Expression of miR-652-3p and Effect on Apoptosis and Drug Sensitivity in Pediatric Acute Lymphoblastic Leukemia.
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ABSTRACT:
SUBMITTER: Jiang Q
PROVIDER: S-EPMC6008837 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:T-cell acute lymphoblastic leukemia (T-ALL) is a rare, aggressive disease arising from T-cell precursors. NOTCH1 plays an important role both in T-cell development and leukemia progression, and more than 60% of human T-ALLs harbor mutations in components of the NOTCH1 signaling pathway, leading to deregulated cell growth and contributing to cell transformation. Besides multiple NOTCH1 target genes, microRNAs have also been shown to regulate T-ALL initiation and progression. Using an established mouse model of T-ALL induced by NOTCH1 activation, we identified several microRNAs downstream of NOTCH1 activation. In particular, we found that NOTCH1 inhibition can induce miR-22-3p in NOTCH1-dependent tumors and that this regulation is also conserved in human samples. Importantly, miR-22-3p overexpression in T-ALL cells can inhibit colony formation in vitro and leukemia progression in vivo. In addition, miR-22-3p was found to be downregulated in T-ALL specimens, both T-ALL cell lines and primary samples, relative to immature T-cells. Our results suggest that miR-22-3p is a functionally relevant microRNA in T-ALL whose modulation can be exploited for therapeutic purposes to inhibit T-ALL progression.
| S-EPMC7408026 | biostudies-literature
Project description:PURPOSE:Treatment outcomes for childhood acute lymphoblastic leukemia (ALL) have improved steadily, but a significant proportion of patients still experience relapse due to drug resistance, which is partly explained by inherited and/or somatic genetic alternations. Recently, we and others have identified genetic variants in the ARID5B gene associated with susceptibility to ALL and also with relapse. In this study, we sought to characterize the molecular pathway by which ARID5B affects antileukemic drug response in patients with ALL. EXPERIMENTAL DESIGN:We analyzed association of ARID5B expression in primary human ALL blasts with molecular subtypes and treatment outcome. Subsequent mechanistic studies were performed in ALL cell lines by manipulating ARID5B expression isogenically, in which we evaluated drug sensitivity, metabolism, and molecular signaling events. RESULTS:ARID5B expression varied substantially by ALL subtype, with the highest level being observed in hyperdiploid ALL. Lower ARID5B expression at diagnosis was associated with the risk of ALL relapse, and further reduction was noted at ALL relapse. In isogenic ALL cell models in vitro, ARID5B knockdown led to resistance specific to antimetabolite drugs (i.e., 6-mercaptopurine and methotrexate), without significantly affecting sensitivity to other antileukemic agents. ARID5B downregulation significantly inhibited ALL cell proliferation and caused partial cell-cycle arrest. At the molecular level, the cell-cycle checkpoint regulator p21 (encoded by CDKN1A) was most consistently modulated by ARID5B, plausibly as its direct transcription regulation target. CONCLUSIONS:Our data indicate that ARID5B is an important molecular determinant of antimetabolite drug sensitivity in ALL, in part, through p21-mediated effects on cell-cycle progression.
| S-EPMC7574699 | biostudies-literature
Project description:BACKGROUND: MicroRNA regulate the activity of protein-coding genes including those involved in hematopoietic cancers. The aim of the current study was to explore which microRNA are unique for seven different subtypes of pediatric acute lymphoblastic leukemia. DESIGN AND METHODS: Expression levels of 397 microRNA (including novel microRNA) were measured by quantitative real-time polymerase chain reaction in 81 cases of pediatric leukemia and 17 normal hematopoietic control cases. RESULTS: All major subtypes of acute lymphoblastic leukemia, i.e. T-cell, MLL-rearranged, TEL-AML1-positive, E2A-PBX1-positive and hyperdiploid acute lymphoblastic leukemia, with the exception of BCR-ABL-positive and 'B-other' acute lymphoblastic leukemias (defined as precursor B-cell acute lymphoblastic leukemia not carrying the foregoing cytogenetic aberrations), were found to have unique microRNA-signatures that differed from each other and from those of healthy hematopoietic cells. Strikingly, the microRNA signature of TEL-AML1-positive and hyperdiploid cases partly overlapped, which may suggest a common underlying biology. Moreover, aberrant down-regulation of let-7b (~70-fold) in MLL-rearranged acute lymphoblastic leukemia was linked to up-regulation of oncoprotein c-Myc (P(FDR)<0.0001). Resistance to vincristine and daunorubicin was characterized by an approximately 20-fold up-regulation of miR-125b, miR-99a and miR-100 (P(FDR)?0.002). No discriminative microRNA were found for prednisolone response and only one microRNA was linked to resistance to L-asparaginase. A combined expression profile based on 14 microRNA that were individually associated with prognosis, was highly predictive of clinical outcome in pediatric acute lymphoblastic leukemia (5-year disease-free survival of 89.4%±7% versus 60.8±12%, P=0.001). CONCLUSIONS: Genetic subtypes and drug-resistant leukemic cells display characteristic microRNA signatures in pediatric acute lymphoblastic leukemia. Functional studies of discriminative and prognostically important microRNA may provide new insights into the biology of pediatric acute lymphoblastic leukemia.
| S-EPMC3084917 | biostudies-literature
Project description:Similar to most cancers, genome-wide DNA methylation profiles are commonly altered in pediatric acute lymphoblastic leukemia (ALL); however, recent observations highlight that a large portion of malignancy-associated DNA methylation alterations are not accompanied by related gene expression changes. By analyzing and integrating the methylome and transcriptome profiles of pediatric B-cell ALL cases and primary tissue controls, we report 325 genes hypermethylated and downregulated and 45 genes hypomethylated and upregulated in pediatric B-cell ALL, irrespective of subtype. Repressed cation channel subunits and cAMP signaling activators and transducers are overrepresented, potentially indicating a reduced cellular potential to receive and propagate apoptotic signals. Furthermore, we report specific DNA methylation alterations with concurrent gene expression changes within individual ALL subtypes. The ETV6-RUNX1 translocation was associated with downregulation of ASNS and upregulation of the EPO-receptor, while Hyperdiploid patients (> 50 chr) displayed upregulation of B-cell lymphoma (BCL) members and repression of PTPRG and FHIT. In combination, these data indicate genetically distinct B-cell ALL subtypes contain cooperative epimutations and genome-wide epigenetic deregulation is common across all B-cell ALL subtypes.
| S-EPMC4053464 | biostudies-literature
Project description:Current standard of care for patients with pediatric acute lymphoblastic leukemia (ALL) is mainly effective, with high remission rates after treatment. However, the genetic perturbations that give rise to this disease remain largely undefined, limiting the ability to address resistant tumors or develop less toxic targeted therapies. Here, we report the use of next-generation sequencing to interrogate the genetic and pathogenic mechanisms of 240 pediatric ALL cases with their matched remission samples. Commonly mutated genes fell into several categories, including RAS/receptor tyrosine kinases, epigenetic regulators, transcription factors involved in lineage commitment, and the p53/cell-cycle pathway. Unique recurrent mutational hotspots were observed in epigenetic regulators CREBBP (R1446C/H), WHSC1 (E1099K), and the tyrosine kinase FLT3 (K663R, N676K). The mutant WHSC1 was established as a gain-of-function oncogene, while the epigenetic regulator ARID1A and transcription factor CTCF were functionally identified as potential tumor suppressors. Analysis of 28 diagnosis/relapse trio patients plus 10 relapse cases revealed four evolutionary paths and uncovered the ordering of acquisition of mutations in these patients. This study provides a detailed mutational portrait of pediatric ALL and gives insights into the molecular pathogenesis of this disease. Cancer Res; 77(2); 390-400. ©2016 AACR.
| S-EPMC5243866 | biostudies-literature
Project description:Aberrant epigenetic modifications are well-recognized drivers for oncogenesis. Pediatric acute lymphoblastic leukemia (ALL) is no exception and serves as a model toward the significant impact these heritable alterations can have in leukemogenesis. In this brief review, we will focus on the main aspects of epigenetics, which control leukemogenesis in pediatric ALL, mainly DNA methylation, histone modification, and microRNA alterations. As we continue to gain better understanding of the driving mechanisms for pediatric ALL at both diagnosis and relapse, therapeutic interventions directed toward these pathways and mechanisms can be harnessed and introduced into clinical trials for pediatric ALL.
| S-EPMC4030177 | biostudies-literature
Project description:Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy and causes a high rate of mortality in affected adults. Many subtypes of ALL exist with disruptions in distinct genetic pathways, including those regulated by miRNAs. Here we identify miR-187-5p as being highly upregulated in B-cell ALL and a driver of cellular proliferation and suppressor of apoptosis. We show that miR-187-5p directly targets the 3'-UTR of DKK2 to mediate these effects. We further determine that inhibition of DKK2 by miR-187-5p in Nalm-6 B cells leads to inappropriate activation of Wnt/?-catenin signaling. Together, these findings reveal that the miR-187-5p-DKK2 pathway regulates Wnt/?-catenin signaling, cell growth, and apoptosis. Our findings provide the first evidence of a role for miR-187-5p in promotion of B-cell ALL.
| S-EPMC7838722 | biostudies-literature
Project description:MicroRNAs (miRNAs) regulate activity of protein-coding genes including those involved in hematopoietic cancers. The goal of the current study was to explore which miRNAs are unique for seven different subtypes of pediatric acute lymphoblastic leukemia (ALL). Therefore, the expression levels of 397 miRNAs (including novel miRNAs) were measured by quantitative RT-PCR in 81 pediatric leukemia cases and 17 normal hematopoietic control cases. Except for BCR-ABL-positive and B-other ALL, all major subtypes i.e. T-ALL, MLL-rearranged, TEL-AML1-positive, E2A-PBX1-positive and hyperdiploid ALL have unique miRNA-signatures that differ from each other and from those in healthy hematopoietic cells. Strikingly, the miRNA signature between TEL-AML1-positive and hyperdiploid cases partly overlapped, which suggests a common underlying biology. Moreover, aberrant downregulation of let-7b (~70-fold) in MLL-rearranged ALL was linked to upregulation of oncoprotein c-Myc (P<0.0001). Besides genetic aberrations, in vitro drug resistance predicts clinical outcome. Resistance to vincristine and daunorubicin was characterized by ~20-fold upregulation of miR-125b, miR-99a and miR-100 (P≤0.002). No discriminative miRNAs were found for prednisolone and only one miRNA was linked to L-asparaginase resistance. Finally we show that the expression levels of 14 miRNAs were --independently of subtype-- associated with clinical outcome in pediatric ALL. We conclude that genetic subtypes and drug resistant leukemic cells display characteristic miRNA signatures in pediatric ALL. Functional studies of discriminative and prognostic important miRNAs may provide new insights into the biology of disease. Experiment type: stem-loop real-time (RT) quantitative PCR (RT-qPCR) Bone marrow and peripheral blood samples were collected from children at newly diagnosis of acute lymphoblastic leukemia (ALL). CD34+ -cells were sorted from G-CSF-stimulated blood cell samples of children with a brain tumor or Wilm’s tumor. Thymocytes were isolated from thymic lobes that were resected from children during surgery for congenital heart disease. RNA from the cell samples was extracted using TRIzol reagents (firma). Only RNA with an RNA Integrity Number (RIN) of ≥ 7.5 as measured by the 2100 Bioanalyzer (Agilent, Amstelveen, the Netherlands) was used as input for the RT-qPCR reactions. All miRNAs were validated with the stem-loop real-time (RT) quantitative PCR (RT-qPCR) technique by using either TaqMan MicroRNA Array MicroRNA arrays (v 1.0, Early Access) or Custom TaqMan MicroRNA Array arrays (Applied Biosystems, Foster City, USA). Values represent ∆Ct in each individual patient for whom the specific subtype, identification number and cellular drug-resistance is shown on top of each column. Drug-resistance was based on median LC50 values (concentration of a drug lethal to 50% of the leukemic cells) that have reported prognostic impact in children with newly diagnosed ALL. Median LC50 values were used to assign patients as sensitive (≤ median LC50) or resistant (> median LC50) to the drug in question. The ∆Ct value was calculated according to the following equation: Ct value of the specific miRNA minus the Ct value of the internal reference. In case of the TaqMan MicroRNA Array MicroRNA arrays the mean Ct values for snoR-13 and snoR-14 were used as reference whereas in case of the Custom TaqMan MicroRNA Array arrays snoR-1 was used. MiRNAs validated by the TaqMan MicroRNA Array MicroRNA arrays are listed together with the part numbers of the corresponding (stem-loop) primers as available by Applied Biosystems, Foster City, USA. Primers for the remaining miRNAs were custom designed by Applied Biosystems. Abbreviations: MLL: MLL-rearranged precursor B-ALL, B-other: precursor B-ALL negative for MLL-rearrangements, TEL-AML1, BCR-ABL, E2A-PBX and hyperdiploidy (> 50 chromosomes). CD34+: normal CD34+-sorted blood progenitor cells, nBM: normal bone marrow.
2011-02-11 | E-GEOD-23024 | biostudies-arrayexpress
Project description:MicroRNAs (miRNAs) regulate activity of protein-coding genes including those involved in hematopoietic cancers. The goal of the current study was to explore which miRNAs are unique for seven different subtypes of pediatric acute lymphoblastic leukemia (ALL). Therefore, the expression levels of 397 miRNAs (including novel miRNAs) were measured by quantitative RT-PCR in 81 pediatric leukemia cases and 17 normal hematopoietic control cases. Except for BCR-ABL-positive and B-other ALL, all major subtypes i.e. T-ALL, MLL-rearranged, TEL-AML1-positive, E2A-PBX1-positive and hyperdiploid ALL have unique miRNA-signatures that differ from each other and from those in healthy hematopoietic cells. Strikingly, the miRNA signature between TEL-AML1-positive and hyperdiploid cases partly overlapped, which suggests a common underlying biology. Moreover, aberrant downregulation of let-7b (~70-fold) in MLL-rearranged ALL was linked to upregulation of oncoprotein c-Myc (P<0.0001). Besides genetic aberrations, in vitro drug resistance predicts clinical outcome. Resistance to vincristine and daunorubicin was characterized by ~20-fold upregulation of miR-125b, miR-99a and miR-100 (P≤0.002). No discriminative miRNAs were found for prednisolone and only one miRNA was linked to L-asparaginase resistance. Finally we show that the expression levels of 14 miRNAs were --independently of subtype-- associated with clinical outcome in pediatric ALL. We conclude that genetic subtypes and drug resistant leukemic cells display characteristic miRNA signatures in pediatric ALL. Functional studies of discriminative and prognostic important miRNAs may provide new insights into the biology of disease. Experiment type: stem-loop real-time (RT) quantitative PCR (RT-qPCR)
2011-02-11 | GSE23024 | GEO
Project description:This study investigated Polo-like kinase 1, a mitotic regulator often over-expressed in solid tumors and adult hematopoietic malignancies, as a potential new target in the treatment of pediatric acute lymphoblastic leukemia. Polo-like kinase 1 protein and Thr210 phosphorylation levels were higher in pediatric acute lymphoblastic leukemia (n=172) than in normal bone marrow mononuclear cells (n=10) (P<0.0001). High Polo-like kinase 1 protein phosphorylation, but not expression, was associated with a lower probability of event-free survival (P=0.042) and was a borderline significant prognostic factor (P=0.065) in a multivariate analysis including age and initial white blood cell count. Polo-like kinase 1 was necessary for leukemic cell survival, since short hairpin-mediated Polo-like kinase 1 knockdown in acute lymphoblastic leukemia cell lines inhibited cell proliferation by G2/M cell cycle arrest and induced apoptosis through caspase-3 and poly (ADP-ribose) polymerase cleavage. Primary patient cells with a high Polo-like kinase 1 protein expression were sensitive to the Polo-like kinase 1-specific inhibitor NMS-P937 in vitro, whereas cells with a low expression and normal bone marrow cells were resistant. This sensitivity was likely not caused by Polo-like kinase 1 mutations, since only one new mutation (Ser335Arg) was found by 454-sequencing of 38 pediatric acute lymphoblastic leukemia cases. This mutation did not affect Polo-like kinase 1 expression or NMS-P937 sensitivity. Together, these results indicate a pivotal role for Polo-like kinase 1 in pediatric acute lymphoblastic leukemia and show potential for Polo-like kinase 1-inhibiting drugs as an addition to current treatment strategies for cases expressing high Polo-like kinase 1 levels.
| S-EPMC3789458 | biostudies-literature