Journal: Nature communications

Article Title: Cdkn1b overexpression in adult mice alters the balance between genome and tissue aging

doi: 10.1038/ncomms3626

Figure Lengend Snippet: Panel A shows western blots for pp53(ser18) (a full-length image of this blot is shown in Supplementary Figure 10, panel B) and actin in lung, intra-abdominal fat (IA Fat), and skin of R26-M2rtTA transgenic mice that either carry or do not carry the TRE-Tight-Cdkn1b transgene as indicated in the figure where, starting at two months of age, mice were continuously treated with 1 mg/ml doxycycline for two months and assessed at 4 months of age. Additionally, Cdkn1b expression in the same tissues from a control 24 month old mouse is included for comparison. Arrows indicate the positions of size markers in kDa. Panels B and C show immune-fluorescence staining for γ-H2AX in epidermal sections of control (B) and Cdkn1b over-expressing (C) mice. Panels D and E show immune-fluorescence staining for TP53BP1 in epidermal sections of control (D) and Cdkn1b over-expressing (E) mice. Panels F and G demonstrate reduced frequency of γ-H2AX (n = 9, error bars indicate s.d., ρ = 0.04, two-tailed t-test) and TP53BP1 (n = 10, error bars indicate s.d , ρ = 3.7 × 10 −5 , two-tailed t-test) foci, respectively, in epidermal sections from Cdkn1b over-expressing mice relative to controls. Panel H shows SA-β galactosidase staining of intra-abdominal fat (IAT) for R26-M2rtTA control and R26-M2rtTA;TRE-Tight-Cdkn1b transgenic mice that were treated with 1 mg/ml doxycycline either from birth through 3 months of age (left panels) or starting at 2 months of age and through 8 months of age (right panels). Bars = 5 mm. Quantitative assessment of SA-β galactosidase activity was made using ONPG as a substrate and results from this assay are shown below each panel. Additionally, the weight of total IAT recovered from each animal is given in grams (g). Qualitatively similar SA-β galactosidase staining was observed in a two additional sets of control and R26-M2rtTA;TRE-Tight-Cdkn1b mice treated with 0.25 mg/ ml doxycycline from months 2–7 although quantitative measures were not performed.

Article Snippet: Following immunoblotting (western blot) Cdkn1b, pp53(ser18), and actin were detected using anti-p27(C-19) (1/1000, Santa Cruz Biotechnology Cat No sc-528), anti-pp53(ser18) (1/1000, Cell Signaling Cat No 9284S), or anti-actin (1/1000, Sigma Cat No A2066) primary antibodies and HRP conjugated anti-rabbit secondary antibody (1/2000, Mllipore AP132P GtxRb IgG (H+L) HRP).

Techniques: Western Blot, Transgenic Assay, Expressing, Control, Comparison, Fluorescence, Staining, Two Tailed Test, Activity Assay

Journal: Radiation Research

Article Title: BMS-345541 Sensitizes MCF-7 Breast Cancer Cells to Ionizing Radiation by Selective Inhibition of Homologous Recombinational Repair of DNA Double-Strand Breaks

doi: 10.1667/rr3034.1

Figure Lengend Snippet: FIG. 4. BMS enhances DNA damage response (DDR) to IR. MCF-7 cells were incubated with vehicle or 5 lM BMS for 1 h before exposure to 2 Gy IR. IR-induced phosphorylation of ATM and Chk2 were analyzed by immunofluorescent staining, and p53 phosphorylation was analyzed by Western blot at 1 and 6 h after irradiation. The cells without exposure to IR were also included as a control (CTL). Panel A: Representative photomicrographs (1003 magnifications) of phosphorylated ATM (pATM, green) and Chk2 (pChk2, red) immunofluorescent stainings and nucleic counterstaining with Hoechst-33342 (blue) are shown. Panels B and C: Average numbers (6SE) of pATM and pChk2 foci/cell are presented. ***P , 0.001 vs. vehicle. Panel D: A representative analysis of the levels of phosphorylated p53 (pp53), total p53 and b-actin in MCF- 7 cells by Western blots is shown. Similar results were also observed in two additional analyses.

Article Snippet: Western blot analysis was carried out as previously reported (3), with the following primary antibodies: anti-Rad51 (no. ab213; Abcam), Brca1 (no. ab16780; Abcam), Oct1 (no. 8157, Cell Signaling Technology, Danvers, MA), eEF2 (no. 2332, Cell Signaling Technology), p53 (no. 9282, Cell Signaling Technology), phosphop53 (pp53 [Ser15]) (no. 9286, Cell Signaling Technology), and Actin (no. SC-1616, Santa Cruz Biotechnology, Santa Cruz, CA).

Techniques: Incubation, Phospho-proteomics, Staining, Western Blot, Irradiation, Control

Journal: Cancers

Article Title: Regulation of PD-L1 Expression by SAHA-Mediated Histone Deacetylase Inhibition in Lung Cancer Cells

doi: 10.3390/cancers17172919

Figure Lengend Snippet: Mechanisms of PD-L1 regulation in lung cancer. PD-L1 expression in tumor cells is regulated at multiple levels. The p53–p21 axis can negatively influence PD-L1 transcription, while oncogenic pathways such as PI3K/AKT and JAK/STAT promote its up-regulation. Epigenetic mechanisms play a critical role: histone acetylation and methylation dynamically regulate chromatin accessibility, and DNA methylation (e.g., via DNMT1) can repress or activate PD-L1 transcription depending on context. Collectively, these mechanisms contribute to PD-L1-mediated immune evasion and tumor survival.

Article Snippet: pp53 (Phospho-p53) , CST , 12571 , 1:1000.

Techniques: Expressing, Methylation, DNA Methylation Assay