مجال
التميز
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تميز دراسي وبحثي
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البحوث المنشورة
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البحث (1):
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عنوان البحث:
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A novel role for atypical MAPK kinase ERK3 in regulating breast cancer
cell morphology and migration
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رابط إلى البحث:
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Click here
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تاريخ النشر:
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19/10/2015
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موجز عن البحث:
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ERK3 is an atypical Mitogen-activated
protein kinases (MAPK6). Despite the fact that the Erk3 gene was originally
identified in 1991, its function is still unknown. MK5 (MAP kinase- activated
protein kinase 5) also called PRAK is the only known substrate for ERK3.
Recently, it was found that group I p21 protein activated kinases (PAKs) are
critical effectors of ERK3. PAKs link Rho family of GTPases to actin
cytoskeletal dynamics and are known to be involved in the regulation of cell
adhesion and migration. In this study we demonstrate that ERK3 protein levels
are elevated as MDA-MB-231 breast cancer cells adhere to collagen I which is
concomitant with changes in cellular morphology where cells become less well
spread following nascent adhesion formation. During this early cellular
adhesion event we observe that the cells retain protrusive activity whilst
reducing overall cellular area. Interestingly exogenous expression of ERK3
delivers a comparable reduction in cell spread area, whilst depletion of ERK3
expression increases cell spread area. Importantly, we have detected a novel
specific endogenous ERK3 localization at the cell periphery. Furthermore we
find that ERK3 overexpressing cells exhibit a rounded morphology and
increased cell migration speed. Surprisingly, exogenous expression of a
kinase inactive mutant of ERK3 phenocopies ERK3 overexpression, suggesting a
novel kinase independent function for ERK3. Taken together our data suggest
that as cells initiate adhesion to matrix increasing levels of ERK3 at the
cell periphery are required to orchestrate cell morphology changes which can
then drive migratory behaviour.
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المؤتمرات العلمية:
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المؤتمر (1):
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عنوان المؤتمر:
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19th World Congress on Advances in Oncology and 17th
International Symposium on Molecular Medicine
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تاريخ الإنعقاد:
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11/10/2014
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مكان
الإنعقاد:
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Athens, Greece
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طبيعة المشاركة:
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Poster
presentation
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عنوان المشاركة:
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The Role
of PAK6 in Breast Cancer
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ملخص المشاركة:
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Breast cancer is the second leading cause of mortality amongst women.
The main cause of this mortality is metastasis. Thus prevention of metastatic
spread will have a positive effect on patient survival rate. p21-activated
kinase (PAKs) are a family of six serine/threonine protein kinases, which are
activated by the Rho GTPases Rac1 and Cdc42. PAKs have been implicated in
many cellular process including cytoskeleton organization, cell motility,
cell cycle progression, cell migration and cell survival. Overexpression of
PAK isoforms has been found in different human cancer tissues including
breast. Therefore, PAKs may provide a therapeutic target for the prevention
breast cancer progression and metastasis. The PAK family consists of six
proteins PAK1-6. Whilst much is known about the biology of PAK1 less is known
about the more recently described family members (PAK 4-6). Although, there
is some evidence to suggest PAK6 is overexpressed in cancer cell lines
relatively little is known about the role of PAK6 in cancer progression. This
study has found using three breast cancer cell lines (MCF10A, MCF-7 and
MDA-MB-231) that there is an increase in PAK6 expression in invasive breast
cancer cell lines. Moreover, in MDA-MB-231 cells expression of activated PAK6
induced cell rounding, whilst PAK6 deficient cells exhibit an elongated
phenotype. Interestingly, treatment with novel HDAC inhibiter (Panobinostat)
reduces PAK6 expression and phenocopies the cell morphology observed for PAK6
knockdown cells. Moreover, PAK6 interacting proteins that belong to a key
family of cytoskeletal regulatory proteins, RhoD and RhoV were identified.
Taken together our results suggest that PAK6 can mediate cytoskeletal changes
in these cells and the novel cytoskeletal associated binding partners using
mass spectrometry were validated.
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المؤتمر (2):
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عنوان المؤتمر:
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7th Saudi Students Conference
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تاريخ الإنعقاد:
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1-2/02/2014
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مكان
الإنعقاد:
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Edinburgh, UK
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طبيعة المشاركة:
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Poster
presentation
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عنوان المشاركة:
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Role of Farnesoid X Receptor in Regulation
of Metastatic Breast Cancer
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ملخص المشاركة:
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Breast
cancer is a primary cause of mortality in women and it is correlated to poor
prognosis. Therefore, understanding the molecular mechanisms of invasive
cancers is fundamental for the
discovery of new generation of treatments. Degradation of extracellualr
matrix is required for the malignancies to invade and migrate to distant organs, and
that occurs by specific endopeptidases which are called Matrix
metalloproteinases (MMPs) with high expression of MMP-2 and -9 in metastatic breast
cancer in particular. MMP activity is tightly regulated by the tissue
inhibitors of metalloproteinases (TIMPs). Researchers have shown that
the nuclear receptor Farnesoid X-receptor (FXR) is involved in regulation of
MMP and TIMP activity in hepatic and vascular tissues. The rationale of the
current study was to investigate whether FXR is a novel regulator of MMP-2
and -9 as it is highly expressed in metastatic breast cancer. Initially the
viability of the breast cancer cell lines MCF7 (Estrogen receptor positive)
and MDA-MB-468 (The triple negative) was measured after exposure to the FXR
agonists chenodeoxycholic acid (CDCA) and3-[2-[2-Chloro-4-[[3-(2,
6-dichlorophenyl)-5-(1-methylethyl)-4 isoxazolyl]methoxy]phenyl]ethenyl]benzoic
acid (GW4064). Our findings showed that FXR ligands caused cell
death and the effects were more significant in the
triple negative cells. Protein and mRNA levels of MMP-2 and -9 within both
cell lines did not change after
FXR activation, when measured by Western blotting and real time PCR.
Furthermore, the migratory response and the effect on activity of MMP for FXR
ligands are being investigated. Our finding suggests that FXR
activation is not pro-metastatic, but can kill tumour cells, so it might be a
novel therapeutic target for metastatic breast cancer.
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المؤتمر (3):
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6th Saudi Students Conference
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عنوان المؤتمر:
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11-14
/10 /2012
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تاريخ الإنعقاد:
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London, UK
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مكان
الإنعقاد:
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Poster
presentation
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طبيعة المشاركة:
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FXR Regulates
Matrix Metalloproteinases in Breast Cancer
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عنوان المشاركة:
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Metastasis is associated with poor
prognosis in breast cancer. Thus it is crucial to understand the molecular
mechanisms of tumour cell invasion and metastasis in order to identify therapeutic
targets. Metastasis requires degradation of the extracellular matrix (ECM),
permitting cancer cells to invade and spread to distant sites. Matrix
metalloproteinases (MMPs) are essential for degrading the proteins of the
ECM. In particular, MMP-2 and -9 expression correlates with poor breast
cancer prognosis. MMP activity is regulated by the tissue inhibitors of
metalloproteinases (TIMPs). TIMP-1 inhibits MMP-9 whereas TIMP-2 inhibits
MMP-2. Studies have shown that the nuclear receptor Farnesoid X receptor
(FXR) is involved in MMP and TIMP regulation in hepatic and vascular tissues
and is highly expressed in breast cancer.
So the aim of this project was to
investigate whether FXR is a novel
regulator of MMP-2 and -9 in breast cancer cells. Initially the
cell viability of breast cancer cell lines MCF7 (Estrogen receptor positive) and
MDA-MB-468 (Estrogen receptor negative) after treatment with FXR agonists
CDCA and GW4064 were measured. FXR ligands decreased the cell viability in
both cell lines and the effects were more significant in MDA-MB-468. The mRNA
and protein levels of MMP-2 and -9 within both cell lines did not change after FXR activation, when measured by real time
PCR and Western blotting. Interestingly, when the activity of the
MMP-2 and -9 enzymes secreted into the culture media was measured using a
fluorescent substrate; GW4064 increased MMP activity in a concentration
dependant manner, whereas CDCA had no effect. To determine whether this was
due to FXR regulation of TIMPs, their mRNA expression was measured by real
time PCR. There was no effect of FXR ligands on TIMP-1
and -2 mRNA levels.
In conclusion, FXR activation by
GW4064 increases secreted MMP-2 and -9 activity in breast cancer cells but
this effect is not via transcriptional regulation of the MMPs or their
inhibitory factors TIMP-1 or -2.
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المؤتمر (4):
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عنوان المؤتمر:
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International Society for the Study of Xenobiotics (ISSX)
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تاريخ الإنعقاد:
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17/06/2012
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مكان
الإنعقاد:
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Noordwijjk, Netherlands
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طبيعة المشاركة:
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Poster presentation
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عنوان المشاركة:
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Regulation Of Matrix
Metalloproteinases By FXR In Metastatic Breast Cancer
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ملخص المشاركة:
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Metastasis is associated with poor
prognosis in breast cancer. Thus it is crucial to understand the molecular
mechanisms of tumour cell invasion and metastasis in order to identify
therapeutic targets. Metastasis requires degradation of the extracellular
matrix (ECM), permitting cancer cells to invade and spread to distant sites.
Matrix metalloproteinases (MMPs) are essential for degrading the proteins of
the ECM. In particular, MMP-2 and -9 expression correlate with poor breast
cancer prognosis. MMP activity is regulated by the tissue inhibitors of
metalloproteinases (TIMPs). TIMP-1 inhibits MMP-9 whereas TIMP-2 inhibits
MMP-2. Studies have shown that the nuclear receptor Farnesoid X receptor
(FXR) is involved in MMP and TIMP regulation in hepatic and vascular tissues
and is highly expressed in breast cancer1-3. So the aim of this
project was to investigate whether FXR is a novel regulator of MMP-2 and -9
in breast cancer cells. Initially the cell viability of breast cancer cell
lines MCF7 (Estrogen receptor positive) and MDA-MB-468 (Estrogen receptor
negative) after treatment with FXR agonists chenodeoxycholic acid (CDCA) and3-[2-[2-Chloro-4-[[3-(2,6-dichlorophenyl)-5-(1-methylethyl)-4
isoxazolyl]methoxy]phenyl]ethenyl]benzoic acid, known as GW4064 were
measured. FXR ligands decreased the cell viability in both cell lines and the
effects were more significant in MDA-MB-468. The mRNA and protein levels of
MMP-2 and -9 within both cell lines did not change after FXR activation, when
measured by real time PCR and Western blotting. Interestingly, when the
activity of the MMP-2 and -9 enzymes secreted into the culture media
was measured using a fluorescent substrate; GW4064 increased MMP activity in
a concentration dependant manner, whereas CDCA had no effect. To determine
whether this was due to FXR regulation of TIMPs, their mRNA expression was
measured by real time PCR. There was no effect of FXR ligands on TIMP-1 and
-2 mRNA levels. In conclusion, FXR activation by GW4064 increases secreted
MMP-2 and -9 activity in breast cancer cells but this effect is not via transcriptional
regulation of the MMPs or their inhibitory factors TIMP-1 or -2.
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المؤتمر (5):
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عنوان المؤتمر:
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5th Saudi Students Conference
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تاريخ الإنعقاد:
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23-26/06/2011
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مكان
الإنعقاد:
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Coventry, UK
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طبيعة المشاركة:
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Poster
presentation
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عنوان المشاركة:
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The Role of Farnesoid X Receptor in Matrix
Metalloproteinase Regulation in Breast Cancer
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Breast cancer is a leading cause of female
death in the UK. Therefore, developing new drugs is crucial. The nuclear
receptor FXR is a potential novel therapeutic target. FXR is
activated by bile acids, is expressed and is pro-apoptotic in breast cancers. Matrix
metalloproteinases (MMP) 9 & 2 are enzymes involved in tissue
remodelling, key to invasion and metastasis of breast tumours.
Could FXR be a novel
regulator of MMP-2 and -9? Initial experiments were performed to establish
the effects of FXR ligands on the cell viability of breast cancer cell lines
MCF7 (Estrogen receptor positive) and MDA-MB-468 (Estrogen receptor
negative). The cells were 100% viable in the vehicle control. For MDA-MB-468, CDCA decreased cell viability
to 80 & 59% (10% serum conditions) and 62 & 33% (serum free
conditions) for 24h and 48h exposures respectively. In contrast, GW4064 only
decreased MDA-MB-468 viability under serum free conditions, to 75% (24h)
& 41% (48h). Similarly, CDCA
decreased MCF7 cell viability to almost 86%, under both serum and serum free
conditions at 24 and 48h time points. Whereas GW4064 only decreased MCF7
viability to 76% after 48h under serum-free conditions. These effects on cell
viability need to be considered during investigations into MMP regulation. MMP-2
&-9 activity were measured using a fluorescent substrate in conditioned
media collected from the cell viability experiments. GW4064 increased, whereas CDCA decreased
MMP activity in a concentration dependant manner. We are now investigating
these opposing results further. In addition we are measuring the protein and
mRNA levels of MMP-2 and -9 by Western blot and real-time PCR.
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