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2004 Pilot Project Summaries |
El Mustapha Bahassi PhD
Department of Cell Biology, Neurobiology and Anatomy
Regulation of BRCA2
Function by ChK2 in response to Irradiation
Breast cancer is the
most common malignancy among women worldwide, and is a
leading cause of cancer-related deaths. A minority of
breast cancer cases is attributable to inherited
mutations in rare high-penetrance breast cancer
susceptibility genes such as BRCA1 and BRCA2, but the
majority appears to be due to multiple low-penetrance
genes. Several such susceptibility alleles have been
previously suggested, but among them the Chk2 low-penetrance
alleles show the most convincing statistical
significance. We have established the first known
connection between BRCA2 and Chk2. We show that Chk2
phosphorylates BRCA2 on a threonine residue (T3246)
located in the C-terminus region of the protein coded by
exon 27. Deletion of exon 27 in mice leads to
hypersensitivity to DNA crosslinks, chromosome
instability, and reduced life span. Frameshift mutations
deleting a part of the C-terminus of BRCA2 have been
reported in hereditary breast cancer patients. The
importance of the C-terminal region of BRCA2 comes from
its key role in homologous recombination via its
interaction with Rad51. We showed that in a mouse cell
line with targeted mutations in Brca2 (Brca2lex1/lex2),
which deletes exon 27, DNA repair proteins failed to
localize to nuclear foci of DNA damage in response to
genotoxic stress. Similarly, a GFP-BRCA2 exon 27
peptide, carrying a T3246A substitution failed to
localize to DNA damage-induced foci after stress,
whereas the wild type peptide did. Our results indicate
that the DNA damage pathway involving the highly
conserved Chk2 protein regulates BRCA2 by direct
phosphorylation, which controls its localization after
DNA damage. |
William Hardie, MD
Division of Pulmonary Biology, Children's Hospital
Mechanisms of
Protection from Nickel-induced Lung Injury by
Transforming Growth Factor α Expression
Acute lung injury has a
diverse etiology, a poor prognosis (30-60% mortality),
and can lead to severe sequelae (pulmonary fibrosis).
Numerous precipitating factors have been identified, yet
questions remain about the pathophysiological mechanisms
controlling this complex condition and their
relationship to therapeutic strategies, which are mainly
supportive measures. We propose that key events in acute
lung injury intersect with select growth-factor mediated
pathways, and that knowledge of these pathways will
provide insights into the mechanisms of this condition
and may redirect or strengthen current clinical
approaches. Transforming growth factor-α (TGFa)
exclusively binds to the epidermal growth factor
receptor (EGFR). Activation of the EGFR leads to
phosphorylation of several intracellular signaling
pathways that activate gene expression controlling
several cellular processes critical to lung function
including cellular proliferation and migration, cell
survival and extracellular matrix and repair. We have
previously generated transgenic mice that constitutively
express TGFa in the lung epithelium and survive
aerosolized nickel (NiSO4)-induced acute lung injury.
Recently, we generated transgenic mice that have
lung-specific TGFa expression controlled by a
conditional promoter. Using this regulatable TGFa
transgenic mouse model our project will determine
mechanisms of TGFa protection by testing the hypothesis
that expression of TGFa prior to lung injury induces
modulators that confer survival by reducing induction of
proinflammatory cytokines and reducing neutrophil
influx. Our project will test this hypothesis by first
determining the timing of TGFa induction conferring
survival, and second, by using microarray of gene
expression, we will identify other candidate modulators
and pathways that may regulate proinflammatory cytokines
and neutrophil influx. |
Gary E. Shull, PhD
Department of Molecular Genetics
Effects of
perturbations in calcium homeostasis on tumorigenesis
This laboratory has
generated an Atp2a2 heterozygous mouse model, in which
one allele of the Atp2a2 gene, encoding the principal,
ubiquitously expressed calcium-sequestering pumps
(SERCA2a/b), has been disrupted. These mutant mice
spontaneously develop squamous cell carcinomas upon
aging with a penetrance of nearly 100%. Thapsigargin, a
known inhibitor of SERCA2 activity, is known to be a
strong tumor-promoter. The affected tissues include the
oral cavity, esophagus, forestomach, genitalia and skin,
all with keratinized, squamous epithelia. PCR analysis
of genomic DNA from neoplastic cells, isolated by
laser-capture microscopy from tumor-sections, has shown
that the tumors result not from the loss of
heterozygozity but due to the presence of a single,
functional copy of the Atp2a2 gene. The objective of
this project is to determine the effects of SERCA2 haploinsufficiency on responses to specific
environmental carcinogens using the multistage
mouse-skin carcinogenesis model. The studies included in
this project are significant for two reasons: (1) They
would indicate whether individuals with perturbed
calcium homeostasis constitute an “outlier population”
with increased susceptibility to environmental mutagens.
This is highly relevant to an aging population: calcium
handling becomes increasingly dysfunctional with age and
the incidence of cancer rises exponentially with age.
Currently, the relationship between aging and cancer is
often viewed simply in terms of the kinetics of the
several mutations needed to transform a cell. (2) They
would address the interplay between somatic mutations,
environmental mutagens and cancer; research into the
mechanistic details underlying cancer often ignores the
role of environmental agents in carcinogenesis.
|
Howard Shertzer, PhD
Department of Environmental Health
CYP1 Gene
Expression and Lung Cancer |
Dorothy Supp,
PhD;
Department of Surgery
Mutations in
the Melanocortin 1 Receptor Gene Increase the
Risk for Skin Cancer by Disrupting DNA Repair
Pathways
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Craig
Tomlinson, PhD;
Department of
Environmental Health
Gene
Expression Profiles to Predict Disease
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Nancy
Steinberg Warren, MS;
Genetic
Counseling Program, UC and Children’s
Hospital
Changing the Face of the Genetic
Counseling Profession
Genetics is fast becoming important in
all areas of clinical medicine and
public health. Genomic research has
identified genetic factors in the
etiology of heart disease, diabetes,
cancer, and psychiatric disorders and
advances in genetics hold tremendous
hope for better disease management.
Along with this hope, however, comes
concern about whether all people will
have access to genetic services that are
provided in a culturally appropriate
manner. It is documented in many health
professions that minority providers are
more likely to serve minority
populations and that underserved
patients are more likely to seek out
care from providers who share similar
cultural and community values. Given the
diverse, and constantly changing,
population demographics, it is critical
to train genetic counselors from diverse
backgrounds to best meet the needs of
the changing US population. The current
minority membership of the National
Society of Genetic Counselors is less
than 5%. Our primary goal is to
establish a Midwest Consortium of
Genetic Counseling Programs to develop a
three-year regional plan to promote
collaborative minority recruitment
efforts for genetic counseling training,
and to publish a white paper for
stakeholders describing the process and
outcomes. The Consortium will conduct an
intensive two-day Retreat, conduct
activities that to increase the number
of minority candidates who are
interested in and prepared for admission
to a genetic counseling graduate
program, and improve understanding of
and address the unique barriers to
minority recruitment into the
profession.
Update: An invited retreat focusing
on minority recruitment, entitled:
"Changing the Face of the Genetic
Counseling Profession" was held
on August 2-3, at the Hueston Woods
Resort & Conference Center. View the
brochure and agenda or
click
here to see pictures from the event.
|
Jianhua
Zhang, PhD;
Department of Cell
Biology, Neurobiology and Anatomy
An endonuclease in breast cancer
development
Breast cancer is a devastating
disease. One in eight women is at
risk in North America. Deficient
apoptosis is generally believed to
enable normal cells to gain survival
advantages and renders cancer cells
resistant to the cytotoxic effects
of chemotherapeutic agents. In
cooperation with increased cell
proliferation, decreased apoptosis
results in predisposition to
tumorigenesis and resistance to
therapy. How apoptosis is regulated
during normal mammary gland
involution and dysregulated in
breast cancer development is
unclear.
In
collaboration with Dr. Nelson
Horseman, we found that deficiencies
of a unique endonuclease cofactor,
DNA fragmentation factor 45 (DFF45),
result in a profound phenotype of
deficient apoptosis in mammary gland
involution. Based on this
observation and our general
understanding of mammary gland
physiology and mechanisms of
apoptosis regulation, we hypothesize
that DFF activity is necessary and
sufficient for mammary gland
apoptosis and is important for
prevention of mammary gland
tumorigenesis. To address the issue
of whether indeed a reduction of
apoptosis by DFF loss-of-function
predisposes to breast cancer, we
will take advantage of our already
generated DFF45-/- mouse model that
is defective of DFF function and
mammary gland involution to examine
the involvement of DFF in
tumorigenesis in response to
carcinogen and oncogene
overexpression. To explore
therapeutic potential of DFF
therapy, we will examine whether DFF
gain-of-function is sufficient to
suppress mammary gland tumorigenesis
in xenografts. This study may
provide a new understanding of the
development and progression of
mammary gland tumorigenesis, and
help design new strategies for
treatment for human breast cancer.
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2003
Pilot Project Summaries |
Michael
T Borchers, PhDDepartment of
Environmental Health
Michael.Borchers@uc.edu
CD8+
Cells in Chronic Obstructive Pulmonary
Disease
Chronic
obstructive pulmonary disease (COPD) is a
progressive disease of the airways. Smoking
is the single major cause of COPD but the
disease also results from or becomes
exacerbated by occupational and
environmental exposures. COPD affects > 10
million adults and is the fourth leading
cause of death in the United States. Only
10-20 % of smokers develop COPD suggesting
the influence of genetic heterogeneity in
the pathogenesis of this disease. COPD is
marked by the presence of increased
macrophages, neutrophils and CD8+ T cells
around the airways. A role for T cells in
the pathogenesis of COPD is suggested from
associations of increased CD8+ T cells in
the lung of smokers that develop COPD.
Acrolein (CH2=CH-CHO) is a respiratory tract
irritant that reproduces the lesions
associated with COPD in experimental
animals. Macrophage likely play a role in
the pathogenesis of COPD through the release
of proteases capable of breaking down
connective tissue and stimulating mucus
secretion. However, the roles of CD8+ T
cells in the development of COPD are
unknown. One hypothesis is that CD8+ T cells
represent a protective function of the
immune system that maintains the integrity
of the airways following injury but, when
accumulation persists, the effector
functions of these cells (e.g. macrophage
recruitment/activation) increase lung
pathology. This proposal seeks to identify
the temporal relationships between CD8+ T
cell and macrophage accumulation in the lung
as they coincide with the development of
COPD and examine the CD8+ T cell dependence
in COPD pathologies. |
|
Iain
Cartwright, PhD
Department of Molecular
Genetics
Email:
Iain.Cartwright@uc.edu
Expression Profiling of Arsenic
Susceptibility Variants
In several
parts of the world arsenic contamination of
the drinking water supply is having severe
pathological consequences. Investigations in
this laboratory of close to 60
geographically distinct strains of
Drosophila melanogaster have led to the
characterization of strains that show
significant variability in their
susceptibility to the toxic effects of
sodium arsenite. Detailed genetic analysis
of those strains that lie at the extremes of
the susceptibility distribution has enabled
us to define a small region of the X
chromosome that contains one or more loci
that are currently being tested in multiple
ways for their specific contributions to
this arsenite susceptibility phenotype. We
plan to capitalize on this information in
two ways. First, we will investigate, by
microarray-based expression profiling,
differences in gene expression between the
most sensitive and most resistant Drosophila
strains, both in the presence and the
absence of sodium arsenite. Second, an RNA
interference assay is currently being used
to evaluate the effects of loss of function
of candidate susceptibility genes on
survival of tissue culture cells in arsenite-containing
media. We will subject cells that show
dramatically enhanced arsenite
susceptibility upon specific mRNA ablation
to expression profiling both before and
after such mRNA ablation. By these combined
approaches we aim to provide a comprehensive
picture of relative gene expression patterns
in both cells and organisms that differ
genetically in respect of their sensitivity
to arsenite, and thereby provide a data
intensive platform on which to further
investigate the cellular response to this
form of environmental stress.
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Ranjan Deka,
PhD
Department of Environmental Health
Email:
Ranjan.Deka@uc.edu
Genetics of Type 2 Diabetes Related
Phenotypes in Adolescents: Development of a
Resource
Type 2
diabetes mellitus (T2DM) is a metabolic
disorder characterized by insulin
resistance, dysfunction of the pancreatic
beta cells and hyperglycemia. Generally
considered to be a disease of the adults,
there has been an alarming increase in its
incidence in children and adolescents
recently. It has been demonstrated that T2DM
has both genetic and environmental
components. While a number of studies have
been undertaken to elucidate the natural
history, epidemiology and pathophysiology of
T2DM in children and adolescents, to our
knowledge, no major study has yet been
initiated to understand the genetics of
intermediate phenotypes associated with
development of T2DM. Our goal is to develop
a major study in this direction focusing on
the genetics of intermediate phenotypes that
progress to T2DM in adolescents. In this
pilot project we will develop a resource and
preliminary data for this proposed study. We
will build this resource based on an ongoing
study ‘The landmarks in the progression to
type 2 diabetes study’ (NIH R01 DK59183; PI:
LM Dolan). Through this funded project, over
2500 blood samples have been collected from
children in the Princeton School district,
grades 5 through 12 and archived in Dr.
Deka’s laboratory. Our aims are to extract
DNA from these blood samples and type
genetic polymorphisms in two genes, calpain
10 and adiponectin, putative candidate genes
for T2DM and obesity. These DNA samples and
the preliminary data on the two candidate
genes will form the base for the proposed
major study on genetics of T2DM in
adolescents. |
|
Kathleen
Dixon, PhD
Department of Environmental
Health
Email:
Kathleen.Dixon@uc.Edu
DNA
Damage-Induce Phosphorylation and
interactions
between BLM and RPA
The purpose
of this proposal is to examine the role of
phosphorylation of two DNA
replication/repair proteins (BLM and RPA) in
protein/protein interaction and protein
function. Both proteins are phosphorylated
in response to certain genotoxic agents and
both are required for maintenance for
genomic stability. BLM is defective in the
genetic instability syndrome, Bloom’s
syndrome (BS)[1]; RPA phosphorylation is
defective in the human genetic instability
syndrome, ataxia telangiectasia (AT) [2].
The specific aims of this proposal are as
follows:
Aim 1: To
characterize DNA damage-specific
phosphorylation of BLM and RPA
Aim 2: To
determine the effect of phosphorylation on
BLM/RPA interaction
Aim 3: To
determine the effect of phosphorylation on
the DNA unwinding activity.
The long
term goal of this proposed research is to
understand the role of DNA damage-induced
phosphorylation of BLM and RPA in DNA
replication and DNA double strand break
repair. Ultimately these studies may provide
insights into the relationship between these
particular genes (BLM and ATM) and
environmental susceptibility; in addition,
they may serve as a paradigm for the role of
protein phosphorylation in the regulation of
DNA replication and DNA repair following
environmental insult. |
|
Mary Beth
Genter, PhD
Department of Environmental
Health
Email:
MaryBeth.Genter@uc.edu
Mechanism and Gender Specificity of
Naphtalene Carcinogenicity
Naphthalene (NP) is the major chemical
component of both whole and filtered
cigarette smoke and is a rodent
respiratory tract carcinogen. These data
cloud the assessment and perception of
human health risks associated with NP,
as NP-based consumer products have been
widely available for many years.
Cigarette smoke is a complex mixture of
direct and indirect acting carcinogens,
irritants, and particles, but the
precise contribution of NP to tobacco
smoke-associated pulmonary disease is
unclear. Several studies suggest that
human females are more susceptible to
components of tobacco smoke than males,
and female mice are susceptible to
NP-induced lung cancer, whereas male
mice are resistant. These observations
suggest that gender-specific metabolic
pathways and/or hormone-mediated
pathways may contribute to
susceptibility to NP-induced
carcinogenesis. While it is known that
several cytochromes P450 contribute to
the bioactivation of NP, and several
Phase II enzymes aid in detoxification,
differences in their levels in male vs.
female lungs are unknown. We will gain
an understanding of NP-induced
respiratory tract carcinogenesis by
testing the hypothesis that direct
comparison of the metabolic responses of
male and female mouse lungs to NP will
reveal genes and proteins critical in NP
carcinogenesis. We will do this by
determining the ratio of cyp2f2 to
microsomal epoxide hydrolase in female
vs. male mouse lung; comparing gene
expression in control and NP-treated
female and male mouse lung; and
determining whether one or more target
tissue-generated NP metabolites is
capable of estrogen receptor activation.
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Gurjit
Khurana Hershey, MD, PhD
Division of
Asthma and Allergy; CCHMC
Email:
Gurjit.Hershey@cchmc.org
Gene-Environment Interactions in Asthma
Outcome
The
pathogenesis of asthma is complex, depending
on genetic and environmental variables. As
the pool of candidate genes for asthma
continues to grow, a necessary next step is
to understand how environmental and genetic
factors work together to contribute to
asthma, especially in early childhood when
asthma often begins. The central hypothesis
of this proposal is that genetic and
environmental factors are critical to the
natural history of asthma in children. To
test this hypothesis we will focus on 3
specific aims. In Aim #1, we will determine
whether immune-related polymorphisms are
associated with asthma in children and
elucidate genotype:phenotype relationships.
We will recruit children with asthma from
the Allergy/Immunology clinics at Children’s
Hospital Medical Center and then genotype
them for snps implicated in asthma. We will
examine the effect of each gene individually
as well as together with other genes as
complex haplotypes. In Aim #2, we will
relate genotype to disease outcome. The
Children's Health Survey for Asthma (CHSA)
will be used to quantify disease related
quality of life for comparison across
genotypes. In Aim #3, we will relate the
effect of mold and dust mite allergen levels
to asthma severity and outcome in sensitive
subjects. We will determine if and how
indoor allergen levels correlate with asthma
symptoms and quality of life in sensitive
and non-sensitive subjects. Furthermore, we
will relate this to the genetic data to
determine if a given genotype is associated
with a certain response to the environmental
load of mold or dust mite.
|
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Dan Nebert, MD
Department of Environmental Health
Email:
Dan.Nebert@uc.edu
Association between the AHR Genotype and
Risk of Head- and Neck Cancer among Smokers
Cytochromes
P450 1A1, 1A2 and 1B1 (CYP1A1, CYP1A2,
CYP1B1) are responsible for both the
detoxication and metabolic activation of
innumerable polycyclic hydrocarbons (PCHCs)
and arylamines present in cigarette smoke.
The dioxin- and PCHC-inducible
CYP1A1/1A2/1B1 genes are up-regulated by the
aromatic hydrocarbon receptor (AHR), which
binds these inducing chemicals and activates
transcription. Metabolic activation of many
of these and other environmental chemicals
is associated with toxicity and cancer. Only
7-10% of cigarette smokers develop cancer of
the lung or head-and-neck, strongly
suggesting a gradient from “highly
sensitive” to “highly resistant” patients
with regard to cigarette smoking-induced
cancers. Numerous laboratory animal studies
have shown that striking genetic differences
in the CYP1A1/1A2/1B1 enzyme levels and in
AHR affinity are directly correlated with
cancer risk caused by PCHCs and arylamines.
A systematic study to search for allelotypes
and haplotypes of the human CYP1A2/1A2/1B1
and AHR genes has not yet been done but is
now possible, due to available data in the
Celera database. The CYP1A1 (6.31 kb) and
CYP1A2 (7.8 kb) genes are oriented
head-to-head, and 24,455 bp apart, on Chr
15q22-24. The CYP1B1 gene spans 8.5 kb on
Chr 2p21. The AHR gene spans 47.2 kb on Chr
7p15. Hypothesis: specific allelotypes and
haplotypes of the CYP1A1/1A2/1B1 and AHR
genes are associated with increased risk of
head-and-neck cancer in cigarette smokers.
We propose to select 100 “most sensitive”
and 100 “most resistant” head-and-neck
cancer patients from Professor Gluckman’s
patient population (cohort of more than
4,200) and perform SNP-typing of these four
genes. |
|
Yoli
Sanchez, PhD
Department of Molecular
Genetics
Email:
sanchey@email.uc.edu
The
Role of Sfp1 in the response to DNA damage
Genomic
integrity is safeguarded in part by checkpoints,
which are biochemical pathways that provide
cells with a mechanism to detect DNA damage and
respond by arresting the cell cycle to allow DNA
repair. The checkpoint response also involves
the transcriptional induction of genes whose
products are involved in DNA metabolism, DNA
repair and cell cycle arrest.
Chk1 is a
conserved checkpoint kinase that is
differentially phosphorylated in response to
different types of DNA damage lesions. In the
past 5 years the picture of how the kinases
signal cell cycle arrest in response to
different lesions has begun to emerge. However,
little is known regarding the mechanism by which
signals from different lesions are integrated by
the transcriptional regulatory network. We have
found that the transcription factor Sfp1, like
Chk1, is phosphorylated in response to ionizing
radiation and oxidative stress. This suggests
that Sfp1 function is regulated by the response
to oxidative damage to DNA. Like Chk1, the
transcription factor Sfp1 is differentially
modified in response to different genotoxic
agents. Therefore, Sfp1 represents a
transcriptional target for specific DNA lesions.
Using biochemical and genomic approaches in
conjunction with the genetically amenable
budding yeast model system we will dissect the
regulatory switches controlling transcriptional
response (or transcriptional repression) to
specific lesions caused by cellular and
environmental agents. A goal of this proposal is
to determine the role that checkpoint signaling
plays in the regulation of the transcriptional
response to oxidative and radiation-induced DNA
damage.
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2002
Pilot Project Summaries |
Zalfa Abdel-Malek, PhD.
Dermatology
Email:
abdelmza@email.uc.edu
Loss-of-function mutations in the
melanocortin 1 receptor gene
sensitize melanocytes to the
photodamaging effects of UV
radiation
The
synthesis of eumelanin in human
melanocytes (hMC) is mainly regulated by
the melanocortin 1 receptor (MCIR), the
receptor for the melanocortins
alpha-melanocyte stimulating hormone
(alpha-MSH) and ACTH. Population studies
have shown that specific mutations in
the human MCIR gene are associated with
red hair phenotype, poor tanning
ability, and increased risk for melanoma
and nonmelanoma skin cancer. We have
found that hMC that naturally express
these mutations fail to respond to
alpha-MSH and are hypersensitive to the
cytotoxic effect of ultraviolet
radiation (UVR). Further, we found that
alpha-MSH reduces the UV-induced
apoptosis and promotes the survival of
hMC. The survival of hMC is only
beneficial if accompanied with genetic
stability. The main goal of this pilot
project is to investigate the hypothesis
that loss-of-function mutations in the
human MC1R gene sensitize hMC to the
photodamaging effects of ultraviolet
radiation (UVR), thus increasing the
risk for skin cancer. |
|
Scott
M Belcher, Ph.D.
Pharmacology and
Cell Biophysics
Email:
Scott.Belcher@uc.edu
Proteomic analysis of differential
estrogen sensitivity in developing
neurons
The
Specific Aim of this proposal is to
define changes in expressed proteins
that may contribute to differential
sensitivity of developing and mature
cerebellar neurons to estrogenic
compounds. This aim is built around
our laboratory's observation that
transient activation of mitogen
activated protein kinase (MAPK) by
0.01nM 17b-estradiol (E2)
differentially influences viability
of immature and mature cerebellar
neurons. We hypothesize that
specific changes in protein
expression and phosphorylation
underlay the differential
E2-sensitivity of these two neuronal
populations. The proposed pilot
studies employ two-dimensional (2D)
gel electrophoresis to identify
differences in expression levels and
phosphorylation-state of the
expressed proteins (proteome) of
primary cultures of E2-sensitive and
that of insensitive mature
cerebellar neurons. The identity of
differentially expressed proteins
will be determined by MALDI-mass
spectrometric (MS) peptide mass
fingerprinting analysis by the CEG's
protein analysis core. These studies
will likely identify important
proteomic differences that
contribute to neuronal sensitivity
to endogenous and environmental
estrogens during neuronal
development. |
|
Nira Ben-Jonathan, Ph.D.
Cell
Biology, Neuorobiology and Anatomy
Email:
Nira.Ben-jonathan@uc.edu
Xenoestrogens and differential
pituitary gene expression profiles
in estrogen-sensitive and
estrogen-insensitive rat strains
Xenoestrogens are chemicals with diverse
structures that mimic or interfere with
the action of endogenous estrogens.
Bisphenol A (BPA), a monomer of
polycarbonate plastics, is abundant in
the environment, binds to the estrogen
receptor (ER) and act as a partial
estrogen agonist or as an antagonist. We
previously reported that BPA induced
lactotroph proliferation, increased
pituitary prolactin (PRL) secretion,
altered the expression of ER-alpha,
ER-beta and c-fos in the pituitary and
downregulated tyrosine hydroxylase (TH)
in the hypothalamus. Given the multiple
interacting pathways and the cascade of
signaling molecules that are activated
by estrogens and xenoestrogens, the best
approach for comparing their overall
effect is by using the gene array
technique. This technique can
simultaneously determine the relative
expression of multiple
hormonally-responsive genes rather than
one or two genes at a time. Our overall
objective is to use two strains of rats
that differ in their
estrogen-sensitivity and compare the
effects of BPA and estradiol (E2) on
global pituitary gene activation. The
DNA gene profiling is a new direction
undertaken by our laboratory to better
understand the spectrum of biological
effects of xenoestrogens with the
ultimate goal of generating sufficient
preliminary results to serve as a
foundation for extramural funding.
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|
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Idiopathic environmental intolerance
(IEI) represents a complex
gene-environment interaction, about
which little is known. We propose to use
a genomics approach to begin to dissect
this complex disease. A subset of IEI is
vasomotor rhinitis (VMR), which can be
further divided into allergic and
nonallergic types. There is experimental
evidence suggesting that nonallergic VMR
has a strong olfactory/gustatory
component. The major histocompatibility
region (MHC) on human Chr 6 is known to
be involved in numerous allergic and
immune responses. Our hypothesis is:
differences in the genotype [SNPs in
olfactory receptor (OR) genes] can be
associated with the phenotype
(nonallergic VMR), whereas the genotype
of the MHC region, known to be
associated with allergic/immune
conditions, will not be correlated with
the nonallergic VMR phenotype. In the 1
year of funding, we therefore will: (a)
select 25 "most severely
affected/unequivocal cases of non
allergic VMR" patients who are
documented to have no atopy and who have
both a mother and father available for
testing; (b)] use the
candidate-gene-region approach,
examining DNA from these patients and
their parents for polymorphisms in the
two largest OR gene clusters, located on
Chr 11, plus the MHC region on Chr 6 (as
control); and (c) search in these family
studies for genotype-phenotype
associations, using the transmission
disequilibrium test (TDT)-in which the
"other chromosome" serves as the
control. Finding a significant
genotype-phenotype association for
explaining this complex environmental
/genetic disease would not only be
exciting and publishable, but would also
provide important preliminary data for
submitting a more substantial RO 1
proposal to request NIH funding. This
approach might lead to important insight
into a complex disease about which
almost nothing is known. |
|
Bandana Chakraborty, Ph.D.
Environmental Health
Email:
Bandana.Chakraborty@uc.edu
Effects of lead exposure and
genes on postural balance
Researchers at the Department of
Environmental Health and their
collaborators have had a
long-term interest in studying
the effects of chronic early
life lead exposure on children's
health, leurobiological, and
cognitive impairments. A key
observation from the data from
the Cincinnati Lead Program
Project (CLPP), a study
initiated in late 1970s in the
inner Cincinnati neighborhoods
to examine the effects of
chronic lead exposure on health,
behavior, and growth of
children, is that the ability to
maintain upright postural
balance in six-year old children
is significantly impaired with
an increase in their blood lead
levels, independent of the
socio-economic, racial and
environmental factors. An
independent study showed that
postural balance might be
influenced by genetic factors,
such as the genotypes at a
glutathione S-transferase (GST)
gene locus (Bhattacharya et al.,
unpublished data). Evidences are
also accumulating, suggesting
that one or more genes, acting
singly or in interaction with
each other, may modify the
toxicokinetics of lead
absorption. Polymorphisms at the
d-Aminolevuline Acid Dehydratase
(ALAD), Vitamin D Receptor
(VDR), and members of the
GST-gene cluster (e.g., GSTM
-locus genotypes) are examples
of such genetic modifiers of
lead exposure induced
leurobiological consequences in
human. Although associations
with lead exposure are yet to be
proven, polymorphisms at
dopamine receptor (DRD2, DRD3,
and DRD4), dopamine transporter,
Monoamine oxidase-A and B
(MAO-A, MAO-B), CYP1D6, and
Nat-2 loci are also implicated
in leurocognitive disabilities.
From such data, we hypothesize
that certain specific genotypes,
singly, or acting in combination
with each other, may
differentially affect the
neurobiological impairment in
children induced by lead
exposure. From the cohort
recruited in the Cincinnati Lead
program Project (CLPP),
approximately 160 children (for
whom informed consent for
genetic analyses of blood are
available and who participated
in earlier postural balance
measurement studies) will be
typed for genotype
determinations (through DNA
malysis) at 10 candidate genes.
Pilot data on these genotypes
will be analyzed to seek for
evidence of gene-gene and
gene-lead exposure interaction
effects on upright postural
imbalance (an indicator of
leuromotor impairement), an
end-point earlier shown to be at
least partially lead exposure
induced.
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Gary Dean, Ph.D.
Molecular
Genetics, Biochemistry and
Microbiology
Email:
Gary.Dean@uc.edu
Worms
and bacteria as environmental tools
How we
teach science education in the United
States is currently undergoing a
thorough re-evaluation. An inquiry based
science curriculum is the current
working model on how to teach science
effectively (National Science Standards,
Project 2061) .We propose to give school
children the opportunity to actively
investigate a problem in biodegradation
by a sound scientific process. The
system involves the microbe Pseudomonas
aeruginosa to detoxify chemical agents
in soil. This detoxification will be
measured by the ability of earthworms,
Allolbophora caliginosa to survive and
lignify toxins. Measurement of earthworm
survival will be measured either
directly by determining their biomass or
indirectly by growing a known quantity
of e.g. soybeans and measuring their
biomass. The scientific education
directions unlocked by this program for
teachers include microbiology, chemical
degradation, spectrophotometry, soil pH,
earthworm anatomy, photosynthesis, etc.
to name a very few. In addition, the
number of potentially interesting and
scientifically novel projects (that
could yield useful data) that could
arise could be equally large; these
might include cataloguing the types of
chemicals that Pseudomonas can treat,
isolation of mutants that treat novel
compounds, selection of earthworms for
particular traits, etc. |
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Mary
Beth Genter, PhD
Environmental
Health
Email:
MaryBeth.Genter@uc.edu
Genetic factors contributing to
alachlor carcinogenesis
The
chloracetanilide herbicides,
including alachlor, are used world
wide for preemergent weed control in
such economically-important crops as
corn, soybeans, peanuts, and rice.
It was estimated that >120 million
pounds of alachlor, metolachlor and
acetochlor was used in the United
States, with other chloracetanilides
(e.g. butachlor and pretilachlor)
widely used in Asian countries for
rice production. These herbicides
are associated with a complex,
species-dependent range of neoplasm:
in laboratory animals; rats treated
chronically with alachlor develop
tumors of the thyroid gland,
stomach, and nasal cavity; brain
tumors found in some rats were felt
to be extensions of olfactory
mucosal tumors, rather than primary
tumors. Our laboratory has shown
that the outbred Long-Evans rat
strain develops olfactory mucosal
tumors following 5 mo of daily
exposure to alachlor (126 mg/kg/day
in the diet), and rats have 10-20
olfactory mucosal polypoid
adenomas/adenocarcinomas per rat
with >6 mo of treatment with
alachlor. Mice, on the other hand,
are reported to develop only lung
adenocarcinomas upon chronic
alachlor exposure. The results of
the mouse bioassay should be
interpreted with caution. This study
was conducted in female CD-1 mice,
which tend to display a slow
acetylation phenotype; however, we
have data suggesting that
acetylation is important in the
bioactivation of alachlor in the
olfactory mucosa. Therefore slow
acetylators would be predicted to be
resistant to alachlor-induced
olfactory mucosa tumors, and we
would propose that rapid
acetylators, e.g. C57BL mice, would
be susceptible.
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Susan Pinney, Ph.D.
Environmental
Health
Email:
Susan.Pinney@uc.edu
Population representative case:
Control series for an association
study of Parkinson's disease
Our
primary hypothesis remains that there
are specific genotypes that greatly
increase the risk of developing
Parkinson's disease through interaction
with pesticides, metals or other
environmental exposures. In the US,
incidence of Parkinson's Disease is
expected to triple over the next 50
years as the population ages. Numerous
studies of PD have suggested have
suggested both genetic and environmental
factors in its multifactorial etiology.
A small fraction (<5%) of PD cases occur
in high-risk families suggesting
inheritance as an autosomal dominant
trait. However, susceptibility genes for
the common adult onset idiopathic form
of PD have not been identified. Clusters
of genes with low penetrance alleles
that interact with environmental,
occupational, or lifestyle risk factors
may be involved in the multifactorial
etiology of PD. Previous studies have
not addressed whether gene-environment
interactions have significant impact on
disease risk additional to the separate
effects of heredity and environment. The
Specific Aims of this pilot project are:
1) To identify and recruit an additional
50 case and 50 control subjects for the
proposed study, and obtain detailed
exposure history and clinical
information; 2) To obtain blood samples
from these case and control subjects and
use extracted DNA to examine for genetic
polymorphisms of candidate genes; 3) To
improve our methodology for control
identification, recruitment and specimen
collection. |
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