Journal: mAbs

Article Title: Structural and functional characterization of MBS301, an afucosylated bispecific anti-HER2 antibody

doi: 10.1080/19420862.2018.1486946

Figure Lengend Snippet: ADCC activity evaluation of anti-HER2 antibodies on four target cancer cells.

Article Snippet: Human breast cancer cell line BT-474 (HTB-20), MDA-MB-175VII (HTB-25), SK-BR-3(HTB-30) and HCC1419(CRL-2326) are HER2-positive cell lines, which were obtained from the ATCC, and HCC1419 is trastuzumab-resistant human breast cancer cell line.

Techniques: Activity Assay

Journal: World Journal of Surgical Oncology

Article Title: Hyperglycemia induces PFKFB3 overexpression and promotes malignant phenotype of breast cancer through RAS/MAPK activation

doi: 10.1186/s12957-023-02990-2

Figure Lengend Snippet: PFKFB3 could be enhanced by hyperglycemia and was correlated with the prognosis of BC patients. A Protein levels of PFKFB3 in benign breast tissues and invasive ductal carcinoma with or without diabetes were detected by IHC. The magnification of the photographs was 200. B The Kaplan–Meier plotter database and C GEO database (GSE61304) were utilized to compare the PFS and OS of breast cancer patients with different PFKFB3 expression levels. D The breast cancer cell lines (BT474 and MCF-7) were cultured in 1640 mediums with different concentrations of glucose (5.5 mM, 15 mM, or 25 mM) and WB was performed to evaluate PFKFB3 expression level. *, P < 0.05; **, P < 0.01; ***, P < 0.001

Article Snippet: Human breast cancer cell lines BT474 and MCF-7 were purchased from ATCC (the American Type Culture Collection, Rockville, MD).

Techniques: Expressing, Cell Culture

Journal: World Journal of Surgical Oncology

Article Title: Hyperglycemia induces PFKFB3 overexpression and promotes malignant phenotype of breast cancer through RAS/MAPK activation

doi: 10.1186/s12957-023-02990-2

Figure Lengend Snippet: PFKFB3 might activate epithelial–mesenchymal transition and RAS/MAPK pathways of breast cancer in a hyperglycemic environment. A GSEA (Gene Set Enrichment Analysis) was performed to investigate the downstream signaling pathways. Pathway lists of PFKFB3 screened out by GSEA were shown on the left, the box plots of EMT (upper) and RAS/MAPK pathway (lower) were shown on the right. B Protein levels of PFKFB3, E-cadherin, N-cadherin, Vimentin, p-ERK1/2, and t-ERK1/2 in BT474-25 mM or MCF-7-25 mM cells after transfected with siPFKFB3-1, siPFKFB3-2 or siNC were detected using western blot. β-actin was detected as control. *, P < 0.05; **, P < 0.01

Article Snippet: Human breast cancer cell lines BT474 and MCF-7 were purchased from ATCC (the American Type Culture Collection, Rockville, MD).

Techniques: Transfection, Western Blot

Journal: World Journal of Surgical Oncology

Article Title: Hyperglycemia induces PFKFB3 overexpression and promotes malignant phenotype of breast cancer through RAS/MAPK activation

doi: 10.1186/s12957-023-02990-2

Figure Lengend Snippet: PFKFB3 promoted proliferation and migration of breast cancer cells in a hyperglycemic environment. BT474-25 mM and MCF-7-25 mM cells were transfected with siPFKFB3-1, siPFKFB3-2, or siNC. A The cell counting assay. B MTT assay. C The cell colony formation assay. D The wound-healing assay. E The migration assay

Article Snippet: Human breast cancer cell lines BT474 and MCF-7 were purchased from ATCC (the American Type Culture Collection, Rockville, MD).

Techniques: Migration, Transfection, Cell Counting, MTT Assay, Colony Assay, Wound Healing Assay

Journal: World Journal of Surgical Oncology

Article Title: Hyperglycemia induces PFKFB3 overexpression and promotes malignant phenotype of breast cancer through RAS/MAPK activation

doi: 10.1186/s12957-023-02990-2

Figure Lengend Snippet: Hyperglycemia might promote PFKFB3 expression by miR-26 downregulation in breast cancer. A TargetScan database, B OncomiR database, and C miRcode database were utilized to predict that miR-26 was a reliable upstream microRNA of PFKFB3. D Protein levels of PFKFB3, E-cadherin, N-cadherin, and Vimentin in BT474-25 mM or MCF-7-25 mM cells after transfected with miR-26-mimic, miR-26-inhibitor, or corresponding-NC were detected by western blot. β-actin was detected as control. *, P < 0.05; **, P < 0.01

Article Snippet: Human breast cancer cell lines BT474 and MCF-7 were purchased from ATCC (the American Type Culture Collection, Rockville, MD).

Techniques: Expressing, Transfection, Western Blot

Journal: World Journal of Surgical Oncology

Article Title: Hyperglycemia induces PFKFB3 overexpression and promotes malignant phenotype of breast cancer through RAS/MAPK activation

doi: 10.1186/s12957-023-02990-2

Figure Lengend Snippet: miR-26 downregulation accelerated the proliferation and migration of breast cancer in a hyperglycemic environment. BT474-25 mM and MCF-7-25 mM cells were transfected with miR-26-mimic, miR-26-inhibitor, or corresponding-NC. A The cell counting assay. B MTT assay. C The cell colony formation assay. D The wound-healing assay. E The migration assay. **, P < 0.01

Article Snippet: Human breast cancer cell lines BT474 and MCF-7 were purchased from ATCC (the American Type Culture Collection, Rockville, MD).

Techniques: Migration, Transfection, Cell Counting, MTT Assay, Colony Assay, Wound Healing Assay

Journal: International Journal of Nanomedicine

Article Title: Polymer–lipid hybrid anti-HER2 nanoparticles for targeted salinomycin delivery to HER2-positive breast cancer stem cells and cancer cells

doi: 10.2147/IJN.S144184

Figure Lengend Snippet: Expression of HER2 in breast cancer cells, analyzed by flow cytometry. Notes: Representative fluorescence-activated cell sorting analysis of ( A ) MDA-MB-361 and ( B ) BT-474 cells tested by ALDEFLUOR assay. In the right image (ALDH+ DEAB), cells incubated with ALDH substrate (BAAA) and the specific inhibitor of ALDH, DEAB, were used to establish the baseline fluorescence of these cells (R1) and to define the ALDEFLUOR-positive region (R2). ( C ) Percentage of HER2 positively stained cells in breast cancer cells. ( D ) HER2 mean fluorescence intensity in breast cancer cells. Data are expressed as mean ± SD (n=3). ** P <0.01. Abbreviations: ALDH, aldehyde dehydrogenase; BAAA, BODIPY-aminoacetaldehyde; DEAB, diethylaminobenzaldehyde.

Article Snippet: Human breast cancer cell lines BT-474 and MDA-MB-361 were purchased from the American Type Culture Collection (ATCC, Manassas, VA, USA).

Techniques: Expressing, Flow Cytometry, Fluorescence, FACS, Incubation, Staining

Journal: International Journal of Nanomedicine

Article Title: Polymer–lipid hybrid anti-HER2 nanoparticles for targeted salinomycin delivery to HER2-positive breast cancer stem cells and cancer cells

doi: 10.2147/IJN.S144184

Figure Lengend Snippet: Cell proliferation assay. Notes: ALDH+ and ALDH− breast cancer cells were seeded in 96-well plates with a density of 1×10 4 cells per well overnight. The cells were incubated with the nanoparticles or salinomycin for 72 h, and cell viability was evaluated using the CCK-8 assay. ( A ) MDA-MB-361 ALDH+, ( B ) MDA-MB-361 ALDH−, ( C ) BT-474 ALDH+, and ( D ) BT-474 ALDH−. Data are expressed as mean ± SD (n=3). Abbreviations: ALDH, aldehyde dehydrogenase; CCK-8, Cell Counting Kit-8; Sali-NP, salinomycin-loaded polymer-lipid nanoparticles; Sali-NP-HER2, salinomycin-loaded polymer–lipid hybrid anti-HER2 nanoparticles.

Article Snippet: Human breast cancer cell lines BT-474 and MDA-MB-361 were purchased from the American Type Culture Collection (ATCC, Manassas, VA, USA).

Techniques: Proliferation Assay, Incubation, CCK-8 Assay, Cell Counting

Journal: International Journal of Nanomedicine

Article Title: Polymer–lipid hybrid anti-HER2 nanoparticles for targeted salinomycin delivery to HER2-positive breast cancer stem cells and cancer cells

doi: 10.2147/IJN.S144184

Figure Lengend Snippet: The IC 50 values of salinomycin and nanoparticles in breast cancer cells

Article Snippet: Human breast cancer cell lines BT-474 and MDA-MB-361 were purchased from the American Type Culture Collection (ATCC, Manassas, VA, USA).

Techniques:

Journal: International Journal of Nanomedicine

Article Title: Polymer–lipid hybrid anti-HER2 nanoparticles for targeted salinomycin delivery to HER2-positive breast cancer stem cells and cancer cells

doi: 10.2147/IJN.S144184

Figure Lengend Snippet: Effect of treatments on the percentage of CSCs. Notes: Effect of the treatments on the proportion of CSCs in breast cancer cells, as reflected by the tumorsphere formation rate ( A and B ) and the proportion of ALDH+ cells ( E and F ). Representative images of tumorspheres formed by ( C ) MDA-MB-361 cells and ( D ) BT-474 cells are shown. The rate of tumorsphere formation is defined as the number of tumorspheres formed in 7 days in the treatment group divided by the number of tumorspheres formed in 7 days in the untreated group; the rate of tumorsphere formation in the untreated group is used as a control and defined as 100%. The two groups were compared by one-way ANOVA with the Newman–Keuls method. Data are expressed as mean ± SD (n=6). * P <0.05; ** P <0.01; *** P <0.001. Abbreviations: ANOVA, analysis of variance; ALDH, aldehyde dehydrogenase; CSCs, cancer stem cells; Sali-NP, salinomycin-loaded polymer–lipid nanoparticles; NP-HER2, polymer–lipid anti-HER2 nanoparticles; Sali-NP-HER2, salinomycin-loaded polymer–lipid hybrid anti-HER2 nanoparticles.

Article Snippet: Human breast cancer cell lines BT-474 and MDA-MB-361 were purchased from the American Type Culture Collection (ATCC, Manassas, VA, USA).

Techniques:

Journal: International Journal of Nanomedicine

Article Title: Polymer–lipid hybrid anti-HER2 nanoparticles for targeted salinomycin delivery to HER2-positive breast cancer stem cells and cancer cells

doi: 10.2147/IJN.S144184

Figure Lengend Snippet: In vivo antitumor assay in mice bearing subcutaneous BT-474 tumors. Notes: BT-474 tumors reached ~50 mm 3 in size by day 10. From day 10, mice were injected with nanoparticles (7.5 mg salinomycin/kg, i.v.) through the tail vein, and salinomycin (7.5 mg salinomycin/kg) dissolved in ethanol was administered by intraperitoneal injection. Therapy was given nine times on alternate days (indicated by arrows), and tumor volume was calculated. ( A ) Tumor growth curve. ( B ) Excised tumors. ( C ) The excised tumors were weighed at the end point. On day 28, the effect of the drug treatments on the CSC proportion in BT-474 tumors in vivo was evaluated by ( D ) the rate of tumorsphere formation and ( E ) the proportion of ALDH+ cells from the excised tumors. ( F ) Representative images of tumorspheres from ( D ) are shown. The two groups were compared by one-way ANOVA with the Newman–Keuls method. Data are expressed as mean ± SD (n=8). * P <0.05; ** P <0.01; *** P <0.001. Abbreviations: ANOVA, analysis of variance; ALDH, aldehyde dehydrogenase; CSC, cancer stem cell; i.v., intravenous; Sali-NP, salinomycin-loaded polymer–lipid nanoparticles; NP-HER2, polymer–lipid anti-HER2 nanoparticles; Sali-NP-HER2, salinomycin-loaded polymer–lipid hybrid anti-HER2 nanoparticles.

Article Snippet: Human breast cancer cell lines BT-474 and MDA-MB-361 were purchased from the American Type Culture Collection (ATCC, Manassas, VA, USA).

Techniques: In Vivo, Injection

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: Trastuzumab resistant cells were developed by culturing parental BT474 cells in the presence of 20/50 μ g trastuzumab for around 6 months.

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques:

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: (a) Proliferation rate of BT474 (parental) and trastuzumab resistant BT474 (BTR50) cells treated with 20 μ g/ml trastuzumab. Proliferation rates were measured daily over 7 days by a luciferase-based viability assay. (b) Sensitivity of BT474 (parental) and trastuzumab resistant BTR50 cells towards increasing concentrations of trastuzumab. Cell viability was determined by a luciferase-based viability assay after 7 days of treatment.

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques: Luciferase, Viability Assay

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: The barchart displays the log2 fold changes of validated candidate genes, which significantly changed their expression in BT474 after trastuzumab treatment. The positive values indicate an upregulation upon drug treatment. Black bars denote values resulting from RNA-Seq analysis. Gray bars denote values resulting from RT-qPCR analysis.

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques: Expressing, RNA Sequencing Assay, Quantitative RT-PCR

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: Upregulated genes in BT474 upon trastuzumab treatment.

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques: Binding Assay

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: The barchart displays the log2 fold changes of validated candidate genes, which showed significant differences in their expression in BT474 and HCC1954, respectively. Positive values indicate an upregulation in BT474. Negative values indicate an upregulation in HCC1954. Black bars denote values resulting from RNA-Seq analysis. Gray bars denote values resulting from RT-qPCR analysis.

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques: Expressing, RNA Sequencing Assay, Quantitative RT-PCR

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: Differentially expressed genes between HCC1954 and BT474.

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques: Binding Assay

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: The plot displays the result of a PCA on the pairwise normalized RNA-Seq expression values of all 23367 annotated genes in the samples BT474, BTR50 and HCC1954 with and without trastuzumab (T) treatment. Same colors denote that the samples belong to the same conducted statistical test and thus were normalized in pair. The five two sample tests included BT474 vs. HCC1954 , BT474 vs. BTR50 , HCC1954+T vs. HCC1954 , BTR50+T vs. BTR50 , and BT474+T vs. BT474 .

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques: RNA Sequencing Assay, Expressing

Journal: PLoS ONE

Article Title: mRNA Profiling Reveals Determinants of Trastuzumab Efficiency in HER2-Positive Breast Cancer

doi: 10.1371/journal.pone.0117818

Figure Lengend Snippet: SNPs called in the BT474 cell line.

Article Snippet: The human breast cancer cell line BT474 was directly obtained from the American Type Culture Collection (ATCC), catalogue no. HTB-20.

Techniques:

Journal: Molecular Cancer

Article Title: Phosphorylation of Ser 78 of Hsp27 correlated with HER-2/ neu status and lymph node positivity in breast cancer

doi: 10.1186/1476-4598-6-52

Figure Lengend Snippet: Effect of heregulin α1 (HRG α1) and p38 MAPK inhibitor (SB 203580) on Hsp27 phosphorylation . Cultures of cells from the BT474 breast cancer cell line were treated with HRG α1 for 10 and 30 min (A) or SB 203580 for 10 hours (B) and total cell lysates were extracted using M-PER reagent (Pierce). Equal amounts of proteins (20 μg) were separated by SDS-PAGE and transferred onto PVDF membrane. The membranes were blocked for 1 hour, followed by being probed with the respective primary antibodies (anti-Hsp27, anti-pSer 15 , anti-pSer 78 and anti-pSer 82 ), and HRP-conjugated secondary antibody. The signals were captured and their intensities were detected as described in Figure 2. The phosphorylation levels of pSer 15 , pSer 78 and pSer 82 were expressed as the ratios of intensity probed with phosphorylation site-specific antibody to the intensity probed with anti-Hsp27. Data with ± SD represents the average of triplicate experiments. C: control; SB: inhibitor SB203580. For the control of HRG-treated cells, untreated cells were cultured for 10 and 30 min and equal amounts of cellular proteins from both time intervals were mixed and used as control. For the control of inhibitor-treated cells, cells were treated with DMSO for 10 hours and cellular proteins were used as the control. * p < 0.05 (student t -test)

Article Snippet: The human BT474 breast cancer cell line was obtained from American Type Culture Collection, and maintained in modified Dulbecco's medium (HybriCare) supplemented with 10% fetal bovine serum (FBS) at 37°C in a humidified atmosphere of 5% CO 2 in an incubator.

Techniques: SDS Page, Cell Culture

Journal: BMC Cancer

Article Title: Enhanced NFκB and AP-1 transcriptional activity associated with antiestrogen resistant breast cancer

doi: 10.1186/1471-2407-7-59

Figure Lengend Snippet: Increased DNA-binding and transcriptional activity of NFκB complexes expressed in TAM-resistant (MCF7/HER2, BT474) relative to TAM-sensitive (MCF7) breast cancer cells. A. Whole cell lysates were immunoblotted to compare endogenous protein expression of p50, p65, and bcl-3 components relative to β-actin. Aliquots were also immunoprecipitated (IP) with antibody to p50, and subsequently Western blotted (WB) to detect bcl-3 complexed to p50 relative to total immunoprecipitated p50. B. DNA-binding by individual NFκB p50 and p65 subunits from nuclear extracts, quantitated by ELISA-based Trans-AM™ assays (mean ± SE OD 450nm values from triplicate samples). C. (NFκB)-luciferase reporter gene expression (mean ± SE values from triplicate samples) measured after transient co-transfection of cells with the firefly reporter plasmid and a Renilla luciferase vector for normalization, as described in Methods. Asterisks (*) indicate significant difference (p < 0.05) from control MCF7 values.

Article Snippet: The ER-positive/ERBB2-negative MCF7 and ER-positive/ERBB2-positive BT474 human breast cancer cell lines were obtained from the American Type Culture Collection (Rockville, MD) and were maintained at 37°C and 5% CO 2 in Dulbecco's modified Eagle's medium (DMEM) for MCF7 or RPMI-1640 medium for BT474, supplemented with 10% fetal bovine serum (FBS), 1% penicillin-streptomycin, and 10 ng/ml insulin.

Techniques: Binding Assay, Activity Assay, Expressing, Immunoprecipitation, Western Blot, Enzyme-linked Immunosorbent Assay, Luciferase, Cotransfection, Plasmid Preparation

Journal: BMC Cancer

Article Title: Enhanced NFκB and AP-1 transcriptional activity associated with antiestrogen resistant breast cancer

doi: 10.1186/1471-2407-7-59

Figure Lengend Snippet: Increased DNA-binding and transcriptional activity of AP-1 complexes expressed in TAM-resistant (MCF7/HER2, BT474) relative to TAM-sensitive (MCF7) breast cancer cells. A. DNA-binding by individual phospho-c-Jun and c-Fos subunits from nuclear extracts, quantitated by ELISA-based Trans-AM™ assays (mean ± SE OD 450 nm values from replicate samples). B. (AP-1)-luciferase reporter gene expression (mean ± SE values from triplicate samples) measured after transient co-transfection of cells with the firefly reporter plasmid and a Renilla luciferase vector for normalization, as described in Methods. Asterisks (*) indicate significant difference (p < 0.05) from control MCF7 values.

Article Snippet: The ER-positive/ERBB2-negative MCF7 and ER-positive/ERBB2-positive BT474 human breast cancer cell lines were obtained from the American Type Culture Collection (Rockville, MD) and were maintained at 37°C and 5% CO 2 in Dulbecco's modified Eagle's medium (DMEM) for MCF7 or RPMI-1640 medium for BT474, supplemented with 10% fetal bovine serum (FBS), 1% penicillin-streptomycin, and 10 ng/ml insulin.

Techniques: Binding Assay, Activity Assay, Enzyme-linked Immunosorbent Assay, Luciferase, Expressing, Cotransfection, Plasmid Preparation

Journal: BMC Cancer

Article Title: Enhanced NFκB and AP-1 transcriptional activity associated with antiestrogen resistant breast cancer

doi: 10.1186/1471-2407-7-59

Figure Lengend Snippet: Treatment interactions between TAM-PS341 and TAM-PA in ER-positive breast cancer models.

Article Snippet: The ER-positive/ERBB2-negative MCF7 and ER-positive/ERBB2-positive BT474 human breast cancer cell lines were obtained from the American Type Culture Collection (Rockville, MD) and were maintained at 37°C and 5% CO 2 in Dulbecco's modified Eagle's medium (DMEM) for MCF7 or RPMI-1640 medium for BT474, supplemented with 10% fetal bovine serum (FBS), 1% penicillin-streptomycin, and 10 ng/ml insulin.

Techniques:

Journal: BMC Cancer

Article Title: Enhanced NFκB and AP-1 transcriptional activity associated with antiestrogen resistant breast cancer

doi: 10.1186/1471-2407-7-59

Figure Lengend Snippet: Comparison of drug treatment effects on expression of (ERE)-luciferase ( A ), (NFκB)-luciferase ( B ), and (AP-1)-luciferase ( C ) reporter genes in TAM-resistant (MCF7/HER2, BT474) and TAM-sensitive (MCF7) breast cancer cells. As described in Methods, cell cultures were transiently transfected with the specific reporter plasmid 20 h before a 24 h culture treatment with the indicated dose of either PS341 or PA, alone or in combination with TAM (500 nM). Reporter activity (firefly luciferase) is presented as mean ± SE fold induction over vehicle treated control cells. * p < 0.05, for drug alone vs. vehicle control; # p < 0.05, for TAM-PS341 or TAM-PA combinations vs. PS341 or PA alone.

Article Snippet: The ER-positive/ERBB2-negative MCF7 and ER-positive/ERBB2-positive BT474 human breast cancer cell lines were obtained from the American Type Culture Collection (Rockville, MD) and were maintained at 37°C and 5% CO 2 in Dulbecco's modified Eagle's medium (DMEM) for MCF7 or RPMI-1640 medium for BT474, supplemented with 10% fetal bovine serum (FBS), 1% penicillin-streptomycin, and 10 ng/ml insulin.

Techniques: Expressing, Luciferase, Transfection, Plasmid Preparation, Activity Assay

Journal: BMC Cancer

Article Title: Enhanced NFκB and AP-1 transcriptional activity associated with antiestrogen resistant breast cancer

doi: 10.1186/1471-2407-7-59

Figure Lengend Snippet: Comparison of drug treatment effects on ER and ER binding to the transcriptional co-repressor, NCoR, in TAM-resistant (MCF7/HER2, BT474) and TAM-sensitive (MCF7) breast cancer cells. Cell cultures were treated for 24 h with vehicle, PS341 (panel A ), or PA (panel B ), alone or in combination with TAM (500 nM). Whole cells were then extracted and Western blotted to detect total ER relative to β-actin, or immunoprecipitated (IP) and then Western blotted (WB) to detect NCoR-bound ER relative to total immunoprecipitated NCoR.

Article Snippet: The ER-positive/ERBB2-negative MCF7 and ER-positive/ERBB2-positive BT474 human breast cancer cell lines were obtained from the American Type Culture Collection (Rockville, MD) and were maintained at 37°C and 5% CO 2 in Dulbecco's modified Eagle's medium (DMEM) for MCF7 or RPMI-1640 medium for BT474, supplemented with 10% fetal bovine serum (FBS), 1% penicillin-streptomycin, and 10 ng/ml insulin.

Techniques: Binding Assay, Western Blot, Immunoprecipitation