Project description:Cutaneous T-cell lymphomas form a heterogeneous group of non-Hodgkin lymphomas characterized by only poor prognosis in advanced stage. Despite significant progress made in the identification of novel genes and pathways involved in the pathogenesis of cutaneous lymphoma, the therapeutic value of these findings has still to be proven. Here, we demonstrate by gene expression arrays that aurora kinase A is one of highly overexpressed genes of the serine/threonine kinase in CTCL. The finding was confirmed by qualitative RT-PCR, Western blotting and immunohistochemistry in CTCL cell lines and primary patient samples. Moreover, treatment with a specific aurora kinase A inhibitor blocks cell proliferation by inducing cell cycle arrest in G2 phase as well as apoptosis in CTCL cell lines. These new data provide a promising rationale for using aurora kinase A inhibition as a therapeutic modality of CTCL. 14 lesional skin biopsies of different MF patients (patch=3, plaque=6, tumor=4) and 9 healthy controls. Comparison between Cutaneus Tcell Lymphoma Samples and Healthy Control Tissue
Project description:Cutaneous T-cell lymphomas form a heterogeneous group of non-Hodgkin lymphomas characterized by only poor prognosis in advanced stage. Despite significant progress made in the identification of novel genes and pathways involved in the pathogenesis of cutaneous lymphoma, the therapeutic value of these findings has still to be proven. Here, we demonstrate by gene expression arrays that aurora kinase A is one of highly overexpressed genes of the serine/threonine kinase in CTCL. The finding was confirmed by qualitative RT-PCR, Western blotting and immunohistochemistry in CTCL cell lines and primary patient samples. Moreover, treatment with a specific aurora kinase A inhibitor blocks cell proliferation by inducing cell cycle arrest in G2 phase as well as apoptosis in CTCL cell lines. These new data provide a promising rationale for using aurora kinase A inhibition as a therapeutic modality of CTCL.
Project description:Chronic lymphocytic leukemia (CLL) B-cells receive signals from the lymph node and bone marrow (BM) microenvironments that regulate their survival and proliferation. These signals and the pathways that propagate them to the interior of the cell represent potential targets for therapeutic intervention. To characterize the pathways that are activated by the BM microenvironment in CLL cells in vivo, we performed gene expression profiling of tumor cells purified from BM and peripheral blood. Functional classification analysis revealed that the most frequently upregulated genes in BM-CLL cells are genes involved in cell cycle and mitosis. Among the most significantly overexpressed were the Aurora A and B kinases. To investigate whether these kinases could represent potential therapeutic targets in CLL, we performed RNA interference experiments in the CLL cell lines MEC1 and EHEB. Downregulation of Aurora A and B inhibited the proliferation and induced apoptosis in these cells. Similar effects were observed with the pan-Aurora kinase inhibitor VX-680 in primary CLL cells induced to proliferate by CpG-ODN and IL-2. VX-680 also inhibited leukemia growth in vivo in a mouse model of CLL. These data suggest that inhibition of Aurora kinases could represent a potential strategy to selectively target the proliferating compartment in CLL. To identify gene expression related to microenvironmental stimuli in B-cell Chronic Lymphocytic Leukemia (CLL) cells in vivo, expression profiles of CLL cells purified (>95%) from bone marrow (BM) and peripheral blood (PB) were compared. Paired BM and PB samples from 6 individuals were used for this analysis.
Project description:Chronic lymphocytic leukemia (CLL) B-cells receive signals from the lymph node and bone marrow (BM) microenvironments that regulate their survival and proliferation. These signals and the pathways that propagate them to the interior of the cell represent potential targets for therapeutic intervention. To characterize the pathways that are activated by the BM microenvironment in CLL cells in vivo, we performed gene expression profiling of tumor cells purified from BM and peripheral blood. Functional classification analysis revealed that the most frequently upregulated genes in BM-CLL cells are genes involved in cell cycle and mitosis. Among the most significantly overexpressed were the Aurora A and B kinases. To investigate whether these kinases could represent potential therapeutic targets in CLL, we performed RNA interference experiments in the CLL cell lines MEC1 and EHEB. Downregulation of Aurora A and B inhibited the proliferation and induced apoptosis in these cells. Similar effects were observed with the pan-Aurora kinase inhibitor VX-680 in primary CLL cells induced to proliferate by CpG-ODN and IL-2. VX-680 also inhibited leukemia growth in vivo in a mouse model of CLL. These data suggest that inhibition of Aurora kinases could represent a potential strategy to selectively target the proliferating compartment in CLL.
Project description:The mitotic kinase Aurora-A is essential for cell cycle progression and considered a priority cancer target. Dozens of ongoing clinical trials are testing the anti-cancer potential of Aurora-A kinase inhibitors. While the catalytic activity of Aurora-A is essential for its function during mitosis, a growing body of evidence indicates an additional non-catalytic function, which is difficult to target by kinase inhibitors. We therefor developed a series of degrader molecules by connecting a kinase inhibitor of Aurora-A to the Cereblon-binding molecule thalidomide. One degrader, JB170, induced the rapid degradation of Aurora-A. We were able to show that JB170 mediated depletion is highly specific for Aurora-A, as degrader mediated complex formation is supported by cooperative binding between Cereblon and Aurora-A. Strikingly, JB-170 mediated depletion caused a strong S-phase arrest, which is not the cell cycle effect observed as a result of Aurora-A kinase inhibition, supporting an important non-catalytic role of Aurora-A during DNA replication. Finally, depletion of Aurora-A resulted in strong induction of apoptosis in various cancer cell lines. The tool compound JB170 presents a versatile starting point for developing new therapeutic drugs to counter Aurora-A function in cancer. In the presented datasets, we determined i) the binding selectivity profile of the Aurora-A PROTAC (JB170) using Kinobeads affinity matrix and ii) its intracellular degradation specificity. We therefore treated IMR5 cells with JB170, the inactive version JB211, or Alisertib and quantified the induced degradation using tandem mass tags.
Project description:Aurora-A has attracted a great deal of interest as a potential therapeutic target. However, the outcomes of inhibitors targeting Aurora-A are not as favorable as expected, and the basis of their ineffectiveness remains unknown. Here, we found that signal transducer and activator of transcription 1 (STAT1) was highly expressed in colorectal cancer (CRC) xenograft mouse models that were resistant to alisertib, an Aurora-A inhibitor, in an interferon/Janus kinase-independent manner, suggesting an unconventional mechanism regulating STAT1 expression. Unexpectedly, we found that alisertib disrupted Aurora-A binding with ubiquitin-like with plant homeodomain and ring finger domain 1 (UHRF1), leading to UHRF1-mediated ubiquitination and degradation of DNA methyltransferase 1 (DNMT1), which in turn resulted in demethylation of the CpG islands in the STAT1 promoter and STAT1 overexpression. Simultaneous silencing of Aurora-A and UHRF1 prevented STAT1 overexpression and effectively inhibited CRC growth. Hence, concomitant targeting of Aurora-A and UHRF1 can be a promising therapeutic strategy for cancer patients.
Project description:PURPOSE: Despite over 70,000 new cases of bladder cancer in the United States annually, patients with advanced disease have a poor prognosis due to limited treatment modalities. We evaluate the role of Aurora A, identified as an upregulated candidate molecule in bladder cancer, in regulating bladder tumor growth. EXPERIMENTAL DESIGN: Gene expression in human bladder cancer samples was evaluated using RNA microarray and reverse-transcriptase PCR. The specific Aurora kinase A inhibitor MLN8237 (Millennium) was used to determine effects on bladder cancer cell growth using in vitro and in vivo models using malignant T24 and UM-UC-3 and papilloma-derived RT4 bladder cells. RESULTS: Urothelial carcinoma upregulates a set of 13 mitotic spindle associated transcripts, as compared to normal urothelium, including MAD2L1 (7.6-fold), BUB1B (8.8-fold), Aurora kinases A (5.6-fold) and Aurora kinase B (6.2-fold). Application of MLN8237 (10nM-1µM) to the human bladder tumor cell lines T24 and UM-UC-3 induced dose-dependent G2 cell cycle arrest, aneuploidy, mitotic spindle abnormalities, and apoptosis. MLN8237 arrested tumor growth when administered orally over 4 weeks in a mouse bladder cancer xenograft model (p<0.05). Finally, in vitro combination of MLN8237 with either paclitaxel or gemcitabine produced schedule-dependent synergistic antiproliferative effects in T24 cells when administered sequentially. CONCLUSIONS: Mitotic spindle checkpoint dysfunction is a common characteristic of human urothelial carcinoma, and can be exploited with pharmacologic Aurora A inhibition. Future studies that explore the mechanisms of spindle checkpoint failure in bladder cancer and evaluate the therapeutic role of Aurora kinases for bladder cancer patients would be of value. Tissue samples with urothelial cell carcinoma from bladder as well as normal references were collected and the gene expression profiles were compared. No technical replicates.
Project description:We studied gene expression profiles of 17 cutaneous B-cell lymphomas that were collected with 4-6 millimeter skin punch biopsies. We also included tissue from 2 cases of mycosis fungoides (MF), 3 normal skin biopsies and 3 tonsils to create a framework for further interpretation. A hierarchical cluster algorithm was applied for data analysis. Our results indicate that small amounts of skin tissue can be used successfully to perform microarray analysis and result in distinct gene expression patterns. Duplicate specimens clustered together demonstrating a reproducible technique. Within the cutaneous B-cell lymphoma specimens two specific B-cell differentiation stage signatures of germinal center B-cells and plasma cells could be identified. Primary cutaneous follicular and primary cutaneous diffuse large B-cell lymphomas had a germinal center B-cell signature while a subset of marginal zone lymphomas demonstrated a plasma cell signature. Primary and secondary follicular B-cell lymphoma of the skin were closely related, despite previously reported genetic and phenotypic differences. In contrast primary and secondary cutaneous diffuse large B-cell lymphoma were less related to each other. This pilot study allows a first glance into the complex and unique microenvironment of B-cell lymphomas of the skin and provides a basis for future studies, that may lead to the identification of potential histologic and prognostic markers as well as therapeutic targets.
Project description:We studied gene expression profiles of 17 cutaneous B-cell lymphomas that were collected with 4-6 millimeter skin punch biopsies. We also included tissue from 2 cases of mycosis fungoides (MF), 3 normal skin biopsies and 3 tonsils to create a framework for further interpretation. A hierarchical cluster algorithm was applied for data analysis. Our results indicate that small amounts of skin tissue can be used successfully to perform microarray analysis and result in distinct gene expression patterns. Duplicate specimens clustered together demonstrating a reproducible technique. Within the cutaneous B-cell lymphoma specimens two specific B-cell differentiation stage signatures of germinal center B-cells and plasma cells could be identified. Primary cutaneous follicular and primary cutaneous diffuse large B-cell lymphomas had a germinal center B-cell signature while a subset of marginal zone lymphomas demonstrated a plasma cell signature. Primary and secondary follicular B-cell lymphoma of the skin were closely related, despite previously reported genetic and phenotypic differences. In contrast primary and secondary cutaneous diffuse large B-cell lymphoma were less related to each other. This pilot study allows a first glance into the complex and unique microenvironment of B-cell lymphomas of the skin and provides a basis for future studies, that may lead to the identification of potential histologic and prognostic markers as well as therapeutic targets. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
Project description:Cutaneous T-Cell Lymphomas (CTCL) represent a group of hematopoietic malignancies that home to the skin and have no known molecular basis for disease pathogenesis. Sézary syndrome (SS) is the leukemic variant of CTCL. Currently, CTCL is incurable, highlighting the need for new therapeutic modalities. We have previously observed that combined small-molecule inhibition of protein kinase C (PKC) β and glycogen synthase kinase 3 (GSK3) causes synergistic apoptosis in CTCL cell lines and patient cells. Through microarray analysis of a SS cell line, we surveyed global gene expression following combined PKCβ-GSK3 treatment to elucidate therapeutic targets responsible for cell death. Clinically relevant targets were defined as genes differentially expressed in SS patients that were modulated by combination-drug treatment of SS cells. Gene set enrichment analysis uncovered candidate genes enriched for an immune cell signature, specifically the T-cell receptor and MAPK signaling pathways. Further analysis identified p38 as a potential therapeutic target that is over-expressed in SS patients and decreased by synergistic-inhibitor treatment. This target was verified through small-molecule inhibition of p38 leading to cell death in both SS cell lines and patient cells. These data establish p38 as a new SS biomarker and potential therapeutic target for the treatment of CTCL. Hut78 cells were treated with 4μM Enzastaurin, 5μM AR-A014418, 4μM Enzastaurin & 5μM AR-A014418, DMSO, or no treatment for three days. RNA was extracted and hybridized to Illumina microarrays.