Plants typically contain two different types of cell walls: a primary wall that is being deposited around all growing cells, and a secondary wall that is produced in cells with specialized functions once they have ceased to grow. In Arabidopsis, VND7 is a transcription factor that is sufficient to activate secondary cell wall synthesis. To artificially turn on the secondary cell wall synthesis, VND7 was fused to the activation domain of the herpes virus VP16 protein and the glucocorticoid receptor (GR) domain. Thus, the transgenic plants harbouring the constructs can then be treated with dexamethasone (DEX), a glucocorticoid derivative, to induce the secondary cell wall formation.
A Transcriptional and Metabolic Framework for Secondary Wall Formation in Arabidopsis.
Specimen part, Treatment
View SamplesUpon illumination, etiolated seedlings experience a transition from heterotrophic to photoautotrophic growth. During this process, the tetrapyrrole biosynthesis pathway provides chlorophyll for photosynthesis. This pathway has to be tightly controlled to prevent the accumulation of photoreactive metabolites and to provide stoichiometric amounts of chlorophyll for its incorporation into photosynthetic protein complexes. Therefore, plants have evolved regulatory mechanisms to synchronize the biosynthesis of chlorophyll and chlorophyll-binding proteins. Two phytochrome-interacting factors (PIF1 and PIF3) and the DELLA proteins, which are controlled by the gibberellin pathway, are key regulators of this process. Here, we show that impairment of TARGET OF RAPAMYCIN (TOR) activity in Arabidopsis (Arabidopsis thaliana), either by mutation of the TOR complex component RAPTOR1B or by treatment with TOR inhibitors, leads to a significantly reduced accumulation of the photoreactive chlorophyll precursor protochlorophyllide in darkness but an increased greening rate of etiolated seedlings after exposure to light. Detailed profiling of metabolic, transcriptomic, and physiological parameters revealed that the TOR-repressed lines not only grow slower, they grow in a nutrient-saving mode, which allows them to resist longer periods of low nutrient availability. Our results also indicated that RAPTOR1B acts upstream of the gibberellin-DELLA pathway and its mutation complements the repressed greening phenotype of pif1 and pif3 after etiolation.
Inhibition of TOR Represses Nutrient Consumption, Which Improves Greening after Extended Periods of Etiolation.
Specimen part, Treatment
View SamplesThree HL cell lines (HD-MyZ, L-540 and HDLM-2) were used to investigate the effects of perifosine and sorafenib using in vitro assays analyzing cell growth, cell cycle distribution, gene expression profiling (GEP), and apoptosis. Western blotting (WB) experiments were performed to determine whether the two-drug combination affected MAPK and PI3K/AKT pathways as well as apoptosis. Additionally, the antitumor efficacy and mechanism of action of perifosine/sorafenib combination were investigated in vivo in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice using tumor growth rates and survival as endpoints. RESULTS: While perifosine and sorafenib as single agents exerted a limited activity against HL cells, exposure of HD-MyZ and L-540 cell lines, but not HDLM-2 cells, to perifosine/sorafenib combination resulted in synergistic cell growth inhibition (40% to 80%) and cell cycle arrest. Upon perifosine/sorafenib exposure, L-540 cell line showed significant levels of apoptosis (up to 70%, P .0001) associated with severe mitochondrial dysfunction (cytochrome c, apoptosis-inducing factor release and marked conformational change of Bax accompanied by membrane translocation). Apoptosis induced by perifosine/sorafenib combination did not result in processing of caspase-8, -9, -3, or cleavage of PARP, and was not reversed by the pan-caspase inhibitor Z-VADfmk, supporting a caspase-independent mechanism of cell death. In responsive cell lines, WB analysis showed that antiproliferative and pro-apototic events were associated with dephosphorylation of MAPK and PI3K/Akt pathways. GEP analysis of HD-MyZ and L-540 cell lines, but not HDLM-2 cells indicated that perifosine/sorafenib treatment induced upregulation of genes involved in amino acid metabolism and downregulation of genes regulating cell cycle, DNA replication and cell death. In addition, in responsive cell lines, perifosine/sorafenib combination strikingly induced the expression of tribbles homologues 3 (TRIB3) both in vitro and in vivo. Silencing of TRIB3 prevented cell growth reduction induced by perifosine/sorafenib treatment. In vivo, the combined perifosine/sorafenib treatment significantly increased the median survival of NOD/SCID mice xenografted with HD-MyZ cell line as compared to controls (81 vs 45 days, P .0001) as well as mice receiving perifosine alone (49 days, P .03) or sorafenib alone (54 days, P .007). In mice bearing subcutaneous nodules generated by HD-MyZ and L-540 cell lines but not HDLM-2 cell line, perifosine/sorafenib treatment induced significantly increased levels of apoptosis (2- to 2.5-fold, P .0001) and necrosis (2- to 8-fold, P .0001), as compared to controls or treatment with single agents. In addition, perifosine/sorafenib treatment had no effect on HDLM-2 nodules, but significantly reduced L-540 nodules with 50% tumor growth inhibition, compared to controls. CONCLUSIONS: Perifosine/sorafenib combination resulted in strong anti-HL activity both in vitro and in vivo. These results warrant clinical evaluation of perifosine/sorafenib combined-treatment in HL patients.
Perifosine and sorafenib combination induces mitochondrial cell death and antitumor effects in NOD/SCID mice with Hodgkin lymphoma cell line xenografts.
Specimen part, Cell line, Treatment
View SamplesThree HL cell lines (HD-MyZ, L-540 and HDLM-2) were used to investigate the effects of perifosine and sorafenib using in vitro assays analyzing cell growth, cell cycle distribution, gene expression profiling (GEP), and apoptosis. Western blotting (WB) experiments were performed to determine whether the two-drug combination affected MAPK and PI3K/AKT pathways as well as apoptosis. Additionally, the antitumor efficacy and mechanism of action of perifosine/sorafenib combination were investigated in vivo in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice using tumor growth rates and survival as endpoints. RESULTS: While perifosine and sorafenib as single agents exerted a limited activity against HL cells, exposure of HD-MyZ and L-540 cell lines, but not HDLM-2 cells, to perifosine/sorafenib combination resulted in synergistic cell growth inhibition (40% to 80%) and cell cycle arrest. Upon perifosine/sorafenib exposure, L-540 cell line showed significant levels of apoptosis (up to 70%, P .0001) associated with severe mitochondrial dysfunction (cytochrome c, apoptosis-inducing factor release and marked conformational change of Bax accompanied by membrane translocation). Apoptosis induced by perifosine/sorafenib combination did not result in processing of caspase-8, -9, -3, or cleavage of PARP, and was not reversed by the pan-caspase inhibitor Z-VADfmk, supporting a caspase-independent mechanism of cell death. In responsive cell lines, WB analysis showed that antiproliferative and pro-apototic events were associated with dephosphorylation of MAPK and PI3K/Akt pathways. GEP analysis of HD-MyZ and L-540 cell lines, but not HDLM-2 cells indicated that perifosine/sorafenib treatment induced upregulation of genes involved in amino acid metabolism and downregulation of genes regulating cell cycle, DNA replication and cell death. In addition, in responsive cell lines, perifosine/sorafenib combination strikingly induced the expression of tribbles homologues 3 (TRIB3) both in vitro and in vivo. Silencing of TRIB3 prevented cell growth reduction induced by perifosine/sorafenib treatment. In vivo, the combined perifosine/sorafenib treatment significantly increased the median survival of NOD/SCID mice xenografted with HD-MyZ cell line as compared to controls (81 vs 45 days, P .0001) as well as mice receiving perifosine alone (49 days, P .03) or sorafenib alone (54 days, P .007). In mice bearing subcutaneous nodules generated by HD-MyZ and L-540 cell lines but not HDLM-2 cell line, perifosine/sorafenib treatment induced significantly increased levels of apoptosis (2- to 2.5-fold, P .0001) and necrosis (2- to 8-fold, P .0001), as compared to controls or treatment with single agents. In addition, perifosine/sorafenib treatment had no effect on HDLM-2 nodules, but significantly reduced L-540 nodules with 50% tumor growth inhibition, compared to controls. CONCLUSIONS: Perifosine/sorafenib combination resulted in strong anti-HL activity both in vitro and in vivo. These results warrant clinical evaluation of perifosine/sorafenib combined-treatment in HL patients.
Perifosine and sorafenib combination induces mitochondrial cell death and antitumor effects in NOD/SCID mice with Hodgkin lymphoma cell line xenografts.
Specimen part, Cell line, Treatment
View SamplesThree HL cell lines (HD-MyZ, L-540 and HDLM-2) were used to investigate the effects of perifosine and sorafenib using in vitro assays analyzing cell growth, cell cycle distribution, gene expression profiling (GEP), and apoptosis. Western blotting (WB) experiments were performed to determine whether the two-drug combination affected MAPK and PI3K/AKT pathways as well as apoptosis. Additionally, the antitumor efficacy and mechanism of action of perifosine/sorafenib combination were investigated in vivo in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. While perifosine and sorafenib as single agents exerted a limited activity against HL cells, exposure of HD-MyZ and L-540 cell lines, but not HDLM-2 cells, to perifosine/sorafenib combination resulted in synergistic cell growth inhibition (40% to 80%) and cell cycle arrest. Upon perifosine/sorafenib exposure, L-540 cell line showed significant levels of apoptosis (up to 70%, P .0001) associated with severe mitochondrial dysfunction (cytochrome c, apoptosis-inducing factor release and marked conformational change of Bax accompanied by membrane translocation). Apoptosis induced by perifosine/sorafenib combination did not result in processing of caspase-8, -9, -3, or cleavage of PARP, and was not reversed by the pan-caspase inhibitor Z-VADfmk, supporting a caspase-independent mechanism of cell death. In responsive cell lines, WB analysis showed that antiproliferative and pro-apototic events were associated with dephosphorylation of MAPK and PI3K/Akt pathways. GEP analysis of HD-MyZ and L-540 cell lines, but not HDLM-2 cells indicated that perifosine/sorafenib treatment induced upregulation of genes involved in amino acid metabolism and downregulation of genes regulating cell cycle, DNA replication and cell death. In addition, in responsive cell lines, perifosine/sorafenib combination strikingly induced the expression of tribbles homologues 3 (TRIB3) both in vitro and in vivo. Silencing of TRIB3 prevented cell growth reduction induced by perifosine/sorafenib treatment. In vivo, the combined perifosine/sorafenib treatment significantly increased the median survival of NOD/SCID mice xenografted with HD-MyZ cell line as compared to controls (81 vs 45 days, P .0001) as well as mice receiving perifosine alone (49 days, P .03) or sorafenib alone (54 days, P .007). In mice bearing subcutaneous nodules generated by HD-MyZ and L-540 cell lines but not HDLM-2 cell line, perifosine/sorafenib treatment induced significantly increased levels of apoptosis (2- to 2.5-fold, P .0001) and necrosis (2- to 8-fold, P .0001), as compared to controls or treatment with single agents. Perifosine/sorafenib combination resulted in strong anti-HL activity both in vitro and in vivo. These results warrant clinical evaluation of perifosine/sorafenib combined-treatment in HL patients.
Perifosine and sorafenib combination induces mitochondrial cell death and antitumor effects in NOD/SCID mice with Hodgkin lymphoma cell line xenografts.
Specimen part, Cell line, Treatment
View SamplesJunction Adhesion Molecule-A (JAM-A) is present on leukocytes and platelets where it promotes cell adhesion and motility. We are interested in an interaction between JAM-A and tumor progression/metastases. To address this point, we mated JAM-A-/- mice and mouse mammary tumor model MMTV-PyMT mice which, which express polyoma middle T antigen under the control of mouse mammary tumor virus. MMTV-PyMT mice show 100% penetration of mammary tumor and highly metastases to lung. MMTV-PyMT mice without JAM-A show less primary tumor progression, therefore JAM-A enhance primary tumor progression. Then we are addressing the molecular mechanism of this phenomenon by in vivo. Furthermore, we would like to examine JAM-A deficient MMTV tumor signature.
Abrogation of junctional adhesion molecule-A expression induces cell apoptosis and reduces breast cancer progression.
Specimen part
View SamplesDemethyl fructiculin A is a diterpenoid quinone component of the exudates from Salvia corrugata (SCO-1) leafes. SCO-1 was recently reported to induce anoikis in mammalian cell lines via a molecular mechanism involving the presence of the membrane scavenging receptor CD36. However, experiments performed with cells lacking CD36, showed that SCO-1 was able to induce apoptosis also via alternate pathways. To contribute to a better characterization of the molecular mechanisms underlining the cytotoxic activity of SCO-1, we decided to pursue an unbiased pharmacogenomic approach by generating the gene expression profile of GBM TICs subjected to the administration of SCO-1 and comparing it with that of control cells exposed to the solvent. With this strategy we hypothesized to highlight those pathways and biological processes unlashed by SCO-1.
Demethyl fruticulin A (SCO-1) causes apoptosis by inducing reactive oxygen species in mitochondria.
Time
View SamplesAstrocyte elevated gene-1 (AEG-1) as a positive inducer of hepatocellular carcinoma (HCC). Transgenic mice with hepatocyte-specific expression of AEG-1 were challenged with N-nitrosodiethylamine (DEN) and developed multinodular HCC with steatotic features. Thus, we have identified the follwoing AEG-1 functions: induction of steatosis, inhibition of senescence and activation of coagulation pathway to augment an aggressive hepatocarcinogenic phenotype.
Astrocyte elevated gene-1 promotes hepatocarcinogenesis: novel insights from a mouse model.
No sample metadata fields
View SamplesAEG-1 is overexpressed in human hepatocellular carcinoma (HCC) and positively regulates development and progression of HCC A conditional hepatocyte-specific knockout mouse was generated by crossing floxed AEG-1 mouse with Alb/Cre mouse in C57BL/6 background Overall design: Livers were harvested from chow-fed 12 wks old AEG-1fl/fl and AEG-1DHEP mice. RNA was extracted and subjected to RNA-Seq.
A novel role of astrocyte elevated gene-1 (AEG-1) in regulating nonalcoholic steatohepatitis (NASH).
Age, Specimen part, Subject
View SamplesNeural stem cells from different brain regions show differencies in gene expression patterns and physiological functions.
Innate neural stem cell heterogeneity determines the patterning of glioma formation in children.
Sex, Specimen part
View Samples