Project description:MDSC (myeloid-derived suppressor cells) were generated in vitro using IL-6 and GM-CSF. To identify the role of STAT3 in MDSC, we treated the generated cells for 24 hours with DMSO (control) or 1 µM STAT3 inhibitor Napabucasin (also known as BBI608) and compared their expression profile by microarray. We found genes and pathways that are up- or downregulated upon STAT3 inhibition in MDSC.
Project description:Activation of Signal Transducer and Activator of Transcription 3 (STAT3) is common in prostate cancers. STAT3 may induce cell proliferation and resistance to apoptosis, as well as promote tumor angiogenesis, invasion, and migration by activating gene expression. Many STAT3-dependent transcriptional responses are mediated through protein-protein interactions that involve the amino-terminal domain (N-domain). In this study, we found that inhibition of the STAT3 N-domain using novel inhibitor ST3-Hel2A-2 induces apoptotic death in prostate cancer cells. The cell death was accomponied by robust activation of pro-apoptotic gene. Using chromatin immunoprecipitation and tiling human promoter arrays (ChIP-chip), we have defined genome-wide targets of STAT3 in DU145 prostate cancer cells. We found that upregulated pro-apoptotic genes were bound by STAT3 in prostate cancer cells, and that STAT3 binding was decreased following inhibition of the STAT3 N-domain. DU145 cells were treated with ST3-Hel2A-2 or DMSO as a control for 3 hr. Total RNA has been extracted and prepared for hybridization on Affymetrix HG-U133A 2.0 arrays.
Project description:Myeloid derived suppressor cells (MDSC) playing the immune suppressive roles in tumor bearing host consists of two major subsets of granulocytic and monocytic cells. Granulocytic MDSC (G-MDSC) express CD11b+ Gr-1high Ly6G+ Ly6Clow and produce high level of reactive oxygen species (ROS). Interestingly, neutrophils are well known ROS producing cells during immune defensive process and share same surface markers with G-MDSC. These similar features always brought the fundamental questions what’s the difference between G-MDSC and neutrophils but it’s not yet proven clearly. In this study, we examined the gene expression of G-MDSC and neutrophils using Affymetrix microarray G-MDSC (CD11b+Ly6G+Ly6Clow) were purifed from splenocytes in EL4 lymphoma tumor bearing mice by positive selection of Ly6G using microbeads isolation. Neutrophils were purified from ascitic fluids induced after injection of milk protein, casein by negative selection of F4/80 and positive selection of Ly6G using microbeads isolation. Their RNA was extracted and gene expression was analyzed using Affymetrix microarray.
Project description:Activation of Signal Transducer and Activator of Transcription 3 (STAT3) is common in prostate cancers. STAT3 may induce cell proliferation and resistance to apoptosis, as well as promote tumor angiogenesis, invasion, and migration by activating gene expression. Many STAT3-dependent transcriptional responses are mediated through protein-protein interactions that involve the amino-terminal domain (N-domain). In this study, we found that inhibition of the STAT3 N-domain using novel inhibitor ST3-Hel2A-2 induces apoptotic death in prostate cancer cells. The cell death was accomponied by robust activation of pro-apoptotic gene. Using chromatin immunoprecipitation and tiling human promoter arrays (ChIP-chip), we have defined genome-wide targets of STAT3 in DU145 prostate cancer cells. We found that upregulated pro-apoptotic genes were bound by STAT3 in prostate cancer cells, and that STAT3 binding was decreased following inhibition of the STAT3 N-domain. STAT3 siRNA knockdow confirmed specificity of STAT3 binding and changes in gene expression. DU145 cells were treated with STAT3 siRNA or scrambled siRNA for 48hr. Total RNA has been extracted and prepared for hybridization on Affymetrix HG-U133A 2.0 arrays.
Project description:Myeloid derived suppressor cells (MDSC) playing the immune suppressive roles in tumor bearing host consists of two major subsets of granulocytic and monocytic cells. Granulocytic MDSC (G-MDSC) express CD11b+ Gr-1high Ly6G+ Ly6Clow and produce high level of reactive oxygen species (ROS). Interestingly, neutrophils are well known ROS producing cells during immune defensive process and share same surface markers with G-MDSC. These similar features always brought the fundamental questions what’s the difference between G-MDSC and neutrophils but it’s not yet proven clearly. In this study, we examined the gene expression of G-MDSC and neutrophils using Affymetrix microarray
Project description:To investigate potential links between Stat3 transcriptional activity and other signaling pathways in breast cancer, we determined the gene expression profiles of three breast cancer cell lines treated with JAK, PTGIS, PFKFB3, CXCR2, HAS1, or NQO1 inhibitor (all of which decreased Stat3 transcriptional activity in Hs 578T cells except for the NQO1 inhibitor), inhibitor treatment vehicle alone (DMSO), STAT3 siRNAs, or non-targeting siRNAs. Using the resulting data, we identified a gene signature that was significantly regulated by STAT3 siRNAs and similarly affected by the JAK and at least 3 other inhibitors (or by 4 other inhibitors) but not by the NQO1 inhibitor in Hs 578T cells that was enriched in genes involved in development and correlated with shorter distant metastasis-free survival in primary lymph-node-negative invasive breast tumors. These results emphasize the central importance of Stat3 in CD44+/CD24- stem-cell-like breast cancer cells. This study includes SAGE-Seq libraries obtained using 27 samples that each underwent individual protocols. There are nine samples of each of three cell lines - Hs 578T, MCF7, and SUM159PT. The samples in each group were treated with either one of the six inhibitors, DMSO only (the background control for inhibitor-treated cells), STAT3 siRNAs, or non-targeting siRNAs (the background control for STAT3 siRNAs).
Project description:Activation of Signal Transducer and Activator of Transcription 3 (STAT3) is common in prostate cancers. STAT3 may induce cell proliferation and resistance to apoptosis, as well as promote tumor angiogenesis, invasion, and migration by activating gene expression. Many STAT3-dependent transcriptional responses are mediated through protein-protein interactions that involve the amino-terminal domain (N-domain). In this study, we found that inhibition of the STAT3 N-domain using novel inhibitor ST3-Hel2A-2 induces apoptotic death in prostate cancer cells. The cell death was accomponied by robust activation of pro-apoptotic gene. Using chromatin immunoprecipitation and tiling human promoter arrays (ChIP-chip), we have defined genome-wide targets of STAT3 in DU145 prostate cancer cells. We found that upregulated pro-apoptotic genes were bound by STAT3 in prostate cancer cells, and that STAT3 binding was decreased following inhibition of the STAT3 N-domain.
Project description:Activation of Signal Transducer and Activator of Transcription 3 (STAT3) is common in prostate cancers. STAT3 may induce cell proliferation and resistance to apoptosis, as well as promote tumor angiogenesis, invasion, and migration by activating gene expression. Many STAT3-dependent transcriptional responses are mediated through protein-protein interactions that involve the amino-terminal domain (N-domain). In this study, we found that inhibition of the STAT3 N-domain using novel inhibitor ST3-Hel2A-2 induces apoptotic death in prostate cancer cells. The cell death was accomponied by robust activation of pro-apoptotic gene. Using chromatin immunoprecipitation and tiling human promoter arrays (ChIP-chip), we have defined genome-wide targets of STAT3 in DU145 prostate cancer cells. We found that upregulated pro-apoptotic genes were bound by STAT3 in prostate cancer cells, and that STAT3 binding was decreased following inhibition of the STAT3 N-domain. STAT3 siRNA knockdow confirmed specificity of STAT3 binding and changes in gene expression.
Project description:Many patients have cancers that have increased activity of a protein called STAT3 that contributes critically to the development and growth of their cancer. Despite our knowledge of STAT3’s importance to cancer, scientists and doctors have not developed a drug that targets it and that patients can take to treat their cancer more effectively than treatments that are now available. Tvardi Therapeutics, Incorporated has developed a compound, TTI-101, which can be given by mouth and acts as a direct inhibitor of STAT3. Administration of TTI-101 to mice demonstrated that it blocked growth of cancers of the breast, head and neck, lung, and liver and it was safe when administered at high doses to mice, rats, and dogs. In this application, Tvardi is proposing to further develop TTI-101 for treatment of solid tumors for which the prognosis is dismal. The investigators will determine how safe it is when administered to patients with cancer, determine whether an adequate dose can be administered to patients with cancer that will block STAT3 in their cancer, and determine whether treatment with TTI-101 leads to reduced growth of their cancer.
Project description:To investigate potential links between Stat3 transcriptional activity and other signaling pathways in breast cancer, we determined the gene expression profiles of three breast cancer cell lines treated with JAK, PTGIS, PFKFB3, CXCR2, HAS1, or NQO1 inhibitor (all of which decreased Stat3 transcriptional activity in Hs 578T cells except for the NQO1 inhibitor), inhibitor treatment vehicle alone (DMSO), STAT3 siRNAs, or non-targeting siRNAs. Using the resulting data, we identified a gene signature that was significantly regulated by STAT3 siRNAs and similarly affected by the JAK and at least 3 other inhibitors (or by 4 other inhibitors) but not by the NQO1 inhibitor in Hs 578T cells that was enriched in genes involved in development and correlated with shorter distant metastasis-free survival in primary lymph-node-negative invasive breast tumors. These results emphasize the central importance of Stat3 in CD44+/CD24- stem-cell-like breast cancer cells.