BCL-2 overexpression attenuates p53 stabilization and activation following RiBi inhibitors treatment
Ontology highlight
ABSTRACT: RNA-seq experiment performed in SUDHL-5 cells incubated with RiBi inhibitors (Doxorubicin, Actinomycin D, CX-5461) for 6h in the presence or absence of BCL-2.
Project description:Constitutive activation of EGFR- and NF-kB-dependent pathways is a hallmark of cancer, yet signaling proteins that connect both oncogenic cascades are poorly characterized. Here we define KIAA1199 as a BCL-3- and p65-dependent gene in transformed keratinocytes. KIAA1199 expression is enhanced upon human papillomavirus (HPV) infection and is aberrantly expressed in clinical cases of cervical (pre)neoplastic lesions. Mechanistically, KIAA1199 binds Plexin A2 and protects from Semaphorin 3A-mediated cell death by promoting EGFR stability and signaling. Moreover, KIAA1199 is an EGFR-binding protein and KIAA1199 deficiency impairs EGF-dependent Src, MEK1 and ERK1/2 phosphorylations. Therefore, EGFR stability and signaling to downstream kinases requires KIAA1199. As such, KIAA1199 promotes EGF-mediated epithelial-mesenchymal transition (EMT). Taken together, our data define KIAA1199 as an oncogenic protein induced by HPV infection and constitutive NF-kB activity that transmits pro-survival and invasive signals through EGFR signaling. We used microarrays to detail the global programme of gene expression upon BCL-3 overexpression We used two experimental conditions, namely HaCat cells infected with a control lentivirus as well as HaCat cells infected with a BCL-3 expressing construct. Both experimental conditions were in triplicates.
Project description:The anti-apoptotic function of Bcl-xL in the heart against reperfusion injury is diminished by K-Ras-Mst1-mediated phosphorylation of Ser14, which allows dissociation of Bcl-xL from Bax and promotes cardiomyocyte death. Here we show that Ser14 phosphorylation of Bcl-xL is also promoted by hemodynamic stress in the heart, through the H-Ras-ERK pathway. Our study suggests that phosphorylation of Bcl-xL at Ser14 in response to acute pressure overload plays an essential role in mediating compensatory hypertrophy by promoting calcium release, alleviating the negative constraint of Bcl-xL upon the IP3R-NFAT pathway.
Project description:The development of antimalarial drug resistance is an ongoing problem threatening progress towards malaria elimination, and antimalarial treatments are urgently needed for drug-resistant malaria infections. Host-directed therapies (HDT) represent an attractive strategy for the devel-opment of new antimalarials with untapped targets and low propensity for resistance. In addi-tion, drug repurposing in the context of HDT can lead to a substantial decrease in the time and resources required to develop novel antimalarials. Host BCL-XL is a major target in anti-cancer therapy and is essential for the development of numerous intracellular pathogens. We hypothe-sised that red blood cell BCL-XL is essential for Plasmodium development and tested this hypoth-esis by using six BCL-XL inhibitors, including one FDA-approved compound. All BCL-xL inhibitors tested impaired proliferation of P. falciparum 3D7 parasites in vitro at low parasite inhibitory concentrations. Western blot analysis and immunofluorescence microscopy assays revealed that host BCL-xL is transferred from the host red blood cells (RBCs) to the parasite upon infection. Further, immunoprecipitation of BCL-XL coupled with mass spectrometry analysis identified that BCL-XL forms unique molecular complexes with human μ-calpain in uninfected RBCs, and with human SHOC2 in infected RBCs. These results open exciting perspectives for the development of host-directed antimalarial therapies and drug repurposing efforts.
Project description:The gene encoding elongation factor G, fusA1, is frequently mutated in clinical isolates of Pseudomonas aeruginosa from patients with cystic fibrosis. Recent work has shown that fusA1 mutants often display elevated aminoglycoside resistance due to increased expression of the aminoglycoside efflux pump, MexXY. We isolated a spontaneous gentamicin-resistant fusA1 mutant (FusA1-P443L) in which mexXY expression was increased. We compared the transcriptome of this fusA1 mutant (EMC1) with the P. aeruginosa PAO1-derived progenitor strain (EMC0) and complemented mutant strain expressing the wild-type fusA1 gene in trans (EMC1*).
Project description:To investigate the function FDX1 in the regulation of elesclomol (ES)-induced cell death, we established SUDHL-4 cell lines in which the full-length coding sequence of FDX1 was overexpressed (FDX1-OE), we then performed gene expression profiling analysis using data obtained from RNA-seq of 2 different cells (control and FDX1-OE SUDHL-4) with or without elsclomol treatment
Project description:To reveal the effect of CX-5461 (a small-molecule inhibitor of ribosome biogenesis)on the proteome of Pancreatic Ductal Adenocarcinoma (PDAC) cells, we carried out two quantitative proteomics analyses, using tumour cells isolated from an inducible mouse model of PDAC (iKras PDAC) (Ying et al., 2012). In this model, oncogenic Kras (G12D) expression can be controlled by administration of doxycycline (Dox). In the first experiment, Tandem Mass Tagging (TMT) was employed for quantitative analysis of mock vs. CX-5461 (100nM) treated iKras cells for 48 hrs, in presence of Dox (Kras on). In the second experiment, TMT was used to quantitatively analyse the proteomics changes induced by Dox removal (48 hrs), in presence or absence of CX-5461. For this purpose, iKras PDAC cells were seeded and grown for 48 hrs with or without Dox, in the background of mock vs. CX-5461 (100nM) co-treatments. TMT labelling was done using the TMT 6plex labelling kit from Thermo Fisher.
Project description:The availability of a suitable lysine for PROTAC-mediated ubiquitination can also determine the degradative ability of a protein target and the selectivity of a PROTAC. PROTAC DT2216 selectively triggers ubiquitination and degradation of BCL-XL. In this study, we identify K87 is the key ubiquitinated lysine under DT2216 treatment through LC-MS/MS.
Project description:Nicotinamide seed treatment is investigated as a method for production of robust plants. Previous studies have shown that nicotinamide promotes the plant defence system and decreases DNA methylation levels. The purpose of the present work was to learn more about the underlying molecular mechanisms. The RNA was extracted from roots of three months old Norway spruce seedlings treated at seed stage. Stress was an overrepresented biological process of upregulated genes. Stress response genes are involved in adaption to and defence against stress. Upregulated stress response genes in the seedling roots were for example transcription factors MYB77 and LHY and two chitinases. Chitinases defend against biotic stress, such as pine weevils. Epigenetic regulating genes were generally downregulated, such as DDM1 which is known to promote DNA-methylation. Previous works suggest the hypothesis that nicotinamide is a defense signal mediator, which is supported by the present study.
Project description:TORC1 is a structurally and functionally conserved multiprotein complex that regulates many aspects of eukaryote growth including the synthesis and assembly of ribosomes. The protein kinase activity of this complex is responsive to environmental cues and is potently inhibited by the natural product macrolide rapamycin. Insights into how TORC1 regulates growth have been provided with the recent identification of the rapamycin-sensitive phosphoproteome in yeast. Building on these data, we show here that Sch9, an AGC family kinase and direct substrate of TORC1, promotes ribosome biogenesis (ribi) and ribosomal protein (RP) gene expression via direct inhibitory phosphorylation of three transcription repressors, Stb3, Dot6 and Tod6. Dephosphorylation of these factors allows them to recruit the RPD3L histone deactelyase complex to ribi/RP gene promoters. Since rRNA and tRNA transcription are also under its control, Sch9 appears to be well positioned to coordinately regulate transcriptional aspects of ribosome biogenesis. mRNA-Seq of 8 S. cerevisiae strains treated with either DMSO alone or 1NM-PP1, a small molecule inhibitor for analog-sensitive kinases such as sch9-as.
Project description:High-risk B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive disease, often characterized by resistance to chemotherapy. A frequent feature of high-risk B-ALL is loss of function of the Ikaros tumor suppressor. In leukemia, Ikaros’ function is impaired by oncogenic Casein Kinase II (CK2), which is overexpressed in B-ALL. Phosphorylation by CK2 reduces Ikaros binding to the promoter of its target gene, particularly Bcl-xL. This results in a loss of Ikaros-mediated repression of Bcl-xL and in increased expression of Bcl-xL. Increased expression of Bcl-xL and/or CK2, as well as reduced Ikaros expression, are associated with resistance to doxorubicin treatment. Molecular and pharmacological inhibition of CK2 with a specific inhibitor CX-4945, enhances Ikaros-mediated repression of Bcl-xL and increases sensitivity to doxorubicin. Combination treatment with CX-4945 and doxorubicin show synergistic therapeutic effects in vitro and in preclinical models of high-risk B-ALL. Results reveal a novel signaling network that regulates chemoresistance in leukemia and lays the groundwork for clinical testing of CK2 inhibitors in combination with doxorubicin for the treatment of hematopoietic malignancies.