Journal: The Journal of biological chemistry

Article Title: Cooperation of a single lysine mutation and a C-terminal domain in the cytoplasmic sequestration of the p53 protein.

doi: 10.1074/jbc.273.31.19817

Figure Lengend Snippet: FIG. 3. Effects of wild-type and Lys-305 mutated p53 on p21/ CIP1/WAF1 induction. Immunoblots display p21 expression in SAOS-2 cells without transfection (lane 1) or transfected with vector alone (pcDNA3; lane 2), wild-type p53 (lane 3), Lys-305 mutated p53 (p53K305N; lane 4), and pRc/CMV-p53R175H (lane 5). The difference of p21 induction by wild-type and Lys-305 mutated p53 was normalized to the amount of p53 protein detected on the same blot.

Article Snippet: Eighty micrograms of protein was separated by SDS-12% polyacrylamide gel electrophoresis, transferred to a polyvinylidene difluoride membrane (Hybond PVDF, Amersham Pharmacia Biotech), and probed with the anti-p21 monoclonal antibody (Santa Cruz Biotechnology) or the anti-p53 PAb1801 antibody (Oncogene).

Techniques: Western Blot, Expressing, Transfection, Plasmid Preparation

Journal: Cancer Medicine

Article Title: Protective role of cytoplasmic p21Cip1/Waf1 in apoptosis of CDK4/6 inhibitor‐induced senescence in breast cancer cells

doi: 10.1002/cam4.4410

Figure Lengend Snippet: p21 in MDA‐MB‐231 cells treated with abemaciclib and/or ABT‐263. (A, B) Cancer cells were treated with abemaciclib (1.5 µM) and ABT‐263 (1.5 µM) for 2 days. After harvesting, the cytoplasmic and nuclear fractions were separated and subjected to immunoblotting. TBP and GAPDH were used as controls. (C) Immunoblotting was performed similarly using whole lysates. (D) MDA‐MB‐231 cells were treated with abemaciclib (1.5 µM) and ABT‐263 (1.5 µM) with zVAD (10 µM) for 24 h. Flow cytometric analysis was done after staining with annexin V‐FITC and PI. The numbers are proportions of the subsets. (Left) Data of the means ± SD of three cells are shown. * p < 0.05, ** p < 0.01. (E) MDA‐MB‐231 cells were treated similarly with zVAD (10 µM) for 24 h and subjected to immunoblotting. (F) Untreated MDA‐MB‐231 cells were cultured with Hoechst 33342 (5 µg/ml) and stained with anti‐p21 and anti‐caspase‐3 antibodies followed by an Alexa 488‐conjugated anti‐rabbit antibody and Cy5‐conjugated anti‐mouse IgG. Confocal imaging reveals nuclei (blue), p21 (green), and caspse‐3 (white). Scale, 10 µm. (G) Control and p21‐overexpressing MDA‐MB‐231 cells were examined for their p21 expression by immunoblotting. (H) Control and p21‐overexpressing MDA‐MB‐231 cells were treated with abemaciclib (1.5 µM) and ABT‐263 (1.5 µM) for 24 h. Flow cytometric analysis was done after staining with annexin V‐APC. Numbers are the proportions of the subset (Left). The means ± SD of four wells are shown. ** p < 0.01. (I) Cancer cells were treated with abemaciclib (1.5 µM) for 24 h, and the cell lysates were subjected to immunoblot to examine the expression of p21 and c‐Myc

Article Snippet: The following siRNAs were used: p21(I) siRNA (#6456; CST), p21(II) siRNA (#6558; CST), and control siRNA (#6568; CST).

Techniques: Western Blot, Staining, Cell Culture, Imaging, Control, Expressing

Journal: Cancer Medicine

Article Title: Protective role of cytoplasmic p21Cip1/Waf1 in apoptosis of CDK4/6 inhibitor‐induced senescence in breast cancer cells

doi: 10.1002/cam4.4410

Figure Lengend Snippet: Effect of genetic knockdown of p21 in MCF‐7 cells on their sensitivity to drugs. (A) siRNA‐transfected cancer cells were cultured for 48 h and subjected to immunoblotting. (B) MDA‐MB‐231 and MCF‐7 cells transfected with siRNA p21(I) 2 days prior were treated with abemaciclib (1.5 µM) and ABT‐263 (1.5 µM) for 48 h. After staining with annexin V‐FITC and PI, flow cytometric analysis was performed. Data are the means of three wells. * p < 0.05, ** p < 0.01. (C) Representative flow cytometry results; numbers are percentages of the subsets. (D) MDA‐MB‐231 cells were cultured with abemaciclib (1.5 µM) and ABT‐263 (1.5 µM) in the presence of caspase inhibitors (10 µM) for 48 h. Flow cytometric analysis was done after staining with annexin V‐FITC and PI. Data are the means of three wells. ** p < 0.01. (E) siRNA p21(I)‐transfected MDA‐MB‐231 and MCF‐7 cells were cultured with TRAIL for 24 h. Flow cytometric analysis was done after staining with annexin V‐FITC and PI. ** p < 0.01

Article Snippet: The following siRNAs were used: p21(I) siRNA (#6456; CST), p21(II) siRNA (#6558; CST), and control siRNA (#6568; CST).

Techniques: Knockdown, Transfection, Cell Culture, Western Blot, Staining, Flow Cytometry

Journal: Cancer Medicine

Article Title: Protective role of cytoplasmic p21Cip1/Waf1 in apoptosis of CDK4/6 inhibitor‐induced senescence in breast cancer cells

doi: 10.1002/cam4.4410

Figure Lengend Snippet: Poor prognosis of breast cancer patients with p21 high compared with those with p21 low . (A, B, C) Kaplan–Meier plotter univariate analysis of survival time in CDKN1A mRNA expression in breast cancer. Version 2021 of the database was used for analysis. Outlier array data were excluded for array quality control. Patients were split into low‐ and high‐expression groups based on the optimal cutoff. (D, E) TRGAted was used for survival analysis according to p21 protein level in patients with invasive breast carcinoma. All subtypes of TCGA‐BRCA‐L4 were used in the analysis. Patients were split into low‐ and high‐expression groups based on the optimal cutoff

Article Snippet: The following siRNAs were used: p21(I) siRNA (#6456; CST), p21(II) siRNA (#6558; CST), and control siRNA (#6568; CST).

Techniques: Expressing, Control