Project description:Chronic lymphocytic leukemia (CLL) cell survival and growth is fueled by aberrant activation of various pro-survival signaling pathways within tumor niches. Specifically, B-cell receptor (BCR) signaling, toll-like receptor signaling, and supportive cellular interactions drive constitutive activation of NF-κB signaling and transcription of proliferative/pro-survival genes. Directly targeting the NF-κB pathway has been a challenge, however, herein, we investigated SpiD3, a spirocyclic dimer and novel NF-κB pathway inhibitor in preclinical models of CLL. Through cross-linking NF-κB proteins, SpiD3 attenuated NF-κB signaling in CLL cells independent of microenvironmental signals. Our integrated multi-omics and functional analyses revealed BCRNF-κB signaling, endoplasmic reticulum stress, oxidative stress, and activation of the unfolded protein response among the top pathways modulated by SpiD3 treatment. This was accompanied by marked inhibition of global protein synthesis, cumulating in profound anti-tumor properties in CLL cells. SpiD3 also modulated tumor microenvironment interactions shown by decreased chemokine and cytokine gene expression as well as decreased CLL chemotaxis towards CXCL-12 and CXCL-13. Moreover, SpiD3 induced apoptosis of stroma-protected primary CLL cells comparable to the BCR-targeting agent, ibrutinib. SpiD3 strikingly demonstrated selective cytotoxicity towards CLL cells compared to healthy lymphocytes, synergized with ibrutinib, and retained its anti-tumor effects in ibrutinib-resistant CLL cells. Altogether, our findings provide preclinical evidence for SpiD3 as an attractive therapeutic agent for CLL, especially in the context of relapsed/refractory disease.
Project description:Comparison of Chronic Lymphocytic Leukemia patients expressing high or low levels of ZAP70 mRNA: prognostic factors and interaction with the microenvironment. Zeta-associated protein 70 (ZAP70) is a widely recognized prognostic factor in chronic lymphocytic leukemia (CLL), but mechanisms by which its higher expression leads to a poor outcome remain to be fully explained. In an attempt to unveil unfavorable cellular properties linked to high ZAP70 expression, we used gene expression profiling to identify genes associated with disparities in B-cells from CLL patients expressing high versus low ZAP70 mRNA, measured by quantitative real-time PCR. Keywords: comparison of poor and good prognosis CLL patient transcriptome regarding ZAP70 expression
Project description:Chronic lymphocytic leukemia (CLL) is a disease with a highly variable prognosis. The clinical course can however be predicted thanks to prognostic markers. Poor prognosis is associated with expression of a B cell receptor (BCR) from unmutated immunoglobulin variable heavy-chain genes (IgVH) and expression of zeta associated protein of 70 kDa (ZAP-70). The reason why ZAP-70 expression is associated with poor prognosis and whether the protein has a direct pathogenic function is at present unknown. By transfer of ZAP-70 to CLL cells, we show here that expression of ZAP-70 in CLL cells leads to increased expression of the NF-κB target genes interleukin-1β (IL-1β), IL-6 and IL-8 upon BCR triggering. This could be blocked by inhibition of NF-κB signaling through inhibition of IκB kinases (IKK). Transcriptome analysis identified a NF-κB RelA signature imposed by ZAP-70 expression in BCR stimulated CLL cells. We conclude that ZAP-70 acts directly as an amplifier of NF-κB signaling in CLL cells which could be an underlying mechanism for its association with poor prognosis and which may represent a therapeutic target.
Project description:Comparison of Chronic Lymphocytic Leukemia patients expressing high or low levels of ZAP70 mRNA: prognostic factors and interaction with the microenvironment. Zeta-associated protein 70 (ZAP70) is a widely recognized prognostic factor in chronic lymphocytic leukemia (CLL), but mechanisms by which its higher expression leads to a poor outcome remain to be fully explained. In an attempt to unveil unfavorable cellular properties linked to high ZAP70 expression, we used gene expression profiling to identify genes associated with disparities in B-cells from CLL patients expressing high versus low ZAP70 mRNA, measured by quantitative real-time PCR. Experiment Overall Design: Two groups of seven CLL patients were compared, selected on the basis of either high or low ZAP70 mRNA expression. Total RNA from CD19+ purified cells was exctracted and hybidyzed on Affymetrix GeneChipî Human Genome U133 Plus 2.0 Array. Amplification, hybridization and scanning were done according to standard Affymetrix protocols (www.affymetrix.com). CEL files were ,normalized with RMA method.
Project description:By binding to specific DNA elements, known collectively as “κB sites”, contained within the promoters/enhancers of target genes, NF-κB regulates gene expression. We found that the identity of the central base pair (bp) of κB sites profoundly impacts the transcriptional activity of NF-κB dimers. RelA dimers prefer an A/T bp at this position for optimum transcriptional activation (A/T-centric) and discriminate against G/C-centric κB sites. The p52 homodimer, in contrast, activates transcription from G/C-centric κB sites in complex with Bcl3 but represses transcription from the A/T-centric sites. The p52:Bcl3 complex binds to these two classes of κB sites in distinct modes permitting recruitment of coactivator, corepressor, or both coactivator and corepressor complexes in promoters containing G/C, A/T or both G/C and A/T-centric sites. Therefore, through sensing of bp differences within κB sites, NF-κB dimers modulate biological programs by activating, repressing and altering expression of effector genes. Total RNA extracted from bone marrow derived macrophages (BMDMs) with Bcl3 siRNA knockdown or mouse scramble siRNA knockdown were subjected to LPS stimulation.
Project description:Tumor cell survival critically depends on heterotypic communication with benign cells in the microenvironment. Here we describe a novel survival signaling pathway activated in stromal cells by contact to B-cells from chronic lymphocytic leukemia (CLL) patients. The expression of PKC-βII and the subsequent activation of NF-κB in bone marrow stromal cells is a prerequisite to support the survival of malignant B-cells. PKC-β knockout mice are insusceptible to CLL-transplantations, underscoring the in vivo significance of the PKC-βII- NF-κB signaling pathway in the tumor microenvironment. Upregulated stromal PKC-βII in biopsies from CLL, breast- and pancreatic- cancer patients suggest that this pathway may commonly be activated in a variety of malignancies. We used microarrays to determine gene expression changes induced by co-culturing with leukemic B-cells (CLL) in EL08-1D2 cells.
Project description:Long non-coding RNAs (lncRNAs) are transcripts of more than 200 nucleotides that are not translated into functional proteins. Cellular lncRNAs have been shown to act as regulators by interacting with target nucleic acids or proteins and modulating their activities. We investigated the role of RNA1.2, which is one of four major lncRNAs expressed by human cytomegalovirus (HCMV), by comparing the properties of parental virus in vitro with those of deletion mutants lacking either most of the RNA1.2 gene or only the TATA element of the promoter. In comparison with parental virus, these mutants exhibited no growth defects and minimal differences in viral gene expression in human fibroblasts. In contrast, 76 cellular genes were consistently up- or down-regulated by the mutants at both the RNA and protein levels at 72 hours after infection. Differential expression of the gene most highly upregulated by the mutants (Tumor protein p63-regulated gene 1-like protein; TPRG1L) was confirmed at both levels by RT-PCR and immunoblotting. Consistent with the known ability of TPRG1L to upregulate IL-6 expression via NF-κB stimulation, RNA1.2 mutant-infected fibroblasts were observed to upregulate IL-6 in addition to TPRG1L. Comparable surface expression of TNF receptors and responsiveness to TNF-α in cells infected by the parental and mutant viruses indicated that activation of signaling by TNF-α is not involved in upregulation of IL-6 by the mutants. In contrast, inhibition of NF-κB activity and knockdown of TPRG1L expression reduced the extracellular release of IL-6 by RNA1.2 mutant-infected cells, thus demonstrating that upregulation of TPRG1L activates NF-κB. The levels of CCL2 and CXCL1 transcripts were also increased in RNA1.2 mutant-infected cells, further demonstrating the presence of active NF-κB signalling. These results suggest that RNA1.2 plays a role in manipulating intrinsic NF-B-dependent cytokine and chemokine release during HCMV infection , thereby impacting downstream immune responses.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Tumor cell survival critically depends on heterotypic communication with benign cells in the microenvironment. Here we describe a novel survival signaling pathway activated in stromal cells by contact to B-cells from chronic lymphocytic leukemia (CLL) patients. The expression of PKC-βII and the subsequent activation of NF-κB in bone marrow stromal cells is a prerequisite to support the survival of malignant B-cells. PKC-β knockout mice are insusceptible to CLL-transplantations, underscoring the in vivo significance of the PKC-βII- NF-κB signaling pathway in the tumor microenvironment. Upregulated stromal PKC-βII in biopsies from CLL, breast- and pancreatic- cancer patients suggest that this pathway may commonly be activated in a variety of malignancies. We used microarrays to determine Nemo/ IKK-gamma dependent gene expression changes in bone marrow stromal cells (BMSCs) induced by co-culturing with leukemic B-cells (CLL)