Human Health Sciences
The primary objectives of the Division of Human Health Sciences are to study etiological role of various environmental toxicants in pathogenesis of acute and chronic human diseases, to determine adverse effects of environmental toxicants on humans, and to design effective prevention strategies for reducing human diseases risks linked to exposure to environmental toxicants.
Major approaches used by members of the Division include:
1. to develop sensitive methods to detect environmental toxicants in human body fluids for assessing human diseases risks;
2. to develop various animal and human cell models for studying potentialmolecular mechanisms of known human diseases related to exposure
to environmental toxicants;
3. to validate molecular biomarkers for environmental toxicants in high-risk human populations; and
4. to study modulative effects of various agents, especially natural products, on prevention of toxicants-caused human diseases.
5. the role of gene-environment interactions in human cancer development
A significant component of the work being done within the Human Health Sciences group involves the investigation, development, and application of rigorous statistical methodologies to the data being collected as part of our human health studies. Specific areas of interest are; 1) the development of rigorous study design protocols, 2) the application of mixed-effects models to epidemiological data, 3) the development of novel techniques for analyzing data from various "omics" approaches, 4) the utility of nonparametric approaches to a variety of epidemiological study designs, and 5) the application of information-theoretic approaches to human health data. Our research group embraces the view that biostatistics (and science in general) will benefit from a reduced emphasis on concepts such as "significant/nonsignificant." Estimation of effect sizes and confidence intervals, as well as the development of tools to address hypotheses directly related to specific biological questions of interest, may provide more insight and scientific understanding of the processes affecting human health.
The long-term goal of this research team is to investigate mechanisms of combinative toxic effects of biotoxin mixture(s) on animal and humans and develop prevention strategies against potential use of these mixture(s) as biological warfare threats (BWT) or terrorist attacks. The research has been supported by RDECOM/DOD for six years with two phases of work: phase one focused on studying acute toxicity of various biotoxin mixtures in animal and human cell models and to develop methods to detect these biotoxin mixtures in environmental samples and biological fluids. Phase two focused on studying molecular mechanisms of combinative acute toxic effects of biotoxin mixtures in animal and human cell models with emphasis on cell signaling pathways. Specific aims for current project include: 1) to explore molecular profiling in protein expression levels of biotoxin mixture targeted human cells using proteomic techniques. 2) To carry out metabnomic studies in biotoxin mixture exposed and unexposed animals and human populations, and 3) To continue detoxifying studies with previously identified chemicals for antagonizing combinative acute toxic or cytotoxic effects caused by biotoxin mixtures.
Cancer Epidemiology and Prevention
The long-term goal of this research team is to study roles of interactions of gene-gene, gene-environment, genotypic and phenotypic biomarkers, and chemical and viral/baterial carcinogens in human carcinogenesis and to develop prevention strategies to reduce human cancer incidence and mortality in high-risk areas. Focusof current research projects are targeted on liver, esophageal, lung, and prostate cancers, including 1) development and validation of carcinogen molecular biomarkers for human cancer risk studies, 2) etiological studies on esophageal cancer in Huaian, China, 3) chemoprevention of natural products on liver cancer in China and Ghana, and 4) proteomic and metabolomic studies on cancer prevention and early detection.
The long-term goal of this research team is to study molecular mechanisms of environmental toxicants linked to the etiology of human acute and chronic diseases and to study molecular pathways for chemical/biological pathogenesis and their interactions. Current research areas include 1) genomic, proteomic, and metablomic studies on molecular carcinogenesis, 2) stem cell research on human metabolic syndromes, and 3) pathway specific genetic polymorphisms. Tools used include normal and diseases stage cells, whole animal models, human molecular epidemiology studies, and various imagine facilities and analytical instruments.
Developmental and Reproductive Toxicology
Current Research Areas and Projects:
Cancer Epidemiology and Prevention
Developmental and Reproductive Toxicology
Environmental Lead Source and Exposure Assessment Group
Thomas Longoria, Ph.D., Director, Center for Public Service
Cole Cowling, Honors College Undergraduate Research Fellow
Although most people are aware of the hazards of exposure to lead (Pb)-based paints, most consider Pb a hazard of the past. What is not fully understood by the general public, is the presence today of health-threatening concentrations of Pb in urban soils as a result of years of burning gasoline supplemented with Pb. Even though leaded gasoline was officially banned in the U.S. in 1986, Pb, once settled into soils, is quite immobile. Because of over 60 years of exposure to Pb, urban soils can have Pb concentrations which greatly exceed health guidelines for soils. Unfortunately, recent work has shown that exposure to these urban soils can result in over 30% of children that live in these areas having blood Pb levels that have been shown to cause neurotoxicity. Our research group is dedicated to increasing the understanding of how environmental chemistry, human behavior and culture intersect to increase the risk of childhood and adult Pb exposure. In this respect we are currently investigating variables affecting the balance between total and bioaccessible lead in dust, soil and toys in Southwestern United States metropolitan areas as well as a geospatial assessment of lead contamination in Managua, Nicaragua. A secondary but essential part of our program is also dedicated to lead poisoning prevention and outreach in the communities that we work.
The Role of Gene-Environment Interactions in Human Cancer Development
In spite of tremendous progress made over the last decades in cancer diagnosis and prevention, the cancer remains as one of the leading causes of death in United States, and therefore it is a major public health issue. With the technological advancement and genetic research, a number of cancer susceptible genes have been identified. In addition to genetic factors, the increasing number of epidemiological and experimental evidences strongly implicates the role of environmental factors in human cancer development. This is further supported by the facts that approximately 75 – 80% of all cancer in the United States is due to environmental factors, and large proportions (90-95%) of the cancer are sporadic (those cases of cancer that are not due to inheritance of genetic defects in cancer susceptible genes). Therefore, cancer is neither purely genetic nor purely environmental. It is the interaction of gene(s) and environment that ultimately determines the risk of cancer development. In order to understand the mechanistic basis for environment associated cancers, it is crucial to understand how the environmental factors interact with gene(s) that results in human malignancies. Though the role of genetic changes of mutations in cancer development is well established, recent reports strongly suggest that epigenetic changes of DNA methylation and histone modifications (methylation and acetylation) play crucial role in the development of human cancers. It is in this context that one of our research objectives is to identify the genetic and epigenetic changes induced by environmental carcinogens and elucidate their role in human malignancy. This study will not only help in understanding the mechanistic basis of environmental carcinogenesis but will also help in developing suitable strategies for reduction of environmental exposure-associated human cancers.
Our research program on gene-environment interaction is designed to provide opportunities for graduate training of theoretical and laboratory-based experimental knowledge on the application of basic biological science (cell biology, molecular biology, and Genetics) to address the adverse effects of environmental exposures on human health.
The training through this program will provide to our graduates the career opportunities not only in academia, but also in government agencies and private industries.
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The Department of Environmental Toxicology (ENTX) is the academic home for the core faculty of The Institute of Environmental and Human Health (TIEHH) and the Institute for Forensic Science (IFS) at Texas Tech University. TIEHH and IFS provide faculty and graduate students opportunities for multidisciplinary research and scholarly engagement related to environmental, forensic and human health sciences.