10 research outputs found
Novel Proteomic Biomarker Panel for Prediction of Aggressive Metastatic Hepatocellular Carcinoma Relapse in Surgically Resectable Patients
The
natural course of early HCC is unknown, and its progression
to intermediate and advanced HCC can be diverse. Some early stage
HCC patients enjoy prolonged disease-free survival, whereas others
suffer aggressive relapse to stage IV metastatic cancer within a year.
Comparative proteomics of HCC tumor tissues was carried out using
2D-DIGE and MALDI-TOF/TOF MS to identify proteins that can distinguish
these two groups of stage I HCC patients. Twelve out of 148 differentially
regulated protein spots were found to differ by approximately 2-fold
for the relapse versus nonrelapse patient tissues. Four proteins,
namely, heat shock 70 kDa protein 1, argininosuccinate synthase, isoform
2 of UTP-glucose-1-phosphate uridylyltransferase, and transketolase,
were shown to have the potential to differentiate metastatic relapse
(MR) from nonrelapse (NR) HCC patients after validation by western
blotting and immunohistochemical assays. Subsequent TMA analysis revealed
a three marker panel of HSP70, ASS1, and UGP2 to be statistically
significant in stratifying the two groups of HCC patients. This combination
panel achieved high levels of sensitivity and specificity, which has
potential for clinical use in identifying HCC tumors prone to MR.
This stratification will allow development of clinical management,
including close follow-up and possibly treatment options, in the near
future
Novel Proteomic Biomarker Panel for Prediction of Aggressive Metastatic Hepatocellular Carcinoma Relapse in Surgically Resectable Patients
The
natural course of early HCC is unknown, and its progression
to intermediate and advanced HCC can be diverse. Some early stage
HCC patients enjoy prolonged disease-free survival, whereas others
suffer aggressive relapse to stage IV metastatic cancer within a year.
Comparative proteomics of HCC tumor tissues was carried out using
2D-DIGE and MALDI-TOF/TOF MS to identify proteins that can distinguish
these two groups of stage I HCC patients. Twelve out of 148 differentially
regulated protein spots were found to differ by approximately 2-fold
for the relapse versus nonrelapse patient tissues. Four proteins,
namely, heat shock 70 kDa protein 1, argininosuccinate synthase, isoform
2 of UTP-glucose-1-phosphate uridylyltransferase, and transketolase,
were shown to have the potential to differentiate metastatic relapse
(MR) from nonrelapse (NR) HCC patients after validation by western
blotting and immunohistochemical assays. Subsequent TMA analysis revealed
a three marker panel of HSP70, ASS1, and UGP2 to be statistically
significant in stratifying the two groups of HCC patients. This combination
panel achieved high levels of sensitivity and specificity, which has
potential for clinical use in identifying HCC tumors prone to MR.
This stratification will allow development of clinical management,
including close follow-up and possibly treatment options, in the near
future
Identification and Functional Validation of Caldesmon as a Potential Gastric Cancer Metastasis-associated Protein
In this study, we aim to identify biomarkers for gastric
cancer
metastasis using a quantitative proteomics approach. The proteins
extracted from a panel of 4 gastric cancer cell lines, two derived
from primary cancer (AGS, FU97) and two from lymph node metastasis
(AZ521, MKN7), were labeled with iTRAQ (8-plex) reagents and analyzed
by 2D-LC–MALDI-TOF/TOF MS. In total, 641 proteins were identified
with at least a 95% confidence. Using cutoff values of >1.5 and
<0.67,
19 proteins were found to be up-regulated and 34 were down-regulated
in the metastatic versus primary gastric cancer cell lines respectively.
Several of these dysregulated proteins, including caldesmon, were
verified using Western blotting. It was found that caldesmon expression
was decreased in the two metastasis-derived cell lines, and this was
confirmed by further analysis of 7 gastric cancer cell lines. Furthermore,
immunohistochemical staining of 9 pairs of primary gastric cancer
and the matched lymph node metastasis tissue also corroborated this
observation. Finally, knockdown of caldesmon using siRNA in AGS and
FU97 gastric cancer cells resulted in an increase in cell migration
and invasion, while the overexpression of caldesmon in AZ521 cells
led to a decrease in cell migration and invasion. This study has thus
established the potential role of caldesmon in gastric cancer metastasis,
and further functional studies are underway to delineate the underlying
mechanism of action of this protein
Identification and Functional Validation of Caldesmon as a Potential Gastric Cancer Metastasis-associated Protein
In this study, we aim to identify biomarkers for gastric
cancer
metastasis using a quantitative proteomics approach. The proteins
extracted from a panel of 4 gastric cancer cell lines, two derived
from primary cancer (AGS, FU97) and two from lymph node metastasis
(AZ521, MKN7), were labeled with iTRAQ (8-plex) reagents and analyzed
by 2D-LC–MALDI-TOF/TOF MS. In total, 641 proteins were identified
with at least a 95% confidence. Using cutoff values of >1.5 and
<0.67,
19 proteins were found to be up-regulated and 34 were down-regulated
in the metastatic versus primary gastric cancer cell lines respectively.
Several of these dysregulated proteins, including caldesmon, were
verified using Western blotting. It was found that caldesmon expression
was decreased in the two metastasis-derived cell lines, and this was
confirmed by further analysis of 7 gastric cancer cell lines. Furthermore,
immunohistochemical staining of 9 pairs of primary gastric cancer
and the matched lymph node metastasis tissue also corroborated this
observation. Finally, knockdown of caldesmon using siRNA in AGS and
FU97 gastric cancer cells resulted in an increase in cell migration
and invasion, while the overexpression of caldesmon in AZ521 cells
led to a decrease in cell migration and invasion. This study has thus
established the potential role of caldesmon in gastric cancer metastasis,
and further functional studies are underway to delineate the underlying
mechanism of action of this protein
Mining the Gastric Cancer Secretome: Identification of GRN as a Potential Diagnostic Marker for Early Gastric Cancer
Gastric cancer is the second leading cause of cancer
deaths worldwide,
and currently, there are no clinically relevant biomarkers for gastric
cancer diagnosis or prognosis. In this study, we applied a 2D-LC-MS/MS
based approach, in combination with iTRAQ labeling, to study the secretomes
of the gastric cancer cell lines AGS and MKN7. By performing a comparative
analysis between the conditioned media and the whole cell lysates,
our workflow allowed us to differentiate the <i>bona fide</i> secreted proteins from the intracellular contaminants within the
conditioned media. Ninety proteins were found to have higher abundance
in the conditioned media as compared to the whole cell lysates of
AGS and MKN7 cells. Using a signal peptide and nonclassical secretion
prediction tool and an online exosome database, we demonstrated that
up to 92.2% of these 90 proteins can be exported out of the cells
by classical or nonclassical secretory pathways. We then performed
quantitative comparisons of the secretomes between AGS and MKN7, identifying
43 differentially expressed secreted proteins. Among them, GRN was
found to be frequently expressed in gastric tumor tissues, but not
in normal gastric epithelia by immunohistochemistry. Sandwich ELISA
assay also showed elevation of serum GRN levels in gastric cancer
patients, particularly those with early gastric cancer. Receiver operating
characteristic (ROC) curves analysis confirmed that serum GRN can
provide diagnostic discriminations for gastric cancer patient
Mining the Gastric Cancer Secretome: Identification of GRN as a Potential Diagnostic Marker for Early Gastric Cancer
Gastric cancer is the second leading cause of cancer
deaths worldwide,
and currently, there are no clinically relevant biomarkers for gastric
cancer diagnosis or prognosis. In this study, we applied a 2D-LC-MS/MS
based approach, in combination with iTRAQ labeling, to study the secretomes
of the gastric cancer cell lines AGS and MKN7. By performing a comparative
analysis between the conditioned media and the whole cell lysates,
our workflow allowed us to differentiate the <i>bona fide</i> secreted proteins from the intracellular contaminants within the
conditioned media. Ninety proteins were found to have higher abundance
in the conditioned media as compared to the whole cell lysates of
AGS and MKN7 cells. Using a signal peptide and nonclassical secretion
prediction tool and an online exosome database, we demonstrated that
up to 92.2% of these 90 proteins can be exported out of the cells
by classical or nonclassical secretory pathways. We then performed
quantitative comparisons of the secretomes between AGS and MKN7, identifying
43 differentially expressed secreted proteins. Among them, GRN was
found to be frequently expressed in gastric tumor tissues, but not
in normal gastric epithelia by immunohistochemistry. Sandwich ELISA
assay also showed elevation of serum GRN levels in gastric cancer
patients, particularly those with early gastric cancer. Receiver operating
characteristic (ROC) curves analysis confirmed that serum GRN can
provide diagnostic discriminations for gastric cancer patient
Mining the Gastric Cancer Secretome: Identification of GRN as a Potential Diagnostic Marker for Early Gastric Cancer
Gastric cancer is the second leading cause of cancer
deaths worldwide,
and currently, there are no clinically relevant biomarkers for gastric
cancer diagnosis or prognosis. In this study, we applied a 2D-LC-MS/MS
based approach, in combination with iTRAQ labeling, to study the secretomes
of the gastric cancer cell lines AGS and MKN7. By performing a comparative
analysis between the conditioned media and the whole cell lysates,
our workflow allowed us to differentiate the <i>bona fide</i> secreted proteins from the intracellular contaminants within the
conditioned media. Ninety proteins were found to have higher abundance
in the conditioned media as compared to the whole cell lysates of
AGS and MKN7 cells. Using a signal peptide and nonclassical secretion
prediction tool and an online exosome database, we demonstrated that
up to 92.2% of these 90 proteins can be exported out of the cells
by classical or nonclassical secretory pathways. We then performed
quantitative comparisons of the secretomes between AGS and MKN7, identifying
43 differentially expressed secreted proteins. Among them, GRN was
found to be frequently expressed in gastric tumor tissues, but not
in normal gastric epithelia by immunohistochemistry. Sandwich ELISA
assay also showed elevation of serum GRN levels in gastric cancer
patients, particularly those with early gastric cancer. Receiver operating
characteristic (ROC) curves analysis confirmed that serum GRN can
provide diagnostic discriminations for gastric cancer patient
Proteomic Analysis of Colorectal Cancer Metastasis: Stathmin-1 Revealed as a Player in Cancer Cell Migration and Prognostic Marker
Metastasis accounts largely for the high mortality rate
of colorectal
cancer (CRC) patients. In this study, we performed comparative proteome
analysis of primary CRC cell lines HCT-116 and its metastatic derivative
E1 using 2-D DIGE. We identified 74 differentially expressed proteins,
many of which function in transcription, translation, angiogenesis
signal transduction, or cytoskeletal remodeling pathways, which are
indispensable cellular processes involved in the metastatic cascade.
Among these proteins, stathmin-1 (STMN1) was found to be highly up-regulated
in E1 as compared to HCT-116 and was thus selected for further functional
studies. Our results showed that perturbations in STMN1 levels resulted
in significant changes in cell migration, invasion, adhesion, and
colony formation. We further showed that the differential expression
of STMN1 correlated with the cells’ metastatic potential in
other paradigms of CRC models. Using immunohistochemistry, we also
showed that STMN1 was highly expressed in colorectal primary tumors
and metastatic tissues as compared to the adjacent normal colorectal
tissues. Furthermore, we also showed via tissue microarray analyses
of 324 CRC tissues and Kaplan–Meier survival plot that CRC
patients with higher expression of STMN1 have poorer prognosis
Proteomic Analysis of Colorectal Cancer Metastasis: Stathmin-1 Revealed as a Player in Cancer Cell Migration and Prognostic Marker
Metastasis accounts largely for the high mortality rate
of colorectal
cancer (CRC) patients. In this study, we performed comparative proteome
analysis of primary CRC cell lines HCT-116 and its metastatic derivative
E1 using 2-D DIGE. We identified 74 differentially expressed proteins,
many of which function in transcription, translation, angiogenesis
signal transduction, or cytoskeletal remodeling pathways, which are
indispensable cellular processes involved in the metastatic cascade.
Among these proteins, stathmin-1 (STMN1) was found to be highly up-regulated
in E1 as compared to HCT-116 and was thus selected for further functional
studies. Our results showed that perturbations in STMN1 levels resulted
in significant changes in cell migration, invasion, adhesion, and
colony formation. We further showed that the differential expression
of STMN1 correlated with the cells’ metastatic potential in
other paradigms of CRC models. Using immunohistochemistry, we also
showed that STMN1 was highly expressed in colorectal primary tumors
and metastatic tissues as compared to the adjacent normal colorectal
tissues. Furthermore, we also showed via tissue microarray analyses
of 324 CRC tissues and Kaplan–Meier survival plot that CRC
patients with higher expression of STMN1 have poorer prognosis
Identification of Potential Pathways Involved in Induction of Apoptosis by Butyrate and 4‑Benzoylbutyrate in HT29 Colorectal Cancer Cells
Butyrate and its analogues have long been investigated as potential
chemotherapeutic agents. Our previous structure–activity relationship
studies of butyrate analogues revealed that 4-benzoylbutyrate had
comparable in vitro effects to butyrate when used to treat HT29 and
HCT116 colorectal cancer cell lines. The aim of this study was to
identify potential mechanisms associated with the antitumorigenic
effects of 4-benzoylbutyrate. In this study, butyrate, 3-hydroxybutyrate
and 4-benzoylbutyrate were also investigated for their effects on
histone deacetylase (HDAC) activity and histone H4 acetylation in
HT29 and HCT116 cells. The biological effects of these analogues on
HT29 cells were further investigated using quantitative proteomics
to determine the proteins potentially involved in their apoptotic
and antiproliferative effects. Because 3-hydroxybutyrate had minimal
to no effect on apoptosis, proliferation or HDAC activity, this analogue
was used to identify differentially expressed proteins that were potentially
specific to the apoptotic effects of butyrate and/or 4-benzoylbutyrate.
Butyrate treatment inhibited HDAC activity and induced H4 acetylation.
4-Benzoylbutyrate inhibited HDAC activity but failed to enhance H4
acetylation. Proteomic analysis revealed 20 proteins whose levels
were similarly altered by both butyrate and 4-benzoylbutyrate. Proteins
that showed common patterns of differential regulation in the presence
of either butyrate or 4-benzoylbutyrate included c-Myc transcriptional
targets, proteins involved in ER homeostasis, signal transduction
pathways and cell energy metabolism. Although an additional 23 proteins
were altered by 4-benzoylbutyrate uniquely, further work is required
to understand the mechanisms involved in its apoptotic effects