Enacting the molecular imperative: How gene-environment interaction research links bodies and environments in the post-genomic age

hOGG1: A novel mediator in nitrosamine-induced esophageal tumorigenesis

BACKGROUND

The effect of human 8-Oxoguanine DNA Glycosylase (hOGG1) on exogenous chemicals in esophageal squamous cell carcinoma (ESCC) remain unclear. The study plans to determine hOGG1 expression levels in ESCC and possible interactions with known environmental risk factors in ESCC.

MATERIAL AND METHODS

We analyzed levels of exposure to urinary nitrosamines in volunteers from high and low prevalence areas by GC-MS. And we performed the interaction between hOGG1 gene and nitrosamine disinfection by-products by analyzing hOGG1 gene expression in esophageal tissues.

RESULTS

In ESCC, nitrosamine levels were significantly increased and hOGG1 mRNA expression levels were significantly decreased. There was a statistically significant interaction between reduced hOGG1 mRNA levels and non-tap drinking water sources in ESCC. The apparent indirect association between ESCC and NMEA indicated that 33.4% of the association between ESCC and NMEA was mediated by hOGG1.

CONCLUSION

In populations which exposed to high levels of environmental pollutants NDMA, low expression of hOGG1 may promote the high incidence of esophageal cancer in Huai'an. hOGG1 may be a novel mediator in nitrosamine-induced esophageal tumorigenesis.

Media framings of the role of genomics in "addiction" in the United States from 2015 to 2019: Individualized risk, biomedical expertise, and the limits of destigmatization

News coverage of the opioid epidemic is a useful site for examining genomic framings of addiction. Qualitative analysis of 139 articles published in the United States from 2015 to 2019 discussing genomics, addiction, and the opioid epidemic found an emphasis on both a postgenomic framing in which genetics operates in relation to social and environmental factors, and a molecularized understanding of addiction which highlighted the role of neurobiology and individual-level genetic risk. Discussions of genetics were often intertwined with calls for a biomedicalized approach that frames addiction as a chronic disease in need of medication, and thus under the purview of medical experts. Finally, while genomic discourses were invoked to reduce stigma, genomics was at times used to describe addicts as biologically distinct from other people, reflecting the possibility that genetics-even in the postgenomic context-can be used to promote a biologically essentialized understanding of people with addiction.

Black Mothers in Racially Segregated Neighborhoods Embodying Structural Violence: PTSD and Depressive Symptoms on the South Side of Chicago

This study employs multi-level and mixed-methods approaches to examine how structural violence affects the health of low-income, single Black mothers. We use multilevel regression models to examine how feeling "trapped" in racially segregated neighborhoods with high levels of violence on the South Side of Chicago affects mothers' (N = 69) reports of posttraumatic stress disorder and depressive symptoms. The relationship between feeling "trapped" and variations in expression of mRNA for the glucocorticoid receptor gene NR3C1 using microarray assays was also examined. The regression models revealed that feeling "trapped" significantly predicted increased mental distress in the form of PTSD, depressive symptoms, and glucocorticoid receptor gene regulation. The mothers' voices revealed a nuanced understanding about how a lack of financial resources to move out of the neighborhood creates feelings of being "trapped" in dangerous situations.

A novel grey projection incidence model for assessing the relationships between cardiovascular diseases and air pollutants

The accurate assessment of the relationships between cardiovascular diseases and various air pollutants is essential for population health protection, especially in low- and middle-income countries or regions with poor air quality and dense populations. In view of this situation, we propose a novel grey incidence model, namely, the grey projection incidence model based on Gaussian function, by integrating the advantages of geometric projection and Gaussian function. Firstly, the basic principles of the proposed model are elaborated. Then, a framework including six steps to evaluate the relationships between CVDs and air pollutants is illustrated. Finally, a case study is utilized to validate the effectiveness of the proposed model. Experimental results show that the proposed model outperforms other grey incidence models in terms of reliability and stability of the relational rank.

On the causal interpretation of heritability from a structural causal modeling perspective

Heritability estimated using the analysis of variance (ANOVA) for ascribing causal responsibility to genes for a phenotype has been criticized widely. First, there are problems associated with articulating the exact causal meaning of heritability in the standard model. Second, in conditions of gene-environment interaction or covariation that violate the assumptions made by the standard model, a causal interpretation of heritability is thought to be unwarranted. This paper aims to rethink these ideas and associated disputes from a structural causal modeling (SCM) perspective. Using SCM, we show that, in the standard model, heritability reflects the causal effect of eliminating genotypic differences on the change of phenotypic variance of a population. In the presence of interaction or covariation, heritability is estimated incorrectly using ANOVA. However, SCM can provide the causal effect of genotypes on the phenotypic variance regarding particular interventions. We also show that SCM can identify different types of causal effect and answer individual-level causal questions. We conclude that SCM has the resources to provide a systematic causal interpretation that can supplement traditional heritability estimates via ANOVA and offer a more substantial causal analysis of genetic causation.

Psychiatric genomics, mental health equity, and intersectionality: A framework for research and practice

The causal mechanisms and manifestations of psychiatric illness cannot be neatly narrowed down or quantified for diagnosis and treatment. Large-scale genome-wide association studies (GWAS) might renew hope for locating genetic predictors and producing precision medicines, however such hopes can also distract from appreciating social factors and structural injustices that demand more socially inclusive and equitable approaches to mental healthcare. A more comprehensive approach begins with recognizing that there is no one type of contributor to mental illness and its duration that should be prioritized over another. We argue that, if the search for biological specificity is to complement the need to alleviate the social distress that produces mental health inequities, psychiatric genomics must incorporate an intersectional dimension to models of mental illness across research priorities, scientific frameworks, and clinical applications. We outline an intersectional framework that will guide all professionals working in the expanding field of psychiatric genomics to better incorporate issues of social context, racial and cultural diversity, and downstream ethical considerations into their work.

Epidemiologists’ ambivalence towards the epigenetics of social adversity

This article studies how social epidemiologists get involved in research carried out on rodent models to explore the biological pathways underpinning exposure to social adversity in early life. We analyze their interdisciplinary exchanges with biologists in a social epigenetics project—i.e., in the experimental study of molecular alterations following social exposures. We argue that social epidemiologists are ambivalent regarding the use of non-human animal models on two levels: first, in terms of whether such models provide scientific evidence useful to social epidemiology, and second, regarding whether such models help promote their conception of public health. While they maintain expectations towards rodent experiments by elevating their functional value over their representational potential, they fear that their research will contribute to a public health approach that focuses on individual responsibility rather than the social causes of health inequalities. This interdisciplinary project demonstrates the difficulties encountered when research in social epigenetics engages with the complexities of laboratory experiments and social environments, as well as the conflicting sociopolitical projects stemming from such research.

Students' Understanding of the Dynamic Nature of Genetics: Characterizing Undergraduates' Explanations for Interaction between Genetics and Environment

The idea of the interaction between genes and environment in the formation of traits is an important component of genetic literacy, because it explains the plastic nature of phenotypes. However, most studies in genetics education characterize challenges in understanding and reasoning about genetic phenomena that do not involve modulation by the environment. Therefore, we do not know enough to inform the development of effective instructional materials that address the influences of environmental factors on genes and traits, that is, phenotypic plasticity. The current study explores college students' understanding of phenotypic plasticity. We interviewed biological sciences undergraduates who are at different stages of their undergraduate studies and asked them to explain several phenomena that involved phenotypic plasticity. Analysis of the interviews revealed two types of mechanistic accounts: one type described the interaction as involving the environment directly acting on a passive organism; while the other described the interaction as mediated by a sensing-and-responding mechanism. While both accounts are plausible, the second account is critical for reasoning about phenotypic plasticity. We also found that contextual features of the phenomena may affect the type of account generated. Based on these findings, we recommend focusing instruction on the ways in which organisms sense and respond.

Neighborhoods to Nucleotides - Advances and gaps for an obesity disparities systems epidemiology model

Purpose of Review

Disparities in obesity rates in the US continue to increase. Here we review progress and highlight gaps in understanding disparities in obesity with a focus on the Hispanic/Latino population from a systems epidemiology framework. We review seven domains: environment, behavior, biomarkers, nutrition, microbiome, genomics, and epigenomics/transcriptomics. We focus on recent advances that include at least two or more of these domains, and then provide a real world example of data collection efforts that reflect these domains.

Recent Findings

Research into DNA methylation related to discrimination and microbiome relating to eating behaviors and food content is furthering understanding of why disparities in obesity persist. Environmental and neighborhood level research is uncovering the importance of exposures such as air and noise pollution and systematic or structural racism for obesity and related outcomes through behaviors such as sleep.

Polygenic risk-stratified screening for cancer: Responsibilization in public health genomics

In this article, we examine professional discourse around the development of polygenic risk-stratified screening (PRSS) for cancer. Analyzing a range of contemporary professional literatures from Europe, North America and Australia, we explore how the drive to screen for molecular markers of cancer risk makes professionals, screening recipients and publics responsible, in different ways, for acquiring, curating and analyzing molecular data. Investigating how these responsibilities are invoked in discussions of new data practices, technologies, organizational arrangements, engagement, education and protocols for participation, we argue that agendas for PRSS for cancer are both expanding and stratifying responsibilities. Data collection is to be achieved by intensified responsibilities for including, reassuring and recruiting populations, as well as by opening and enriching the datasets on which models and preventative screening arrangements are based. Enhanced responsibilities for screening recipients and publics are also invoked, not just in relation to personal health but for population health more generally, via research participation and consenting to data re-use in the public interest. Professionals, screening recipients and publics are also to become responsible for moderating expectations of screening according to genomic designations. Together these discourses go beyond individual risk management to extend and diversify the responsibilities of practitioners, screening recipients and publics as public health genomics develops.

Calibrating cancer risk, uncertainty and environments: Genetics and their contexts in southern Brazil

Drawing on empirical ethnographic research in Brazil this paper examines how in the spaces between identifying genetic markers and conditional cancer risk, environments and diverse epigenetic logics are emerging and being negotiated among research and clinical communities, patients and their families. Focusing on an arena of research and medical intervention related to a gene variant known as R337h, thought to occur with high frequency in the south of Brazil and linked to the cancer syndrome Li-Fraumeni, it emphasises the relevance of examining epigenetics as an emic category but also its utility as an analytic category. It shows how in a context of not yet fully knowing how and in what ways R337h contributes to increased cancer, a range of different 'environments' are invoked that unevenly articulate an emerging and still inchoate and unfolding terrain of understanding. In an arena of expanding genomic research and medicine, where the identification of low risk mutations associated with cancer is increasingly common, the Brazilian case provides a particular lens on the way environments and genes are being meaningfully calibrated and how differently implicated communities resourcefully populate the gaps in knowledge and understanding with consequences for research, care and embodied risk.

Solidarity after nature: From biopolitics to cosmopolitics

What is sustaining the divide between nature and nurture, even though sciences like epigenetics have been challenging it for at least two decades? Evelyn Fox Keller asked this question and considered it a logical problem rooted in terminological confusion within the sciences. In this article, we propose a complementary diagnosis of the problem: the nature-nurture divide is (re-)mobilized when society faces questions of inclusion and solidarity. With examples stemming from the fields of insurance and health care, immigration policy and epigenetics, we demonstrate how the nature-nurture divide is performed through techniques of classification for a politics of solidarity. We identify a common operation to these different examples that we coin 'biopolitical imputation'. We use this term to draw attention to how (Western) societal institutions, including science, create solvable problems out of complex situations, defining human actors and their agency along the lines of the nature-nurture divide as a moral guide. We argue that the tenacity of the nature-nurture divide is therefore not only a logical problem needing better scientific concepts, but also a cosmopolitical problem asking for a more profound reflection on the ontology and ethics of solidarity in order to move beyond the biopolitics of nature versus nurture.

An Epigenetic Prism to Norms and Values

In this article, we ask to what extent the specific characteristics of epigenetics may affect the type of questions one can ask about human society. We pay particular attention to the way epigenetic research stirs debate about normative and moral issues. Are these issues implied by scientific evidence as an outcome of research? Or do moral and normative issues also shape how research is done and which problems it addresses? We briefly explore these questions through examples and discussions in (social-) scientific literature. In the final section, we propose an additional dimension and a refocusing of attention from issues of scientific evidence alone (asking what kind of evidence epigenetics produces and how it does so) to a broader picture on epigenetics as a mode of attention that encourages relational and process-oriented thinking with entities, values and scales that may not yet fit within conventional problem-frames that inform research funding and policy-making. We argue that the task of (post-)ELSI approaches is to take inspiration from the ecological complexity of epigenetics in order to bring more relations, relief and gradient in our ethical and political questions.

The sociology of cancer: a decade of research

Biomedicine is often presented as the driving force behind improvements in cancer care, with genomics the latest innovation poised to change the meaning, diagnosis, treatment, prevention and lived experience of cancer. Reviewing sociological analyses of a diversity of patient and practitioner experiences and accounts of cancer during the last decade (2007-17), we explore the experiences of, approaches to and understandings of cancer in this period. We identify three key areas of focus: (i) cancer patient experiences and identities; (ii) cancer risk and responsibilities and (iii) bioclinical collectives. We explore these sociological studies of societal and biomedical developments and how sociologists have sought to influence developments in cancer identities, care and research. We end by suggesting that we extend our understanding of innovations in the fields of cancer research to take better account of these wider social and cultural innovations, together with patients, activists' and sociologists' contributions therein.

Consuming DNA: The Good Citizen in the Age of Precision Medicine

The convergence of increasingly efficient high-throughput genetic sequencing technology and ubiquitous Internet use has fueled the proliferation of companies that provide direct-to-consumer (DTC) personal genetic information. The emergence of consumer genetics reflects several shifts in the governance of genetic testing and management of human genetic data. This article discusses DTC genetics as a case study of neoliberalism and contemporary transformations in medicine that construe disease and its management through economic rationalities. At stake are shifts in subjectivities from “patient” to “consumer” and the meaning of being a “good citizen” in the context of precision medicine. Engaging concepts of biopower, biosociality, and biovalue in the public consumption of genetic information, this article analyzes DTC genetics and its effect on social connection, identity, and modes of participation in the production of biomedical knowledge and the management of health and risk.

Molecularisation and metaphor

This article explores the molecularisation of medicine thesis by investigating reports on genetics and molecular medicine in the New England Journal of Medicine. While there has indeed been a large increase in the number of references to molecules in the context of genetics over the last few decades these are mostly embedded in a framework of explanatory metaphors, namely (gene) expressivity, penetrance, regulation and pathways. As most of these metaphors are drawn from the social world it would appear that the molecularisation thesis - that social life is becoming dominated by the molecular - needs to be tempered by the ways in which understanding of that molecular world is itself a reflection of social life.

The Ethics of Translational Science: Imagining Public Benefit in Gene-Environment Interaction Research

Biomedical research is increasingly informed by expectations of "translation," which call for the production of scientific knowledge that can be used to create services and products that improve health outcomes. In this paper, we ask how translation, in particular the idea of social responsibility, is understood and enacted in the post-genomic life sciences. Drawing on theories examining what constitutes "good science," and interviews with 35 investigators who study the role of gene-environment interactions in the etiology of cancer, diabetes, and cardiovascular disease, we describe the dynamic and unsettled ethics of translational science through which the expected social value of scientific knowledge about complex disease causation is negotiated. To describe how this ethics is formed, we first discuss the politics of knowledge production in interdisciplinary research collectives. Researchers described a commitment to working across disciplines to examine a wide range of possible causes of disease, but they also pointed to persistent disciplinary and ontological divisions that rest on the dominance of molecular conceptions of disease risk. The privileging of molecular-level causation shapes and constrains the kinds of knowledge that can be created about gene-environment interactions. We then turn to scientists' ideas about how this knowledge should be used, including personalized prevention strategies, targeted therapeutics, and public policy interventions. Consensus about the relative value of these anticipated translations was elusive, and many scientists agreed that gene-environment interaction research is part of a shift in biomedical research away from considering important social, economic, political and historical causes of disease and disease disparities. We conclude by urging more explicit engagement with questions about the ethics of translational science in the post-genomic life sciences. This would include a consideration of who will benefit from emerging scientific knowledge, how benefits will accrue, and the ways in which normative assumptions about the public good come to be embedded in scientific objects and procedures.

Gene-environment interactions in development and disease

Developmental geneticists continue to make substantial jumps in our understanding of the genetic pathways that regulate development. This understanding stems predominantly from analyses of genetically tractable model organisms developing in laboratory environments. This environment is vastly different from that in which human development occurs. As such, most causes of developmental defects in humans are thought to involve multifactorial gene-gene and gene-environment interactions. In this review, we discuss how gene-environment interactions with environmental teratogens may predispose embryos to structural malformations. We elaborate on the growing number of gene-ethanol interactions that might underlie susceptibility to fetal alcohol spectrum disorders. WIREs Dev Biol 2017, 6:e247. doi: 10.1002/wdev.247 For further resources related to this article, please visit the WIREs website.

The Socio-Exposome: Advancing Exposure Science and Environmental Justice in a Post-Genomic Era

We propose the socio-exposome as a conceptual framework for integrative environmental health research. Environmental scientists coined the term "exposome" with the goal of inventorying and quantifying environmental exposures as precisely as scientists measure genes and gene expression. To date, the exposome's proponents have not thoroughly engaged social scientific theoretical and methodological expertise, although the exclusion of sociological expertise risks molecularizing complex social phenomena and limiting the possibility of collective action to improve environmental conditions. As a corrective, and to demonstrate how "omic" technologies could be made more relevant to public health, our socio-exposome framework blends insights from sociological and public health research with insights from environmental justice scholarship and activism. We argue that environmental health science requires more comprehensive data on more and different kinds of environmental exposures, but also must consider the socio-political conditions and inequalities that allow hazards to continue unchecked. We propose a multidimensional framework oriented around three axes: individual, local, and global, and suggest some sociomarkers and data sources that could identify exposures at each level. This framework could also guide policy, by creating a predictive framework that helps communities understand the repercussions of corporate and regulatory practices for public health and social justice.

Additive Interaction between Heterogeneous Environmental Quality Domains (Air, Water, Land, Sociodemographic, and Built Environment) on Preterm Birth

BACKGROUND

Environmental exposures often occur in tandem; however, epidemiological research often focuses on singular exposures. Statistical interactions among broad, well-characterized environmental domains have not yet been evaluated in association with health. We address this gap by conducting a county-level cross-sectional analysis of interactions between Environmental Quality Index (EQI) domain indices on preterm birth in the Unites States from 2000 to 2005.

METHODS

The EQI, a county-level index constructed for the 2000-2005 time period, was constructed from five domain-specific indices (air, water, land, built, and sociodemographic) using principal component analyses. County-level preterm birth rates (n = 3141) were estimated using live births from the National Center for Health Statistics. Linear regression was used to estimate prevalence differences (PDs) and 95% confidence intervals (CIs) comparing worse environmental quality to the better quality for each model for (a) each individual domain main effect, (b) the interaction contrast, and (c) the two main effects plus interaction effect (i.e., the "net effect") to show departure from additivity for the all U.S. counties. Analyses were also performed for subgroupings by four urban/rural strata.

RESULTS

We found the suggestion of antagonistic interactions but no synergism, along with several purely additive (i.e., no interaction) associations. In the non-stratified model, we observed antagonistic interactions, between the sociodemographic/air domains [net effect (i.e., the association, including main effects and interaction effects) PD: -0.004 (95% CI: -0.007, 0.000), interaction contrast: -0.013 (95% CI: -0.020, -0.007)] and built/air domains [net effect PD: 0.008 (95% CI 0.004, 0.011), interaction contrast: -0.008 (95% CI: -0.015, -0.002)]. Most interactions were between the air domain and other respective domains. Interactions differed by urbanicity, with more interactions observed in non-metropolitan regions.

CONCLUSION

Observed antagonistic associations may indicate that those living in areas with multiple detrimental domains may have other interfering factors reducing the burden of environmental exposure. This study is the first to explore interactions across different environmental domains and demonstrates the utility of the EQI to examine the relationship between environmental domain interactions and human health. While we did observe some departures from additivity, many observed effects were additive. This study demonstrated that interactions between environmental domains should be considered in future analyses.