18 research outputs found
Biomarkers of Breast Cancer Apoptosis Induced by Chemotherapy and TRAIL
Treatment of breast cancer is complex and challenging
due to the
heterogeneity of the disease. To avoid significant toxicity and adverse
side-effects of chemotherapy in patients who respond poorly, biomarkers
predicting therapeutic response are essential. This study has utilized
a proteomic approach integrating 2D-DIGE, LC–MS/MS, and bioinformatics
to analyze the proteome of breast cancer (ZR-75-1 and MDA-MB-231)
and breast epithelial (MCF-10A) cell lines induced to undergo apoptosis
using a combination of doxorubicin and TRAIL administered in sequence
(Dox-TRAIL). Apoptosis induction was confirmed using a caspase-3 activity
assay. Comparative proteomic analysis between whole cell lysates of
Dox-TRAIL and control samples revealed 56 differentially expressed
spots (≥2-fold change and <i>p</i> < 0.05) common
to at least two cell lines. Of these, 19 proteins were identified
yielding 11 unique protein identities: CFL1, EIF5A, HNRNPK, KRT8,
KRT18, LMNA, MYH9, NACA, RPLP0, RPLP2, and RAD23B. A subset of the
identified proteins was validated by selected reaction monitoring
(SRM) and Western blotting. Pathway analysis revealed that the differentially
abundant proteins were associated with cell death, cellular organization,
integrin-linked kinase signaling, and actin cytoskeleton signaling
pathways. The 2D-DIGE analysis has yielded candidate biomarkers of
response to treatment in breast cancer cell models. Their clinical
utility will depend on validation using patient breast biopsies pre-
and post-treatment with anticancer drugs
Biomarkers of Breast Cancer Apoptosis Induced by Chemotherapy and TRAIL
Treatment of breast cancer is complex and challenging
due to the
heterogeneity of the disease. To avoid significant toxicity and adverse
side-effects of chemotherapy in patients who respond poorly, biomarkers
predicting therapeutic response are essential. This study has utilized
a proteomic approach integrating 2D-DIGE, LC–MS/MS, and bioinformatics
to analyze the proteome of breast cancer (ZR-75-1 and MDA-MB-231)
and breast epithelial (MCF-10A) cell lines induced to undergo apoptosis
using a combination of doxorubicin and TRAIL administered in sequence
(Dox-TRAIL). Apoptosis induction was confirmed using a caspase-3 activity
assay. Comparative proteomic analysis between whole cell lysates of
Dox-TRAIL and control samples revealed 56 differentially expressed
spots (≥2-fold change and <i>p</i> < 0.05) common
to at least two cell lines. Of these, 19 proteins were identified
yielding 11 unique protein identities: CFL1, EIF5A, HNRNPK, KRT8,
KRT18, LMNA, MYH9, NACA, RPLP0, RPLP2, and RAD23B. A subset of the
identified proteins was validated by selected reaction monitoring
(SRM) and Western blotting. Pathway analysis revealed that the differentially
abundant proteins were associated with cell death, cellular organization,
integrin-linked kinase signaling, and actin cytoskeleton signaling
pathways. The 2D-DIGE analysis has yielded candidate biomarkers of
response to treatment in breast cancer cell models. Their clinical
utility will depend on validation using patient breast biopsies pre-
and post-treatment with anticancer drugs
Fludarabine and Cladribine Induce Changes in Surface Proteins on Human B‑Lymphoid Cell Lines Involved with Apoptosis, Cell Survival, and Antitumor Immunity
Fludarabine and cladribine are purine analogues used
to treat hematological
malignancies. Alone or in combination with therapeutic antibodies,
they are effective in treating patients with chronic lymphocytic leukemia
and non-Hodgkin's lymphoma. However, the mechanisms of action of these
drugs are not well understood. Plasma membrane proteins perform a
variety of essential functions that can be affected by malignancy
and perturbed by chemotherapy. Analysis of surface proteins may contribute
to an understanding of the mechanisms of action of purine analogues
and identify biomarkers for targeted therapy. The surface of human
cells is rich in N-linked glycoproteins, enabling use of a hydrazide-coupling
technique to enrich for glycoproteins, with iTRAQ labeling for quantitative
comparison. A number of plasma membrane proteins on human leukemia
and lymphoma cells were affected by treatment with a purine analogue,
including decreases in CD22 (an adhesion and signaling molecule) and
increases in CD205 (a “damaged cell marker”) and CD80
and CD50 (T-cell interaction molecules). Purine analogues may affect
B-cell receptor (BCR) signaling and costimulatory molecules, leading
to multiple signals for apoptosis and cell clearance. Fludarabine
and cladribine induce differential effects, with some cell survival
proteins (ECE-1 and CD100) more abundant after fludarabine treatment.
Cell surface proteins induced by fludarabine and cladribine may be
targets for therapeutic antibodies
iTRAQ-Based Proteomic Profiling of Breast Cancer Cell Response to Doxorubicin and TRAIL
Breast cancer is a molecularly heterogeneous disease,
and predicting
response to chemotherapy remains a major clinical challenge. To minimize
adverse side-effects or cumulative toxicity in patients unlikely to
benefit from treatment, biomarkers indicating treatment efficacy are
critically needed. iTRAQ labeling coupled with multidimensional LC–MS/MS
of the enriched mitochondria and endoplasmic reticulum fraction, key
organelles regulating apoptosis, has led to the discovery of several
differentially abundant proteins in breast cancer cells treated with
the chemotherapeutic agent doxorubicin followed by the death receptor
ligand, TRAIL, among 571 and 801 unique proteins identified in ZR-75-1
and MDA-MB-231 breast cancer cell lines, respectively. The differentially
abundant proteins represent diverse biological processes associated
with cellular assembly and organization, molecular transport, oxidative
stress, cell motility, cell death, and cancer. Despite many differences
in molecular phenotype between the two breast cancer cell lines, a
comparison of their subproteomes following drug treatment revealed
three proteins displaying common regulation: PPIB, AHNAK, and SLC1A5.
Changes in these proteins, detected by iTRAQ, were confirmed by immunofluorescence,
visualized by confocal microscopy. These novel potential biomarkers
may have clinical utility for assessing response to cancer treatment
and may provide insight into new therapeutic targets for breast cancer
iTRAQ-Based Proteomic Profiling of Breast Cancer Cell Response to Doxorubicin and TRAIL
Breast cancer is a molecularly heterogeneous disease,
and predicting
response to chemotherapy remains a major clinical challenge. To minimize
adverse side-effects or cumulative toxicity in patients unlikely to
benefit from treatment, biomarkers indicating treatment efficacy are
critically needed. iTRAQ labeling coupled with multidimensional LC–MS/MS
of the enriched mitochondria and endoplasmic reticulum fraction, key
organelles regulating apoptosis, has led to the discovery of several
differentially abundant proteins in breast cancer cells treated with
the chemotherapeutic agent doxorubicin followed by the death receptor
ligand, TRAIL, among 571 and 801 unique proteins identified in ZR-75-1
and MDA-MB-231 breast cancer cell lines, respectively. The differentially
abundant proteins represent diverse biological processes associated
with cellular assembly and organization, molecular transport, oxidative
stress, cell motility, cell death, and cancer. Despite many differences
in molecular phenotype between the two breast cancer cell lines, a
comparison of their subproteomes following drug treatment revealed
three proteins displaying common regulation: PPIB, AHNAK, and SLC1A5.
Changes in these proteins, detected by iTRAQ, were confirmed by immunofluorescence,
visualized by confocal microscopy. These novel potential biomarkers
may have clinical utility for assessing response to cancer treatment
and may provide insight into new therapeutic targets for breast cancer
iTRAQ-Based Proteomic Profiling of Breast Cancer Cell Response to Doxorubicin and TRAIL
Breast cancer is a molecularly heterogeneous disease,
and predicting
response to chemotherapy remains a major clinical challenge. To minimize
adverse side-effects or cumulative toxicity in patients unlikely to
benefit from treatment, biomarkers indicating treatment efficacy are
critically needed. iTRAQ labeling coupled with multidimensional LC–MS/MS
of the enriched mitochondria and endoplasmic reticulum fraction, key
organelles regulating apoptosis, has led to the discovery of several
differentially abundant proteins in breast cancer cells treated with
the chemotherapeutic agent doxorubicin followed by the death receptor
ligand, TRAIL, among 571 and 801 unique proteins identified in ZR-75-1
and MDA-MB-231 breast cancer cell lines, respectively. The differentially
abundant proteins represent diverse biological processes associated
with cellular assembly and organization, molecular transport, oxidative
stress, cell motility, cell death, and cancer. Despite many differences
in molecular phenotype between the two breast cancer cell lines, a
comparison of their subproteomes following drug treatment revealed
three proteins displaying common regulation: PPIB, AHNAK, and SLC1A5.
Changes in these proteins, detected by iTRAQ, were confirmed by immunofluorescence,
visualized by confocal microscopy. These novel potential biomarkers
may have clinical utility for assessing response to cancer treatment
and may provide insight into new therapeutic targets for breast cancer
iTRAQ-Based Proteomic Profiling of Breast Cancer Cell Response to Doxorubicin and TRAIL
Breast cancer is a molecularly heterogeneous disease,
and predicting
response to chemotherapy remains a major clinical challenge. To minimize
adverse side-effects or cumulative toxicity in patients unlikely to
benefit from treatment, biomarkers indicating treatment efficacy are
critically needed. iTRAQ labeling coupled with multidimensional LC–MS/MS
of the enriched mitochondria and endoplasmic reticulum fraction, key
organelles regulating apoptosis, has led to the discovery of several
differentially abundant proteins in breast cancer cells treated with
the chemotherapeutic agent doxorubicin followed by the death receptor
ligand, TRAIL, among 571 and 801 unique proteins identified in ZR-75-1
and MDA-MB-231 breast cancer cell lines, respectively. The differentially
abundant proteins represent diverse biological processes associated
with cellular assembly and organization, molecular transport, oxidative
stress, cell motility, cell death, and cancer. Despite many differences
in molecular phenotype between the two breast cancer cell lines, a
comparison of their subproteomes following drug treatment revealed
three proteins displaying common regulation: PPIB, AHNAK, and SLC1A5.
Changes in these proteins, detected by iTRAQ, were confirmed by immunofluorescence,
visualized by confocal microscopy. These novel potential biomarkers
may have clinical utility for assessing response to cancer treatment
and may provide insight into new therapeutic targets for breast cancer
iTRAQ-Based Proteomic Profiling of Breast Cancer Cell Response to Doxorubicin and TRAIL
Breast cancer is a molecularly heterogeneous disease,
and predicting
response to chemotherapy remains a major clinical challenge. To minimize
adverse side-effects or cumulative toxicity in patients unlikely to
benefit from treatment, biomarkers indicating treatment efficacy are
critically needed. iTRAQ labeling coupled with multidimensional LC–MS/MS
of the enriched mitochondria and endoplasmic reticulum fraction, key
organelles regulating apoptosis, has led to the discovery of several
differentially abundant proteins in breast cancer cells treated with
the chemotherapeutic agent doxorubicin followed by the death receptor
ligand, TRAIL, among 571 and 801 unique proteins identified in ZR-75-1
and MDA-MB-231 breast cancer cell lines, respectively. The differentially
abundant proteins represent diverse biological processes associated
with cellular assembly and organization, molecular transport, oxidative
stress, cell motility, cell death, and cancer. Despite many differences
in molecular phenotype between the two breast cancer cell lines, a
comparison of their subproteomes following drug treatment revealed
three proteins displaying common regulation: PPIB, AHNAK, and SLC1A5.
Changes in these proteins, detected by iTRAQ, were confirmed by immunofluorescence,
visualized by confocal microscopy. These novel potential biomarkers
may have clinical utility for assessing response to cancer treatment
and may provide insight into new therapeutic targets for breast cancer
iTRAQ-Based Proteomic Profiling of Breast Cancer Cell Response to Doxorubicin and TRAIL
Breast cancer is a molecularly heterogeneous disease,
and predicting
response to chemotherapy remains a major clinical challenge. To minimize
adverse side-effects or cumulative toxicity in patients unlikely to
benefit from treatment, biomarkers indicating treatment efficacy are
critically needed. iTRAQ labeling coupled with multidimensional LC–MS/MS
of the enriched mitochondria and endoplasmic reticulum fraction, key
organelles regulating apoptosis, has led to the discovery of several
differentially abundant proteins in breast cancer cells treated with
the chemotherapeutic agent doxorubicin followed by the death receptor
ligand, TRAIL, among 571 and 801 unique proteins identified in ZR-75-1
and MDA-MB-231 breast cancer cell lines, respectively. The differentially
abundant proteins represent diverse biological processes associated
with cellular assembly and organization, molecular transport, oxidative
stress, cell motility, cell death, and cancer. Despite many differences
in molecular phenotype between the two breast cancer cell lines, a
comparison of their subproteomes following drug treatment revealed
three proteins displaying common regulation: PPIB, AHNAK, and SLC1A5.
Changes in these proteins, detected by iTRAQ, were confirmed by immunofluorescence,
visualized by confocal microscopy. These novel potential biomarkers
may have clinical utility for assessing response to cancer treatment
and may provide insight into new therapeutic targets for breast cancer
Hsp90 Inhibitor SNX-7081 Dysregulates Proteins Involved with DNA Repair and Replication and the Cell Cycle in Human Chronic Lymphocytic Leukemia (CLL) Cells
The proteomic effects of the Hsp90
inhibitor, SNX-7081, have been
determined on the p53-mutated B-cell chronic lymphocytic leukemia
(CLL) cell line, MEC1. Following SNX-7081 treatment (500 nM, 24 h),
51 proteins changed abundance by more than 2-fold (<i>p</i> < 0.05); 7 proteins increased while 44 proteins decreased. Proteins
identified as differentially abundant by LC–MS/MS were validated
by Western blotting (DDB1, PCNA, MCM2, Hsp90, Hsp70, GRP78, PDIA6,
HLA-DR). RT-PCR showed that SNX-7081 unexpectedly modulates a number
of these proteins in MEC1 cells at the mRNA level (PCNA, MCM2, Nup155,
Hsp70, GRP78, PDIA6, and HLA-DR). Pathway analysis determined that
3 of the differentially abundant proteins (cyclin D1, c-Myc and pRb)
were functionally related. p53 levels did not change upon SNX-7081
treatment of p53 wild-type Raji cells or p53-mutated MEC1 and U266
cells, indicating that SNX-7081 has a p53-independent mechanism. The
decreases in DDB1, MCM2, c-Myc, and PCNA and increases of pRb and
cyclin D1 were confirmed in MEC1, U266, Raji, and p53 null HL60 cells
by Western blotting. These data suggest that SNX-7081 arrests
the cell cycle and inhibits DNA replication and repair and provides evidence for the mechanism of the observed
synergy between Hsp90 inhibitors and drugs that induce DNA strand
breaks