| 1. |
- Jobby, Renitta, et al.
(författare)
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Differential expression of antioxidant enzymes under arsenic stress in Enterobacter sp.
- 2016
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442. ; 35:6, s. 1642-1645
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic is a major contaminating heavy metal due to its frequent occurrence and toxicity. Out of different remediation approaches, bioremediation using bacteria has been extensively studied. In this study, 29 bacterial isolates were screened for their arsenic tolerance capacity. One of the isolate, MUM2 showed maximum arsenic tolerance (10mM). Antioxidant enzymes were assayed in this isolate under arsenic stress. Although, the CAT activity was found to increase significantly, the SOD activity showed a significant decrease under 9mM arsenic stress. The results obtained suggest a possible role of CAT in combating arsenic stress. Further studies at genetic level would help in developing highly tolerant strains for remediation of arsenic.
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| 2. |
- Barretina, Jordi, et al.
(författare)
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Subtype-specific genomic alterations define new targets for soft-tissue sarcoma therapy.
- 2010
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 42:8, s. 715-21
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Tidskriftsartikel (refereegranskat)abstract
- Soft-tissue sarcomas, which result in approximately 10,700 diagnoses and 3,800 deaths per year in the United States, show remarkable histologic diversity, with more than 50 recognized subtypes. However, knowledge of their genomic alterations is limited. We describe an integrative analysis of DNA sequence, copy number and mRNA expression in 207 samples encompassing seven major subtypes. Frequently mutated genes included TP53 (17% of pleomorphic liposarcomas), NF1 (10.5% of myxofibrosarcomas and 8% of pleomorphic liposarcomas) and PIK3CA (18% of myxoid/round-cell liposarcomas, or MRCs). PIK3CA mutations in MRCs were associated with Akt activation and poor clinical outcomes. In myxofibrosarcomas and pleomorphic liposarcomas, we found both point mutations and genomic deletions affecting the tumor suppressor NF1. Finally, we found that short hairpin RNA (shRNA)-based knockdown of several genes amplified in dedifferentiated liposarcoma, including CDK4 and YEATS4, decreased cell proliferation. Our study yields a detailed map of molecular alterations across diverse sarcoma subtypes and suggests potential subtype-specific targets for therapy.
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| 3. |
- Chougule, Rohit A., et al.
(författare)
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Glucocorticoid-resistant B cell acute lymphoblastic leukemia displays receptor tyrosine kinase activation
- 2019
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Ingår i: npj Genomic Medicine. - : Springer Science and Business Media LLC. - 2056-7944. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- The response of childhood acute lymphoblastic leukemia (ALL) to dexamethasone predicts the long-term remission outcome. To explore the mechanisms of dexamethasone resistance in B cell ALL (B-ALL), we generated dexamethasone-resistant clones by prolonged treatment with dexamethasone. Using RNA-sequencing and high-throughput screening, we found that dexamethasone-resistant cells are dependent on receptor tyrosine kinases. Further analysis with phosphokinase arrays showed that the type III receptor tyrosine kinase FLT3 is constitutively active in resistant cells. Targeted next-generation and Sanger sequencing identified an internal tandem duplication mutation and a point mutation (R845G) in FLT3 in dexamethasone-resistant cells, which were not present in the corresponding sensitive clones. Finally, we showed that resistant cells displayed sensitivity to second-generation FLT3 inhibitors both in vitro and in vivo. Collectively, our data suggest that long-term dexamethasone treatment selects cells with a distinct genetic background, in this case oncogenic FLT3, and therefore therapies targeting FLT3 might be useful for the treatment of relapsed B-ALL patients.
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| 4. |
- Kazi, Julhash U, et al.
(författare)
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ABL2 suppresses FLT3-ITD-induced cell proliferation through negative regulation of AKT signaling
- 2017
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8:7, s. 12194-12202
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Tidskriftsartikel (refereegranskat)abstract
- The type III receptor tyrosine kinase FLT3 is one of the most commonly mutated oncogenes in acute myeloid leukemia (AML). Inhibition of mutated FLT3 in combination with chemotherapy has displayed promising results in clinical trials. However, one of the major obstacles in targeting FLT3 is the development of resistant disease due to secondary mutations in FLT3 that lead to relapse. FLT3 and its oncogenic mutants signal through associating proteins that activate downstream signaling. Thus, targeting proteins that interact with FLT3 and their downstream signaling cascades can be an alternative approach to treat FLT3-dependent AML. We used an SH2 domain array screen to identify novel FLT3 interacting proteins and identified ABL2 as a potent interacting partner of FLT3. To understand the role of ABL2 in FLT3-mediated biological and cellular events, we used the murine pro-B cell line Ba/F3 as a model system. Overexpression of ABL2 in Ba/F3 cells expressing an oncogenic mutant of FLT3 (FLT3-ITD) resulted in partial inhibition of FLT3-ITD-dependent cell proliferation and colony formation. ABL2 expression did not alter the kinase activity of FLT3, its ubiquitination or its stability. However, it partially blocked FLT3-induced AKT phosphorylation without affecting ERK1/2 and p38 activation. Taken together our data suggest that ABL2 acts as negative regulator of signaling downstream of FLT3.
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| 5. |
- Moharram, Sausan A., et al.
(författare)
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Efficacy of the CDK inhibitor dinaciclib in vitro and in vivo in T-cell acute lymphoblastic leukemia
- 2017
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Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835. ; 405, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous disease of the blood affecting children, adolescents and adults. Although current treatment protocols for T-ALL have improved overall survival, a portion of T-ALL patients still experiences treatment failure. Thus, the development of novel therapies is needed. In this study, we used several patient-derived T-ALL cell lines to screen for an effective drug for T-ALL. Using a panel of 378 inhibitors against different kinases, we identified the CDK inhibitor dinaciclib as a potential drug for T-ALL. Dinaciclib treatment significantly reduced cell viability and completely blocked colony formation. Furthermore, cells treated with dinaciclib showed decreased expression of several pro-survival proteins including survivin, cyclin T1 and c-MYC. Dinaciclib treatment also increased accumulation of cells in G2/M phase and significantly induced apoptosis. Finally, dinaciclib extended survival of mice in a T-ALL cell xenograft model. Collectively, these data suggest that the CDK inhibitor dinaciclib is an active drug for T-ALL in the preclinical settings.
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| 6. |
- Moharram, Sausan A., et al.
(författare)
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T-cell acute lymphoblastic leukemia cells display activation of different survival pathways
- 2017
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Ingår i: Journal of Cancer. - : Ivyspring International Publisher. - 1837-9664. ; 8:19, s. 4124-4129
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Tidskriftsartikel (refereegranskat)abstract
- T-cell acute lymphoblastic leukemia (T-ALL) is a disease of the blood affecting T-lymphocytes. Although notable improvements have been achieved in T-ALL treatment, half of the adult T-ALL patients still experience treatment failure. In order to develop a targeted therapy, we need a better understanding of T-ALL pathogenesis. In this study, we used patient-derived cell lines which display resistance to glucocorticoids. We observed that different cell lines are dependent on different survival signaling pathways. Aberrant activation of AKT, p38, S6K or ERK signaling was not found to the same degree in all cell lines studied. To understand the molecular differences in T-ALL cells, we compared gene expression and somatic mutations. Gene set enrichment analysis showed enrichment of the mTORC1, MAPK or TGF-beta signaling pathways. Loss-of-function mutations in the TP53 and FBXW7 genes were identified in all cell lines investigated. Thus, we suggest that T-ALL cells from different patients are addicted to different mutations and thereby to different signaling pathways. Therefore, understanding the enrichment of molecular pathways for each individual patient will provide us with a more precise and specific treatment plan.
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| 7. |
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| 8. |
- Shah, Kinjal, et al.
(författare)
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Acute leukemia cells resistant to PI3K/mTOR inhibition display upregulation of P2RY14 expression
- 2018
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Ingår i: Clinical Epigenetics. - : Springer Science and Business Media LLC. - 1868-7075 .- 1868-7083. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The PI3K/mTOR pathway is the second most frequently deregulated pathway in a majority of cancers such as breast cancer, lung cancer, and melanomas as well as leukemia. Mutations in the genes coding for receptor tyrosine kinases (RTKs) and G-protein-coupled receptors (GPCRs) are quite common in all forms of acute leukemia. This can be a major cause of deregulation of the PI3K-mTOR pathway. To understand how cells display resistance to the dual PI3K/mTOR inhibitor, we used a panel of 25 acute leukemia cell lines. We observed that while a number of cell lines displayed sensitivity to the dual PI3K/mTOR pathway inhibitor PKI-587, many cells displayed substantial resistance. Cells sensitive to PKI-587 also showed aberrant activation of PI3K/mTOR pathway components such as AKT and S6K and also displayed sensitivity to a panel of various other PI3K/mTOR inhibitors. Using RNA sequencing data, we observed that expression of a G protein-coupled receptor, P2RY14, was upregulated nine-fold in cells showing resistance to the PI3K/mTOR inhibitor. P2RY14 has not been much studied in hematologic malignancies. However, this receptor seems to have a role in the localization of hematopoietic stem cells (HSCs) and in promoting regenerative capabilities following injury. We observed that acute lymphoblastic leukemia (ALL) and FLT3-ITD-positive acute myeloid leukemia (AML) patients with higher expression of P2RY14 mRNA displayed relatively poor survival compared to patients carrying lower expression of P2RY14 suggesting a role of P2RY14 in patient survival. To understand the role of this receptor in cell signaling, we used phospho-protein arrays and observed activation of distinct signaling cascades. Furthermore, array data were verified using murine pro-B cell line Ba/F3 stably transfected with P2RY14. We observed that activation of P2RY14 by its ligand, UDP-glucose, resulted in selective induction of ERK1/2 phosphorylation. Taken together, our data suggest that acute leukemia cells resistant to PI3K/mTOR inhibition display upregulation of a GPCR, P2RY14, which has a role in patient survival and also couples to the activation of ERK signaling.
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| 9. |
- Shah, Kinjal, et al.
(författare)
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Phosphorylation-Dependent Regulation of WNT/Beta-Catenin Signaling
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 12
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Forskningsöversikt (refereegranskat)abstract
- WNT/β-catenin signaling is a highly complex pathway that plays diverse roles in various cellular processes. While WNT ligands usually signal through their dedicated Frizzled receptors, the decision to signal in a β-catenin-dependent or -independent manner rests upon the type of co-receptors used. Canonical WNT signaling is β-catenin-dependent, whereas non-canonical WNT signaling is β-catenin-independent according to the classical definition. This still holds true, albeit with some added complexity, as both the pathways seem to cross-talk with intertwined networks that involve the use of different ligands, receptors, and co-receptors. β-catenin can be directly phosphorylated by various kinases governing its participation in either canonical or non-canonical pathways. Moreover, the co-activators that associate with β-catenin determine the output of the pathway in terms of induction of genes promoting proliferation or differentiation. In this review, we provide an overview of how protein phosphorylation controls WNT/β-catenin signaling, particularly in human cancer.
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| 10. |
- Shah, Kinjal, et al.
(författare)
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PLK1 as a cooperating partner for BCL2-mediated antiapoptotic program in leukemia
- 2023
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Ingår i: Blood Cancer Journal. - 2044-5385. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- The deregulation of BCL2 family proteins plays a crucial role in leukemia development. Therefore, pharmacological inhibition of this family of proteins is becoming a prevalent treatment method. However, due to the emergence of primary and acquired resistance, efficacy is compromised in clinical or preclinical settings. We developed a drug sensitivity prediction model utilizing a deep tabular learning algorithm for the assessment of venetoclax sensitivity in T-cell acute lymphoblastic leukemia (T-ALL) patient samples. Through analysis of predicted venetoclax-sensitive and resistant samples, PLK1 was identified as a cooperating partner for the BCL2-mediated antiapoptotic program. This finding was substantiated by additional data obtained through phosphoproteomics and high-throughput kinase screening. Concurrent treatment using venetoclax with PLK1-specific inhibitors and PLK1 knockdown demonstrated a greater therapeutic effect on T-ALL cell lines, patient-derived xenografts, and engrafted mice compared with using each treatment separately. Mechanistically, the attenuation of PLK1 enhanced BCL2 inhibitor sensitivity through upregulation of BCL2L13 and PMAIP1 expression. Collectively, these findings underscore the dependency of T-ALL on PLK1 and postulate a plausible regulatory mechanism. [Figure not available: see fulltext.]
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