Role of estrogen in hepatocellular carcinoma: is inflammation the key?

Recent advances in the molecular mechanism of sex disparity in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is more frequently observed and aggressive in men compared with women. Increasing evidence demonstrates that the sex disparity appears to be mediated by the stimulatory effects of androgens and the protective effects of estrogen in the development and progression of HCC. In the past few decades, studies on the sex difference of HCC mainly focused on the effect of sex hormones on the transactivation of hepatitis B virus X protein and the release of inflammatory cytokines, and these studies have further intensified in recent years. Sex hormones are also involved in genetic alterations and DNA damage repair in hepatocytes through binding to their specific cellular receptors and affecting the corresponding signaling pathways. Furthermore, the theory of sex chromosomes participating in HCC has been considered. The present review discussed the recent advances in the molecular mechanisms of sex disparity in HCC, with the aim of improving the understanding of the underlying critical factors and exploring more effective methods for the prevention and treatment of HCC.

Hormone Replacement Therapy in Cancer Survivors - Review of the Literature

Rapid advance in oncology leads to increasing survival of oncologic patients. More and more of them live long enough to reach either the natural age of menopause or, as a side effect of their oncotherapy, experience the cessation of gonadal function, leading to premature ovarian insufficiency, with disturbing vasomotor symtoms and long-term negative cardiovascular and skeletal effects. Thus, an ever increasing number of cancer survivors search endocrinologic help in the form of hormone replacement therapy (HRT). The misinterpretation of the WHI (Women's Health Initiative) Study has lead to an irrational fear of female hormone replacement, both by the general population and medical professionals. It has seemed the logical and safe conclusion to many physicians to avoid HRT, supposing that this attitude definitely causes no harm, whereas the decision of prescribing estrogen alone or with progestins might bear oncologic and thromboembolic risks and may even lead to litigation in case of a potentially related complication. However, it was known even before the WHI results that premature menopause and hypogonadism decreases the life expectancy of women by years through its skeletal and cardiovascular effects, and this negative effect correlates with the length of the hypoestrogenaemic period. Therefore, the denial of HRT also needs to be supported by evidence and should be weighed againts the risks of HRT. Yet, the oncologic risk of HRT is extremely difficult to assess. In this work we review the latest evidence from in vitro experiments to clinical studies, regarding HRT in survivors of gynecologic and non-gynecologic cancers. Based on our literature research, we group tumours regarding the oncologic risk of properly chosen female hormone replacement therapy in cancer survivors as follows: ’HRT is advanageous’ (e.g. endometrial cancer type I, cervical adenocarcinoma, haematologic malignancies, local cutaneous malignant melanoma, colorectal cancer, hepatocellular cancer); ’HRT is neutral’ (e.g. BRCA 1/2 mutation carriers without cancer, endometrial cancer type II, uterinal carcinosarcoma and adenosarcoma, certain types of ovarian cancer, cervical, vaginal and vulvar squamous cell carcinoma, prolactinoma, kidney cancer, pancreatic cancer, thyroid cancer); ’HRT is relatively contraindicated’ for various reasons (e.g. leiomyosarcoma, certain types of ovarian tumours, brain tumours, advanced metastatic malignant melanoma, lung cancer, gastric cancer, bladder cancer); ’HRT is diasadvantageous and thus contraindicated’ (e.g. breast cancer, endometrial stroma sarcoma, meningioma, glioma, hormone receptor positive gastric and bladder cancer).

PES1 enhances proliferation and tumorigenesis in hepatocellular carcinoma via the PI3K/AKT pathway

AIM

We investigated the potential role of pescadillo ribosomal biogenesis factor 1 (PES1) in the development of hepatocellular carcinoma (HCC).

MATERIAL AND METHODS

One hundred and thirty-four patients with hepatocellular carcinoma were chosen to evaluate the association between the expression of PES1 and survival, clinical characteristics of these patients. Western blotting, real-time PCR, immunohistochemistry, CCK-8 assay, colony formation and subcutaneous tumors in nude mice were conducted.

KEY FINDINGS

We found that PES1 was commonly upregulated in HCC tissues and cells. Immunohistochemical analysis of 134 paraffin-embedded archived HCC tissues showed that the protein expression level of PES1 was positively correlated with clinical characteristics and reduced the survival time of HCC patients. Univariate and multivariate analysis revealed that PES1 expression may be an independent prognostic indicator of poorer overall survival in HCC patients. Furthermore, silencing of endogenous PES1 significantly inhibited the proliferation and tumorigenicity of SMMC 7721 and HepG2 cells in vitro as well as in vivo in nude mice. Finally, we found that PES1 affected cell proliferation by regulating the PI3K/AKT/GSK3β/cyclinD1 signaling pathway.

SIGNIFICANCE

Our data suggest that PES1 may promote proliferation and tumorigenicity, and potentially representing a novel prognostic marker for overall survival in HCC.

CORE TIP

We report that pescadillo ribosomal biogenesis factor 1 (PES1) plays an oncogenic role in hepatocellular carcinoma, which was commonly upregulated in hepatocellular carcinoma tissues and cells. Immunostaining analysis found that the protein expression level of PES1 was positively correlated with clinical characteristics and reduced survival time of hepatocellular carcinoma patients. Multivariate analysis revealed that PES1 expression might be an independent prognostic indicator of survival in hepatocellular carcinoma patients. Furthermore, PES1 knockdown inhibited the proliferation and tumorigenesis in hepatocellular carcinoma cell lines. Additionally, we found that PES1 is involved in the cell proliferation by regulating the AKT/GSK3β/cyclinD1 signaling pathway.

Dietary intake of genistein suppresses hepatocellular carcinoma through AMPK-mediated apoptosis and anti-inflammation

Background

Women have a lower risk of hepatocellular carcinoma (HCC) than men, and the decreased possibility of HCC in women is thought to depend on estrogen levels. As a soybean-isoflavone product, genistein has estrogenic activity in various reproductive tissues, because it mimics 17β-estradiol and binds the estrogen receptor. Though genistein is a known liver cancer suppressor, its effects have not been studies in long-term experiment, where genistein is fed to a female animal model of HCC.

Methods

Mice were treated with diethylnitrosamine (DEN) to induce HCC at 2 weeks of age and fed with supplemental genistein for 5 months, from 40 to 62 weeks of age.

Results

The dietary intake of genistein decreased the incidence of HCC and suppressed HCC development. Genistein induced phospho-AMPK in total liver extracts, Hep3B cells, and Raw 264.7 cells, and phospho-AMPK promoted apoptosis in liver and Hep3B cells. Moreover, phospho-AMPK down-regulated pro-inflammatory responses and ameliorated liver damage. A suppressed pro-inflammatory response with increased mitochondrial respiration was concomitantly observed after genistein treatment.

Conclusions

Genistein-mediated AMPK activation increases hepatocyte apoptosis through energy-dependent caspase pathways, suppresses the inflammatory response in resident liver macrophages by increased cellular respiration, and consequently inhibits the initiation and progression of HCC.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5222-8) contains supplementary material, which is available to authorized users.

The association between methylation patterns of DNAH17 and clinicopathological factors in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is a malignancy with poor prognosis. Complex genetic and epigenetic alterations are the two primary causes of HCC. The aim of the study was mainly to explore the correlation between the methylation status of DNAH17 and HCC.

Methods

We evaluated the methylation levels of DNAH17 in 163 HCC samples and their paired normal tissue using Sequenom EpiTYPER assays and performed the TaqMan copy number assay to assess the copy number status of DNAH17 in HCC samples.

Results

The mean methylation levels were significantly decreased in the tumor tissues compared to the paired normal tissues in both selected regions of DNAH17 (amplicon 1:58.7% vs 84.5%, P < 0.0001; amplicon 2:69.9% vs 84.5%, P = 0.0060). Contrarily，both RNA‐seq and immunohistochemistry indicated the expression of DNAH17 was increased in tumor tissues (P < 0.05). DNMT inhibitor decitabine treatment could increase the expression of DNAH17 in HCC cell lines. DNAH17 gene amplification always companied with hypomethylation status. Moreover, hypomethylation status was associated with several clinical characteristics, such as male patients, higher AFP values, higher age of onset, fibrous capsules, tumor necrosis, liver cirrhosis, and tumor thrombus (P < 0.05). Receiver operator characteristic (ROC) curve analysis demonstrated the methylation levels of DNAH17 could efficiently predict the existence of the fibrous capsule (AUC = 0.695) and tumor thrombus (AUC = 0.806).

Conclusions

These findings suggested that aberrant methylation of DNAH17 was associated with comprehensive HCC clinicopathological factors and could be a promising biomarker for tumor thrombosis in HCC patients.

Tamoxifen mechanically deactivates hepatic stellate cells via the G protein-coupled estrogen receptor

Tamoxifen has been used for many years to target estrogen receptor signalling in breast cancer cells. Tamoxifen is also an agonist of the G protein-coupled estrogen receptor (GPER), a GPCR ubiquitously expressed in tissues that mediates the acute response to estrogens. Here we report that tamoxifen promotes mechanical quiescence in hepatic stellate cells (HSCs), stromal fibroblast-like cells whose activation triggers and perpetuates liver fibrosis in hepatocellular carcinomas. This mechanical deactivation is mediated by the GPER/RhoA/myosin axis and induces YAP deactivation. We report that tamoxifen decreases the levels of hypoxia-inducible factor-1 alpha (HIF-1α) and the synthesis of extracellular matrix proteins through a mechanical mechanism that involves actomyosin-dependent contractility and mechanosensing of tissue stiffness. Our results implicate GPER-mediated estrogen signalling in the mechanosensory-driven activation of HSCs and put forward estrogenic signalling as an option for mechanical reprogramming of myofibroblast-like cells in the tumour microenvironment. Tamoxifen, with half a century of safe clinical use, might lead this strategy of drug repositioning.

Aberrant expression of alternative isoforms of transcription factors in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide and the second leading cause of death among all cancer types. Deregulation of the networks of tissue-specific transcription factors (TFs) observed in HCC leads to profound changes in the hepatic transcriptional program that facilitates tumor progression. In addition, recent reports suggest that substantial aberrations in the production of TF isoforms occur in HCC. In vitro experiments have identified distinct isoform-specific regulatory functions and related biological effects of liver-specific TFs that are implicated in carcinogenesis, which may be relevant for tumor progression and clinical outcome. This study reviews available data on the expression of isoforms of liver-specific and ubiquitous TFs in the liver and HCC and their effects, including HNF4α, C/EBPs, p73 and TCF7L2, and indicates that assessment of the ratio of isoforms and targeting specific TF variants may be beneficial for the prognosis and treatment of HCC.

Estrogen Regulation of T-Cell Function and Its Impact on the Tumor Microenvironment

Epidemiologic studies demonstrate significant gender-specific differences in immune system function. Males are more prone to infection and malignancies, while females are more vulnerable to autoimmune diseases. These differences are thought to be due to the action of gonadal hormones: Estrogen increases the inflammatory response and testosterone dampens it. More specifically, estrogen stimulation induces inflammatory cytokine production including interferon γ, interleukin (IL) 6, and tumor necrosis factor α, while testosterone induces IL-10, IL-4, and transforming growth factor β. More recent studies demonstrate threshold effects of estrogen stimulation on immune cell function: physiologic doses of estrogen (approximately 0.5 nmol/L) stimulate inflammatory cytokine production, but superphysiologic dosages (above 50 nmol/L) can result in decreased inflammatory cytokine production. This review reports findings concerning the impact of estrogen on CD8+ cytotoxic T cells and the overall immune response in the tumor microenvironment. Variables examined include dosage of hormone, the diversity of immune cells involved, and the nature of the immune response in cancer. Collective review of these points may assist in future hypotheses and studies to determine sex-specific differences in immune responses that may be used as targets in disease prevention and treatment.

From the Cover: Genomic Effects of Androstenedione and Sex-Specific Liver Cancer Susceptibility in Mice

Current strategies for predicting carcinogenic mode of action for nongenotoxic chemicals are based on identification of early key events in toxicity pathways. The goal of this study was to evaluate short-term key event indicators resulting from exposure to androstenedione (A4), an androgen receptor agonist and known liver carcinogen in mice. Liver cancer is more prevalent in men compared with women, but androgen-related pathways underlying this sex difference have not been clearly identified. Short-term hepatic effects of A4 were compared with reference agonists of the estrogen receptor (ethinyl estradiol, EE) and glucocorticoid receptor (prednisone, PRED). Male B6C3F1 mice were exposed for 7 or 28 days to A4, EE, or PRED. EE increased and PRED suppressed hepatocyte proliferation, while A4 had no detectable effects. In a microarray analysis, EE and PRED altered >3000 and >670 genes, respectively, in a dose-dependent manner, whereas A4 did not significantly alter any genes. Gene expression was subsequently examined in archival liver samples from male and female B6C3F1 mice exposed to A4 for 90 days. A4 altered more genes in females than males and did not alter expression of genes linked to activation of the mitogenic xenobiotic receptors AhR, CAR, and PPARα in either sex. A gene expression biomarker was used to show that in female mice, the high dose of A4 activated the growth hormone-regulated transcription factor STAT5b, which controls sexually dimorphic gene expression in the liver. These findings suggest that A4 induces subtle age-related effects on STAT5b signaling that may contribute to the higher risk of liver cancer in males compared with females.

Estrogen Replacement Reduces Risk and Increases Survival Times of Women With Hepatocellular Carcinoma

BACKGROUND & AIMS

Environmental factors have been identified that affect risk of hepatocellular carcinoma (HCC), but little is known about the effects of sex hormones on liver cancer development or outcome. The authors investigated whether menopause hormone therapy (MHT) affects risk, age at onset, or outcome of HCC.

METHODS

We performed a case-control study of 234 female patients treated for HCC at a tertiary medical center and with 282 healthy women (controls) from January 1, 2004 through May 31, 2015. We collected detailed information on environmental exposures, ages of menarche and menopause, hysterectomies, and uses of birth control and MHT. We performed multivariable logistic and Cox regression analyses to determine the independent effects of factors associated with women on risk and clinical outcome in HCC. The primary outcomes were effect of MHT on HCC risk, the relationship between MHT with hepatitis virus infection on HCC development, and effect of MHT on age at HCC onset or survival after diagnosis of HCC.

RESULTS

The estimated adjusted odds ratio (AOR) for HCC in women who ever used estrogen was 0.53 (95% confidence interval [CI], 0.32-0.88). This association was supported by the older age of HCC onset among estrogen users (mean, 64.5 ± 0.9 years) vs nonusers (mean 59.2 ± 1.1 years; P = .001) and the reduced risk of HCC among long-term users (more than 5 years) (AOR, 0.36; 95% CI, 0.20-0.63). Users of estrogen also had a reduced risk for hepatitis-associated HCC: AOR for users, 4.37 (95% CI, 1.67-11.44) vs AOR for nonusers, 17.60 (95% CI, 3.88-79.83). Estrogen use reduced risk of death from HCC (hazard ratio, 0.55; 95% CI, 0.40-0.77; P = .01). Median overall survival times were 33.5 months for estrogen users (95% CI, 25.7-41.3 months) and 24.1 months for nonusers (95% CI, 19.02-29.30 months; P = .008).

CONCLUSION

In a case-control study of women with HCC vs female control subjects at a single center, we associated use of estrogen MHT with reduced risk of HCC and increased overall survival times of patients with HCC. Further studies are needed to determine the benefits of estrogen therapy for women and patients with HCC, and effects of tumor expression of estrogen receptor.

Merlin, the product of NF2 gene, is associated with aromatase expression and estrogen formation in human liver tissues and liver cancer cells

The product of neurofibromatosis type 2 (NF2) gene, also known as Merlin/neurofibromin 2, homeostatically regulates liver stem cells by controlling abundance and signaling of epidermal growth factor receptor (EGFR), with a mechanism independent of the Hippo pathway. We have reported that locally elevated estrogen formation, driven by abnormally high expression and function of aromatase, may be implicated in development and progression of human hepatocellular carcinoma (HCC) through activation of a rapid signaling pathway mediated by amphiregulin (AREG) and EGFR. We have recently presented a model by which the aromatase-estrogen-amphiregulin-EGFR axis is activated in response to tissue injury and/or inflammatory disease, with its alteration eventually leading to development of major human tumors (liver, breast, prostate) and other chronic diseases (diabetes, obesity, Alzheimer's and heart disease). In this study, we investigated NF2 expression in liver cancer cells and tissues in relation to aromatase expression/function, estrogen receptor (ER) status and amphiregulin. Our data indicate that NF2 expression is associated with aromatase and AREG expression, being elevated in HCC tissues and HepG2 cells, intermediate in cirrhotic tissues and Huh7 cells, and lower in nontumoral liver and HA22T cells. In addition, NF2 expression is inversely related to wild type hERα66 and proportional to the expression of the membrane-associated hERα36 splice variant, as measured by exon-specific RT-PCR analysis, both in vivo and in vitro. Furthermore, incubation with estradiol induced a significant decrease of NF2 expression in both HA22T and Huh7 cells (over 54% and 22%, respectively), while no change could be observed in HepG2 cells, this effect being inversely related to aromatase expression and activity in HCC cell lines. Based on the above combined evidence, we hypothesize that NF2 behaves as a protein sensing tissue damage and aromatase-driven local estrogen formation, eventually leading to regulation of stem cells differentiation and tissue repair.

Liver transplantation recipients with nonalcoholic steatohepatitis have lower risk hepatocellular carcinoma

Liver transplantation (LT) is a well-established treatment for hepatocellular carcinoma (HCC) in carefully selected patients. Risk factors for tumors with poor prognostic features on explant have not been well described in a national cohort. We performed a retrospective cohort study of adult LT recipients with HCC transplanted from April 8, 2012 (when explant pathology in United Network for Organ Sharing [UNOS] became available) until September 30, 2014. We evaluated the association between listing diagnosis and other demographic factors with tumor features on explant using logistic regression. High-risk tumor features included the following: > 3 tumors, largest tumor > 5 cm, presence of vascular invasion, presence of metastases, and poor differentiation of tumor. In total, 3733 LT recipients with HCC who had complete explant data in UNOS were included. The median age was 60 years; 78% were male; and 68% were white. Of the primary non-HCC listing diagnoses, 2608 (70%) had hepatitis C virus (HCV); 271 (7%) had nonalcoholic steatohepatitis (NASH); 246 (7%) had alcoholic cirrhosis; and 189 (5%) had hepatitis B virus. Also, 1140 (31%) had evidence of ≥ 1 high-risk explant feature(s). The presence of ≥ 1 high-risk explant feature(s) was associated with HCC recurrence after transplant (odds ratio [OR], 5.00; P < 0.001). Compared with HCV-associated HCC transplant recipients, individuals with NASH had lower likelihood of high-risk explant features (OR, 0.71; P = 0.02) after adjusting for covariables. Women were more likely to have high-risk explant features (OR, 1.23; P = 0.04). Diabetes mellitus (DM) was not associated with high-risk explant features. In conclusion, LT recipients with NASH-associated HCC had fewer high-risk tumor features on explant compared with HCV-associated HCC, despite having higher rates of DM and other potential risk factors for the development of HCC. Women had a higher likelihood of high-risk tumor features. Further study is warranted whether these differences are due to disease-specific or sex-specific influences on tumor biology or due to selection criteria for transplant. Liver Transplantation 23 1015-1022 2017 AASLD.

Association between complicated liver cirrhosis and the risk of hepatocellular carcinoma in Taiwan

Hepatic encephalopathy, ascites, and variceal bleeding are the three major complications of cirrhosis. It is well known that cirrhosis is the most important risk factor of hepatocellular carcinoma (HCC). However, little is known about whether the severity of liver cirrhosis has an effect on the incidence of HCC. This population-based cohort study aimed to explore the association between complicated cirrhosis and HCC, and identify the risk factors of HCC in patients with complicated cirrhosis. Data of the years 1997–2011 were extracted from the National Health Insurance Research Database of Taiwan. A total of 2568 patients with complicated cirrhosis without HCC at baseline were enrolled. After propensity score matching, another 2568 patients with non-complicated cirrhosis were included. Hazards Cox regression analysis by using a competing risk regression model to control for possible confounding factors was utilized to estimate the association of the complications of liver cirrhosis with the risk of HCC. We observed by using competing risk analysis that the adjusted hazard ratio (HR) for developing HCC during the follow-up period after the initial hospitalization was higher among the patients with baseline complicated cirrhosis than in those with uncomplicated cirrhosis (HR, 1.23; 95% confidence interval, CI, 1.10–1.37, p<0.001). Additionally, older patients (HR, 1.01; 95% CI, 1.01–1.02, p<0.001), males (HR, 0.84; 95% CI, 0.74–0.96, p = 0.009), and patients with alcohol-related cirrhosis (HR, 1.93; 95% CI, 1.65–2.26, p<0.001) had a statistically significant difference in the incidence of HCC. In conclusion, complicated liver cirrhosis is associated with a higher risk of HCC in Taiwan compared with cirrhosis without complications.

Disruption of Estrogen Receptor Alpha in Rats Results in Faster Initiation of Compensatory Regeneration Despite Higher Liver Injury After Carbon Tetrachloride Treatment

Estrogen receptor alpha (ESR1) is 1 of the 2 intracellular receptors for estrogen and is expressed by hepatocytes in the liver. The role of ESR1 in the regulation of toxicant-induced liver injury and compensatory regeneration is not completely clear. We investigated the role of ESR1 in liver regeneration after carbon tetrachloride (CCl₄)-induced liver injury using wild type (WT) and ESR1 knockout (ESR1-KO) rats. Adult female WT and ESR1-KO rats were treated with 1 mL/kg CCl₄ and euthanized over a time course of 0 to 48 hours. Liver injury measured by serum alanine amino transaminase, and histopathological analysis showed significantly higher liver injury in ESR1-KO as compared to WT rats. Hematoxylin and eosin staining revealed 2-fold higher necrosis and significant inflammatory cell infiltration in ESR1-KO rats. Chloracetate esterase staining revealed higher neutrophil infiltration in ESR1-KO rat livers. Interestingly, proliferating cell nuclear antigen immunohistochemistry showed that in spite of 2-fold higher liver injury, the ESR1-KO rats had equal liver regeneration as compared to WT rats. Western blot analysis of cyclin D1 and phosphorylated Rb, proteins involved in the initiation of the cell cycle, was significantly higher at all time points in ESR1-KO rats. Further analysis revealed faster activation of canonical Wnt/β-catenin and NF-κB signaling in ESR1-KO rats characterized by higher activated β-catenin and phosphorylated p65 at 12 hours after CCl₄ treatment. Taken together, these data indicate that ESR1-mediated signaling inhibits liver regeneration by downregulation of Wnt signaling resulting in lower cyclin D1 activation after chemical-induced liver injury.

Epidemiological trends of hormone-related cancers in Slovenia

The incidence of hormone-related cancers tends to be higher in the developed world than in other countries. In Slovenia, six hormone-related cancers (breast, ovarian, endometrial, prostate, testicular, and thyroid) account for a quarter of all cancers. Their incidence goes up each year, breast and prostate cancer in particular. The age at diagnosis is not decreasing for any of the analysed cancer types. The risk of breast cancer is higher in the western part of the country, but no differences in geographical distribution have been observed for other hormone-related cancers. Furthermore, areas polluted with endocrine-disrupting chemicals that affect hormone balance such as PCBs, dioxins, heavy metals, and pesticides, do not seem to involve a greater cancer risk. We know little about how many cancers can be associated with endocrine disruptors, as there are too few reliable exposure studies to support an association.

IL6-mediated inflammatory loop reprograms normal to epithelial-mesenchymal transition+ metastatic cancer stem cells in preneoplastic liver of transforming growth factor beta-deficient β2-spectrin+/- mice

Hepatocellular carcinoma (HCC) is the second-leading cause of cancer-related deaths worldwide with a poor survival rate. As many as 40% of HCCs are clonal, with alteration of key tumor-suppressor pathways in stem cells as the primary cause of HCC initiation. However, mechanisms that generate metastatic stem cells in preneoplastic liver tissue are not well understood. We hypothesized that chronic inflammation is a major driver of the transformation of genetically defective liver stem cells (LSCs) into highly metastatic liver cancer cells in premalignant liver tissue. We developed models of chronic inflammation in wild-type (WT) and β2-spectrin (β2SP)^+/- (SPTBN1) mice. CD133⁺ LSCs derived from preneoplastic livers of β2SP^+/- mice treated with interleukin-6 (pIL6; ^IL6 β2SP^+/- LSCs) were highly tumorigenic and metastatic, whereas those derived from WT mice treated with pIL6 (^IL6 WT LSCs) had significantly less proliferation and no tumorigenic properties. ^IL6 β2SP^+/- LSCs not only exhibited nuclear localization of Twist and Slug, markers of epithelial-mesenchymal transition (EMT), but also constitutive activation of nuclear factor kappa B (NFκB; RELA). Knockdown of NFκB decreased the EMT phenotypes and metastatic capacity of these cells. NFκB in ^IL6 β2SP^+/- LSCs was activated by transforming growth factor β (TGFβ)-activated kinase 1 (TAK1; MAP3K7), which is associated with poor survival in HCC and interleukin-6 (IL6) expression. The amount of constitutively activated NFκB increased dramatically from normal to cirrhotic to HCC tissues from human patients.

CONCLUSION

IL6-mediated inflammation programs constitutive activation of the TAK1-NFκB signaling cascade in CD133⁺ LSCs, and this program interacts with deficient TGFβ signaling, thereby accelerating the transformation of normal LSCs to metastatic cancer stem cells (mCSCs). Indeed, this study delineates the development of EMT-positive mCSCs in HCC-free liver tissue upon chronic inflammation. (Hepatology 2017;65:1222-1236).

Hepatocellular carcinoma (HCC): beyond sorafenib-chemotherapy

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with poor prognosis. The incidence of HCC and HCC-related deaths have increased over the last several decades. However, the treatment options for advanced HCC are very limited. Sorafenib remains the only drug approved for systemic treatment for advanced HCC. However, prior to sorafenib era conventional cytotoxic chemotherapies have been studied in advanced HCC. In this review, clinical studies of systemic chemotherapy for advanced HCC will be summarized and discussed.

Prognostic value of pre-treatment F-18-FDG PET-CT in patients with hepatocellular carcinoma undergoing radioembolization

AIM

To evaluate the value of pre-treatment 18F-FDG PET/CT in patients with HCC following liver radioembolization.

METHODS

We identified 34 patients with HCC who underwent an FDG PET/CT scan prior to hepatic radioembolization at our institution between 2009 and 2013. Patients were seen in clinic one month after radioembolization and then at 2-3 mo intervals. We assessed the influence of FDG tumor uptake on outcomes including local liver control (LLC), distant liver control (DLC), time to distant metastases (DM), progression free survival (PFS) and overall survival (OS).

RESULTS

The majority of patients were males (n = 25, 74%), and had Child Pugh Class A (n = 31, 91%), with a median age of 68 years (46-84 years). FDG-avid disease was found in 19 (56%) patients with SUVmax ranging from 3 to 20. Female patients were more likely to have an FDG-avid HCC (P = 0.02). Median follow up of patients following radioembolization was 12 months (1.2-62.8 mo). FDG-avid disease was associated with a decreased 1 year LLC, DLC, DM and PFS (P < 0.05). Using multivariate analysis, FDG avidity predicted for LLC, DLC, and PFS (all P < 0.05).

CONCLUSION

In this retrospective study, pre-treatment HCC FDG-avidity was found to be associated with worse LLC, DLC, and PFS following radioembolization. Larger studies are needed to validate our initial findings to assess the role of F-18-FDG PET/CT scans as biomarker for patients with HCC following radioembolization.

Alternative splicing of estrogen receptor alpha in hepatocellular carcinoma

BACKGROUND

The role of estrogen receptor alpha (ERa), estrogen receptor beta (ERb) and ERa36 signaling in hepatocellular carcinoma (HCC) is not fully addressed.

METHODS

In this study, three cohorts were included: (i) primary HCC patients (N = 76, cohort P), (ii) colorectal liver metastasis (mCRC) (N = 32, cohort S), and (iii) HCC from The Cancer Genome Atlas (TCGA) (N = 121). The levels of ERa36 and wtER36 were measured and their correlation with clinicopathologic features was determined.

RESULTS

WtERa was downregulated and that ERa36 was upregulated in tumor tissues in both cohort P and TCGA data set. ERa36 was downregulated in tumor tissues in cohort S. In cohort P, wtERa was differentially expressed in gender (P < 0.000), age (P = 0.004), tumor number (P = 0.043), tumor size (P = 0.002), intrahepatic recurrence (P = 0.054). ERa36 was unequally expressed in different non-tumor liver status (P = 0.040). WtERa was negatively associated with overall survival (OS) and disease free survival (DFS) in cohort P. Compared with non-tumor tissues, the expression of ERa36 was increased in primary HCC but decreased in secondary HCC, showing opposite expression patterns of ERa36 between primary HCC and secondary HCC.

CONCLUSIONS

Primary HCC is associated with the decreased WtERa but increased ERa36. The expression pattern of ERa36 is different between primary HCC and secondary HCC, as the former with the increased ERa36 but the latter with the decreased ERa36. Therefore, the expression of ERa36 may be used to differentiate the primary HCC and the secondary one.

Stat3 is a candidate epigenetic biomarker of perinatal Bisphenol A exposure associated with murine hepatic tumors with implications for human health

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) that has been implicated as a potential carcinogen and epigenotoxicant. We have previously reported dose-dependent incidence of hepatic tumors in 10-month-old isogenic mice perinatally exposed to BPA. Here, we evaluated DNA methylation at 3 candidate genes (Esr1, Il-6st, and Stat3) in liver tissue of BPA-exposed mice euthanized at 2 time points: post-natal day 22 (PND22; n = 147) or 10-months of age (n = 78, including n = 18 with hepatic tumors). Additionally, DNA methylation profiles were analyzed at human homologs of murine candidate genes in human fetal liver samples (n = 50) with known liver tissue BPA levels. Candidate genes were chosen based on reported expression changes in both rodent and human hepatocellular carcinoma (HCC). Regions for bisulfite sequencing were chosen by mining whole genome next generation sequencing methylation datasets of both mice and human liver samples with known perinatal BPA exposures. One of 3 candidate genes, Stat3, displayed dose-dependent DNA methylation changes in both 10-month mice with liver tumors as compared to those without liver tumors and 3-week sibling mice from the same exposure study, implicating Stat3 as a potential epigenetic biomarker of both early life BPA exposure and adult disease in mice. DNA methylation profiles within STAT3 varied with liver tissue BPA level in human fetal liver samples as well, suggesting STAT3 may be a translationally relevant candidate biomarker. These data implicate Stat3 as a potential early life biomarker of adult murine liver tumor risk following early BPA exposure with early evidence of relevance to human health.

Targeting Hepatocellular Carcinoma: What did we Discover so Far?

Hepatocellular carcinoma (HCC) is increasingly considered an issue of global importance. Its rates of incidence and mortality have been markedly increasing over the last decades. Among risk factors, some should be highlighted, namely the infections by hepatitis B and C virus, as well as clinical cases of cirrhosis. HCC is characterized as asymptomatic disease in the initial stages which most often leads to a late diagnosis. At molecular and genetic level HCC represents a highly complex tumor entity, including a wide variety of mutations, thus accounting for different mechanisms of resistance towards therapeutic approaches. In particular, mutations of the TP53 gene, as well as a deregulation between the expression of pro- and anti-apoptotic proteins of the BCL-2 family are observed. Regarding treatment modalities, surgical procedures offer the best chance of cure, however, due to a late diagnosis, most of concerned patients cannot be subjected to them. Chemotherapy and radiotherapy are also ineffective, and currently, the treatment with sorafenib is the most commonly used systemic therapy although it can only increase the patient survival for some months. In this sense, a quick and accurate investigation is of utmost importance in order to develop ways of early diagnosis as well as new therapies for HCC.

Reproductive factors, menopausal hormone therapies and primary liver cancer risk: a systematic review and dose-response meta-analysis of observational studies

BACKGROUND

A striking gender disparity in the incidence and outcome of primary liver cancer (PLC) has been well recognized. Mounting evidence from basic research suggests that hormonal factors may be involved in the gender disparity of PLC. Whether hormonal exposures in human subjects are associated with PLC risk is largely unknown.

OBJECTIVE AND RATIONALE

Whether reproductive factors and use of menopausal hormone therapies (MHTs) in women are associated with PLC risk remains controversial. We conducted this study to clarify this issue.

SEARCH METHODS

PubMed and EMBASE were searched to July, 2016 for studies published in English or Chinese. Observational studies (cohort, nested case-control and case-control) that provided risk estimates of reproductive factors, MHTs and PLC risk were eligible. The quality of included studies was determined based on the Newcastle-Ottawa quality assessment scale. Summary risk ratios (RRs) were calculated using a random-effects model. Dose-response analysis was conducted where possible.

OUTCOMES

Fifteen peer-reviewed studies, involving 1795 PLC cases and 2 256 686 women, were included. Overall meta-analyses on parity and PLC risk did not find any significant associations; however, when restricting to studies with PLC cases ≥100, increasing parity was found to be significantly associated with a decreased risk of PLC [RR for the highest versus lowest parity 0.67, 95% CI 0.52, 0.88; RR for parous versus nulliparous 0.71, 95% CI 0.53, 0.94; RR per one live birth increase 0.93, 95% CI 0.88, 0.99]. A J-shaped relationship between parity and PLC risk was identified (P_{non-linearity} < 0.01). Compared with never users, the pooled RRs of PLC were 0.60 (95% CI 0.37, 0.96) for ever users of MHT, 0.73 (95% CI 0.46, 1.17) for ever users of estrogen-only therapy (ET) and 0.67 (95% CI 0.45, 1.02) for ever users of estrogen-progestin therapy (EPT). The pooled RR of PLC for the oldest versus youngest category of menarcheal age was 0.50 (95% CI 0.32, 0.79). Oophorectomy was significantly associated with an increased risk of PLC (RR 2.23, 95% CI 1.46, 3.41). No significant association of age at first birth, and spontaneous or induced abortion with PLC risk was found. No meta-analysis was performed for the association of age at menopause, breastfeeding, hysterectomy, menopausal status and stillbirth with PLC risk owing to huge methodological heterogeneity and/or very limited studies.

WIDER IMPLICATIONS

Parity is associated with PLC risk in a J-shaped dose-response pattern. Late age at menarche and ever use of MHT are associated with a reduced risk of PLC, whereas there is no association of ever use of ET and EPT, age at first birth, or spontaneous and induced abortion with PLC risk. Compared to women with no history of oophorectomy, those with a history of oophorectomy are at an increased risk of PLC. Our findings provide some epidemiological support for a role of hormonal exposures in the development of PLC in women. However, these findings should be interpreted with much caution because of the limited number of studies and potential biases, and need to be validated by studies with good design and large sample size.

Diabetes mellitus and metformin in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Diabetes mellitus, a risk factor for cancer, is also globally endemic. The clinical link between these two diseases has been the subject of investigation for a century, and diabetes mellitus has been established as a risk factor for HCC. Accordingly, metformin, a first-line oral anti-diabetic, was first proposed as a candidate anti-cancer agent in 2005 in a cohort study in Scotland. Several subsequent large cohort studies and randomized controlled trials have not demonstrated significant efficacy for metformin in suppressing HCC incidence and mortality in diabetic patients; however, two recent randomized controlled trials have reported positive data for the tumor-preventive potential of metformin in non-diabetic subjects. The search for biological links between cancer and diabetes has revealed intracellular pathways that are shared by cancer and diabetes. The signal transduction mechanisms by which metformin suppresses carcinogenesis in cell lines or xenograft tissues and improves chemoresistance in cancer stem cells have also been elucidated. This review addresses the clinical and biological links between HCC and diabetes mellitus and the anti-cancer activity of metformin in clinical studies and basic experiments.

Epigenome-wide DNA methylation analysis implicates neuronal and inflammatory signaling pathways in adult murine hepatic tumorigenesis following perinatal exposure to bisphenol A

Developmental exposure to the endocrine-active compound bisphenol A (BPA) has been linked to epigenotoxic and potential carcinogenic effects in rodent liver, prostate, and mammary glands. A dose-dependent increase in hepatic tumors in 10-month mice perinatally exposed to one of three doses of BPA (50 ng, 50 µg, or 50 mg BPA/kg chow) was previously reported. These tumors represent early-onset disease and lack classical sexual dimorphism in incidence. Here, adult epigenome-wide liver DNA methylation profiles to identify gene promoters associated with perinatal BPA exposure and disease in 10-month mice with and without liver tumors were investigated. Mice with hepatic tumors showed 12,822 (1.8%) probes with differential methylation as compared with non-tumor animals, of which 8,656 (67.5%) were hypomethylated. A significant enrichment of differential methylation in Gene Ontology (GO) terms and biological processes related to morphogenesis and development, and epigenomic alteration were observed. Pathway enrichment revealed a predominance of hypermethylated neuronal signaling pathways linked to energy regulation and metabolic function, supporting metabolic consequences in the liver via BPA-induced disruption of neuronal signaling pathways. Hypothesis-driven pathway analysis revealed mouse and human genes linked to BPA exposure related to intracellular Jak/STAT and MAPK signaling pathways. Taken together, these findings are indicators of the relevance of the hepatic tumor phenotype seen in BPA-exposed mice to human health. This work demonstrated that epigenome-wide discovery experiments in animal models were effective tools for identification and understanding of paralagous epimutations salient to human disease. Environ. Mol. Mutagen. 57:435-446, 2016. © 2016 Wiley Periodicals, Inc.

Cytochrome P450 1A2 Metabolizes 17β-Estradiol to Suppress Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) occurs more frequently in men than in women. It is commonly agreed that estrogen plays important roles in suppressing HCC development, however, the underlying mechanism remains largely unknown. Since estrogen is mainly metabolized in liver and its metabolites affect cell proliferation, we sought to investigate if the liver-specific cytochrome P450 1A2 (CYP1A2) mediated the inhibitory effect of estrogen on HCC. In this study, the expression of estrogen-metabolizing enzyme CYP1A2 was determined in HCC tissues and cell lines. Cell proliferation and apoptosis were assessed in cells with or without CYP1A2 overexpression. The levels of 17β-estradiol (E2) and its metabolite 2-methoxyestradiol (2-ME) were determined. A xenograft tumor model in mice was established to confirm the findings. It was found that CYP1A2 expression was greatly repressed in HCC. E2 suppressed HCC cell proliferation and xenograft tumor development by inducing apoptosis. The inhibitory effect was significantly enhanced in cells with CYP1A2 overexpression, which effectively conversed E2 to the cytotoxic 2-ME. E2 in combination with sorafenib showed an additive effect on HCC. The anti-HCC effect of E2 was not associated with estrogen receptors ERα and ERβ as well as tumor suppressor P53 but enhanced by the approved anti-HCC drug sorafenib. In addition, HDAC inhibitors greatly induced CYP1A2 promoter activities in cancer cells, especially liver cancer cells, but not in non-tumorigenic cells. Collectively, CYP1A2 metabolizes E2 to generate the potent anti-tumor agent 2-ME in HCC. The reduction of CYP1A2 significantly disrupts this metabolic pathway, contributing the progression and growth of HCC and the gender disparity of this malignancy.

Association of Single Nucleotide Polymorphism rs1053004 in Signal Transducer and Activator of Transcription 3 (STAT3) with Susceptibility to Hepatocellular Carcinoma in Thai Patients with Chronic Hepatitis B

The single nucleotide polymorphism (SNP) rs1053004 in Signal transducer and activator of transcription 3 (STAT3) was recently reported to be associated with chronic hepatitis B (CHB)-related hepatocellular carcinoma (HCC) in a Chinese cohort. This study was aimed at investigating whether the SNP might also contribute to HCC susceptibility in the Thai population. Study subjects were enrolled and divided into 3 groups including CHB-related HCC (n=211), CHB without HCC (n=233) and healthy controls (n=206). The SNP was genotyped using allelic discrimination assays based on TaqMan real-time PCR. Data analysis revealed that the distribution of different genotypes was in Hardy-Weinberg equilibrium (P>0.05). The frequencies of allele T (major allele) in HCC patients, CHB patients and healthy controls were 51.4%, 58.6% and 61.4%, respectively, whereas the frequencies of C allele (minor allele) were 48.6%, 41.4% and 38.6%. The C allele frequency was higher in HCC when compared with CHB patients (odds ratio (OR)=1.34, 95% confidence interval (CI)=1.02-1.74, P=0.032). The genotype of SNP rs1053004 (CC versus TT+TC) was significantly associated with an increased risk when compared with CHB patients (OR=1.83, 95% CI=1.13-2.99, P=0.015). In addition, we observed a similar trend of association when comparing HCC patients with healthy controls (OR=1.77, 95% CI=1.07-2.93, P=0.025) and all controls (OR=1.81, 95% CI=1.19-2.74, P=0.005). These findings suggest that the SNP rs1053004 in STAT3 might contribute to HCC susceptibility and could be used as a genetic marker for HCC in the Thai population.

Long noncoding RNA FTX inhibits hepatocellular carcinoma proliferation and metastasis by binding MCM2 and miR-374a

It has long been known that males are more susceptible than females to hepatocellular carcinoma (HCC), but the reason remains elusive. In this study, we investigated the expression and function of the long noncoding RNA FTX (lnc-FTX), an X-inactive-specific transcript (XIST) regulator transcribed from the X chromosome inactivation center, in both HCC and HCC gender disparity. lnc-FTX is expressed at higher levels in female livers than in male livers and is significantly downregulated in HCC tissues compared with normal liver tissues. Patients with higher lnc-FTX expression exhibited longer survival, suggesting that lnc-FTX is a useful prognostic factor for HCC patients. lnc-FTX inhibits HCC cell growth and metastasis both in vitro and in vivo. Mechanistically, lnc-FTX represses Wnt/β-catenin signaling activity by competitively sponging miR-374a and inhibits HCC cell epithelial-mesenchymal transition and invasion. In addition, lnc-FTX binds to the DNA replication licensing factor MCM2, thereby impeding DNA replication and inhibiting proliferation in HCC cells. In conclusion, these findings suggest that lnc-FTX may act as a tumor suppressor in HCC through physically binding miR-374a and MCM2. It may also be one of the reasons for HCC gender disparity and may potentially contribute to HCC treatment.

Targeting Androgen Receptor (AR)→IL12A Signal Enhances Efficacy of Sorafenib plus NK Cells Immunotherapy to Better Suppress HCC Progression

Gender disparity has long been considered as a key to fully understand hepatocellular carcinoma (HCC) development. At the same time, immunotherapy related to IL12 still need more investigation before being applied in clinical settings. The aim of this study is to investigate the influence of the androgen receptor (AR) on natural killer (NK) cell-related innate immune surveillance in liver cancer, and provide a novel therapeutic approach to suppress HCC via altering IL12A. By using in vitro cell cytotoxicity test and in vivo liver orthotopic xenograft mouse model, we identified the role of AR in modulating NK cell cytotoxicity. Luciferase report assay and chromatin immunoprecipitation assay were applied for mechanism dissection. IHC was performed for sample staining. Our results showed AR could suppress IL12A expression at the transcriptional level via direct binding to the IL12A promoter region that resulted in repressing efficacy of NK cell cytotoxicity against HCC, and sorafenib treatment could enhance IL12A signals via suppressing AR signals. These results not only help to explain the AR roles in the gender disparity of HCC but also provide a potential new therapy to better suppress HCC via combining sorafenib with NK cell-related immunotherapy. Mol Cancer Ther; 15(4); 731-42. ©2016 AACR.

The Estrogen Receptors: An Overview from Different Perspectives

The estrogen receptors, ERα, ERβ, and GPER, mediate the effects of estrogenic compounds on their target tissues. Estrogen receptors are located in the tissues of the female reproductive tract and breast as one would expect, but also in tissues as diverse as bone, brain, liver, colon, skin, and salivary gland. The purpose of this discussion of the estrogen receptors is to provide a brief overview of the estrogen receptors and estrogen action from perspectives such as the historical, physiological, pharmacological, pathological, structural, and ligand perspectives.

Pesticide exposure and hepatocellular carcinoma risk: A case-control study using a geographic information system (GIS) to link SEER-Medicare and California pesticide data

BACKGROUND

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is associated with low survival. U.S. studies examining self-reported pesticide exposure in relation to HCC have demonstrated inconclusive results. We aimed to clarify the association between pesticide exposure and HCC by implementing a novel data linkage between Surveillance, Epidemiology, and End Results (SEER)-Medicare and California Pesticide Use Report (PUR) data using a geographic information system (GIS).

METHODS

Controls were frequency-matched to HCC cases diagnosed between 2000 and 2009 in California by year, age, race, sex, and duration of residence in California. Potential confounders were extracted from Medicare claims. From 1974 to 2008, pounds (1 pound represents 0.45 kg) of applied organophosphate, organochlorine, and carbamate pesticides provided in PURs were aggregated to the ZIP Code level using area weighting in a GIS. ZIP Code exposure estimates were linked to subjects using Medicare-provided ZIP Codes to calculate pesticide exposure. Agricultural residents were defined as living in ZIP Codes with a majority area intersecting agricultural land cover according to the 1992, 2001, and 2006 National Land Cover Database (NLCD) rasters. Multivariable conditional logistic regression was used to estimate the association between pesticide exposure and HCC.

RESULTS

Among California residents of agriculturally intensive areas, previous annual ZIP Code-level exposure to over 14.53 kg/km(2) of organochlorine pesticides (75(th) percentile among controls) was associated with an increased risk of HCC after adjusting for liver disease and diabetes (adjusted odds ratio [OR] 1.87, 95% confidence interval [CI] 1.17, 2.99; p=0.0085). ZIP Code-level organochlorines were significantly associated with an increased risk of HCC among males (adjusted OR 2.76, 95% CI 1.58, 4.82; p=0.0004), but not associated with HCC among females (adjusted OR 0.83, 95% CI 0.35, 1.93; p=0.6600) (interaction p=0.0075).

CONCLUSIONS

This is the first epidemiologic study to use GIS-based exposure estimates to study pesticide exposure and HCC. Our results suggest that organochlorine pesticides are associated with an increase in HCC risk among males but not females.

Myeloid cells in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is highly associated with inflammation. Myeloid cells, including tumor-associated macrophages and myeloid-derived suppressor cells, are abundant in the HCC microenvironment and are often associated with poor prognosis. Myeloid cells in HCC play a vital role in supporting tumor initiation, progression, angiogenesis, metastasis, and therapeutic resistance. Here, we summarize our current knowledge about myeloid cells in HCC and focus on their immune-suppressive activities and tumor-promoting functions, as well as the relevance to potential new therapies in HCC.

Role of estrogen receptors in digestive system tumors

Estrogen receptors are steroid hormone receptors that modulate the expression of target genes when bound to ligand. Humans have two ligand-activated transcription factors that bind to estrogen, encoded by separate genes, estrogen receptor α (ERα) and estrogen receptor β (ERβ). In addition, the membrane localized G protein-coupled estrogen receptor 1 (GPER1) can be activated by estradiol and mediate non-genomic signaling. Many studies have described the role of estrogen receptors in human cancers. Digestive system tumors account for a large proportion of all the tumors, and the mortality is very high in many digestive system tumors, such as esophageal cancer, gastric cancer, hepatocellular carcinoma, colorectal cancer, cholangiocarcinoma and pancreatic carcinoma. This review summarizes the role of estrogen receptors in digestive system tumors, aiming at finding new routes for the rational design of targeted anticancer therapies for digestive system tumors.

Inflammasomes are neuroprotective targets for sex steroids

Neuroinflammation in the central nervous system is triggered by toxic stimuli or degenerative events, orchestrates the interplay of brain-intrinsic immune cells and neighboring neural cells, and sequentially allows leukocyte extravasation from the periphery into the brain parenchyma. During the inflammatory cascade, immune-competent cells become activated and secrete a plethora of cytokines and chemokines which form a local inflammatory signaling network important for warding off harmful stimuli to the host but are likewise necessary to preserve damaged brain tissue. Inflammatory responses are initiated by extra- and intra-cellular pathogen and danger-associated receptors. These signals are processed by multi-protein complexes termed inflammasomes which trigger the production of biologically active interleukins-1 and 18 after the cleavage of caspase-1. Estrogens and progesterone are neuroprotective and anti-inflammatory in diverse disease models of the brain in particular under acute inflammatory conditions such as stroke and traumatic brain injury. Both steroids are able to attenuate pro-inflammatory cytokine activity. Recent literature and our own studies provide convincing evidence that the anti-inflammatory potency of these steroids result from a complex interaction with the inflammasome activation and their up-stream regulatory network of miRNAs in brain-intrinsic innate immune cells. This article examines steroid-inflammasome interactions in the brain during brain injury and illuminates the importance of regulation initial upstream events during neuroinflammation. This article is part of a Special Issue entitled 'Steroid Perspectives'.

Neonatal exposure of 17β-estradiol has no effects on mutagenicity of 7,12-dimethylbenz [a] anthracene in reproductive tissues of adult mice

INTRODUCTION

Biological studies in animals and epidemiological findings in humans clearly demonstrate that estrogens including 17β-estradiol (E2) are weak carcinogens via both genetic and epigenetic mechanisms. Carcinogenesis analyses have indicated that female mice exposed to E2 as neonates develop more mammary and ovarian tumors when compared to adult exposures. In the present study, Big Blue transgenic mice were used to investigate the effects of E2 on mutagenicity of 7,12-dimethylbenz [a] anthracene (DMBA), a genotoxic carcinogen, in mammary gland and ovary following neonatal exposure.

RESULTS

DMBA treatment resulted in significant increases in cII mutant frequencies (MFs) in both mammary glands and ovaries, with A:T → T:A transversion as the predominant type of mutation. However, co-exposure to E2 daily for the first 5 days after birth and to DMBA at 6 months of age did not significantly increase cII MFs compared to DMBA treatment alone. Further, there were also no significant differences in mutational spectra between DMBA exposure alone and E2 + DMBA treatment.

CONCLUSION

These results suggest that early life exposures of mice to estrogens like E2 do not enhance mutagenicity by subsequent exposure to a chemical like DMBA in later life.

Diagnosis and treatment of hepatocellular carcinoma: An update

Hepatocellular carcinoma (HCC) is one of the most common malignancies leading to high mortality rates in the general population; in cirrhotic patients, it is the primary cause of death. The diagnosis is usually delayed in spite of at-risk population screening recommendations, i.e., patients infected with hepatitis B or C virus. Hepatocarcinogenesis hinges on a great number of genetic and molecular abnormalities that lead to tumor angiogenesis and foster their dissemination potential. The diagnosis is mainly based on imaging studies such as computed tomography and magnetic resonance, in which lesions present a characteristic classical pattern of early arterial enhancement followed by contrast medium “washout” in late venous phase. On occasion, when imaging studies are not conclusive, biopsy of the lesion must be performed to establish the diagnosis. The Barcelona Clinic Liver Cancer staging method is the most frequently used worldwide and recommended by the international guidelines of HCC management. Currently available treatments include tumor resection, liver transplant, sorafenib and loco-regional therapies (alcoholization, radiofrequency ablation, chemoembolization). The prognosis of hepatocarcinoma is determined according to the lesion’s stage and in cirrhotic patients, on residual liver function. Curative treatments, such as liver transplant, are sought in patients diagnosed in early stages; patients in more advanced stages, were not greatly benefitted by chemotherapy in terms of survival until the advent of target molecules such as sorafenib.

Impaired function of CD4+ T follicular helper (Tfh) cells associated with hepatocellular carcinoma progression

Background and Aims

CD4+ T follicular helper (Tfh) cells, a new subset of immune cells, have been demonstrated to be involved in the development and prognosis of tumors. However, their functional role in human hepatocellular carcinoma (HCC) is relatively unknown, and the detailed mechanisms in HCC development remain to be described.

Methods

A total of 85 HCC patients with hepatitis B virus (HBV) infection, 25 HBV-relative liver cirrhosis (LC) patients, and 20 healthy controls (HC) were randomly enrolled. Flow cytometric analysis, immunohistochemical staining, and relative function (i.e., cytokine secretion, B cell maturation) assays were used to analyze the properties of CXCR5+CD4+ T cells. In addition, the relationship between the frequency of CXCR5+CD4+ T cells and overall survival rates or disease-free survival rates was also analyzed by the Kaplan-Meier method.

Results

The frequency of circulating CXCR5+CD4+ T cells was significantly decreased in HCC patients compared with HBV-relative liver cirrhosis (LC) patients and healthy controls, and the decrease in circulating CXCR5+CD4+ T cells correlated with disease progression. The proportion of infiltrated CXCR5+CD4+ T cells was significantly decreased in tumor regions compared with nontumor regions. Furthermore, compared with healthy controls, the function of circulating CXCR5+CD4+ T cells in HCC was impaired, with reduced IL-21 secretion and dysfunction in promoting B cell maturation. Importantly, follow-up data indicated that a decreased frequency of circulating CXCR5+CD4+ T cells was also associated with reduced disease-free survival time in HCC patients.

Conclusions

Impairment of CD4+ T follicular helper cells may influence the development of HBV-associated HCC. Decreased CD4+ T follicular helper cells may represent a potential prognostic marker and serve as a novel therapeutic target for HCC patients.

NF-κB increased expression of 17β-hydroxysteroid dehydrogenase 4 promotes HepG2 proliferation via inactivating estradiol

Hepatocellular carcinoma (HCC) arises in a setting of chronic inflammation induced by inflammatory cytokines, such as nuclear factor-kappaB (NF-κB). HCC is a male-predominant cancer that can be attenuated by estradiol (E2) in vitro and in vivo. Although 17β-hydroxysteroid dehydrogenase 4 (HSD17B4) has been implicated as an estradiol-inactivating enzyme, and its promoter sequence contains two putative NF-κB elements: it is currently unknown whether HSD17B4 is the link between inflammation, estradiol and proliferation in hepatoma cells. In this study, HepG2 cells were used to investigate the role of HSD17B4 in the proliferation of liver cancer cells treated with the NF-κB activator, tumor necrosis factor-alpha (TNF-α), with the inhibitor of NF-κB activation, pyrrolidinedithiocarbamate (PDTC), or with a related specific siRNA. We demonstrated that the human HSD17B4 gene is a target for NF-κB activation in inflammation-stimulated HepG2 cells. HSD17B4 is up-regulated via the binding of activated NF-κB to the distal NF-κB-responsive element via TNF-α stimulation, which then promotes cell proliferation by decreasing the levels of E2 and enhancing the expression of interleukin 6 (IL-6), cyclin D1 and proliferating cell nuclear antigen (PCAN). These results from HepG2 cells are consistent with the observation that HSD17B4 is highly expressed and activated NF-κB is highly co-localized with the NF-κB-responsive element of HSD17B4 in liver tumor tissues from HCC patients. Our findings indicate for the first time that HSD17B4 plays an important role in aggravated HCC progression and provides a novel therapeutic target for HCC.

A new animal model for Polygonum multiflorum Thunb-induced liver injury in rats and its potential mechanisms

The model is established successfully with the activation of LPS. Its pathogenesis is associated with the expression of mTLR4 in rats' liver. MicroRNA-122 is certificated to be an ideal potential serum biomarker for this model.

Role of antiviral therapy in reducing recurrence and improving survival in hepatitis B virus-associated hepatocellular carcinoma following curative resection (Review)

Hepatocellular carcinoma (HCC) is one of the major causes of cancer-related mortality worldwide, with the majority of cases associated with persistent hepatitis B virus (HBV) or hepatitis C virus infection. In particular, chronic HBV infection is a predominant risk factor for the development of HCC in Asian and African populations. Hepatic resection, liver transplantion and radiofrequency ablation are increasingly used for the curative treatment of HCC, however, the survival rate of HCC patients who have undergone curative resection remains unsatisfactory due to the high recurrence rate. HCC is a complex disease that is typically resistant to the most commonly used types of chemotherapy and radiotherapy; therefore, the development of novel treatment strategies is required to improve the survival rate of this disease. A high viral load of HBV DNA is the most important correctable risk factor for HCC recurrence, for example nucleos(t)ide analogs improve the outcome following curative resection of HBV-associated HCC, and interferon-α exhibits antitumor activity against various types of cancer via direct inhibitory effects on tumor cells, anti-angiogenesis, enhanced immunogenicity of tumors, immunomodulatory effects and liver dysfunction. In the present review, antiviral treatment for HBV-associated HCC is described as a strategy to reduce recurrence and improve survival.