Cross-generational effects of alcohol dependence in humans on HRAS and TP53 methylation in offspring

Inter- and transgenerational heritability of preconception chronic stress or alcohol exposure: Translational outcomes in brain and behavior

Chronic stress and alcohol (ethanol) use are highly interrelated and can change an individual's behavior through molecular adaptations that do not change the DNA sequence, but instead change gene expression. A recent wealth of research has found that these nongenomic changes can be transmitted across generations, which could partially account for the "missing heritability" observed in genome-wide association studies of alcohol use disorder and other stress-related neuropsychiatric disorders. In this review, we summarize the molecular and behavioral outcomes of nongenomic inheritance of chronic stress and ethanol exposure and the germline mechanisms that could give rise to this heritability. In doing so, we outline the need for further research to: (1) Investigate individual germline mechanisms of paternal, maternal, and biparental nongenomic chronic stress- and ethanol-related inheritance; (2) Synthesize and dissect cross-generational chronic stress and ethanol exposure; (3) Determine cross-generational molecular outcomes of preconception ethanol exposure that contribute to alcohol-related disease risk, using cancer as an example. A detailed understanding of the cross-generational nongenomic effects of stress and/or ethanol will yield novel insight into the impact of ancestral perturbations on disease risk across generations and uncover actionable targets to improve human health.

Cell fate regulation governed by p53: Friends or reversible foes in cancer therapy

Cancer is a leading cause of death worldwide. Targeted therapies aimed at key oncogenic driver mutations in combination with chemotherapy and radiotherapy as well as immunotherapy have benefited cancer patients considerably. Tumor protein p53 (TP53), a crucial tumor suppressor gene encoding p53, regulates numerous downstream genes and cellular phenotypes in response to various stressors. The affected genes are involved in diverse processes, including cell cycle arrest, DNA repair, cellular senescence, metabolic homeostasis, apoptosis, and autophagy. However, accumulating recent studies have continued to reveal novel and unexpected functions of p53 in governing the fate of tumors, for example, functions in ferroptosis, immunity, the tumor microenvironment and microbiome metabolism. Among the possibilities, the evolutionary plasticity of p53 is the most controversial, partially due to the dizzying array of biological functions that have been attributed to different regulatory mechanisms of p53 signaling. Nearly 40 years after its discovery, this key tumor suppressor remains somewhat enigmatic. The intricate and diverse functions of p53 in regulating cell fate during cancer treatment are only the tip of the iceberg with respect to its equally complicated structural biology, which has been painstakingly revealed. Additionally, TP53 mutation is one of the most significant genetic alterations in cancer, contributing to rapid cancer cell growth and tumor progression. Here, we summarized recent advances that implicate altered p53 in modulating the response to various cancer therapies, including chemotherapy, radiotherapy, and immunotherapy. Furthermore, we also discussed potential strategies for targeting p53 as a therapeutic option for cancer.

The repertoire of mutational signatures in tobacco- and non-tobacco-induced oral cancer

The use of tobacco products is one of the established contributors toward the development and spread of oral cancer. Additionally, recent research has indicated oral microbiome, infections with Human papilloma virus (HPV), Epstein-Barr virus (EBV), Candida as significant contributing factors to this disease along with lifestyle habits. Deregulation of cellular pathways envisaging metabolism, transcription, translation, and epigenetics caused by these risk factors either individually or in unison is manifold, resulting in the increased risk of oral cancer. Globally, this cancer continues to exist as one of the major causes of cancer-related mortalities; the numbers in the developing South Asian countries clearly indicate yearly escalation. This review encompasses the variety of genetic modifications, including adduct formation, mutation (duplication, deletion, and translocation), and epigenetic changes evident in oral squamous cell carcinoma (OSCC). In addition, it highlights the interference caused by tobacco products in Wnt signaling, PI3K/Akt/mTOR, JAK-STAT, and other important pathways. The information provided also ensures a comprehensive and critical revisit to non-tobacco-induced OSCC. Extensive literature survey and analysis has been conducted to generate the chromosome maps specifically highlighting OSCC-related mutations with the potential to act as spectacles for the early diagnosis and targeted treatment of this disease cancer.

Learning and memory deficits produced by aspartame are heritable via the paternal lineage

Environmental exposures produce heritable traits that can linger in the population for one or two generations. Millions of individuals consume substances such as artificial sweeteners daily that are declared safe by regulatory agencies without evaluation of their potential heritable effects. We show that consumption of aspartame, an FDA-approved artificial sweetener, daily for up to 16-weeks at doses equivalent to only 7-15% of the FDA recommended maximum daily intake value (equivalent to 2-4 small, 8 oz diet soda drinks per day) produces significant spatial learning and memory deficits in mice. Moreover, the cognitive deficits are transmitted to male and female descendants along the paternal lineage suggesting that aspartame's adverse cognitive effects are heritable, and that they are more pervasive than current estimates, which consider effects in the directly exposed individuals only. Traditionally, deleterious environmental exposures of pregnant and nursing women are viewed as risk factors for the health of future generations. Environmental exposures of men are not considered to pose similar risks. Our findings suggest that environmental exposures of men can produce adverse impact on cognitive function in future generations and demonstrate the need for considering heritable effects via the paternal lineage as part of the regulatory evaluations of artificial sweeteners.

Genome-wide associations between alcohol consumption and blood DNA methylation: evidence from twin study

Aim: Alcohol intake alters DNA methylation profiles and methylation might mediate the association between alcohol and disease, but limited number of positive CpG sites repeatedly replicated. Materials & methods: In total, 57 monozygotic (MZ) twin pairs discordant for alcohol drinking from the Chinese National Twin Registry and 158 MZ and dizygotic twin pairs in the Swedish Adoption/Twin Study of Aging were evaluated. DNA methylation was detected using the Infinium HumanMethylation450 BeadChip. Results: Among candidate CpG sites, cg07326074 was significantly correlated with drinking after adjusting for covariates in MZ twins in both datasets but not in the entire sample or dizygotic twins. Conclusion: The hypermethylation of cg07326074, located in the tumor-promoting gene C16orf59, was associated with alcohol consumption.

A Narrative Review of the Role of Diet and Lifestyle Factors in the Development and Prevention of Endometrial Cancer

Simple Summary

The incidence and prevalence of endometrial cancer is increasing globally. The main factors involved in this increase have been the way women live today and what they eat and drink. In fact, the obesity pandemic that is sweeping across the planet is considered to be the main contributory feature. This review aims to introduce to a new audience, those that are not experts in the field, what is known about the different types of endometrial cancer and the mechanisms for their induction and protection. We also seek to summarise the existing knowledge on dietary and lifestyle factors that prevent endometrial development in susceptible populations and identify the main problem in this arena; the paucity of research studies and clinical trials that investigate the interaction(s) between diet, lifestyle and endometrial cancer risk whilst highlighting those areas of promise that should be further investigated.

Abstract

Endometrial cancer is the most common cancer affecting the reproductive organs of women living in higher-income countries. Apart from hormonal influences and genetic predisposition, obesity and metabolic syndrome are increasingly recognised as major factors in endometrial cancer risk, due to changes in lifestyle and diet, whereby high glycaemic index and lipid deposition are prevalent. This is especially true in countries where micronutrients, such as vitamins and minerals are exchanged for high calorific diets and a sedentary lifestyle. In this review, we will survey the currently known lifestyle factors, dietary requirements and hormonal changes that increase an individual’s risk for endometrial cancer and discuss their relevance for clinical management. We also examine the evidence that everyday factors and clinical interventions have on reducing that risk, such that informed healthy choices can be made. In this narrative review, we thus summarise the dietary and lifestyle factors that promote and prevent the incidence of endometrial cancer.

Exposure to drugs of abuse induce effects that persist across generations

Substance use disorders are highly prevalent and continue to be one of the leading causes of disability in the world. Notably, not all people who use addictive drugs develop a substance use disorder. Although substance use disorders are highly heritable, patterns of inheritance cannot be explained purely by Mendelian genetic mechanisms. Vulnerability to developing drug addiction depends on the interplay between genetics and environment. Additionally, evidence from the past decade has pointed to the role of epigenetic inheritance in drug addiction. This emerging field focuses on how environmental perturbations, including exposure to addictive drugs, induce epigenetic modifications that are transmitted to the embryo at fertilization and modify developmental gene expression programs to ultimately impact subsequent generations. This chapter highlights intergenerational and transgenerational phenotypes in offspring following a history of parental drug exposure. Special attention is paid to parental preconception exposure studies of five drugs of abuse (alcohol, cocaine, nicotine, cannabinoids, and opiates) and associated behavioral and physiological outcomes in offspring. The highlighted studies demonstrate that parental exposure to drugs of abuse has enduring effects that persist into subsequent generations. Understanding the contribution of epigenetic inheritance in drug addiction may provide clues for better treatments and therapies for substance use disorders.

Regulating tumor suppressor genes: post-translational modifications

Tumor suppressor genes cooperate with each other in tumors. Three important tumor suppressor proteins, retinoblastoma (Rb), p53, phosphatase, and tensin homolog deleted on chromosome ten (PTEN) are functionally associated and they regulated by post-translational modification (PTMs) as well. PTMs include phosphorylation, SUMOylation, acetylation, and other novel modifications becoming growing appreciated. Because most of PTMs are reversible, normal cells use them as a switch to control the state of cells being the resting or proliferating, and PTMs also involve in cell survival and cell cycle, which may lead to abnormal proliferation and tumorigenesis. Although a lot of studies focus on the importance of each kind of PTM, further discoveries shows that tumor suppressor genes (TSGs) form a complex “network” by the interaction of modification. Recently, there are several promising strategies for TSGs for they change more frequently than carcinogenic genes in cancers. We here review the necessity, characteristics, and mechanisms of each kind of post-translational modification on Rb, p53, PTEN, and its influence on the precise and selective function. We also discuss the current antitumoral therapies of Rb, p53 and PTEN as predictive, prognostic, and therapeutic target in cancer.

Sphingolipids and the link between alcohol and cancer

Epidemiological evidence underscores alcohol consumption as a strong risk factor for multiple cancer types, with liver cancer being most commonly associated with alcohol intake. While mechanisms linking alcohol consumption to malignant tumor development are not fully understood, the likely players in ethanol-induced carcinogenesis are genotoxic stress caused by formation of acetaldehyde, increased oxidative stress, and altered nutrient metabolism, including the impairment of methyl transfer reactions. Alterations of sphingolipid metabolism and associated signaling pathways are another potential link between ethanol and cancer development. In particular, ceramides are involved in the regulation of cellular proliferation, differentiation, senescence, and apoptosis and are known to function as important regulators of malignant transformation as well as tumor progression. However, to date, the cross-talk between ceramides and alcohol in cancer disease is largely an open question and only limited data are available on this subject. Most studies linking ceramide to cancer considered liver steatosis as the underlying mechanism, which is not surprising taking into consideration that ceramide pathways are an integral part of the overall lipid metabolism. This review summarizes the latest studies pointing to ceramide as an important mediator of cancer-promoting effects of chronic alcohol consumption and underscores the necessity of understanding the role of sphingolipids and lipid signaling in response to alcohol in order to prevent and/or successfully manage diseases caused by alcohol.

Intergenerational Effects of Alcohol: A Review of Paternal Preconception Ethanol Exposure Studies and Epigenetic Mechanisms in the Male Germline

While alcohol use disorder (AUD) is a highly heritable psychiatric disease, efforts to elucidate that heritability by examining genetic variation (e.g., single nucleotide polymorphisms) have been insufficient to fully account for familial AUD risk. Perhaps not coincidently, there has been a burgeoning interest in novel nongenomic mechanisms of inheritance (i.e., epigenetics) that are shaped in the male or female germ cells by significant lifetime experiences such as exposure to chronic stress, malnutrition, or drugs of abuse. While many epidemiological and preclinical studies have long pointed to a role for the parental preconception environment in offspring behavior, over the last decade many studies have implicated a causal relationship between the environmentally sensitive sperm epigenome and intergenerational phenotypes. This critical review will detail the heritable effects of alcohol and the potential role for epigenetics.

Construction and Analysis of Protein-Protein Interaction Network of Heroin Use Disorder

Heroin use disorder (HUD) is a complex disease resulting from interactions among genetic and other factors (e.g., environmental factors). The mechanism of HUD development remains unknown. Newly developed network medicine tools provide a platform for exploring complex diseases at the system level. This study proposes that protein–protein interactions (PPIs), particularly those among proteins encoded by casual or susceptibility genes, are extremely crucial for HUD development. The giant component of our constructed PPI network comprised 111 nodes with 553 edges, including 16 proteins with large degree (k) or high betweenness centrality (BC), which were further identified as the backbone of the network. JUN with the largest degree was suggested to be central to the PPI network associated with HUD. Moreover, PCK1 with the highest BC and MAPK14 with the secondary largest degree and 9^th highest BC might be involved in the development HUD and other substance diseases.

Binge Drinking and Intergenerational Implications: Parental Preconception Alcohol Impacts Offspring Development in Rats

Preconception behaviors and experiences of mothers and fathers can affect future offspring. Recently, our laboratory showed that alcohol-naive offspring of parents who were exposed to repeated binge alcohol during adolescence showed altered DNA methylation patterns in the hypothalamus, a brain region involved in regulation of pubertal development, stress, and behavior. These observations have potentially far-reaching consequences for human health, as more than 4.6 million Americans under the age of 21 years report engaging in the rapid intoxication behavior of binge-pattern alcohol (EtOH) drinking. Therefore, we tested the hypothesis that offspring of binge EtOH‒exposed parents would have altered hypothalamic function manifested phenotypically as improper pubertal development, impaired socialization, and dysregulated stress response. In addition, we tested the hypothesis that parental EtOH exposure would confer adaptive protection from the negative effects of EtOH when offspring were themselves exposed to EtOH. Rats received EtOH via oral gavage once daily for 6 days at both early [postnatal day (PND) 37] and late puberty (PND 67). Animals were paired (EtOH-EtOH, vehicle-vehicle) for mating 24 hours after the last EtOH dose. After weaning, offspring were randomized to vehicle treatment to assess changes in normal development or to EtOH treatment to assess the effect of parental EtOH exposure on offspring response to this treatment. We found that offspring had smaller body weights and displayed fewer play behaviors when parents had been exposed to EtOH before conception. In addition, offspring showed a reduction in pubertal development markers that could indicate that parental preconception EtOH exposure confers maladaptive epigenetic traits in first-generation offspring.