The impact of sex on hepatotoxic, inflammatory and proliferative responses in mouse models of liver carcinogenesis

Gender Dimorphism in Hepatic Carcinogenesis-Related Gene Expression Associated with Obesity as a Low-Grade Chronic Inflammatory Disease

Non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) show clear evidence of sexual dimorphism, with a significantly higher incidence in males. Among the determining factors that could explain this sex-based difference, the specific distribution of fat by sex has been suggested as a primary candidate, since obesity is a relevant risk factor. In this context, obesity, considered a low-grade chronic inflammatory pathology and responsible for the promotion of liver disease, could lead to sexual dimorphism in the expression profile of genes related to tumor development. When we compared the expression levels of genes associated with the early stages of carcinogenesis in the liver between male and female diet-induced obesity (DIO) rats, we observed that the expression pattern was similar in obese male and female animals. Interestingly, the SURVIVIN/BIRC5 oncogene showed a higher expression in male DIO rats than in female DIO and lean rats. This trend related to sexual dimorphism was observed in leukocytes from patients with obesity, although the difference was not statistically significant. In conclusion, this study evidenced a similar pattern in the expression of most carcinogenesis-related genes in the liver, except SUVIVIN/BIRC5, which could be a predictive biomarker of liver carcinogenesis predisposition in male patients with obesity.

Sexual Dimorphism in Chronic Hepatitis B Virus (HBV) Infection: Evidence to Inform Elimination Efforts

Sexual dimorphism in infectious diseases refers to the different infection susceptibilities and outcomes between males and females, and has been described for many pathogens, including hepatitis B virus (HBV). HBV is a substantial global health problem, with close to 300 million people chronically infected, and accounting for a million deaths each year, with an urgent need for enhanced interventions to support progress towards elimination goals. Sexual dimorphism has a strong influence in HBV infection, with males more likely to be exposed, to develop chronic infection, and to suffer from complications including cirrhosis and hepatocellular carcinoma (HCC) compared to females. Different outcomes are driven by differential immune responses, sexual dimorphism of the liver, and androgen response elements in the HBV genome. The impact of sex may also vary with age, with changes at puberty and influences of menarche, pregnancy and menopause in females. In addition, gender has complex influences on education, beliefs, behaviour and access to / engagement with healthcare services, which may contribute to differences in diagnosis and treatment. Interplay between these complex factors, alongside other attributes of host, virus and the environment, accounts for different outcomes of infection. However, gaps remain in our understanding of sexual dimorphism in HBV, and little effort has previously been made to harness this knowledge for translational gains. In this review, we assimilate human and animal data to consider the mechanism, outcomes and impact of sexual dimorphism, and consider how these insights can be used to inform advances in surveillance, treatment and prevention for HBV infection.

Sexual Dimorphism in Chronic Hepatitis B Virus (HBV) Infection: Evidence to Inform Elimination Efforts

Sexual dimorphism in infectious diseases refers to the different infection susceptibilities and outcomes between males and females, and has been described for many pathogens, including hepatitis B virus (HBV). HBV is a substantial global health problem, with close to 300 million people chronically infected, and accounting for a million deaths each year, with an urgent need for enhanced interventions to support progress towards elimination goals. Sexual dimorphism has a strong influence in HBV infection, with males more likely to be exposed, to develop chronic infection, and to suffer from complications including cirrhosis and hepatocellular carcinoma (HCC) compared to females. Different outcomes are driven by differential immune responses, sexual dimorphism of the liver, and androgen response elements in the HBV genome. The impact of sex may also vary with age, with changes at puberty and influences of menarche, pregnancy and menopause in females. In addition, gender has complex influences on education, beliefs, behaviour and access to / engagement with healthcare services, which may contribute to differences in diagnosis and treatment. Interplay between these complex factors, alongside other attributes of host, virus and the environment, accounts for different outcomes of infection. However, gaps remain in our understanding of sexual dimorphism in HBV, and little effort has previously been made to harness this knowledge for translational gains. In this review, we assimilate human and animal data to consider the mechanism, outcomes and impact of sexual dimorphism, and consider how these insights can be used to inform advances in surveillance, treatment and prevention for HBV infection.

SDC: An Integrated Database for Sex Differences in Cancer

Sex differences are evident in the incidence and mortality of diverse cancers. With the development of personalized approaches in cancer treatment, the impact of sex differences has not been systematically incorporated into preclinical and clinical cancer research. The molecular mechanisms underlying sex differences in cancer have not been elucidated. Here, we developed the first database of Sex Differences in Cancer (SDC), a web-based public database that integrates resources from multiple databases, including The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression Project (GTEx), UCSC Xena, Broad Institute Cancer Cell Line Encyclopedia (CCLE), Genomics of Drug Sensitivity in Cancer (GDSC). SDC contains 27 types of cancers, 6 types of molecular data, more than 10,000 donors, 977 cancer cell lines were used to analyze sex differences among cancers. It provides five main modules: Survival and phenotype, Molecular differences, Signatures and pathways, Therapy response, Download. Users can download the all the visualized results and raw data after analysis. Collectively, SDC is the first integrated database to analyze sex differences in cancer on the web server, which will strengthen our understanding of the role of sex in cancers. It is implemented in Shiny-server and freely available for public use at http://sdc.anticancer.xyz.

Sexual Dimorphism in Chronic Hepatitis B Virus (HBV) Infection: Evidence to Inform Elimination Efforts

Sexual dimorphism in infectious diseases refers to the different infection susceptibilities and outcomes between males and females, and has been described for many pathogens, including hepatitis B virus (HBV) infection. HBV is a substantial global health problem, with close to 300 million people infected, and accounting for a million deaths each year, with an urgent need for enhanced interventions to support progress towards elimination goals. Sexual dimorphism has a strong influence in HBV infection, with males more likely to be exposed, to develop chronic infection, and to suffer from complications including cirrhosis and hepatocellular carcinoma (HCC) compared to females. Different outcomes are driven by differential immune responses, sexual dimorphism of the liver, and androgen response elements in the HBV genome. The impact of sex may also vary with age, with changes at puberty and influences of menarche, pregnancy and menopause in females. In addition, gender has complex influences on education, beliefs, behaviour and access to / engagement with healthcare services, which may contribute to differences in diagnosis and treatment. Interplay between these complex factors, alongside other attributes of host, virus and the environment, accounts for different outcomes of infection. However, gaps remain in our understanding of sexual dimorphism in HBV, and little effort has previously been made to harness this knowledge for translational gains. In this review, we assimilate human and animal data to consider the mechanism, outcomes and impact of sexual dimorphism, considering how these insights can be used to inform advances in surveillance, treatment and prevention for HBV infection.

Harnessing natural variation to identify cis regulators of sex-biased gene expression in a multi-strain mouse liver model

Sex differences in gene expression are widespread in the liver, where many autosomal factors act in tandem with growth hormone signaling to regulate individual variability of sex differences in liver metabolism and disease. Here, we compare hepatic transcriptomic and epigenetic profiles of mouse strains C57BL/6J and CAST/EiJ, representing two subspecies separated by 0.5-1 million years of evolution, to elucidate the actions of genetic factors regulating liver sex differences. We identify 144 protein coding genes and 78 lncRNAs showing strain-conserved sex bias; many have gene ontologies relevant to liver function, are more highly liver-specific and show greater sex bias, and are more proximally regulated than genes whose sex bias is strain-dependent. The strain-conserved genes include key growth hormone-dependent transcriptional regulators of liver sex bias; however, three other transcription factors, Trim24, Tox, and Zfp809, lose their sex-biased expression in CAST/EiJ mouse liver. To elucidate the observed strain specificities in expression, we characterized the strain-dependence of sex-biased chromatin opening and enhancer marks at cis regulatory elements (CREs) within expression quantitative trait loci (eQTL) regulating liver sex-biased genes. Strikingly, 208 of 286 eQTLs with strain-specific, sex-differential effects on expression were associated with a complete gain, loss, or reversal of the sex differences in expression between strains. Moreover, 166 of the 286 eQTLs were linked to the strain-dependent gain or loss of localized sex-biased CREs. Remarkably, a subset of these CREs apparently lacked strain-specific genetic variants yet showed coordinated, strain-dependent sex-biased epigenetic regulation. Thus, we directly link hundreds of strain-specific genetic variants to the high variability in CRE activity and expression of sex-biased genes and uncover underlying genetically-determined epigenetic states controlling liver sex bias in genetically diverse mouse populations.