rabbit polyclonal anti p21  (Santa Cruz Biotechnology)

Journal: Antioxidants

Article Title: Exploring the Anticancer Potential of the Multistrain Probiotic Formulation OxxySlab in Bladder Cancer Cell Lines

doi: 10.3390/antiox14111282

Figure Lengend Snippet: Senescence induction in BC cells following OxxySlab lysate treatment. Cell lines were treated with OxxySlab lysate (75–150 μg/mL) for 48 h. Senescent cells were identified by β-galactosidase staining (β-gal). Representative phase-contrast images of T24 ( A ), 5637 ( E ) and SV-HUC-1 ( I ) β-gal-positive cells (blue staining) are shown. Quantification of senescence was performed by measuring the Mean Gray Value of blue staining intensity using ImageJ software, with data expressed as Inverted Mean Gray Value (255 − MGV), which directly reflects β-gal activity. Data are expressed as mean ± SEM of two independent experiments in triplicate. Western blot analysis of the senescence markers p21, p53 and p16 was performed in untreated (CNTR) and OxxySlab -treated T24 ( B – D ), 5637 ( F – H ), and SV-HUC1 ( J – L ) cells. Protein levels were quantified by densitometry, normalized to GAPDH, and expressed as fold change relative to CNTR of three independent experiments (mean ± SEM). Statistical significance was assessed by one-way ANOVA followed by Tukey post hoc test (* p < 0.05, ** p < 0.01).

Article Snippet: Following incubation with 5% non-fat dry milk in Tris-buffered saline for 1 h at room temperature, the membranes were incubated overnight at 4 °C with primary antibodies: goat anti-human vimentin polyclonal antibody (Chemicon International, Temecula, CA, USA; dilution 1:100), mouse anti-human E-cadherin monoclonal antibody (Cell Signaling Technology; dilution 1:1000), rabbit anti-human β-catenin monoclonal antibody (Cell Signaling Technology; dilution 1:1000), rabbit anti-human p21 polyclonal antibody (Santa Cruz Biotechnology, Dallas, TX, USA dilution 1:1000); rabbit anti-human phospho-Nrf2 monoclonal antibody (S40) (1:2000, Abcam, Cambridge, UK); rabbit anti-human p16 polyclonal antibody (Santa Cruz Biotechnology, dilution 1:200); mouse anti-human p53 monoclonal antibody (Santa Cruz Biotechnology, dilution 1:1000); mouse anti-human GAPDH monoclonal antibody (Immunological Sciences, Rome, Italy; dilution 1:1000).

Techniques: Staining, Software, Activity Assay, Western Blot

Journal: Renal Failure

Article Title: Canagliflozin ameliorates high-salt-induced renal injury and premature aging in male Dahl salt-sensitive rats, with associated changes in SIRT6/HIF-1α signaling

doi: 10.1080/0886022X.2025.2546624

Figure Lengend Snippet: Representative images of senescence-associated β-galactosidase (SA-β-gal) staining and the expression of aging-related proteins in the kidneys of the three groups of rats. A. Renal SA-β-gal staining. Magnification, ×200; scale bar, 50 μm. B. Expression of the aging-related proteins P53 and P21 in the kidneys. C. SA-β-gal-positive area in rat kidneys ( n = 4). D. P53 protein expression. E. P21 protein expression. (D, E, n = 6). NSD: normal salt dahl salt-sensitive rats; HSD: high salt dahl salt-sensitive rats; HSD + CANA: high salt dahl salt-sensitive rats + canagliflozin (30 mg/kg/day). HSD vs. NSD: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. HSD vs. HSD + CANA: # p < 0.05, ## p < 0.01, ### p < 0.001, #### p < 0.0001.

Article Snippet: The antibodies used for rat tissues included rabbit monoclonal anti-SIRT6 (1:1000, Abcam, ab191385), rabbit polyclonal anti-p53 (1:800, Proteintech, 10442-1-AP), rabbit polyclonal anti-p21 (1:5000, Proteintech, 10355-1-AP), rabbit polyclonal anti-HIF-1α (1:100, affinity, AF1009), and rabbit monoclonal anti-αSMA (alpha smooth muscle, 1:1000, Zenbio, R380653) antibodies.

Techniques: Staining, Expressing

Journal: Renal Failure

Article Title: Canagliflozin ameliorates high-salt-induced renal injury and premature aging in male Dahl salt-sensitive rats, with associated changes in SIRT6/HIF-1α signaling

doi: 10.1080/0886022X.2025.2546624

Figure Lengend Snippet: Immunohistochemical results of the three groups of rats. A. Representative image of SIRT6 in the kidney. B. Representative image of HIF-1α in the kidney. C. Representative image of α-SMA in the kidney. D. Representative image of P53 in the kidney. E. Representative image of P21 in the kidney. Magnification, ×200; scale bar, 20 μm. NSD: normal salt dahl salt-sensitive rats; HSD: high salt dahl salt-sensitive rats; HSD + CANA: high salt dahl salt-sensitive rats + canagliflozin (30 mg/kg/day). HSD vs. NSD: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. HSD vs. HSD + CANA: # p < 0.05, ## p < 0.01, ### p < 0.001, #### p < 0.0001 ( n = 6).

Article Snippet: The antibodies used for rat tissues included rabbit monoclonal anti-SIRT6 (1:1000, Abcam, ab191385), rabbit polyclonal anti-p53 (1:800, Proteintech, 10442-1-AP), rabbit polyclonal anti-p21 (1:5000, Proteintech, 10355-1-AP), rabbit polyclonal anti-HIF-1α (1:100, affinity, AF1009), and rabbit monoclonal anti-αSMA (alpha smooth muscle, 1:1000, Zenbio, R380653) antibodies.

Techniques: Immunohistochemical staining

Journal: Molecular Medicine Reports

Article Title: CDK5 targets p21 CIP1 to regulate thyroid cancer cell proliferation and malignancy in patients

doi: 10.3892/mmr.2025.13547

Figure Lengend Snippet: CDK5 interacts with p21. (A) Structural prediction of the interaction between CDK5 and p21 using AlphaFold 3.0. CDK5 is shown in red and p21 in green. (B) Detailed visualization of the CDK5-p21 interaction interface using UCSF Chimera software. CDK5 is shown in surface representation, while p21 is depicted in a ribbon diagram. The binding sites are highlighted. Heat map of the interaction interface indicating the degree of interaction strength between CDK5 and p21, with red representing strong interaction sites and blue representing weak or no interaction. (C) Sequence alignment of CDK5 and p21 showing the interacting regions predicted by AlphaFold. Residues involved in the interaction are highlighted in red for CDK5 and green for p21. (D) Immunoprecipitation assay demonstrating the interaction between CDK5 and p21 in TPC-1 cells. Cells were treated with 10 µM MG132 to inhibit proteasomal degradation. CDK5 was immunoprecipitated from cell lysates and co-precipitated p21 was detected by western blotting. Input lysates (bottom panels) show the expression levels of p21, CDK5 and β-actin, the latter was used as the loading control. The results confirm the interaction between CDK5 and p21 and suggested that CDK5 regulates p21 stability via the ubiquitin-proteasome pathway. CDK5, cyclin-dependent kinase 5.

Article Snippet: The tissue sections were incubated overnight at 4°C with the following primary antibodies: Mouse monoclonal anti-CDK5 (cat. no. sc-249; Santa Cruz Biotechnology, Inc.; 1:20) or rabbit polyclonal anti-p21 (cat. no. 2947; Cell Signaling Technology, Inc.; 1:50).

Techniques: Structural Proteomics, Software, Binding Assay, Sequencing, Immunoprecipitation, Western Blot, Expressing, Control, Ubiquitin Proteomics

Journal: Molecular Medicine Reports

Article Title: CDK5 targets p21 CIP1 to regulate thyroid cancer cell proliferation and malignancy in patients

doi: 10.3892/mmr.2025.13547

Figure Lengend Snippet: CDK5 downregulates p21 in TC cells. (A) Western blot analysis of p21 protein expression levels in BCPAP cells transfected with EV or a CDK5 overexpression plasmid. Cells were treated with 50 µg/ml CHX for 0, 2, 4 or 6 h to inhibit protein synthesis. Short and long exposures of p21 are shown. (B) Quantification of p21 protein levels. Data are presented as the fold change relative to time 0 for EV and CDK5 transfected cells. (C) Western blot analysis of p21 and CDK5 protein expression levels in BCPAP cells transfected with EV or CDK5, with or without treatment with 10 µM MG132 for 6 h. (D) Quantification of p21 protein expression. Data are presented as fold change relative to EV-transfected mock-treated cells. (E) Immunofluorescence staining of p21 (green) in BCPAP cells transfected with vector or CDK5, with or without MG132 treatment. The results indicate that CDK5 overexpression reduces p21 levels in TC cells and this effect was reversed following proteasome inhibition. Scale bar, 20 µm. (F) Co-immunoprecipitation analysis of CDK5 and p21 was performed to investigate the interaction between CDK5 and p21 in thyroid cancer cells. Panels show the interaction of CDK5 with WT p21 and MT p21 following proteasome inhibition using MG132. Red arrows indicate the presence of p21 in the immunoprecipitated complex. (G) Cell counting assay was performed to evaluate p21 WT and MT p21 on cell proliferation. For all blots, β-actin was used as the loading control. Values are presented as the mean ± SD from three independent experiments. Data were compared using an unpaired Student's t-test. *P<0.05, **P<0.01, ***P<0.001. CDK5, cyclin-dependent kinase; 5TC, thyroid cancer; EV, empty vector; HCX, cycloheximide; n.s., not significant; WT, wild-type; MT, S130A mutant.

Article Snippet: The tissue sections were incubated overnight at 4°C with the following primary antibodies: Mouse monoclonal anti-CDK5 (cat. no. sc-249; Santa Cruz Biotechnology, Inc.; 1:20) or rabbit polyclonal anti-p21 (cat. no. 2947; Cell Signaling Technology, Inc.; 1:50).

Techniques: Western Blot, Expressing, Transfection, Over Expression, Plasmid Preparation, Immunofluorescence, Staining, Inhibition, Immunoprecipitation, Cell Counting, Control, Mutagenesis

Journal: Molecular Medicine Reports

Article Title: CDK5 targets p21 CIP1 to regulate thyroid cancer cell proliferation and malignancy in patients

doi: 10.3892/mmr.2025.13547

Figure Lengend Snippet: CDK5 negatively regulates p21 in TC cells. Reverse transcription-quantitative PCR analysis of (A) CDK5 and (B) CDKN1A mRNA expression in TC cell lines BCPAP and TPC-1. (C) Western blot analysis of p21 and CDK5 protein levels in BCPAP and TPC-1 cells treated with or without 10 µM MG132 for 6 h. (D) Western blot analysis of p21 and CDK5 protein levels in TPC-1 and BCPAP cells transfected with shGFP or shCDK5 (#1, #2, and #3). (E) Quantitative analysis of CDK5 mRNA levels in both TPC-1 and BCPAP cells. Data are presented as the fold change relative to shGFP-transduced cells. The results demonstrated that knockdown of CDK5 increases p21 protein expression levels in TC cells. Values are presented as the mean ± SD from three independent experiments. Data were compared using an unpaired Student's t-test. *P<0.05, **P<0.01, ***P<0.001 vs. shGFP. CDK5, cyclin-dependent kinase; TC, papillary thyroid cancer; sh, short hairpin; n.s., not significant.

Article Snippet: The tissue sections were incubated overnight at 4°C with the following primary antibodies: Mouse monoclonal anti-CDK5 (cat. no. sc-249; Santa Cruz Biotechnology, Inc.; 1:20) or rabbit polyclonal anti-p21 (cat. no. 2947; Cell Signaling Technology, Inc.; 1:50).

Techniques: Reverse Transcription, Real-time Polymerase Chain Reaction, Expressing, Western Blot, Transfection, Knockdown

Journal: Molecular Medicine Reports

Article Title: CDK5 targets p21 CIP1 to regulate thyroid cancer cell proliferation and malignancy in patients

doi: 10.3892/mmr.2025.13547

Figure Lengend Snippet: Analysis of TCGA data showing the clinical relevance of CDK5 and p21 in thyroid cancer. (A) Scatter plot showing the correlation between CDK5 and p21 mRNA expression in thyroid cancer samples from TCGA. Pearson correlation coefficient (r) and P-value are indicated. (B) Kaplan-Meier overall survival analysis of patients with thyroid cancer stratified by high and low CDK5 expression levels. (C) Kaplan-Meier overall survival analysis of patients with thyroid cancer stratified by high and low p21 expression levels. Survival was compared using a log-rank test. (D) Pathological stage plot showing CDK5 expression levels across different stages of thyroid cancer. (E) Pathological stage plot illustrating p21 expression levels across different stages of thyroid cancer. Pathological stage plots were obtained from GEPIA, and differential gene expression was analyzed by one-way ANOVA ( https://gepia.cancer-pku.cn/ ). Higher CDK5 expression was associated with poorer overall survival, while p21 expression was not markedly associated with survival outcomes. TCGA, The Cancer Genome Atlas; CDK5, cyclin-dependent kinase.

Article Snippet: The tissue sections were incubated overnight at 4°C with the following primary antibodies: Mouse monoclonal anti-CDK5 (cat. no. sc-249; Santa Cruz Biotechnology, Inc.; 1:20) or rabbit polyclonal anti-p21 (cat. no. 2947; Cell Signaling Technology, Inc.; 1:50).

Techniques: Expressing, Gene Expression

Journal: Molecular Medicine Reports

Article Title: CDK5 targets p21 CIP1 to regulate thyroid cancer cell proliferation and malignancy in patients

doi: 10.3892/mmr.2025.13547

Figure Lengend Snippet: IHC analysis of CDK5 and p21 nuclear expression in papillary thyroid cancer patient specimens. (A) IHC staining for CDK5 and p21 in patients with thyroid cancer demonstrating the relationship between CDK5 and p21 nuclear expression. Left panels, CDK5 staining showed strong nuclear localization in several patient samples, particularly in tumor cells. The nuclear expression of CDK5 was more prominent in aggressive regions of the thyroid cancer samples, suggesting a role in tumor proliferation. Right panels, p21 staining was inversely correlated with CDK5. In samples where CDK5 was strongly expressed in the nucleus, p21 nuclear staining was weak or absent. Conversely, in areas were CDK5 expression was low, p21 nuclear localization was more evident. This expression pattern supported the hypothesis that CDK5 negatively regulated p21 expression at the nuclear level, contributing to cancer cell cycle dysregulation and malignancy. Scale bar, 50 µm. (B) The heatmap illustrates the correlation between nuclear CDK5 and p21 expression across multiple samples, with darker red indicating higher CDK5 expression and lower p21 levels. (C) Significant differences in expression patterns between groups with high CDK5/low p21 and low CDK5/high p21 expression (*P<0.05). This suggested that elevated nuclear CDK5 was associated with decreased p21 expression, supporting the hypothesis that CDK5 promoted thyroid cancer progression. IHC, immunohistochemistry; CDK5, cyclin-dependent kinase.

Article Snippet: The tissue sections were incubated overnight at 4°C with the following primary antibodies: Mouse monoclonal anti-CDK5 (cat. no. sc-249; Santa Cruz Biotechnology, Inc.; 1:20) or rabbit polyclonal anti-p21 (cat. no. 2947; Cell Signaling Technology, Inc.; 1:50).

Techniques: Expressing, Immunohistochemistry, Staining

Journal: Molecular Medicine Reports

Article Title: CDK5 targets p21 CIP1 to regulate thyroid cancer cell proliferation and malignancy in patients

doi: 10.3892/mmr.2025.13547

Figure Lengend Snippet: Graphical abstract. The present study examined the interaction between CDK5 and the cyclin-dependent kinase inhibitor p21 CIP1 . CDK5 promoted the degradation of p21 through the ubiquitin-mediated pathways, thereby reducing the tumor-suppressive effects of p21. High CDK5 levels were associated with increased tumor malignancy and worse survival outcomes, while higher p21 expression was associated with an improved prognosis. TC stages and aggressive tumors exhibit elevated CDK5 and reduced p21 levels. This suggested that CDK5-mediated degradation of p21 contributed to TC progression. CDK5, cyclin-dependent kinase 5; TC, thyroid cancer.

Article Snippet: The tissue sections were incubated overnight at 4°C with the following primary antibodies: Mouse monoclonal anti-CDK5 (cat. no. sc-249; Santa Cruz Biotechnology, Inc.; 1:20) or rabbit polyclonal anti-p21 (cat. no. 2947; Cell Signaling Technology, Inc.; 1:50).

Techniques: Ubiquitin Proteomics, Expressing