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Carol Bier-Laning, MD
Genetic instability initiated by apoptotic DNA cleavage in cancer cells
American Cancer Society – Illinois Division
07/01/08 – 06/30/09
$69,852
Cancer occurs as the result of multiple genetic abnormalities occurring
within a single cell. This proposal seeks to understand the mechanism of
one type of genetic abnormality that results from the loss of part of a
chromosome and is known as loss of heterozygosity or LOH. Understanding
the mechanism of this loss of genetic material is crucial because it
represents an important site to target for treatment. When we more
clearly understand how LOH occurs, we can design treatments that could
act by preventing LOH and thereby interrupt the sequence of events that
leads to a cell becoming cancerous. Alternatively, we could design
treatments that could force cells that undergo LOH to self destruct so
that they no longer exist as precancerous targets. Not only could such
treatments be aimed at curing existing cancers, but treatments could be
targeted at prevention of cancers as well. Such treatment would be
applicable to many types of cancer since LOH is common to many different
forms of cancer.
Loss of heterozygosity initiated by apoptotic DNA cleavage in head &
neck cancer
Triological Society
08/01/08 – 07/31/09
$40,000 Loss of heterozygosity (LOH) is important in tumorigenesis. The
mechanism of LOH is currently thought to be a random result of
chromosome non-disjunction during mitosis or of somatic homologous
recombination. We propose that an alternate mechanism of LOH in head and
neck cancer is apoptosis-initiated DNA cleavage at specific chromosome
sites with repair by non-homologous end joining (NHEJ). Such cleavage
may be due to apoptotic nucleases such as caspase-activated DNase (CAD).
Resultant LOH may be transmitted to progeny if they abort apoptosis and
divide.
Maurizio
Bocchetta, PhD
Targeting Notch-1 in adenocarcinoma of the lung:
New therapeutic strategies
Riviera Country Club and Sports Center
04/01/08 – 03/31/09
$20,000
Non-Small Cell Lung Cancer (NSCLC) is the leading
cause of cancer-related deaths in the U.S. Among the three major
histological types of NSCLC, adenocarcinoma of the lung (ACL) is the
most prevalent, and the incidence is steadily rising. ACL is relatively
common (from 15-20% of cases) in people who have never smoked, is
normally diagnosed at advanced stages because early detection remains
problematic, and median survival after advanced ACL diagnosis is only
five months. It is therefore imperative to find novel strategies to
treat this deadly disease.
In this project we plan to target the Notch pathway in advanced ACL
using small chemical inhibitors in preclinical mouse models. This
approach has proven very promising in vitro (Chen et al., Cancer Res 67:
7954-9).
Rutao Cui, MD, PhD
The Role of
Pheomelanin in DNA Damage and Repair
American Cancer Society – Illinois Division
04/01/08 – 03/31/09
$100,000Ultraviolet (UV)
radiation represents a definitive risk factor for skin cancer,
particularly in combination with certain underlying genetic traits such
as red hair and fair skin. Skin pigmentation results from the synthesis
of melanin in pigment-producing cells, the melanocytes, followed by
distribution and transport of the pigment granules to neighboring
keratinocytes. Epidemiological studies have found less skin cancer in
people who have high levels of constitutive pigment and/or tan well.
However, we cannot account for other factors vital in the development
of skin cancer such as capacity to repair photo-damage in people of
different skin colors. This research is focused on the role of
pheomelanin in DNA damage, at both genomic and individual nucleotide
levels, and on the subsequent activation of DNA repair, alteration in
chromatin structure, and ultimately melanoma formation. Our hypothesis
is that pheomelanin contributes to UV-induced DNA damage that is
incompletely repaired. Although the DNA repair may be activated to a
larger extent in response to the greater DNA damage in pheomelanin
containing skin, the repair will be insufficient to eliminate all
mutagenic adducts.
Transactivation of POMC/MSH in suntan response and skin cancer
prevention
Pardee Foundation
09/01/08 – 08/31/09
$125,000
The research proposed here is focusing on understanding the mechanisms
that underlie UV-mediated expression of a- Melanocyte Stimulating
Hormone (MSH), the role of p63 (family member of p53) in POMC induction,
and the possibility of mimicking this pathway using small molecular
compounds. Preliminary data suggests that p63 binds to
pro-opiomelanocortin (POMC) promoter in keratinocytes. We have also
discovered several additional cytokines whose expression is induced by
UV in a p53-dependent fashion in kerationcytes. We propose to explore
the molecular pathways that are involved in this induction with an aim
to understanding their roles in melanocyte activation in response to UV.
At the same time, the correlation between p53 polymorphisms and skin
response to UV will also be examined. Finally, transgenic, p53-null and
wild-type mice will be used to study whether topically delivered
Nutlin-3, a small molecule inhibitor of the mdm2:p53 interaction, is
capable of stimulating p53 and inducing skin pigmentation.
Kimberly Foreman, PhD
Targeting Notch signaling and hepatocyte growth
factor in breast cancer
Ticket for a Cure Program, Illinois Department of Public Health
1/01/08 – 6/30/09
$100,000 Breast cancer is the second leading cause of
cancer deaths among women. Recent studies have identified Notch
signaling as an exciting new therapeutic target for breast cancer based
on studies showing Notch signaling is activated in breast cancer cells
in vitro and in vivo, and Notch inhibition (using gamma-secretase
inhibitors) can kill breast cancer cells in vitro. Hepatocyte growth
factor (HGF) is a multifunctional protein produced primarily by stromal
cells that enhances cell survival and angiogenesis. A recent report
indicates HGF can induce Notch ligand expression in head and neck
cancer. These ligands can engage Notch receptors on adjacent endothelial
cells resulting in capillary-like network formation. Here we present new
data demonstrating HGF, which is overexpressed in breast cancer, induces
Notch expression and activation in breast cancer cells and can activate
Notch in endothelial cells resulting in network formation. HGF-induced
Notch activation also promoted cell survival as treated cells were able
to resist cell death induced by a potent Notch inhibitor. The overall
hypothesis of this study is that HGF promotes breast cancer progression
by deregulating Notch signaling leading to cell survival and
angiogenesis. This hypothesis will be tested in three specific aims (1)
to determine the mechanisms by which HGF protects breast cancer cells
from cell death induced by Notch inhibition (2) to explore the role of
HGF-induced Notch signaling in crosstalk between breast cancer cells and
endothelial cells resulting in angiogenesis and 3) to determine the
effect of HGFinduced Notch signaling in an in vivo model of breast
cancer. Notch inhibitors are currently in clinical trials for treatment
of breast cancer. Our data suggest that HGF promotes tumor progression
by inducing Notch activation, and can rescue breast cancer cells from
death induced by Notch inhibition. This data indicates blockade of both
Notch activation and HGF may be essential to effectively treat patients
with breast cancer. The proposed studies may have significant clinical
implications, and successful completion of the work may provide critical
mechanistic information necessary to pursue Notch inhibitors as a
therapeutic option for breast cancer patients.
Targeting Notch signaling in breast tumor initiating cells
American Cancer Society – Illinois Division
07/01/08 – 06/30/09
$99,909
A model of mammary carcinogenesis has emerged suggesting that
breast cancer originates from a subset of tumor cells referred to as
tumor initiating cells (TIC) or cancer stem cells. These cells possess
key properties of normal stem cells including the ability to self-renew,
unlimited proliferative capacity, slow replication, and resistance to
many chemical insults. In contrast, the bulk of the tumor is composed of
TIC daughter cells that have arrested in various stages of
differentiation. These cells have a limited replicative capacity, divide
rapidly, and are more sensitive to toxic agents. It has been suggested
that chemotherapy effectively targets the majority of tumor cells, but
TIC persist and eventually cause relapse and metastatic disease. The
Notch signaling pathway is an important mediator of mammary gland
development and has been implicated in mammary stem cell self-renewal
and differentiation. Deregulated Notch signaling has been identified in
breast cancer and is associated with a poor prognosis. We hypothesize
that breast TIC for one or more subtypes of breast cancer are dependent
upon Notch activity for self-renewal, proliferation, differentiation,
and/or survival. We propose to investigate Notch signaling in breast TIC
derived from different subtypes of primary human breast cancer, and
determine if Notch inhibition can selectively kill them or make them
vulnerable to standard chemotherapeutic agents.
Targeting Notch signaling and hepatocyte growth
factor in breast cancer
Susan G. Komen Breast Cancer Research Foundation
07/09/08 – 06/30/11
$586,582
One of the most promising new approaches for treating breast cancer is
inhibition of the Notch signaling pathway. Notch proteins play a fundamental
role in cell fate decisions and deregulated Notch signaling is associated with
breast cancer. Gamma secretase inhibitors (GSIs, which block Notch activation),
are known to kill breast cancer cells in preclinical studies; however, it is
unknown how to best utilize them to treat human disease. In this study, we seek
to demonstrate that hepatocyte growth factor (HGF, a cytokine that engages the
c-Met receptor tryosine kinase and is involved in tumor progression,
angiogenesis and cell survival) is able to preserve Notch expression /
activation in breast cancer cells and protects the cells from GSI-induced death.
Our results to date suggest that we have discovered a new signaling mechanism
linking HGF / c-Met and Notch with respect to cell survival. In addition, HGF
promotes expression of Notch ligands on breast cancer cells that activate Notch
on adjacent endothelial cells to promote angiogenesis. As HGF is commonly
overexpressed in advanced breast cancer.
Charles Hemenway, MD, PhD
Disrupting the AF4-AF9 protein complex in MLL leukemias.
National Cancer Institute
03/12/08 - 02/28/10
$258,390
Despite improvements in the treatment of leukemia, some
forms of the disease remain resistant to therapy. Here, we describe a
system to rapidly identify chemicals that may serve as new drugs for the
treatment of one of the most resistant forms of acute leukemia. The
ultimate goal of this project is to develop promising new agents for the
treatment of acute lymphoblastic leukemia (ALL) characterized by a
specific t(4;11) chromosome translocation, a relatively common subtype
of ALL unusually resistant to cytotoxic chemotherapy. The isolation,
validation, and optimization of new compounds to treat t(4;11) leukemia
is important given the limitations of currently available treatments.
Caroline Le Poole, PhD
Chemopreventive Treatment of Familial Melanoma
National Cancer Institute
07/01/07 – 06/30/09
$148,500
Several
tumor types are currently associated with specific gene mutations.
Individuals carrying such mutations may undergo elective surgery of
targeted organs to prevent cancer. This option has not been available to
familial melanoma patients, where cells prone to undergo malignant
transformation are dispersed throughout the basal layer of the
epidermis. Here we propose to selectively eliminate melanocytes from the
skin to prevent tumorigenesis in patients with familial melanoma.
Melanocytes and their malignant derivatives uniquely express tyrosinase,
the rate-limiting enzyme responsible for melanogenesis and pigmentation
of the skin. Tyrosinase catalyzes the conversion of substrate amino acid
L-tyrosine to L-DOPA as well as of L-DOPA to dopaquinone, rendering a
product ultimately converted to melanin. Several compounds have been
described that cause depigmentation of the skin through competitive
inhibition of the tyrosinase enzyme. These same compounds are cytotoxic
to melanocytic cells when converted into toxic orthoquinones by
tyrosinase. In contrast to dopaquinone, reaction products from
competitive tyrosinase inhibitors cannot be converted into the radical
scavenging molecule melanin. Cell death thus results selectively in
tyrosinase expressing cells, including melanocytes and melanoma cells.
Whereas such prodrugs can themselves be toxic upon systemic use,
bleaching phenols have been approved for topical use in skin
depigmenting creams for patients with progressive vitiligo. When
topically applied these compounds selectively deplete melanocytes from
the epidermis. The cytotoxic activity of bleaching phenols further
generates a source of melanocyte differentiation antigens that are
processed by skin infiltrating dendritic cells which, in turn, leads to
an autoimmune response to melanocytes and progressive loss of skin
pigmentation. Vitiligo is commonly considered an undesirable autoimmune
condition, yet the development of progressive depigmentation is a
positive prognostic sign for melanoma patients, reflecting immune
reactivity to antigens shared between melanocytes and melanoma cells.
Here we hypothesize that topical application of well characterized
depigmenting agents can be used to combat melanoma by a 2-tierd
approach, through eliciting anti-tumor immune responses to the tumor and
through depletion of melanoma precursor cells. This approach is thus of
particular importance for patients that carry mutations in p16/Arf or
CDK4 genes contributing to familial melanoma. In these patients the
presence of melanocytes is a constant concern for the development of
future melanomas. We propose to test our hypothesis according to the
following specific aims:
1] To generate p16/Arf knockout mice that express pigmented melanocytes
in the epidermal compartment
2] To assess skin depigmentation in SCF transgenic mice in response to
monobenzyl ether of hydroquinone and 4-tertiary butyl phenol.
3] To quantify tumor growth and measure immunologic parameters in mice
treated with and without bleaching agents in combination with IL-2.
Caroline Le Poole, Ph.D.
Targeting HSP70 in autoimmune vitiligo
National Institute of Arthritis, Musculoskeletal and Skin Diseases
09/01/08 - 08/31/13
$1,664,321 In vitiligo, skin depigmentation is associated with focal infiltrates of
CD8+ cytotoxic lymphocytes reactive, at least in part, with melanocyte
differentiation antigens. In melanoma, a similar T cell mediated immune
response targeting melanocyte differentiation antigens is observed where
breaking of tolerance to self antigens can be explained by the
increasing abundance of target antigens. In vitiligo however, a
qualitative difference involving HSP70 appears to be crucial for
breaking of tolerance to melanocyte differentiation antigens. We
hypothesize that eliminating HSP70 as a key player in precipitating and
perpetuating the autoimmune response to melanocytes will halt the spread
of vitiligo. We propose to further demonstrate a crucial role for HSP70
in vitiligo and to derive therapeutic intervention methods potentially
suitable for treatment of progressive disease.
Lucio Miele, MD, PhD
PKC Alpha as a Marker for Logical Therapeutic Approaches to Breast
Cancer
National Cancer Institute/University of Illinois-Chicago
06/01/07 – 03/31/12
$350,000
For the past 30 years, tamoxifen (TAM) has been the most often
prescribed endocrine treatment for breast cancer. In the past few years
it was demonstrated that aromatase inhibitors are superior to TAM as
adjuvant therapy in the postmenopausal patient population. Furthermore,
aromatase inhibitors are effective as a second-line treatment following
the emergence of TAM resistance and are being tested in the
chemoprevention setting. This will bring a paradigm shift in the
standard endocrine therapy for breast cancer in the near future.
Identification of the key factors involved in the molecular mechanism of
resistance to both TAM and aromatase inhibitors will undoubtedly lead to
the development of logical therapeutic targets. We have developed and
characterized a preclinical model of TAM resistance in the
hormone-dependent T47D:A18 cell line that was engineered to overexpress
protein kinase C alpha (PKCa). Tumors derived from these cells grow in
athymic mice in an estrogen (E2)-independent and TAM-resistant fashion.
Based on this model we examined clinical specimens and discovered that
overexpression of PKCa is frequently associated with TAM resistance in
human breast cancers. More recent preliminary data indicate that the
T47D:A18/PKCα cells and tumors express high levels of Notch-4, a known
breast oncogene and putative marker of breast cancer stem cells. Most
interesting is our finding that T47D:A18/PKCα TAM-resistant tumors
regress in the presence of E2 or raloxifene. This study will explore the
opportunity to utilize PKCα overexpression as a guide for therapeutic
choice. The T47D:A18/PKCα breast cancer tumor model will be used to
explore three therapeutic treatment strategies: (1) the opposing actions
of tamoxifen and raloxifene and the potential therapeutic application of
raloxifene and other SERMS, (2) the role of Notch4 and effect of Notch
inhibitors in TAM-resistance; and (3) the efficacy of estrogen as
compared to aromatase inhibitor therapy. Relavance: The emergence of
tamoxifen-resistant breast cancer is a critical problem in the
management of advanced disease. Since essentially all patients with
metastatic disease will relapse during tamoxifen treatment, alternative
therapeutic strategies are needed. This proposal will address three
potential approaches to treatment based on protein kinase C alpha (PKCa)
as a biomarker to guide therapeutic choice.
Clodia Osipo, PhD
ErbB-2 inhibition activates Notch-1: A novel therapeutic
combination
American Cancer Society
– Illinois Division
01/01/08 – 12/31/08
$100,000
30% of women with breast
cancer have ErbB-2-positive tumors. These tumors are malignant and women
bearing such tumors have the worst prognosis. ErbB-2 is activated on the
cell surface by growth factorinduced interaction with EGFR, ErbB-3, or
ErbB-4. Activated ErbB-2 sends signals from the surface to inside the
cell to stimulate tumor growth. Trastuzumab (Herceptin®) blocks ErbB-2
at the cell surface, inhibits receptor-receptor interaction, activation,
and signaling inside the cell to slow growth. Unfortunately, Herceptin®
alone is only effective in 26% of women and combining Herceptin® with
chemotherapy increases the overall benefit to 50-60% with a significant
increase of 13% in cardiac toxicity. Therefore, it is critical to
understand how ErbB-2 is activated and what other pathways
cross-communicate with ErbB-2 to regulate its growth signal.
Recently, another receptor, Notch is activated and shown to cause breast
cancer. Specifically, high coexpression of Notch1 and its ligand,
Jagged-1 was observed in breast cancer with the poorest overall
survival. Our preliminary results show a novel crosstalk between ErbB-2
and Notch-1 in ErbB-2-positive breast cancer cells which will have
consequences for current therapies. Overexpression of ErbB-2 inhibits
Notch-1 and Herceptin® or a dual EGFR/ErbB-2 tyrosine kinase inhibitor (TKI)
similar to Lapatinib reactivates Notch-1. Conversely, Notch-1 activates
ErbB-2 creating a proliferation and survival loop. Growth of
ErbB-2-positive breast cancer cells is minimally inhibited by Herceptin®
or a Notch inhibitor (g-secretase inhibitor, GSI) alone. However, growth
was synergistically inhibited by Herceptin® plus GSI.
Objectives/Hypothesis/Specific Aims/Study
Design: Based on our novel findings, we hypothesize that blocking ErbB-2
with Herceptin® or a TKI activates Notch-1, a potent survival pathway
that reactivates ErbB-2 creating a proliferation and survival loop. The
objective of the study is to: 1. Determine how inhibiting ErbB-2
activates Notch-1 by measuring expression of Notch ligands, Jagged-1 and
Delta-like 4 which have been shown to be overexpressed specifically in
breast cancer, and activity of the gamma-secretase complex, the critical
enzyme responsible for cleavage of full length Notch to the mature
active form (NIC); 2. Determine how Notch-1 activates ErbB-2 by
measuring expression of heregulin and subsequent heterodimerization of
ErbB-2 with ErbB-3 and expression and interaction of E3 ubiquitin
ligases, c-Cbl and AIP4 with ErbB-2; and 3. Perform a preclinical study
to determine the optimal therapy by using Herceptin® plus GSI in athymic
mice-bearing ErbB-2-positive tumors and treating them with increasing
doses of Herceptin®, GSI, or the combination of Herceptin® plus GSI. The
most immediate outcome from this study is the delineation of mechanisms
by which Notch signaling, a potent survival pathway is increased in
response to Herceptin® and how a Notch inhibitor (GSI) sensitizes ErbB-2
positive breast cancer cells and tumors to Herceptin®. This potential
outcome will provide a basis for future clinical trials.
Paola Rizzo, PhD
Targeting breast cancer through the cross talk between estrogen and
Notch
Ticket for a Cure Program,
Illinois Department of Public Health
1/01/08 – 6/30/09
$125,000
Recent evidence indicates that activated Notch signaling is common in
breast cancer and high expression of Notch-1 is associated with poor
prognosis. Notch signaling is an attractive target in breast cancer also
because putative breast cancer stem cells appear to depend on it. γ-Secretase
inhibitors, (GSIs) which block Notch activation, are in phase 1 clinical
trials. However, a rational basis for designing breast cancer
therapeutic regimens including GSIs is lacking, due to our very limited
understanding of how Notch signaling cross-talks with other pathways
known to be relevant in breast cancer. Our data indicate that there is
cross-talk between the estrogen receptor α (ERα) and Notch.
Specifically, estrogen inhibits Notch signaling via physical association
of ERα with Notch-1. Tamoxifen and raloxifene prevent this effect,
causing Notch activation. In turn, intracellular Notch-1 binds to ERα
and activates its transcriptional activity in the presence or absence of
estradiol. Based on these data, we propose this hypothesis: Notch-1
enhances the transcriptional activity of ERα while estrogen inhibits
Notch activity via ERα. Blocking ERα results in uncontrolled Notch
activation. This in turn protects some cancer cells, including cancer
stem cells, from death and promotes recurrence. Estrogen inhibitors or
the absence of estrogen render breast cancer cell growth or survival
Notch-dependent. Hence, a combination of a Notch inhibitor with an
anti-estrogen in ERα positive cancers should have a synergistic effect
in vivo and reduce or eradicate breast cancer stem cells. Our Specific
Aims are to determine: 1) The mechanisms whereby estradiol inhibits
Notch signaling; 2) The mechanisms whereby Notch-1 activates
ER-dependent transcription and 3) Whether a combination of tamoxifen and
a GSI delivers synergistic efficacy and reduces the breast cancer stem
cell population in ER-positive xenografts. Our Study Design will involve
co-immunoprecipitation, ChIP, GST-pulldown and real-time RT-PCR for Aims
1 and 2. In Aim 3, we will isolate and characterize breast cancer stem
cells and determine the effects of combined ER and Notch inhibition on
these cells in vitro and in 1 xenograft model. This proposal would not
only advance our knowledge on an important pathway as Notch signaling
but could give preclinical evidence that a combination of an
anti-estrogen plus a Notch inhibitor delivers synergistic efficacy and
decreases or eradicates the breast cancer stem cell population in ERα-positive
tumors
Jiwang Zhang, MD, PhD.
The role of C-MYC in the pathogenesis of leukemia initiation,
progression and relapse
Leukemia Research Foundation
07/01/08 – 06/30/09
$100,000
C-MYC, a tumor promoting protein, is a common downstream molecule of
most leukemic oncogenes. Deregulation of C-MYC is a key event in the
pathogenesis of many blood malignancies. Transgenic expression of C-MYC
gene in mice and fish induces leukemia development. Therefore, C-MYC has
been proposed as an appealing target for developing novel anti-leukemia
therapy.
Leukemia, a clonegenic disease, initiates from a mutant blood stem cell
or progenitor which serves as a seed (leukemia stem cells, LSCs) for
leukemia development. LSCs are relatively quiescent, resistant to
chemotherapy treatment, and have self-renewal capacity (can produce
themselves) which is also responsible for the leukemia relapse. Leukemia
related signal pathways and molecules contribute differently to
leukemogenesis at leukemia initiation, progression and relapse.
Therefore, defining the roles of a specific signal pathway or molecule
on the different stages of leukemogenesis will allow us to develop new
strategies for leukemia therapy.
Our preliminary data demonstrated that C-MYC is required for Notch1
induced-leukemia initiation, but dispensable for leukemia progression.
We proposed that C-MYC is not necessary for LSC survival and
self-renewal, but essential for LSC differentiation and proliferation,
therefore critical for leukemia initiation and relapse. Inhibition of
C-MYC may not able to cure leukemia, but can significantly delay the
leukemia relapse after chemotherapy induced remission. The predicted
results will provide insights into the molecular details of leukemia
initiation, progression and relapse. We expect that our work will permit
a more detailed understanding of the pathogenesis of blood malignancies,
and should allow us to develop new strategies for leukemia therapy.
The role of PTEN in c-terminal phosphorylation on leukemogenesis
American Cancer Society – Illinois Division
07/01/08 – 06/30/09
$100,000
Deletions and mutations of the PTEN gene, a tumor suppressor, are
frequently found in many human cancers. Although PTEN is essential for
normal blood formation and mice with PTEN deletion develop leukemia,
PTEN mutations or deletions are not common in leukemia patients.
Recently we found PTEN phosphorylation which were detected in most
leukemia patients might contribute to the pathogenesis of leukemia. PTEN
might gain oncogenic properties after it is phosphorylated. To address
our hypothesis, we will test whether P-PTEN (phosphorylated form of PTEN)
can induce leukemia development in mice with cooperation with other
oncogenic events that we have found in PTEN deficient leukemia. We also
intend to explore whether P-PTEN contributes to the pathogenesis of
leukemia induced by other leukemic oncogenes, such as active Notch1.
These studies will provide new insights into how PTEN is involved in
leukemia development. The phosphorylation remodeling process makes PTEN
an oncogene or a tumor suppressor, completely opposite players in normal
tissue regeneration and leukemogenesis.
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