Discovery of Subtype-Specific Mirnas and New MiR-Genes In Pediatric Acute Lymphoblastic Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3232-3232 ◽  
Author(s):  
Diana Schotte ◽  
Renee X de Menezes ◽  
Farhad Akbari Moqadam ◽  
Ellen Lange-Turenhout ◽  
Ronald W Stam ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Mirna Expression ◽  
Lymphoblastic Leukemia ◽  
Cell Type ◽  
Quantitative Real Time Pcr ◽  
Aberrant Expression ◽  
Stem Loop ◽  
Expression Levels ◽  
Genetic Subtypes ◽  
Pediatric All

Abstract Abstract 3232 MicroRNAs (miRNAs) are non-coding RNAs that regulate the activity of protein-coding genes and some miRNAs have been shown to be dysregulated in cancer. The function of miRNAs differs per cell type and prominent miRNAs in e.g. B-cell lymphoma may not be important in acute lymphoblastic leukemia (ALL). To identify which miRNAs may be relevant in pediatric ALL the expression level of 397 different miRNAs was measured in leukemic cells (>90% purity) of 81 pediatric ALL and 17 normal hematopoietic control samples by stem-loop reverse-transcriptase (RT) quantitative real-time PCR. Except for BCRABL1-positive and B-other ALL, all major subtypes including T-ALL, MLL-rearranged, TELAML1-positive, E2APBX1-positive and hyperdiploid (>50 chromosomes) ALL presented with unique miRNA signatures that differ from each other and from those in healthy hematopoietic cells. The expression levels highly varied amongst subtypes and, for example, differed by 4000-fold for miR-708 in T-ALL (P<0.0001) and 1700-fold for miR-383 in TELAML1-positive ALL (P<0.0001) compared to other precursor B-ALL cases. Some subtypes shared similarities in their miRNA expression signatures suggesting a common underlying biology; e.g. miR-196b was highly expressed in 9/12 MLL-rearranged and 14/22 T-ALL patients. In particular, all T-ALL cases carrying CALM-AF10, MLL-AF6, SET-NUP214 or an inversion of chromosome 7 expressed high levels of miR-196b similar to MLL-rearranged ALL. These genetic subtypes have all been functionally linked to upregulation of HOXA cluster genes. In correspondence, miR-196b expression levels were also highly correlated with HOXA (Rs>0.7, p<0.003), which was not seen for HOXB and HOXC cluster genes. High levels of miR-196b coincide with reduced methylation of the DNA at CpG islands directly upstream of miR-196b in MLL-rearranged cases compared to non-MLL precursor B-ALL and normal bone marrow cases, suggesting an epigenetic origin for miR-196b overexpression in these patients. High-throughput sequencing (Solexa technology) of small RNA libraries representing 7 subtypes of ALL and 3 normal hematopoietic tissue types followed by application of stringent computational miRNA precursor prediction algorithms resulted into the identification of 28 novel and 431 candidate novel miR-genes (besides 554 known miR-genes) for which the expression levels differed between genetic subtypes of pediatric ALL and normal hematopoietic cells. Stem-loop RT-quantitative real-time PCR confirmed aberrant expression levels of newly discovered miR-genes in a different set of patients. These data may point to leukemia-associated miRNAs for which the (aberrant) expression level and activity may be cell type (e.g. MLL-subtype) specific. These subtype-specific (known and novel) miRNAs may have stayed unrecognized when analyzed in a set of genetically unspecified ALL cases. In conclusion, genetic subtypes of ALL display unique miRNA expression signatures. Functional studies are in progress for these discriminative miRNAs since this may provide new insights into the biology of ALL subtypes. Disclosures: No relevant conflicts of interest to declare.

MicroRNAs Characterize Genetic Diversity and Drug Sensitivity in Pediatric Acute Lymphoblastic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 89-89 ◽  
Author(s):  
Diana Schotte ◽  
Renee X de Menezes ◽  
Farhad Akbari Moqadam ◽  
Ellen Lange-Turenhout ◽  
Caifu Chen ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Mirna Expression ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Hematopoietic Cells ◽  
Mirna Expression Profile ◽  
Leukemic Cells ◽  
Expression Levels ◽  
Genetic Subtypes

Abstract Abstract 89 MicroRNAs (miRNAs) are a new class of small non-coding RNAs that regulate the activity of protein-coding genes, including those involved in cancer. The function of a miRNA depends on the cellular context and hence prominent miRNAs in lymphoma may not be important in acute lymphoblastic leukemia (ALL). To understand which miRNAs may be relevant in pediatric ALL, the expression levels of 397 miRNAs including seven newly cloned miRNAs were measured in seven genetic subtypes of ALL and normal hematopoietic cells. 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. The expression of miR-383, miR-125b, miR-99a, miR-100 and let-7c was increased by a five to 1700-fold (P < 0.001) in TEL-AML1-positive cases. Hyperdiploid patients demonstrated a three to 24-fold upregulation (P < 0.001) of miR-222/222*, miR-223, miR-511 and miR-660, encoded on either chromosome X or 10 which is often duplicated in hyperdiploid cases. Some ALL subtypes shared similarities in their miRNA expression signature suggesting a common underlying biology e.g. both E2A-PBX1 and T-ALL cases demonstrated a downregulation of eight miRNAs (P ≤ 0.02) and within the TEL-AML1-positive subtype, two distinct groups were identified of which one showed an overlapping miRNA expression profile with hyperdiploid cases. Aberrant miRNA expression may result in dysregulated expression of their targeted proteins. Here we observed that the 70-fold downregulation of let-7b in MLL-rearranged ALL was associated with a 2-fold upregulation of oncoprotein c-Myc (P< 0.0001). Furthermore, a classifier built with a selection of 28 miRNAs predicted the MLL-rearranged, TEL-AML1-positive, E2A-PBX-positive and T-ALL subtypes with 100% sensitivity and specificity. Besides the genetic subtype, cellular drug resistance determines outcome of ALL. In vitro resistance of patients to vincristine, daunorubicin and L-asparginase was characterized by abnormal expression of 27 miRNAs (P < 0.05) whereas no discriminative miRNAs were found for resistance to prednisolone. Most striking was the 14- to 25-fold upregulation (P ≤ 0.002) of miR-125b, miR-99a and miR-100 in cases resistant to vincristine or daunorubicin. In conclusion, genetic subtypes and drug resistant leukemic cells display characteristic miRNA expression levels. Functional studies are indicated for discriminative miRNAs and may provide new insights into leukemogenesis. Disclosures: No relevant conflicts of interest to declare.

Expression of Mir-196b Is Not Exclusively MLL-Driven but Especially Linked to Activation of HOXA Genes in Children with Acute Lymphoblastic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 580-580
Author(s):  
Diana Schotte ◽  
Ellen Lange-Turenhout ◽  
Dominique JPM Stumpel ◽  
Ronald W. Stam ◽  
Jessica Buijs-Gladdines ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Chromosome 7 ◽  
High Expression ◽  
Expression Level ◽  
Aberrant Expression ◽  
Expression Levels ◽  
Pediatric All ◽  
Hoxa Genes ◽  
High Expression Level

Abstract Abstract 580 MicroRNAs (miRNAs) play important roles in diverse biological processes including hematopoiesis. As a consequence, aberrant expression of miRNAs may contribute to hematopoietic malignancies. It has been reported that miR-196b is transcriptionally activated by MLL and MLL-fusion genes and is therefore highly expressed in MLL-rearranged leukemia. In order to investigate whether high expression levels of miR-196b are restricted to MLL-rearranged leukemia cases, we measured the expression in samples of 72 selected pediatric acute lymphoblastic leukemia (ALL) cases i.e. MLL-rearranged and non-MLL-rearranged precursor B-ALL and T-ALL patients. MiR-196b was highly expressed in 9/12 MLL-rearranged precursor B-ALL patients, but also in 14/22 T-ALL patients. In particular, 100% of T-ALL cases carrying CALM-AF10 (n=5), MLL-AF6 (n=2), SET-NUP214 (n=3) and an inversion of chromosome 7 (n=1) showed high expression levels of miR-196b comparable to the high levels found in MLL-rearranged ALL. Like MLL-rearrangements, these genetic abnormalities have been functionally linked with upregulation of HOXA cluster genes. MiR-196b expression levels in these patients were strongly correlated with the expression of HOXA family but not with HOXB and HOXC cluster genes (Rs ≥ 0.7, P≤0.003). Since miR-196b is located between HOXA9 and HOXA10 on chromosome 7, our data suggest co-activation of miR-196b and HOXA family genes in pediatric ALL. In parallel to the high expression level of miR-196b we found decreased methylation at CpG islands located 5' of miR-196b in MLL-rearranged cases compared to normal bone marrow cells, which suggests an epigenetic origin for the high expression level of miR-196b in these patients. Despite the fact that MLL-rearranged ALL patients often respond poorly to prednisolone and L-asparaginase, upregulation of miR-196b was not indicative for the resistance to these drugs in pediatric ALL. In conclusion, high-level expression of miR-196b is not only MLL-driven, but can also be found in other types of leukemia that display aberrant activation of HOXA genes. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Expression Analysis of Circulating miR-22, miR-122, miR-217 and miR-367 as Promising Biomarkers of Acute Lymphoblastic Leukemia

2021 ◽  
Author(s):  
Fatemeh hosseinpour-soleimani ◽  
Gholamreza Khamisipour ◽  
Zahra Derakhshan ◽  
Bahram Ahmadi
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Lymphoblastic Leukemia ◽  
Area Under The Curve ◽  
Diagnostic Value ◽  
Healthy Individuals ◽  
Quantitative Real Time Pcr ◽  
Expression Levels

Abstract Background Currently, the role of serum-based biomarkers such as microRNAs in cancer diagnosis has been extensively established. This study aimed to determine expression levels of bioinformatically selected miRNAs and whether they can be used as biomarkers or a new therapeutic target in patients with Acute Lymphoblastic Leukemia (ALL). Materials and Methods The expression levels of serum miR-22, miR-122, miR-217, and miR-367 in 21 ALL patients and 21 healthy controls were measured using quantitative real-time PCR. The receiver operating characteristic (ROC) curve and the associated area under the curve (AUC) was used to assess candidate miRNAs' diagnostic value as a biomarker. Results The results showed that miR-217 was markedly decreased in patients with ALL compared to controls. Moreover, miR-22, miR-122, and miR-367 were found to be upregulated. Furthermore, ROC analysis showed that serum miR-217 and miR-367 could differentiate ALL patients from the healthy individuals, while miR-22 has approximate discriminatory power that requires further investigation. Conclusion Collectively, the results suggested that miR-217 may play a tumor suppressor role in ALL, whereas miR-22, miR-122, and miR-367 could function as an oncogene. Overall, miR-22, miR-217, and miR-367 could be considered possible biomarkers for the early diagnosis of ALL.

In-Vitro Efficacy of the Deoxyguanoside Analogs Forodesine (BCX-1777) and ARA-G in Pediatric Acute Lymphoblastic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2038-2038
Author(s):  
Irene Homminga ◽  
Michel C. Zwaan ◽  
Amel Seghouani ◽  
Chantal Y. Manz ◽  
Shanta Bantia ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Nucleoside Transporter ◽  
Nucleotide Synthesis ◽  
Pediatric Acute Lymphoblastic Leukemia ◽  
Expression Levels ◽  
Lc50 Value ◽  
Pediatric All

Abstract Abstract 2038 Poster Board II-15 Purine nucleoside phosphorylase (PNP) deficiency in humans is associated with elevated deoxyguanosine (dGuo) plasma levels. DGuo is converted into dGTP inducing apoptosis in T-cells and this provides the rationale for the development of deoxyguanosine analogues as a potential treatment option for T-cell malignancies. Forodesine (BCX-1777; BioCryst-Mundipharma) is an efficient blocker of PNP activity, thereby boosting the conversion of dGuo into dGTP and raising intracellular dGTP levels. AraG (9-b-D-arabinofuranosyl-guanine) is a compound that is resistant to PNP-mediated degradation that is efficiently converted into AraGTP. AraGTP becomes incorporated in the DNA, blocking DNA synthesis and promoting apoptosis. In a phase II clinical trial, the AraG prodrug Nelarabine enforced a complete remission rate of 55% for pediatric T-ALL patients at 1st relapse. (Berg, JCO 2005). Clinical data of Forodesine treatment in pediatric ALL patients are not yet available. As tested on primary pediatric acute lymphoblastic leukemia (ALL) patient samples (4 T-ALL, 2 BCP-ALL), 1μM of Forodesine is sufficient to completely block PNP and abolish rapid dGuo degradation resulting in a median 7.9 (range 0.5-378) fold raise of intracellular dGTP levels. Accumulation of dGTP is comparable for T-ALL (n=31) and BCP-ALL (n=11) patient samples. This reflects equal intrinsic ability of salvage nucleotide synthesis for both T-ALL and BCP-ALL cells. Cytotoxic effect of Forodesine was tested on primary leukemia cells from newly diagnosed pediatric ALL patients in-vitro by incubating cells with Forodesine (1μM) in the presence of increasing concentrations of dGuo (0.001-50μM). In accordance with selective T-cell toxicity, T-ALL cells were more sensitive to Forodesine/dGuo treatment (median T-ALL LC50 value: 1.1μM dGuo/1μM Forodesine, n=27, p=0.001) compared to BCP-ALL cells, which had a median LC50 value of 8.8μM dGuo/1μM Forodesine (n=30). All patients that responded demonstrated dGTP accumulation (1.5-222.1 fold), although the raise of dGTP levels did not correlate with Forodesine/dGuo toxicity (r2= 0.10, p=0.22). Studying in-vitro responsiveness to AraG, T-ALL cells were more sensitive compared to BCP-ALL cells (p=0.0002) with a median AraG LC50 value of 20.5μM for T-ALL samples (n=24) versus 48.3μM for BCP-ALL samples (n=20). Remarkably, TELAML1 positive BCP-ALL cases were insensitive to AraG treatment (median LC50 value >50μM, n=9). No correlation was identified between in-vitro Forodesine/dGuo and AraG cytotoxicities (r2=0.05, p=0.29). Most patient samples that displayed AraG resistance still responded to Forodesine/dGuo treatment. This may be explained by the fact that the uptake of both drugs may be facilitated by different transporters. Using RQ-PCR we could demonstrate that AraG toxicity, in contrast to Forodesine, was significantly associated with ENT1 (equilibrative nucleoside transporter 1) expression levels (p=0.008), which was previously identified as strong predictor for AraC cytotoxicity in pediatric ALL (Stam RW. et al., Blood 2003). AraG cytotoxicity strongly correlated with AraC cytotoxicity (r2=0.71, p<0.0001). We found no significant correlation between Forodesine sensitivity and the expression levels of other nucleoside transporters (CNT1, CNT2, CNT3, ENT2), kinases (dCK, dGK), nucleotidases (NT5C1A, NT5C2, PNI) or other enzymes that are involved in dGuo metabolism (PNP, RRM1, RRM2). In conclusion, T-ALL cells are more sensitive to Forodesine/dGuo treatment in-vitro than BCP-ALL cells that have nearly 8 fold higher dGuo LC50 values. Resistance to AraG treatment does not preclude responsiveness to Forodesine treatment and vice versa, indicating that Forodesine and AraG rely on different cellular mechanisms for cytotoxicity, possibly involving differences in dependence on the nucleoside transporter ENT1. Disclosures: No relevant conflicts of interest to declare.

The Level of Histone Deacetylase 7 in Pediatric ALL and Its Effect on Survival

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5099-5099
Author(s):  
Bei Hou ◽  
Huyong Zheng
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Histone Deacetylase ◽  
Conflicts Of Interest ◽  
Risk Group ◽  
Lymphoblastic Leukemia ◽  
Intermediate Risk ◽  
Newly Diagnosed ◽  
Altered Expression ◽  
Expression Levels ◽  
Pediatric All

Abstract Background Leukemia is the most common pediatric malignancy and a major cause of mortality and morbidity in children. Nearly 15,000 children are newly diagnosed with leukemia in China each year and among them, acute lymphoblastic leukemia (ALL) accounts for more than 75%. Altered expression of histone deacetylases (HDACs) is a common feature in several human malignancies and may represent an interesting target for cancer treatment . With increasing focus on precision medicine, HDACs have emerged as promising therapeutic target in pediatric ALL. Methods We detect the histone deacetylase 7(HDAC7) expression in the bone marrow samples of 254 children with newly diagnosed acute lymphoblastic leukemia (ALL) at Hematology Oncology Center of Beijing Children`s Hospital from January 2010 to the end of 2012 via qRT-PCR using the TaqMan gene expression probes. 3 patients that have been completely remission for 3 years are used as normal control. We find out that the expression levels of HDAC7 are associated with the unfavorable events (such as induction failure, relapse and/or death due to any cause ) occurence rates and 5-EFS. Results Here we find that the HDAC7 expression levels are associated with the unfavorable events occurence rates and 5-EFS. We find that in the intermediate risk group of 157 patients, the patients who have lower level of HDAC7 expression have higher unfavorable event occurence rates than the higher expression of HDAC7 group (p=0.001). The group of higher HDAC7 expression have higher 5-EFS than the lower group in both the intermediate risk group(p=0.001) and the T-ALL group(n=18). Conclusion We conclude that HDAC7 has a potent anti-oncogenic effect on specific pediatric B-cell leukemia, indicating that its deregulation may contribute to the pathogenesis of the disease. Disclosures No relevant conflicts of interest to declare.

Aberrant expression of the homeobox gene CDX2 in pediatric acute lymphoblastic leukemia

Blood ◽  
2009 ◽  
Vol 113 (17) ◽  
pp. 4049-4051 ◽  
Author(s):  
Tamara Riedt ◽  
Martin Ebinger ◽  
Helmut R. Salih ◽  
Jürgen Tomiuk ◽  
Rupert Handgretinger ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Residual Disease ◽  
Lymphoblastic Leukemia ◽  
Embryonic Stem ◽  
Homeobox Gene ◽  
Lymphoid Cells ◽  
Aberrant Expression ◽  
Expression Levels ◽  
Cdx2 Expression ◽  
Human Acute Myeloid Leukemia

Abstract Members of the caudal (cdx) family of homeobox proteins are essential regulators of embryonic blood development in zebrafish. Previously, we reported that the murine homologues (Cdx1, Cdx2, and Cdx4) affect formation and differentiation of embryonic stem cell (ESC)–derived hematopoietic progenitor cells. Consistent with the notion that embryonic pathways can reactivate during adult oncogenesis, recent studies suggest involvement of CDX2 in human acute myeloid leukemia (AML). Here we study CDX2 in healthy and leukemic human lymphoid cells, and show that a majority of leukemic samples display various degrees of aberrant CDX2 expression. Analysis of a cohort of 37 childhood acute lymphoblastic leukemia (ALL) patients treated in our hospital reveals that high CDX2 expression levels at diagnosis correlate with persistence of minimal residual disease (MRD) during the course of treatment. Thus, CDX2 expression levels may serve as a marker for adverse prognosis in pediatric ALL.

Expression Pattern Of Mirnas Is Not Predictive For Poor Prognosis In BCR-ABL1-Like Childhood Acute Lymphoblastic Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2631-2631
Author(s):  
Farhad Akbari Moqadam ◽  
Ellen Lange-Turenhout ◽  
Arian van der Veer ◽  
João R.M. Marchante ◽  
Rob Pieters ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Expression Pattern ◽  
Mirna Expression ◽  
Lymphoblastic Leukemia ◽  
Mirna Signature ◽  
Altered Expression ◽  
Expression Levels ◽  
Mirna Expression Pattern ◽  
Significant Difference

Abstract Childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a heterogeneous disease in which the 5-years event-free survival rates are currently above 80%. We recently identified a poor prognostic set of patients within unclassified BCP-ALL patients. These patients have a high risk of relapse and a gene expression profile similar to BCR-ABL1-positive ALL cases. This so-called BCR-ABL1-like (or Ph-like) group of patients showed similar high frequencies of deletion in B-cell development genes (den Boer et al, Lancet Oncology, 2009 and Mullighan et al. New Eng J Med, 2009). Here, we investigate the miRNA expression pattern in BCR-ABL1-like ALL. Further, we addressed whether altered expression levels of discriminative miRNAs of BCR-ABL1-like ALL has prognostic importance. MiRNA expression levels of leukemic cells of 91 newly identified children with BCP-ALL: i.e. 15 BCR-ABL1-like, 14 BCR-ABL1-positive, 9 TCF3-rearranged, 14 hyperdiploid (>50 chromosomes), and 15 B-other patients (negative for BCR-ABL1-like ALL and other known genetic lesions) were measured by Taqman® Array Human miRNA cards (TLDA cards, Applied Biosystems). Using the R statistics program (R-2.15, release June 2012), the Limma package was applied to compare the expression levels of miRNAs between the groups. Each genetic subtype was compared to the remaining cases to identify subtype-specific miRNAs. Our data revealed that children with ETV6-RUNX1-positive, hyperdiploid, TCF3-rearranged and MLL-rearranged ALL demonstrate a subtype-specific miRNA signature. In contrast, BCR-ABL1-positive and BCR-ABL1-like cases showed a more variable miRNA expression pattern, resulting in 2 clusters of patients. The majority of the children with BCR-ABL1-like ALL (11 out of 15) showed a miRNA expression pattern different from that of BCR-ABL1-negative genetic subtypes of pediatric BCP-ALL and cluster with 43% of BCR-ABL1-positive patients (6 out of 14, cluster-I). The remaining 8 BCR-ABL1-positive and 4 BCR-ABL1-like cases showed more heterogeneous expression patterns (cluster-II). The prognosis of patients in both clusters, however, did not differ. Similarly, there was no significant difference in IKZF1, PAX5, JAK2 or CDKN2A/B status between these two clusters. Top-10 most differentially expressed miRNAs of the children with BCR-ABL1-like ALL were miR-324-5p, miR-345, miR-190, miR-130a, miR-545, miR-152, miR-103, miR-191, miR-197 and miR-101. None of these discriminative miRNAs was predictive for clinical outcome of BCR-ABL1-like patients. In conclusion, our data suggest that a miRNA signature is not suitable to dissect good and poor prognostic BCR-ABL1-like cases. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Ultraconserved Long Non-Coding RNA Uc.112 is Abnormally Expressed in Childhood Acute Lymphoblastic Leukemia Subtypes

2018 ◽  
Author(s):  
Pablo Chagas ◽  
Graziella Sousa ◽  
Marcio Kodama ◽  
Carlos Biagi Junior ◽  
José Yunes Andres ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Potential Role ◽  
Lymphoblastic Leukemia ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Aberrant Expression ◽  
Non Coding Rna ◽  
Pediatric All ◽  
Long Non Coding Rna

Long non-coding RNA (lncRNA) aberrant expression have been found in several types of cancer, including acute lymphoblastic leukemia (ALL), but lncRNA mapped in transcribed ultraconserved regions (T-UCRs) are little explored. The T-UCRs uc.112, uc.122, uc.160 and uc.262 were evaluated in pediatric ALL and uc.112 expression was higher in T-ALL compared to patients with B-ALL and in patients with hyperdiploid karyotype. These findings suggest a potential role of this uc.112 in pediatric ALL and emphasize the need for further investigation of T-UCR in pediatric ALL.

scholarly journals TIM-3 Expression on CD4+ Bone Marrow T Cells Predicts Relapse of Pediatric B-Precursor Acute Lymphoblastic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2833-2833
Author(s):  
Franziska Blaeschke ◽  
Semjon Willier ◽  
Dana Stenger ◽  
Mareike Lepenies ◽  
Martin A. Horstmann ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cells ◽  
Expression Levels ◽  
Pediatric All

Abstract Introduction Pediatric acute lymphoblastic leukemia (ALL) is a cancer entity of minimal mutational load and low immunogenicity. The interaction of ALL cells with bone marrow (BM) T cells has not been investigated as a pathogenic driver or prognostic marker for pediatric ALL. We defined BM T cells of pediatric ALL patients as tumor-infiltrating lymphocytes (TILs) and investigated the prognostic relevance of co-stimulatory and co-inhibitory signals between ALL and BM T cells. Methods BM samples of 100 pediatric ALL patients were analyzed at time of initial diagnosis. T-cell subpopulations and expression of co-stimulatory and co-inhibitory molecules were defined by flow cytometry and correlated with clinical outcome of the patients. To investigate the role of TIM-3 for the interaction between T cells and leukemic cells, CRISPR/Cas9-mediated TIM-3 knockout (KO) was performed in primary T cells by ribonucleoprotein electroporation. T-cell activation and proliferation after contact with leukemic target cells were analyzed in TIM-3 KO cells and compared to wildtype T cells and T cells with retroviral TIM-3 overexpression. Interaction of T cells with leukemic target cells was induced by addition of anti-CD19/-CD3 bispecific T-cell engager (BiTE). Fold change (FC) of T-cell activation and proliferation was analyzed before and after co-culture. BM expression levels of known TIM-3 inducers were identified by RNA next generation sequencing of the bone marrow samples. Results Multivariate analyses identified high TIM-3 expression on CD4+ BM T cells at initial diagnosis as strong predictor for relapse of pediatric acute lymphoblastic leukemia (relapse free survival (RFS) 94.6% vs. 70.3%). The risk to develop ALL relapse was 7.1-fold higher in the group of TIM-3 high expressing patients (n=37) compared to TIM-3 low expressing patients (n=37). Expression levels of known TIM-3 ligands and inducers in the bone marrow of the patients were analyzed by RNA next generation sequencing and compared between patients with high TIM-3 expression (n=12) and low TIM-3 expression (n=15) on BM T cells. Presence of known TIM-3 ligands HMGB1 (High-Mobility-Group-Protein B1) and Galectin-9 was confirmed, but expression levels did not show significant differences. Known TIM-3 inducers IL-2, -7, -15 and -21 were not expressed on RNA level indicating that another mechanism must be responsible for TIM-3 overexpression. In vitro experiments showed that the interaction with leukemic cells induces TIM-3 expression on the surface of T cells (mean TIM-3 expression 51.1% vs. 29.7% on T cells with vs. without addition of leukemic cells, n=3). To investigate the functional relevance of TIM-3 expression in pediatric leukemia, TIM-3 KO and overexpression was performed on primary T cells. TIM-3 KO T cells showed higher activation levels after co-culture with leukemic cell lines plus CD3-/CD19-specific BiTE compared to wildtype (WT) T cells (FC of CD69 surface expression 5.0 vs. 3.2, n=3). FC of anti-leukemic proliferation was impaired in TIM-3 overexpressing T cells compared to WT T cells (FC 1.6 vs. 2.3, n=3) whereas TIM-3 KO T cells showed a higher proliferation FC compared to controls (FC 6.5 vs. 2.4, n=3). Conclusions Our study identifies TIM-3 expression on CD4+ bone marrow T cells at initial diagnosis as a strong predictor for pediatric ALL relapse. TIM-3 expression is induced by interaction of T cells with leukemic cells and results in impaired anti-leukemic T-cell activation and proliferation. TIM-3-mediated T-cell inhibition represents a new mechanism of impaired immune surveillance in pediatric ALL and blockade of this axis may be of importance for future immunotherapy in ALL. Disclosures No relevant conflicts of interest to declare.

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