OR, 2.57; 95% CI, 1.42-4.63). Use of hormone replacement therapy (HRT) (multivariate-adjusted OR, 0.46; 95% CI, 0.27-0.79) was associated with a lower risk of HCC, and there was a trend in the risk with increasing duration of HRT (P(trend) = 0.0013). All reproductive factors had a similar impact on HBsAg-positive and -negative women except for an early menarche (<or=12 vs. >or=16 years), which increased HCC risk in HBsAg carriers (multivariate-adjusted OR, 6.96; 95% CI, 2.52-19.18) but posed no increased risk in noncarriers (P(interaction) =.0053). In conclusion, increased exposure to estrogen during adulthood may provide a protective effect against HCC. Nevertheless, an early menarche, which results in early estrogen exposure, does not confer protection for HBsAg carriers.
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PMID:Role of reproductive factors in hepatocellular carcinoma: Impact on hepatitis B- and C-related risk. 1464 50

Suppressors of cytokine signaling (SOCS) are important negative regulators of cytokine action. We recently reported that estrogen stimulates SOCS-2 expression and inhibits GH signaling in kidney cells. The effects of estrogen on SOCS expression in other tissues are unclear. The aim of this study was to investigate in vivo and in vitro whether estrogen affected SOCS expression in the liver, a major target organ of GH. The in vivo hepatic effects of estrogen on ovariectomized mice lacking estrogen receptor (ER)-alpha, ERbeta, or both and their wild-type littermates were examined by DNA microarray analysis. In vitro, the effects of estrogen on SOCS expression in human hepatoma cells were examined by reverse transcription quantitative PCR. Long-term (3 wk) estrogen treatment induced a 2- to 3-fold increase in hepatic expression of SOCS-2 and -3 in wild-type and ERbeta knockout mice but not in those lacking ERalpha or both ER subtypes. Short-term treatment (at 24 h) increased the mRNA level of SOCS-3 but not SOCS-2. In cultured hepatoma cells, estrogen increased SOCS-2 and -3 mRNA levels by 2-fold in a time- and dose-dependent manner (P < 0.05). Estrogen induced murine SOCS-3 promoter activity by 2-fold (P < 0.05) in constructs containing a region between nucleotides -1862 and -855. Moreover, estrogen and GH had additive effects on the SOCS-3 promoter activity. In summary, estrogen, via ERalpha, up-regulated hepatic expression of SOCS-2 and -3, probably through transcriptional activation. This indicates a novel mechanism of estrogen regulation of cytokine action.
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PMID:Estrogen up-regulates hepatic expression of suppressors of cytokine signaling-2 and -3 in vivo and in vitro. 1531 56

Estrogen has been related to the development of hepatocellular carcinoma (HCC). In this molecular epidemiological study, we used logistic regression to compare the genotype frequencies of estrogen-metabolizing genes that are involved in estrogen biogenesis (CYP17), hydroxylation (CYP1A1) and inactivation of the reactive metabolites (catechol-O-methyltransferase, COMT) in HCC patients and control subjects, and determined their relationship with the risk of female HCC. The heterozygous or homozygous variants of high activity CYP17 (A2), high inducibility CYP1A1(m1), and low activity COMT (L) alleles were considered as high-risk genotypes. We found that the risk of HCC was elevated in women harboring either heterozygous or homozygous variants of the CYP1A1 gene and the respective OR (and 95% confidence interval) were 6.61 (1.35, 32.43) and 12.00 (1.73, 83.46). Moreover, we found that the risk of HCC was increased in the female subjects harboring higher numbers of high-risk genotypes, but not in male subjects. The OR for female HCC associated with two putative high-risk genotypes was 12.63 (1.50, 106.37), and the OR for three putative high-risk genotypes was 16.67 (1.82, 152.77). These findings strongly suggest that estrogen play a critical role in female hepatocarcinogenesis.
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PMID:Polymorphisms of estrogen-metabolizing genes and risk of hepatocellular carcinoma in Taiwan females. 1534 Oct 23

Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the cognate elements.
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PMID:Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor. 1571 31

Hepatocellular carcinoma (HCC), the major manifestation of primary liver cancer, is one of the most frequent and malignant cancers worldwide, especially in Taiwan. Estrogen receptors (ERs) have been reported to play either a proliferation- or apoptosis-enhancing role in the differentiation of cancers, including HCC. In a previous experiment, we showed that transient overexpressed estrogen receptor-alpha induced early stage HCC cell line Hep 3B cell apoptosis by increasing the hTNF-alpha gene expression in a ligand-independent manner. To further clarify if the apoptotic effect occurs in poorly differentiated HCC cell line, HA22T, and elucidate the roles of ERs and TNF-alpha, DNA fragmentation and caspase activity were measured in late stage HCC cell line, HA22T, by measuring the expression of hER-alpha and hER-beta using a Tetracycline-inducible system (Tet-on). Increased DNA fragmentation and caspase-3 activity were found in hERbeta-overexpressed HA22T cells treated with estrogen (10(-8) M) but not in hERalpha-overexpressed HA22T cells. Using RT-PCR/PCR and western blotting in HA22T cells, overexpressed hER-beta was also found to increase the expression of hTNF-alpha mRNA and induce hTNF-alpha-dependent luciferase activity in a ligand-dependent manner. Additionally, LPS treatment and hER-beta overexpression both enhance caspase-8 activities, whereas neither hER-beta nor E2 treatment affected caspase-9 activities. In addition, the overexpressed hER-beta plus E2 enhanced DNA fragmentation and caspase-8 activities were only partially reduced by anti-hTNF-alpha (0.1 ng/ml), which was possibly due to the involvement of P53 and TGF-beta. Taken together, our data indicates that overexpressed hER-beta but not hER-alpha may induce caspase-8-mediated apoptosis by increasing the hTNF-alpha gene expression in a ligand-dependent manner in poorly differentiated HA22T cells.
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PMID:Opposing action of estrogen receptors alpha and beta on tumor necrosis factor-alpha gene expression and caspase-8-mediated apoptotic effects in HA22T cells. 1663 37

Hepatitis B virus (HBV) X protein (HBx) is considered to play a role in the development of hepatocellular carcinoma (HCC) during HBV infection. HCC was shown to be more prevalent in men than in women. Estrogen, which exerts its biological function through estrogen receptor (ER), can inhibit HBV replication. ERDelta5, an ERalpha variant lacking exon 5, was found to be preferentially expressed in patients with HCC compared with patients with normal livers. Here, we report the biological role of ERDelta5 and a novel link between HBx and ERalpha signaling in hepatoma cells. ERDelta5 interacts with ERalpha in vitro and in vivo and functions as a dominant negative receptor. Both ERalpha and ERDelta5 associate with HBx. HBx decreases ERalpha-dependent transcriptional activity, and HBx and ERDelta5 have additive effect on suppression of ERalpha transactivation. The HBx deletion mutant that lacks the ERalpha-binding site abolishes the HBx repression of ERalpha. HBx, ERalpha and histone deacetylase 1 (HDAC1) form a ternary complex. Trichostatin A, a specific inhibitor of HDAC enzyme, can restore the transcriptional activity of ERalpha inhibited by HBx. Our data suggest that HBx and ERDelta5 may play a negative role in ERalpha signaling and that ERalpha agonists may be developed for HCC therapy.
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PMID:Hepatitis B virus X protein and the estrogen receptor variant lacking exon 5 inhibit estrogen receptor signaling in hepatoma cells. 1675 75

Hepatocellular carcinoma is the fifth most common malignant neoplasm worldwide. Most patients are not candidates to surgical treatment. The prognosis of this neoplasm is poor, with an overall survival rate of 8 weeks in unresectable tumors. Estrogen receptors have been found in up to 33% of this tumors, reason why treatment with tamoxifen or progesterone compounds have been tried to diminish this neoplasm's progression but its use remains controversial. In our institution, thirteen patients were treated with tamoxifen (20- 40 mg/day) and 26 received supportive measures only. The clinical and tumoral characteristics were similar in both groups. Survival in the Tamoxifen group was of 5.5 +/- 1.7 months while in the supportive measures group was of 2.1 +/- 0.5 months (p = 0.018). Other factors related to an increased survival were: female gender and the Okuda score; age, TNM and alphaFP were not related to survival. The multivariate analysis showed that treatment with tamoxifen duplicates survival independently of the tumoral stage and functional hepatic reserve. It seems that the benefit of treatment with tamoxifen is limited and is not associated to the presence of estrogen receptors. In our study a 69 year-old man with diagnosis of non-resectable hepatocellular carcinoma and negative estrogen receptors, was treated with tamoxifen with a partial response and an overall survival of 4 years until November 2005. Despite some case reports that have shown tumoral regression, while other studies do not report any survival benefits. It is important to identify patients that would benefit from treatment with tamoxifen.
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PMID:Response of negative estrogen-receptor hepatocarcinoma to tamoxifen, and survival of non-resectable patients. 1715 78


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