Testosterone regulation of cyclin E kinase: A key factor in determining gender differences in hepatocarcinogenesis

Exploiting gender-based biomarkers and drug targets: advancing personalized therapeutic strategies in hepatocellular carcinoma

This review systematically examines gender differences in hepatocellular carcinoma (HCC), identifying the influence of sex hormones, genetic variance, and environmental factors on the disease's epidemiology and treatment outcomes. Recognizing the liver as a sexually dimorphic organ, we highlight how gender-specific risk factors, such as alcohol consumption and obesity, contribute differently to hepatocarcinogenesis in men and women. We explore molecular mechanisms, including the differential expression of androgen and estrogen receptors, which mediate diverse pathways in tumor biology such as cell proliferation, apoptosis, and DNA repair. Our analysis underscores the critical need for gender-specific research in liver cancer, from molecular studies to clinical trials, to improve diagnostic accuracy and therapeutic effectiveness. By incorporating a gender perspective into all facets of liver cancer research, we advocate for a more precise and personalized approach to cancer treatment that acknowledges gender as a significant factor in both the progression of HCC and its response to treatment. This review aims to foster a deeper understanding of the biological and molecular bases of gender differences in HCC and to promote the development of tailored interventions that enhance outcomes for all patients.

Sex difference in liver diseases: How preclinical models help to dissect the sex-related mechanisms sustaining NAFLD and hepatocellular carcinoma

Only a few preclinical findings are confirmed in the clinic, posing a critical issue for clinical development. Therefore, identifying the best preclinical models can help to dissect molecular and mechanistic insights into liver disease pathogenesis while being clinically relevant. In this context, the sex relevance of most preclinical models has been only partially considered. This is particularly significant in NAFLD and HCC, which have a higher prevalence in men when compared to pre-menopause women but not to those in post-menopausal status, suggesting a role for sex hormones in the pathogenesis of the diseases. This review gathers the sex-relevant findings and the available preclinical models focusing on both in vitro and in vivo studies and discusses the potential implications and perspectives of introducing the sex effect in the selection of the best preclinical model. This is a critical aspect that would help to tailor personalized therapies based on sex.

The role of sex hormones and receptors in HBV infection and development of HBV-related HCC

Gender disparity in hepatitis B virus (HBV)-related diseases has been extensively documented. Epidemiological studies consistently reported that males have a higher prevalence of HBV infection and incidence of hepatocellular carcinoma (HCC). Further investigations have revealed that sex hormone-related signal transductions play a significant role in gender disparity. Sex hormone axes showed significantly different responses to virus entry and replication. The sex hormones axes change the HBV-specific immune responses and antitumor immunity. Additionally, Sex hormone axes showed different effects on the development of HBV-related disease. But the role of sex hormones remains controversial, and researchers have not reached a consensus on the role of sex hormones and the use of hormone therapies in HCC treatment. In this review, we aim to summarize the experimental findings on sex hormones and provide a comprehensive understanding of their roles in the development of HCC and their implications for hormone-related HCC treatment.

Impact of donor sex on hepatocellular carcinoma recurrence in liver transplantation after brain death

BACKGROUND

Hepatocellular carcinoma (HCC) is predominantly seen in males but has a better prognosis in females. No prior studies have investigated HCC recurrence based on sex combination following liver transplant donated after brain death (DBDLT). This study sought to elucidate the effects of donor and recipient sex on HCC recurrence rates.

METHODS

9232 adult recipients from the United Network for Organ Sharing (UNOS) database who underwent DBDLT for HCC from 2012 to 2018 were included. Donor-recipient pairs were divided into (1) female donor/female recipient (F-F) (n = 1089); (2) male donor/female recipient (M-F) (n = 975); (3) female donor/male recipient (F-M) (n = 2691); (4) male donor/male recipient (M-M) (n = 4477). The primary prognostic outcome was HCC recurrence. A multivariable competing risk regression analysis was used to assess prognostic influences.

RESULTS

The median recipient age and model for end-stage liver disease (MELD) scores were similar among the four groups. Livers of male recipients demonstrated greater in size and number of HCC (both p-values were <.0001). There was also a higher rate of vascular invasion in male recipients compared to female (p < .0001). Competing risk analyses showed that the cumulative HCC recurrence rate was significantly lower in the M-F group (p = .013). After adjusting for tumor characteristics, liver grafts from male donors were associated with a lower HCC recurrence rate in female recipients (HR: .62 95%CI: .42-.93) (p = .021).

CONCLUSION

In DBDLT, male donor to female recipient pairing exhibited lower HCC recurrence rates.

SUMMARY

Lowest rates of HCC recurrence were confirmed among the female recipients of male donor grafts group in the deceased donor LT cohort. A competing risk multivariable regression analysis demonstrated that male donor sex was significantly associated with low HCC recurrence in female but not male recipients.

Endogenous sex steroid hormones and risk of liver cancer among US men: Results from the Liver Cancer Pooling Project

Background & Aims

Incidence rates of liver cancer in most populations are two to three times higher among men than women. The higher rates among men have led to the suggestion that androgens are related to increased risk whereas oestrogens are related to decreased risk. This hypothesis was investigated in the present study via a nested case-control analysis of pre-diagnostic sex steroid hormone levels among men in five US cohorts.

Methods

Concentrations of sex steroid hormones and sex hormone-binding globulin were quantitated using gas chromatography-mass spectrometry and a competitive electrochemiluminescence immunoassay, respectively. Multivariable conditional logistic regression was used to calculate odds ratios (ORs) and 95% CIs for associations between hormones and liver cancer among 275 men who subsequently developed liver cancer and 768 comparison men.

Results

Higher concentrations of total testosterone (OR per one-unit increase in log₂ = 1.77, 95% CI = 1.38-2.29), dihydrotestosterone (OR = 1.76, 95% CI = 1.21-2.57), oestrone (OR = 1.74, 95% CI = 1.08-2.79), total oestradiol (OR = 1.58, 95% CI=1.22-20.05), and sex hormone-binding globulin (OR = 1.63, 95% CI = 1.27-2.11) were associated with increased risk. Higher concentrations of dehydroepiandrosterone (DHEA), however, were associated with a 53% decreased risk (OR = 0.47, 95% CI = 0.33-0.68).

Conclusions

Higher concentrations of both androgens (testosterone, dihydrotestosterone) and their aromatised oestrogenic metabolites (oestrone, oestradiol) were observed among men who subsequently developed liver cancer compared with men who did not. As DHEA is an adrenal precursor of both androgens and oestrogens, these results may suggest that a lower capacity to convert DHEA to androgens, and their subsequent conversion to oestrogens, confers a lower risk of liver cancer, whereas a greater capacity to convert DHEA confers a greater risk.

Impact and implications

This study does not fully support the current hormone hypothesis as both androgen and oestrogen levels were associated with increased risk of liver cancer among men. The study also found that higher DHEA levels were associated with lower risk, thus suggesting the hypothesis that greater capacity to convert DHEA could be associated with increased liver cancer risk among men.

Validation of a supplementary condition of eighth AJCC staging system for stage II hepatocellular carcinoma

INTRODUCTION

The eighth American Joint Committee on Cancer (AJCC) staging system was flawed regarding the prognosis of stage II hepatocellular carcinoma (HCC). The aims of this study were to reveal the defect and make updates.

METHODS

Clinical and survival data of HCC patients from the Surveillance, Epidemiology, and End Results database were used. We re-classified stage II into T2aN0M0 (tumors >2 cm with vascular invasion) and T2bN0M0 (multiple tumors ≤5 cm). The Kaplan-Meier method and log-rank test were used to estimate differences in overall survival (OS). Three propensity score matching analyses without (PSM1) or with (PSM2 and PSM3) consideration of surgical treatment were performed. Cox regression was used to reveal risk factors.

RESULTS

HCC patients identified as T1bN0M0, T2aN0M0, T2bN0M0, and T3N0M0 were recruited. OS in T2N0M0 was consistent with the eighth AJCC staging system after PSM1. T2bN0M0 had increased OS compared with T2aN0M0 after PSM2 (hazard ratio [HR] = 1.36; 95% confidence interval [CI] = 1.06-1.73; P = 0.0141) or PSM3 (HR = 1.18; 95%CI = 1.01-1.37; P = 0.0283). No survival benefit existed between T1bN0M0 and T2bN0M0 after PSM2 (HR = 0.92; 95%CI = 0.80-1.05; P = 0.2171) or PSM3 (HR = 0.92; 95%CI = 0.84-1.01; P = 0.0888). Compared with T2aN0M0, T3N0M0 had shorter OS after PSM2 (HR = 0.64; 95%CI = 0.50-0.82; P = 0.0003) or PSM3 (HR = 0.63; 95%CI = 0.54-0.73; P < 0.0001). Cox regression analysis revealed that surgical treatment was associated with better prognosis (HR = 0.3; 95%CI = 0.3-0.4; P < 0.001).

CONCLUSIONS

The current staging for T2N0M0 is imprecise because surgical treatment is not adequately evaluated and would be ineffective if the proportion of T2bN0M0 patients with surgical treatment was increased.

Sex steroid axes in determining male predominance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death. The mechanisms for male propensity in HCC incidence, prognosis and treatment responses are complicated and remain inconclusive. Sex-biased molecular signatures in carcinogenesis, viral infections and immune responses have been studied predominantly within the context of sex hormones effects. This review integrates current knowledge on the mechanisms through which the hormones regulate HCC development in sexually dimorphic fashion. Firstly, the androgen/androgen receptor (AR) accelerate cell proliferation and virus infection, especially during the initial stage of HCC, while estrogen/estrogen receptor (ER) function in an opposite way to induce cell apoptosis and immune responses. Interestingly, the controversial effects of AR in late stage of HCC metastasis are summarized and the reasons are attributed to inconsistent cancer grading or experimental models between the studies. In addition, the new insights into these intricate cellular and molecular mechanisms underlying sexual dimorphism are fully discussed. A detailed understanding of sex hormones-associated regulation to male predominance in HCC may help to develop personalized therapeutic strategies in high-risk populations.

Overexpressed GNAZ predicts poor outcome and promotes G0/G1 cell cycle progression in hepatocellular carcinoma

AIMS

We aimed to investigate the role of G protein subunit alpha Z(GNAZ) in the progression and prognosis of patients with hepatocellular carcinoma (HCC).

METHODS

Oncomine, GEO, TCGA, GEPIA2, Kaplan-Meier Plotter, TIMER2, Metascape, CCLE, LinkedOmics, and UALCAN databases were used to analyze the differential expression of GNAZ in HCC and normal liver tissues, relationship between GNAZ expression and prognosis of patients with HCC, and expression of GNAZ in common human HCC cell lines. Western blotting was performed to analyze GNAZ expression, while the Cell Counting Kit 8 assay was used to determine cell proliferation, and flow cytometry was used to evaluate the cell cycle and apoptosis. Wound healing and transwell invasion assays were used to investigate cell metastasis and invasion.

RESULTS

Using Oncomine, Gene Expression Omnibus (GEO), and GEPIA2 databases, GNAZ was found to be overexpressed in HCC tissues compared with that in adjacent normal liver tissues, and western blotting analysis showed GNAZ overexpression in seven patients with HCC who underwent surgical resection of HCC and para-cancerous tissues (p < 0.01). Survival analysis revealed that high GNAZ expression was negatively associated with overall survival (OS), recurrence-free survival, progression-free survival, and disease-specific survival in patients with HCC (p < 0.05). GNAZ overexpression was associated with worse 4- month, 6- month, 12- month, 24- month, 36- month, 48- month, and 60-month OS, as well as with different clinicopathological characteristics of patients with HCC, including hepatitis virus infection state; alcohol consumption state; male; female; Asian; microvascular invasion, Stage I-II, Stage II-III, and Stage III-IV; and grade II (Cox regression, p < 0.05). KEGG/GO biological process enrichment indicated that the genes similar to GNAZ in HCC were mainly enriched in the cell cycle, cell cycle phase transition, DNA replication checkpoint, and regulation of G0 to G1 transition. siRNA-GNAZ significantly reduced the viability of JHH-2 and SNU-761 cells from 12 to 96 h; increased the percentage of cells in the G0/G1 phase and decreased that of cells in the S and G2/M phases (p < 0.05); and markedly downregulated the expression of cyclin D, cyclin E, and CDK2 protein. siRNA-GNAZ also significantly increased the percentage of JHH-2 and SNU-761 cell apoptosis at late stages, while the number of surviving cells decreased (p < 0.05), and upregulated the expression of apoptosis-related proteins Bax and caspase 3 protein. Furthermore, siRNA-GNAZ remarkably reduced the healing of scratch wounds in JHH-2 and SNU-761 cells and the number of invasive cells compared with that in the control group (p < 0.001).

CONCLUSION

Our study demonstrated that GNAZ plays a pivotal role as a potential oncogene and predicts poor prognosis in patients with HCC. It promotes tumor proliferation via cell cycle arrest, apoptosis, migration, and invasion. Thus, GNAZ may be a potential candidate biomarker providing useful insight into hepatocarcinogenesis and aggressiveness.

Natural Killer Cells and Type 1 Innate Lymphoid Cells in Hepatocellular Carcinoma: Current Knowledge and Future Perspectives

Natural killer (NK) cells and type 1 innate lymphoid cells (ILC1) are specific innate lymphoid cell subsets that are key for the detection and elimination of pathogens and cancer cells. In liver, while they share a number of characteristics, they differ in many features. These include their developmental pathways, tissue distribution, phenotype and functions. NK cells and ILC1 contribute to organ homeostasis through the production of key cytokines and chemokines and the elimination of potential harmful bacteria and viruses. In addition, they are equipped with a wide range of receptors, allowing them to detect “stressed cells’ such as cancer cells. Our understanding of the role of innate lymphoid cells in hepatocellular carcinoma (HCC) is growing owing to the development of mouse models, the progress in immunotherapeutic treatment and the recent use of scRNA sequencing analyses. In this review, we summarize the current understanding of NK cells and ILC1 in hepatocellular carcinoma and discuss future strategies to take advantage of these innate immune cells in anti-tumor immunity. Immunotherapies hold great promise in HCC, and a better understanding of the role and function of NK cells and ILC1 in liver cancer could pave the way for new NK cell and/or ILC1-targeted treatment.

Role of Sex in the Therapeutic Targeting of p53 Circuitry

Sex profoundly affects cancer incidence and susceptibility to therapy, with sex hormones highly contributing to this disparity. Various studies and omics data suggest a relationship between sex and the oncosuppressor p53 circuitry, including its regulators MDM2 and MDM4. Association of this network with genetic variation underlies sex-related altered cancer risk, age of onset, and cancer sensitivity to therapy. Moreover, sex-related factors, mainly estrogenic hormones, can affect the levels and/or function of the p53 network both in hormone-dependent and independent cancer. Despite this evidence, preclinical and clinical studies aimed to evaluate p53 targeted therapy rarely consider sex and related factors. This review summarizes the studies reporting the relationship between sex and the p53 circuitry, including its associated regulators, MDM2 and MDM4, with particular emphasis on estrogenic hormones. Moreover, we reviewed the evaluation of sex/hormone in preclinical studies and clinical trials employing p53-target therapies, and discuss how patients’ sex and hormonal status could impact these therapeutic approaches.

Anti-Hepatocellular Carcinoma Effect and Molecular Mechanism of the Estrogen Signaling Pathway

There are significant gender differences in the incidence and mortality of hepatocellular carcinoma (HCC). Compared with men, the incidence and mortality of HCC in women are relatively low. The estrogen signaling pathway, composed of estrogen and estrogen receptors, has been postulated to have a protective effect on the occurrence and development of HCC. There have been multiple studies that have supported anti-HCC effects of the estrogen signaling pathways, including direct and indirect pathways such as genomic pathways, rapid transduction pathways, non-coding RNA, tumor microenvironment, estrogen metabolites, and inhibition of hepatitis infection and replication. Based on the evidence of an anti-HCC effect of the estrogen signaling pathway, a number of strategies have been investigated to determine the potential therapeutic effect. These have included estrogen replacement therapy, targeting the estrogen receptor, key molecules, inflammatory mediators, and regulatory pathways of the estrogen signaling pathway. In this review, we have systematically summarized the latest developments in the complex functions and molecular mechanisms of the estrogen signaling pathway in liver cancer. Furthermore, we have highlighted the potential targets of treatment strategies based on the estrogen signaling pathway in the treatment of liver cancer and the principal obstacles currently encountered for future investigation.

Biomarkers in Hepatocellular Carcinoma: Current Status and Future Perspectives

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and one of the leading causes of cancer-related death worldwide. HCC is highly heterogeneous, both within the tumor and among individuals, which is closely related to the HCC surveillance, diagnosis, prognosis, and treatment response. With the advances of next-generation sequencing, the genomic landscape of HCC has been identified which vastly improves our understanding of genetic and epigenetic changes and their interaction during HCC development. In particular, gene mutations, epigenetic modifications, aberrant expression of coding and non-coding RNAs have been extensively explored and many of them are considered as biomarkers for HCC. Most recently, the gut microbiome has been proposed as potential non-invasive biomarkers for HCC diagnosis. In this review, we summarize the current development of HCC biomarkers studies and provide insights on further steps towards precision medicine of HCC.

Effect of menopausal status on the survival and recurrence of sex-classified hepatocellular carcinoma after liver resection: a case-matched study with propensity score matching

OBJECTIVE

To investigate the impact of menopausal status on the prognosis for sex-classified Hepatocellular carcinoma (HCC) and to establish prognostic nomograms for patients after liver resection.

RESULTS

After propensity score matching (PSM), statistically significant differences in both overall survival (OS) and recurrence-free survival (RFS) were found between men and women HCC patients. Based on Cox regression analysis, these differences were evident in the normal menstruation (N) group expanded with male patients, but not in either the expanded postmenopausal (P) or intermediate (I) groups. Sex disparity was also apparent in the recurrence-free survival (RFS) of the total HCC patients. Integrated with independent factors, nomograms for the OS and RFS of the expanded N group showed higher C-indices of 0.773 and 0.724, respectively, than those of nomograms for the total patients and BCLC stage (P<0.001).

CONCLUSION

Sex disparity appears to affect both the survival and recurrence of HCC only in normal menstruation women and their matched men. For predicting survival, prognostic nomograms derived from the expanded N group of HCC patients were more accurate for patients with the same clinical conditions.

METHODS

The patients (390 females and 1920 males), who underwent curative liver resection for HCC during 2008 to 2012, were screened. The 390 women were divided into three groups: normal menstruation, intermediate, and postmenopausal. To overcome selection bias, the three groups of females were matched with males at a ratio of 1:2, using propensity score matching. Based on further Cox regression analysis, independent factors were integrated into nomograms for OS and RFS by R rms. The accuracy and discrimination of the nomograms were evaluated by the C-index, calibration curve, and decision curve analysis.

Exercise retards hepatocarcinogenesis in obese mice independently of weight control

BACKGROUND & AIMS

Obesity and type 2 diabetes increase hepatocellular carcinoma (HCC) incidence in humans and accelerate diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. We investigated whether exercise reduces HCC development in obese/diabetic Alms1 mutant (foz/foz) mice and studied protective mechanisms.

METHODS

We measured HCC development in DEN-injected male foz/foz and wild-type (WT) littermates housed with or without an exercise wheel from week 4 until 12 or 24 weeks, and in foz/foz mice pair-fed to WT littermates. We also studied HCC development in DEN-injected Jnk1^-/-.foz/foz mice generated by cross breeding, as well as their genetic controls. Dysplastic hepatocytes were identified by glutathione-S-transferase pi form (GST-pi) immunohistochemistry, liver nodules were counted, and HCC was analysed by histopathology.

RESULTS

Exercising foz/foz mice maintained similar weight as WT mice up to 10 weeks, but then gained weight and were obese by 24 weeks; a similar body weight profile was obtained by pair-feeding foz/foz mice to WT. At 12 weeks, livers of exercising foz/foz mice exhibited fewer GST-pi positive hepatocytes than sedentary counterparts; by 24 weeks, fewer exercising foz/foz mice developed HCC (15% vs. 64%, p <0.05). Conversely, pair-feeding foz/foz mice failed to reduce HCC incidence. In these insulin-resistant foz/foz mice, exercise failed to activate hepatic AMPK or Akt/mTORC1. Instead, it improved insulin sensitivity, ameliorated steatosis and liver injury, activated p53 to increase p27 expression, and prevented JNK activation. This was associated with suppression of hepatocellular proliferation. DEN-injected Jnk1^-/-.foz/foz mice failed to develop liver tumours or HCC at 24 weeks.

CONCLUSIONS

Direct effects of exercise dampen proliferation of dysplastic hepatocytes to reduce 3-month dysplastic foci and 6-month incidence of DEN-induced HCC in obese, insulin-resistant mice. The effects of exercise that potentially slow hepatocarcinogenesis include p53-mediated induction of p27 and prevention of JNK activation.

LAY SUMMARY

Fatty liver disease commonly occurs alongside obesity and diabetes, contributing to rapidly increasing rates of liver cancer throughout the world. Herein, we show that exercise reduces the incidence and progression of hepatocellular carcinoma in mouse models. The effect of exercise on cancer risk was shown to be independent of changes in weight. Exercise could be a protective mechanism against liver cancer in at-risk individuals.

Sex Hormone-Dependent Physiology and Diseases of Liver

Sexual dimorphism is associated not only with somatic and behavioral differences between men and women, but also with physiological differences reflected in organ metabolism. Genes regulated by sex hormones differ in expression in various tissues, which is especially important in the case of liver metabolism, with the liver being a target organ for sex hormones as its cells express estrogen receptors (ERs: ERα, also known as ESR1 or NR3A; ERβ; GPER (G protein-coupled ER, also known as GPR 30)) and the androgen receptor (AR) in both men and women. Differences in sex hormone levels and sex hormone-specific gene expression are mentioned as some of the main variations in causes of the incidence of hepatic diseases; for example, hepatocellular carcinoma (HCC) is more common in men, while women have an increased risk of autoimmune liver disease and show more acute liver failure symptoms in alcoholic liver disease. In non-alcoholic fatty liver disease (NAFLD), the distinction is less pronounced, but increased incidences are suggested among men and postmenopausal women, probably due to an increased tendency towards visceral fat accumulation.

A Concise Review on the Frequency, Major Risk Factors and Surveillance of Hepatocellular Carcinoma (HCC) in β-Thalassemias: Past, Present and Future Perspectives and the ICET-A Experience

Due to the recent alarming increase in the incidence of hepatocellular carcinoma (HCC) in thalassemias, the present report reviews briefly the frequency, the major risk factors, and the surveillance of HCC in β-thalassemias. Over the past 33 years, 153 cases of HCC were reported in patients with thalassemia, mainly in Italy and Greece. Among HCV-infected patients, additional factors promoting the development of HCC included: advanced age, male sex, chronic hepatitis B (CHB) co-infection, and iron overload. For early diagnosis of HCC, sequential ultrasound screening is recommended especially for thalassemia patients with chronic hepatitis C (CHC), which coincides with (one or more) additional risk factors for HCC. Here we report also the preliminary data from thalassemic patients, above the age of 30 years, followed in 13 ICET-A centers. The total number of enrolled patients was 1,327 (males: 624 and 703 females). The prevalence of HCC in thalassemia major patients [characterized by transfusion-dependency (TDT)] and thalassemia intermedia [characterized by nontransfusion dependency (NTDT)] was 1.66 % and 1.96 %, respectively. The lowest age at diagnosis of HCC was 36 years for TDT and 47 years for NTDT patients. We hope that this review can be used to develop more refined and prospective analyses of HCC magnitude and risk in patients with thalassemia and to define specific international guidelines to support clinicians for early diagnosis and treatment of HCC in thalassemic patients.

Kinase-independent function of E-type cyclins in liver cancer

E-type cyclins (cyclins E1 and E2) are components of the core cell cycle machinery and are overexpressed in many human tumor types. E cyclins are thought to drive tumor cell proliferation by activating the cyclin-dependent kinase 2 (CDK2). The cyclin E1 gene represents the site of recurrent integration of the hepatitis B virus in the pathogenesis of hepatocellular carcinoma, and this event is associated with strong up-regulation of cyclin E1 expression. Regardless of the underlying mechanism of tumorigenesis, the majority of liver cancers overexpress E-type cyclins. Here we used conditional cyclin E knockout mice and a liver cancer model to test the requirement for the function of E cyclins in liver tumorigenesis. We show that a ubiquitous, global shutdown of E cyclins did not visibly affect postnatal development or physiology of adult mice. However, an acute ablation of E cyclins halted liver cancer progression. We demonstrated that also human liver cancer cells critically depend on E cyclins for proliferation. In contrast, we found that the function of the cyclin E catalytic partner, CDK2, is dispensable in liver cancer cells. We observed that E cyclins drive proliferation of tumor cells in a CDK2- and kinase-independent mechanism. Our study suggests that compounds which degrade or inhibit cyclin E might represent a highly selective therapeutic strategy for patients with liver cancer, as these compounds would selectively cripple proliferation of tumor cells, while sparing normal tissues.

Deriving and testing of dysplastic murine hepatocytes: A new platform in liver cancer research

Dysplastic hepatocytes (DH) represent altered hepatocytes with potential for malignant transformation. To date, most research on pathways to hepatocarcinogenesis has focused on use of "hepatoma" cell lines derived from hepatocellular carcinoma (HCC). We describe a novel technique for deriving/culturing DH and demonstrate their utility for functional studies in vitro, compared to primary hepatocytes (PH) and HCC. PH and DH were prepared by portal vein collagenase perfusion from C57BL/6J mice. DH were subsequently subjected to FACS. HCC from diethylnitrosamine (DEN)-injected mice were mechanically isolated. Cell cycle analyses were performed by flow cytometry and PCNA immunohistochemistry. To establish utility of DH, we studied pathways of p53 turnover, apoptosis and cell proliferation using pfithrin-α (PFT) and nutlin-3. Like PH, DH were minimally proliferative compared to HCC. Only 30±0.03% of DH were in G₂/M phase versus 51±0.01% of HCC; this difference corroborated with PCNA-immunostaining of dysplastic nodules from DEN-injected mice. In DH and HCC, nutlin-3 suppressed p53 mRNA, induced p53 and mdm2 activation but paradoxically resulted in increased anti-apoptotic and proliferative activity. Primary murine DH display distinctive biological characteristics compared with PH and HCC. As an intermediate cell type to HCC, they offer a new pathobiologically relevant primary cell culture system with which to interrogate the molecular changes in hepatocarcinogenesis.

Gender disparity in hepatocellular carcinoma (HCC): multiple underlying mechanisms

On the global scale, hepatitis B virus (HBV) infection is the main cause of hepatocellular carcinoma (HCC) especially in regions of Asia where HBV infection is endemic. Epidemiological studies show that the incidence of inflammation-driven HCC in males is three times as high as in females. Recent studies suggest that sex hormones have a crucial role in the pathogenesis and development of HBV-induced HCC. We found that the estrogen/androgen signaling pathway is associated with decreased/increased transcription and replication of HBV genes and can promote the development of HBV infections by up/downregulating HBV RNA transcription and inflammatory cytokines levels, which in turn slow down the progression of HBV-induced HCC. Additionally, sex hormones can also affect HBV-related HCC by inducing epigenetic changes. The evidence that both morphology and function of the human liver are affected by sex hormones was found over 60 years ago. However, the underlying molecular mechanism largely remains to be elucidated. This review focuses mainly on the molecular mechanisms behind the sex difference in HCC associated with HBV and other factors. In addition, several potential treatment and therapeutic strategies for inflammation-driven HCC will be introduced in this review.

No contribution of lifestyle and environmental exposures to gender discrepancy of liver disease severity in chronic hepatitis b infection: Observations from the Haimen City cohort

BACKGROUND

Previous studies have noted significant gender difference in the risk of liver cancer among hepatitis B chronic infection patients. Some indicated that it might be due to lifestyle-related differences. This paper tests whether or not such a gender discrepancy among the chronic hepatitis B population is confounded by lifestyle and environment related exposures.

METHODS

We retrieved a sample of 1863 participants from a prospective cohort in Haimen City, China in 2003. Liver disease severity was categorized as "normal", "mild", "moderate", and "severe" based on a clinical diagnosis. Lifestyle and environmental exposures were measured by questionnaires. We used factor analysis and individual variables to represent lifestyle and environmental exposures. We applied the cumulative logit models to estimate the effect of gender on liver disease severity and how it was impacted by lifestyle and environmental exposures.

RESULTS

Gender and HBeAg positivity were independent risk factors for more severe liver disease. Compared to females, males were 2.08 times as likely to develop more severe liver disease (95% CI: 1.66-2.61). Participants who were HBeAg positivite were 2.19 times (95% CI: 1.61-2.96) as likely to develop more severe liver disease compared to those who were negative. Controlling for lifestyle and environmental exposures did not change these estimations.

CONCLUSIONS

Males in the HBV infected population have an increased risk of severe liver disease. This gender effect is independent of the lifestyle and environmental exposures addressed in this study. Our findings support the hypothesis that gender discrepancies in HCC risk are attributable to intrinsic differences between males and females.