Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA231485 | ENA |
REPOSITORIES: ENA
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Project description:PI3K/AKT pathway is activated by miRNA-22 in the proliferative CLL subset (miRNA)
| PRJNA231477 | ENA
Project description:Understanding the crosstalk between malignant B-cells and their milieu could provide clues on the molecular and clinical biology of Chronic Lymphocytic Leukemia (CLL). Aiming to generate novel therapeutic strategies, different groups have studied different CLL proliferative fractions. We previously, identified one of these proliferative subsets in the peripheral blood from progressive unmutated CLL patients. Since the presence of this small subset appears to be a hallmark of a proliferative disease in which B lymphocytes are being constitutively activated in the proliferative centers of these patients, we performed gene expression analysis comparing the global mRNA and microRNAs expression of this leukemic subpopulation. Our results suggest that the proliferative behaviour of this fraction appears to depend on microRNA-22 over-expression, which induces PTEN downregulation and PI3K/AKT pathway activation. Transfection experiments demonstrated that miR-22 overexpression in CLL B-cells switches on PI3K/AKT leading to FOXO1 inactivation, p27-Kip1 downregulation, and overexpression of Survivin and Ki-67 proteins. We also demonstrated that this pathway could be triggered by microenvironment signals like CD40L/IL4 and more importantly, that this regulatory loop is also present in lymph nodes from progressive UM patients. Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide rationale for the usage of PI3K inhibitors. Two-subset of B cells, QF vs PF. 8 samples of 4 patients.
2014-05-15 | E-GEOD-53236 | biostudies-arrayexpress
Project description:Understanding the crosstalk between malignant B-cells and their milieu could provide clues on the molecular and clinical biology of Chronic Lymphocytic Leukemia (CLL). Aiming to generate novel therapeutic strategies, different groups have studied different CLL proliferative fractions. We previously, identified one of these proliferative subsets in the peripheral blood from progressive unmutated CLL patients. Since the presence of this small subset appears to be a hallmark of a proliferative disease in which B lymphocytes are being constitutively activated in the proliferative centers of these patients, we performed gene expression analysis comparing the global mRNA and microRNAs expression of this leukemic subpopulation. Our results suggest that the proliferative behaviour of this fraction appears to depend on microRNA-22 over-expression, which induces PTEN downregulation and PI3K/AKT pathway activation. Transfection experiments demonstrated that miR-22 overexpression in CLL B-cells switches on PI3K/AKT leading to FOXO1 inactivation, p27-Kip1 downregulation, and overexpression of Survivin and Ki-67 proteins. We also demonstrated that this pathway could be triggered by microenvironment signals like CD40L/IL4 and more importantly, that this regulatory loop is also present in lymph nodes from progressive UM patients. Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide rationale for the usage of PI3K inhibitors. B cells from Chronic Lymphpcytic Leukaemia patients were isolated from blood. By sorting experiments we purify the QF from PF from progressive patients. We extract the total RNA from 8 samples and perform microRNA arrays.
2014-05-15 | E-GEOD-53235 | biostudies-arrayexpress
Project description:Understanding the crosstalk between malignant B-cells and their milieu could provide clues on the molecular and clinical biology of Chronic Lymphocytic Leukemia (CLL). Aiming to generate novel therapeutic strategies, different groups have studied different CLL proliferative fractions. We previously, identified one of these proliferative subsets in the peripheral blood from progressive unmutated CLL patients. Since the presence of this small subset appears to be a hallmark of a proliferative disease in which B lymphocytes are being constitutively activated in the proliferative centers of these patients, we performed gene expression analysis comparing the global mRNA and microRNAs expression of this leukemic subpopulation. Our results suggest that the proliferative behaviour of this fraction appears to depend on microRNA-22 over-expression, which induces PTEN downregulation and PI3K/AKT pathway activation. Transfection experiments demonstrated that miR-22 overexpression in CLL B-cells switches on PI3K/AKT leading to FOXO1 inactivation, p27-Kip1 downregulation, and overexpression of Survivin and Ki-67 proteins. We also demonstrated that this pathway could be triggered by microenvironment signals like CD40L/IL4 and more importantly, that this regulatory loop is also present in lymph nodes from progressive UM patients. Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide rationale for the usage of PI3K inhibitors.
2014-05-15 | GSE53236 | GEO
Project description:Understanding the crosstalk between malignant B-cells and their milieu could provide clues on the molecular and clinical biology of Chronic Lymphocytic Leukemia (CLL). Aiming to generate novel therapeutic strategies, different groups have studied different CLL proliferative fractions. We previously, identified one of these proliferative subsets in the peripheral blood from progressive unmutated CLL patients. Since the presence of this small subset appears to be a hallmark of a proliferative disease in which B lymphocytes are being constitutively activated in the proliferative centers of these patients, we performed gene expression analysis comparing the global mRNA and microRNAs expression of this leukemic subpopulation. Our results suggest that the proliferative behaviour of this fraction appears to depend on microRNA-22 over-expression, which induces PTEN downregulation and PI3K/AKT pathway activation. Transfection experiments demonstrated that miR-22 overexpression in CLL B-cells switches on PI3K/AKT leading to FOXO1 inactivation, p27-Kip1 downregulation, and overexpression of Survivin and Ki-67 proteins. We also demonstrated that this pathway could be triggered by microenvironment signals like CD40L/IL4 and more importantly, that this regulatory loop is also present in lymph nodes from progressive UM patients. Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide rationale for the usage of PI3K inhibitors.
2014-05-15 | GSE53235 | GEO
Project description:Hyperactivation of the PI3K/AKT pathway is observed in most NSCLCs, promoting proliferation, migration and resistance to therapy. AKT can be activated through several mechanisms that include loss of the negative regulator PTEN, activating mutations of the catalytic subunit of the positive regulator phosphatydil-inositol-3â phosphate kinase (PIK3CA) and/or mutations of AKT1 itself. However, whereas the effects of AKT activation on mRNAs and proteins in the cell are fairly clear, the role of miRNAs as downstream targets of activated PI3K/AKT signalling is still poorly defined so far. To identify miRNAs that are targets of constitutive signalling of PI3K/AKT in lung cancer cells, we performed miRNA profiling of human lung epithelial cells expressing active mutant AKT1 (E17K), active mutant PI3KCA (E545K) or that are silenced for PTEN. We identified 28 differentially expressed miRNAs (8 up-regulated, 20 down-regulated) that were common to BEAS-AKT1-E17K, BEAS-PIK3CA-E545K and BEAS-shPTEN cells. Among the 8 up-regulated miRNAs that were common to all the alterations, the miRNA most consistently up-regulated by activation of the PI3K/AKT pathway in BEAS-2B cells was miR-196a. The results reported here demonstrate that miR-196a acts as oncogene downstream the PI3K/AKT pathway, mediating the proliferative, pro-migratory and tumorigenic activity of this pathway in NSCLC cells by targeting FoxO1 and p27 expression. By adoptive expression of miR-196a in BEAS-2B cells, we demonstrated that miR-196a stimulates anchorage-dependent and -independent proliferation, migration and tumorigenicity in BEAS-2B cells. On the other hand, by use of antimir-196a in NCI-H460 cells to silence the endogenous expression of miR-196a, we demonstrate that miR-196a plays a pivotal role in mediating the stimulation of proliferation, migration and tumorigenicity induced by aberrant activation of PI3K/AKT signalling. Accordingly, we found that miR-196a was significantly overexpressed in human NSCLC-derived cell lines (n=6) and primary lung cancer samples (n=28). Finally, based on predicted binding sites for miR-196a by microRNA analysis software, we found that miR-196a affects protein levels of FoxO1 and p27 in NSCLC cells.
2016-06-13 | E-MTAB-4263 | biostudies-arrayexpress
Project description:Richter's syndrome (RS) is an aggressive transformation of Chronic Lymphocytic Leukaemia (CLL) frequently due to TP53, CDKN2, MYC or NOTCH1 mutations. whereas a significant proportion displays no specifically acquired driver mutation. We observe constitutive AKT phosphorylation not only in high-risk CLL patients harbouring p53 and NOTCH mutations but also in numerous RS patients. Consistently, genetic over-activation of AKT within the Eµ-TCL1 CLL mouse model results in a high-grade lymphoma phenotype of Richters syndrome. Multiomics assessment of our novel mouse model revealed a S100 defined subcluster of highly proliferative lymphoma cells developing from indolent CLL-like B-cells as a consequence of sudden NOTCH activation being fueled by enhanced NOTCH ligand exposure from T-cells in the microenvironment. Our data link AKT and NOTCH signaling in patient samples, genomic alterations, phosphoproteome and single-cell transcriptome profiles. Collectively, we have identified active AKT as a causative transforming pathway of indolent CLL towards aggressive RS thus providing novel mechanistic insights into the molecular understanding of RS.
2021-02-25 | PXD017457 | Pride
Project description:JNK is a member of the mitogen-activated protein kinase (MAPK) family and there are three genes that encode for JNK1, JNK2 and JNK3 respectively. JNK3 is mainly expressed in the central nervous system and it plays a crucial role in neuronal death in several neurodegenerative diseases, including epilepsy, Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. By contrast, the isoforms JNK1 and JNK2 seem to be involved in brain development. The lack of Jnk3 gene confers neuroprotection, although the specific mechanism underlying this has yet to be elucidated. The present study analyze the gene expression profiling in mice lacking Jnk3, comparing them to wild-type mice. The microarray analysis showed that 22 genes are differentially expressed in Jnk3 null mice. Of these we focused in pik3cb, since it is directly related to the pro-survival PI3K/AKT pathway. Results from Jnk3 null mice showed an increase in pik3cb transcript, together with an increase in PI3K activity and hyperphosphorylation of AKT. By contrast, these changes were not observed in Jnk1 null mice, indicating that activation of PI3K/AKT pathway is specifically related to the lack of JNK3. The data obtained in this study demonstrates activation of the PI3K/AKT pathway in Jnk3 null mice through the increase of pik3cb transcript. We performed arrays from Jnk3 null mice respect wilde-type mice. For each experiment (sample) a RNA pool from hippocampus form three different mice were used. Moreover, a second independent hybridization were done with new sample of RNA (sample 2). The genes differentially expressed were determined based on the results from both samples.
2010-12-01 | E-GEOD-22267 | biostudies-arrayexpress
Project description:In this study, using ChIP sequencing, we identified EZH2 target genes in two prognostic subgroups of chronic lymphocytic leukemia with distinct outcome, i.e. IGHV-unmutated/subset #1 and IGHV-mutated/subset #4. Our data identified many oncogenic pathways enriched equally by EZH2 target genes in both prognostic subgroups. Importantly, we identified PI3K pathway as differentially enriched pathway by EZH2 between the two prognostic sub groups. Validation of EZH2 target genes for EZH2 occupancy on selected PI3K pathway target genes were performed using independent CLL patient samples and CLL cell lines using siRNA mediated down regulation and ChIP assays. In conclusion, for the first time we characterized EZH2 target genes in CLL to understand the role of EZH2 in regulating the oncogenic pathways for improved therapeutic intervention and designing better drugs for targeting EZH2 in CLL.
2019-06-24 | GSE115772 | GEO