stat3 inhibitor sta 21  (Santa Cruz Biotechnology)

Journal: Cell Death Discovery

Article Title: Interleukin-6 derived from cancer-associated fibroblasts attenuates the p53 response to doxorubicin in prostate cancer cells

doi: 10.1038/s41420-020-0272-5

Figure Lengend Snippet: a Levels of Tyr705-phosphorylated STAT3 (p-STAT3) and total STAT3 in LNCaP cells after treatment with 1 μM doxorubicin for 8 h in the presence or absence of IL-6 as shown by western blotting. Cells were pre-treated with IL-6 (0.1, 1 or 10 ng/mL) for 16 h ( N = 5). b Levels of Tyr705-phosphorylated STAT3 (p-STAT3) in 22Rv1 cells after treatment with 1 μM doxorubicin for 8 h in the presence or absence of IL-6 as shown by western blotting. Cells were pre-treated with 10 ng/mL IL-6 for 16 h ( N = 4). STAT3 phosphorylation at Tyr705 indicates STAT3 activation upon IL-6 treatment. The blots in a , b were cut into two pieces and probed with antibodies against p-STAT3 and GAPDH separately. The p-STAT3 blots were then stripped and blotted with an antibody against STAT3. c Survival of LNCaP cells as assessed by the WST assay after treatment with 1 μM doxorubicin for 48 h in the presence or absence of IL-6 and 1 μM JAK kinase inhibitor Ruxolitinib or 20 μM STAT3 inhibitor STA-21. Cells were pre-treated with IL-6 (0.1, 1 or 10 ng/mL) for 16 h. Cell survival is shown as fold change relative to cell survival in the absence of JAK/STAT3 inhibitor (S.E.M. is indicated by bars; N = 6). d Left panel: p53 levels in LNCaP cells after treatment with 1 μM doxorubicin for 8 h in the presence or absence of IL-6 and 1 μM JAK kinase inhibitor Ruxolitinib or 20 μM STAT3 inhibitor STA-21. Cells were pre-treated with IL-6 (10 ng/mL) for 16 h. The blot was cut into two pieces and probed with anti-p53 DO-1 and anti-GAPDH antibody separately. Samples to be compared were loaded on the same gel and transferred onto the same membrane. Right panel: quantification of the western blot data shown as ratio of p53 to GAPDH (S.E.M. is indicated by bars; N = 2). e STAT3 protein phosphorylation and total STAT3 protein levels in LNCaP cells after treatment with 1 μM doxorubicin for 8 h in the presence or absence of IL-6 and 1 μM JAK kinase inhibitor Ruxolitinib or 20 μM STAT3 inhibitor STA-21. Cells were pre-treated with 10 ng/mL IL-6 for 16 h ( N = 2). The blot was cut into two pieces and probed with antibodies against p-STAT3 and GAPDH separately. The p-STAT3 blot was then stripped and blotted with anti-STAT3 antibody.

Article Snippet: The inhibitors used were JAK inhibitors Ruxolitinib (INCB018424 Selleckchem, Rungsted, Denmark) and Pyridone 6 (Calbiochem) and STAT3 inhibitors STA-21 and Stattic (both from Selleckchem, Denmark).

Techniques: Western Blot, Phospho-proteomics, Activation Assay, WST Assay, Membrane

Journal: Cell Death Discovery

Article Title: Interleukin-6 derived from cancer-associated fibroblasts attenuates the p53 response to doxorubicin in prostate cancer cells

doi: 10.1038/s41420-020-0272-5

Figure Lengend Snippet: a Oncoprint from cBioportal of two selected prostate cancer studies showing genetic alteration profiles of IL-6R, STAT3, MDM2, and TP53. Each row represents the genetic alteration according to the figure legend with individual patient in the column. b mRNA Expression, RSEM (Batch normalized from Illumina HiSeq_RNASeqV2) of IL-6R, STAT3 or MDM2 from prostate adenocarcinoma (prad) of the TCGA PanCancer Atlas study based on patients that have no TP53 alterations or putative driver TP53 mutations (missense or truncating). N = 414 no alterations, and N = 56 putative driver mutations. Mann–Whitney test, for IL-6R ** p = 0.003, STAT3 p = 0.47 and MDM2 *** p < 0.0001. c Scatter plots of mRNA Expression, RSEM (Batch normalized from Illumina HiSeq_RNASeqV2) of IL-6R, JAK1, JAK2, STAT3 vs MDM2 in prostate adenocarcinoma patients of the TCGA PanCancer Atlas study that have no alterations in TP53. Indicated r and p values are analysis by Spearman correlation. N = 414 in all plots. d Scatter plots of mRNA expression, RSEM (Batch normalized from Illumina HiSeq_RNASeqV2) of IL-6R, JAK1, JAK2, STAT3 vs MDM2 in prostate adenocarcinoma patients of the TCGA PanCancer Atlas study that have putative driver alterations (missense and truncating) in TP53. Indicated r and p values are analysis by Spearman correlation. N = 56 in all plots, except the correlation with JAK2 N = 55. e Survival of patients with metastatic prostate adenocarcinoma from the study by Abida et al. . N is indicated in the figure. Black dot indicates censored patient. Left panel; patients with no TP53 alterations were grouped as having IL-6R alterations (amplification ( N = 12), mRNA high ( N = 1) missense mutation ( N = 1)) or having no IL-6R alterations. Log-rank (Mantel–Cox) test p = 0.09 or Gehan–Breslow–Wilcoxon test ** p = 0.01. Right panel; patients with putative driver TP53 mutations (missense, truncating, inframe) were grouped as having IL-6R alterations (amplification ( N = 4), mRNA high ( N = 3)) or having no IL-6R alterations. Log-rank (Mantel–Cox) test p = 0.5 or Gehan–Breslow–Wilcoxon test p = 0.9.

Article Snippet: The inhibitors used were JAK inhibitors Ruxolitinib (INCB018424 Selleckchem, Rungsted, Denmark) and Pyridone 6 (Calbiochem) and STAT3 inhibitors STA-21 and Stattic (both from Selleckchem, Denmark).

Techniques: Expressing, MANN-WHITNEY, Amplification, Mutagenesis

Journal: Cell Death Discovery

Article Title: Interleukin-6 derived from cancer-associated fibroblasts attenuates the p53 response to doxorubicin in prostate cancer cells

doi: 10.1038/s41420-020-0272-5

Figure Lengend Snippet: CAFs secrete IL-6, which binds to IL-6 receptors (IL-6R) expressed on cancer cells. IL-6 binding to its receptor leads to activation of JAK kinase and STAT3, respectively. STAT3 is activated by phosphorylation at Tyr705, which induces dimerization, nuclear translocation, and DNA binding. This stimulates Mdm2-mediated p53 ubiquitination and p53 degradation in the proteasome, thereby inhibiting upregulation of the p53 target Bax upon treatment with doxorubicin. As a result, prostate cancer cell survival is enhanced.

Article Snippet: The inhibitors used were JAK inhibitors Ruxolitinib (INCB018424 Selleckchem, Rungsted, Denmark) and Pyridone 6 (Calbiochem) and STAT3 inhibitors STA-21 and Stattic (both from Selleckchem, Denmark).

Techniques: Binding Assay, Activation Assay, Phospho-proteomics, Translocation Assay, Ubiquitin Proteomics