Identification of JAK1 Mutation In 40 Cases of Adult Acute T Lymphoblastic Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4652-4652
Author(s):  
Aining Sun ◽  
Wenjuan Wang ◽  
Guanghua Chen ◽  
Wu Depei ◽  
Suning Chen ◽  
...  

Abstract Abstract 4652 Objective This study was purposed to analyze the mutations of JAK1 in bone marrow cells from adult patients with newly-diagnosed T cell acute lymphoblastic leukemia (T-ALL). Methods The entire coding sequence of JAK1 in bone marrow mononuclear cells (MNCs) from 40 adult T cell ALL patients were screened by polymerase chain reaction (PCR) and direct sequencing, then the clinical features of JAK1 mutation positive patients were analyzed. Results JAK1 mutations were identified in 5%(2/40) patients, one is point mutation, the other is insertion mutation, resulting in changes in amino acid sequences, and the two types of mutations are different from those mutations found before. Conclusion The JAK1 mutations were found in about 5% newly-diagnosed T cell acute lymphoblastic leukemia, which was lower than those report abroad. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5197-5197
Author(s):  
Niroshaathevi Arumuggam ◽  
Nicole Melong ◽  
Catherine K.L. Too ◽  
Jason N. Berman ◽  
H.P. Vasantha Rupasinghe

Abstract T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignant disease that accounts for about 15% of pediatric and 25% of adult ALL. Although risk stratification has provided more tailored therapy and improved the overall survival of T-ALL patients, clinical challenges such as suboptimal drug responses, morbidity from drug toxicities, and drug resistance still exist. Plant polyphenols have therapeutic efficacy as pharmacological adjuvants to help overcome these challenges. They can be acylated with fatty acids to overcome issues concerning bioavailability, such as poor intestinal absorption and low metabolic stability. Phloridzin (PZ), a flavonoid found in apple peels, was acylated with an omega-3 fatty acid, docosahexaenoic acid (DHA), to generate a novel ester called phloridzin docosahexaenoate (PZ-DHA). The cytotoxic effect of PZ-DHA was studied in the human Jurkat T-ALL cell line. PZ-DHA significantly reduced the viability and cellular ATP levels of treated cells. PZ-DHA was found to selectively induce apoptosis in Jurkat cells, while sparing normal murine T-cells. Apoptosis was further confirmed by demonstrating the ability of PZ-DHA to induce morphological alterations, DNA fragmentation, caspase activation, and the release of intracellular lactate dehydrogenase. PZ-DHA also significantly inhibited cell division in Jurkat cells. Furthermore, interferon-α-induced phosphorylation of the transcription factor, STAT3, was downregulated following PZ-DHA treatment. The in vitro efficacy of PZ-DHA was recapitulated in vivo in an established zebrafish xenograft model, where the proliferation of transplanted Jurkat cells was inhibited when PZ-DHA was added to the embryo water. Overall, these findings provide evidence for PZ-DHA as a novel therapeutic agent with activity in T-ALL. Studies examining the effect of PZ-DHA on patient-derived ALL cells engrafted in zebrafish are currently underway. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2539-2539
Author(s):  
Min Wei ◽  
Jessica Blackburn

The tyrosine protein tyrosine phosphatase PTP4A3 has been extensively reported to play a causative role in numerous cancers, including several types of acute leukemia. We found PTP4A3 to be highly expressed in T-cell Acute Lymphoblastic Leukemia samples, and show that PTP4A3 accelerates T-ALL onset and increases the invasive ability of T-ALL cells in a zebrafish model, and is required for T-ALL engraftment and progression in mouse xenograft. Our in vitro studies showed that PTP43A3 enhances T-ALL migration, in part via modulation of SRC signaling. However, whether SRC is a direct substrate of PTP4A3, and whether the phosphatase activity of PTP4A3 actually plays a role in T-ALL or other types of leukemia progression is unknown and remains a major question in the field. We used a BioID-based proximity labeling approach combined with PTP4A3 substrate trapping mutant pull down assay to capture the PTP4A3 substrates candidates. BioID, a biotin ligase, was fused to PTP4A3 to generate a Biotin-PTP4A3 (BP) fusion protein. The overexpression of BP in T-ALL cell lines led to biotin modification of 288 PTP4A3 proximal proteins, including the potential direct PTP4A3 substrates. PANTHER pathway analysis showed that PTP4A3 interacting proteins are largely clustered in the T-cell activation, PDGF signaling, and angiogenesis. We are in process of validating potential substrates using immunoprecipitation and phosphoenrichement assays. Finally, we are using a novel zebrafish Myc+PTP4A3 induced T-ALL model to assess the function of PTP4A3 in leukemia progression. We have created several PTP4A3 protein mutants, including a phosphatase-dead mutant, a mutant unable to bind magnesium transporter, and a prenylation deficient mutant, and are in process of assessing the effects of these mutants in T-ALL onset and progression in our in vivo model. In total, these studies will allow us to better understand function of PTP4A3 in T-ALL progression, and may provide a strong rationale for the development of PTP4A3 inhibitors for use in leukemia. Disclosures No relevant conflicts of interest to declare.


2017 ◽  
Vol 1 (20) ◽  
pp. 1760-1772 ◽  
Author(s):  
Xavier Cahu ◽  
Julien Calvo ◽  
Sandrine Poglio ◽  
Nais Prade ◽  
Benoit Colsch ◽  
...  

Key Points BM niches differentially support T-ALL. BM niches differentially protect T-ALL cells from chemotherapy.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 470-470
Author(s):  
Ana Rita Fragoso ◽  
Tin Mao ◽  
Song Wang ◽  
Steven Schaffert ◽  
Hyeyoung Min ◽  
...  

Abstract Abstract 470 MiRNA-mediated gene regulation represents a fundamental layer of post-transcriptional control of gene expression with diverse functional roles in normal development and tumorigenesis. Whereas some studies have shown that over-expression of miRNA genes may contribute to cancer development and progression, it is yet to be rigorously tested by the loss-of-function genetic approaches whether miRNA genes are required for cancer development and maintenance in mice. Here we show that mir-181a1/b1 coordinates Notch and pre-TCR signals during normal thymocyte differentiation and plays an essential role in development and onset of T-cell acute lymphoblastic leukemia (T-ALL) induced by some Notch mutations. Using gain-of-function and loss-of-function approaches, we demonstrated that mir-181a1/b1 controls Notch and pre-TCR receptor signals during the early stages of T cell development in the thymus by repressing multiple negative regulators of both pathways, including Nrarp, PTPN-22, SHP2, DUSP5, and DUSP6. These results illustrate that a single miRNA can coordinate multiple signaling pathways by modulating the timing and strength of signaling at different stages. Intriguingly, synergistic signaling between Notch and pre-TCR pathways is necessary for the development of T-ALL, and miR-181 family miRNAs are aberrantly expressed in T-ALL patients. These observations raise the possibility that mir-181a1/b1 might contribute to the onset or maintenance of T-ALL by targeting similar pathways in tumor cells as it does in normal thymic progenitor cells. In support of this notion, we found that loss of mir-181a1/b1 significantly delayed the onset and development of T-ALL induced by intracellular domain of Notch1 (ICN1) and caused a 32% increase in the median survival time from 41 days to 54 days in T-ALL mice. Importantly, we noted that loss of mir-181a1/b1 more efficiently repressed the leukemogeneic potential of cells with lower levels of ICN1 expression, suggesting that mir-181a1/b1 may be more effective in inhibiting T-ALL development induced by a Notch mutant with weaker signal strength. Indeed, we demonstrated that loss of mir-181a1b1 essentially blocked T-ALL development induced by the weaker Notch mutant and dramatically decreased mortality from 60% to 10% in these T-ALL mice. Since human Notch mutations identified in T-ALL patients generally have weaker signaling strength and lower oncogenic potential than that of ICN1, our findings indicate that mir-181a1/b1 may play an essential role in development of normal thymic progenitors and Notch-induced T-ALL and may be targeted to treat T-ALL patients harboring Notch mutations. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5149-5149
Author(s):  
Elena N. Parovichnikova ◽  
Vera V. Troitskaya ◽  
Andrey N. Sokolov ◽  
Larisa A. Kuzmina ◽  
Sergey Bondarenko ◽  
...  

Abstract Introduction T-cell acute lymphoblastic leukemia (T-ALL) and lymphoma (T-LBL) originate from the common T-cell precursors and are formally differentiated by bone marrow blast count with less than 25% considered as T-LBL. ALL treatment protocols are successfully applied with quite similar long-term results in both entities. Dose intense chemotherapy is proposed to be the best option. RALL is conducting a prospective multicenter trial in the treatment of Ph-negative adult ALL patients based on the opposite approach - non-intensive but non-interruptive treatment (NCT01193933). T-LBL pts were included in the study.So we decided to define whether the difference in response rate and long-term results exists in T-ALL and T-LBL patients treated according to RALL-2009 protocol. Patients and Methods The therapy was unified for all Ph-negative ALL pts, but in T-cell ALL/LBL autologous hematopoietic stem cell transplantation (auto-HSCT) after non-myeloablative BEAM conditioning was scheduled as late intensification (+3-4 mo of CR) followed by prolonged 2 years maintenance. From Jan 2009, till Jul 2016, 30 centers enrolled 107 T-ALL/LBL pts. Median age was 28 years (15-54 y), 34 f / 73 m; early T-cell (TI/II) phenotype was verified in 56 (52.3%), mature (T-IV) - in 10 (9.4%), thymic (TIII, CD1a+) ALL - in 41 pts (38.3%). T-lymphoblastic lymphoma (T-LBL= <25% b/m blasts) was diagnosed in 22 pts (20,5%). We divided the analyzed population into 3 groups: < 5% b/m blasts, with 5-24%, ≥25%. Pts' characteristics according to the b/m involvement are depicted in Table 1. Autologous HSCT was performed in 35, allogeneic-in 7 pts. The analysis was performed in July 2016. Results As it's shown in Table 1 the patients with T-LBL disregarding the % of blasts cells (<5% or 5-24%) have much less initial WBC and LDH levels, more frequent mediastinum involvement, less frequent CNS disease in comparison with T-ALL patients. There were no patients with pro-T-subtype (T1) T-LBL comparing with 42% of patients with pro-T-ALL. Mature T-subtype was slightly more frequent (4/22 vs 6/85) (p=0,1) in T-LBL. Total CR rate in 97 available for analysis patients was 87,6% (n=85), induction death was registered in 5,1% (n=5), resistance-in 7,2% (n=7). All induction deaths occurred in T-ALL patients, resistant cases were registered much more frequently (p=0,01) in T-LBL with less than 5% of blast cells than in T-ALL (3/10 vs 4/85). Only 35 of 85 (41,2%) CR pts underwent autologous HSCT due to logistics problems and refusals. Auto-HSCT was done at a median time of 6 mo from CR and pts proceeded to further maintenance. We compared 5-y disease-free survival (DFS) and probability of relapse (RP) in transplanted pts and those who survived in CR ≥ 6 months (land-mark) receiving only chemotherapy. This analysis was carried out in 2 cohorts of patients: T-LBL (<5%; 5-24%) and T-ALL (≥25%). Land-mark analysis demonstrated the essential benefit of auto-HSCT only for T-ALL patients: DFS from time of transplantation was 95% and from land-mark for chemotherapy group - 61% (p=0,005), RP-5% vs 30% (p=0,02). But in T-LBL pts there were no benefit of autologous HSCT over chemotherapy (DFS -100% vs 86%, RP-0% vs 14%, p=0,3). At 5 years overall survival (OS) for the whole T-ALL/T-LBL group constituted-66%, DFS-76%. There were no differences in OS (77% vs 66%, p=0,8) and in DFS (87% vs 74%, p=0,7) in T-LBL and T-ALL. Conclusions Our data demonstrate that non-intensive, but non-interruptive treatment approach is effective as in T-ALL so in T-LBL. T-LBL patients had no induction mortality but more frequently were reported as having resistant disease on RALL-2009 protocol. Auto-HSCT after BEAM conditioning followed by maintenance provided substantial benefit only for patients with T-ALL, but not T-LBL. Table 1 Clinical characteristics and treatment outcome in T-ALL and T-LBL patients Table 1. Clinical characteristics and treatment outcome in T-ALL and T-LBL patients Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 439-439
Author(s):  
Yali Ding ◽  
Chunhua Song ◽  
Chandrika S. Gowda ◽  
Malika Kapadia ◽  
Kimberly Payne ◽  
...  

Abstract LIM domain only protein 2 (LMO2) is a regulator of hematopoiesis and an oncogene that is overexpressed in a subset of T-cell acute lymphoblastic leukemia (T-ALL). Overexpression of LMO2 in T-ALL is associated with a poor prognosis. The mechanisms that regulate LMO2 expression in T-ALL are still unknown. Here, we present evidence that expression of LMO2 in T-ALL is regulated at the transcriptional level by Ikaros, a tumor suppressor protein whose deletion is associated with the development T-ALL. Global chromatin immunoprecipitation coupled with next-generation sequencing (ChIP-seq) studies in primary human acute lymphoblastic leukemia cells and in cell lines demonstrated Ikaros occupancy of the LMO2 promoter. Ikaros binding at the LMO2 promoter was confirmed by quantitative chromatin immunoprecipitation (qChIP) in primary T-ALL and B-ALL cells. The role of Ikaros in the regulation of LMO2 transcription in T-ALL was tested using gain-of-function and loss-of-function experiments. Ikaros knock-down with siRNA resulted in increased transcription of LMO2 in T-ALL. Overexpression of Ikaros in human T-ALL was associated with strongly reduced transcription of LMO2. In mice, T-ALL cells that are derived from Ikaros-knockout mice express high levels of LMO2. Transduction of these cells with Ikaros-containing retrovirus, results in a sharp reduction of LMO2 expression. Since Ikaros function in T-ALL is negatively regulated by the pro-oncogenic Casein Kinase II (CK2), we tested whether CK2 inhibition can enhance Ikaros-mediated transcriptional repression of LMO2. Molecular inhibition of CK2 using shRNA, as well as pharmacological inhibition with a specific CK2 inhibitor, resulted in reduced expression of LMO2 in primary human T-ALL. Inhibition of CK2 was associated with increased Ikaros binding at the LMO2 promoter. Ikaros knock-down restored high expression of LMO2 in T-ALL cells that were treated with CK2 inhibitors. These data show that Ikaros is a major regulator of LMO2 transcription in T-ALL and that CK2 inhibition requires Ikaros activity to repress LMO2 transcription. Increased Ikaros binding was associated with reduced histone H3K9ac and H3K4me3 marks at the LMO2 promoter suggesting that Ikaros regulates LMO2 transcription via chromatin remodeling. In conclusion, these results provide evidence that expression of the LMO2 oncogene is regulated by Ikaros and CK2 in T-ALL. Targeting CK2 with specific inhibitors has been used as a therapeutic strategy in a preclinical model of T-ALL. The presented data reveal a novel mechanism of therapeutic action for CK2 inhibitors - repression of LMO2 expression via Ikaros. These results provide a rationale for the use of CK2 inhibitors in T-ALL with LMO2 overexpression. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2752-2752
Author(s):  
Kinjal Shah ◽  
Julhash U. Kazi

Background: Acute lymphoblastic leukemia (ALL) is the most frequent pediatric malignancy, of which T- cell acute lymphoblastic leukemia (T-ALL) constitutes an aggressive subset. Due to the advent of new therapies, T-ALL now has a 5-year event-free survival (EFS) rate exceeding 85%. However, some patients still relapse and display resistance to therapy. Moreover, adverse side-effects of intensive chemotherapy worsen the duration of treatment. Therefore, we still need to improve our current treatment beyond that of the chemotherapeutic approaches. It has been shown that the maturation stage of T-ALL decides its dependency on Bcl-2/Bcl-xL. The immature early T cell progenitor ALL (ETP-ALL) rely on Bcl-2 for their survival while all the other stages of T-ALL and primary patient samples depend on Bcl-xL. Bcl-2 inhibitors have thus shown to display promising antitumor activity against ETP-ALL, a subgroup with a high risk of relapse, but with a variable response across these patients. Therefore, there is a need for predictive biomarkers and further investigation towards finding a combination of drugs for the treatment of these patients. Methodology & Aim: We screened 10 different T-ALL cell lines with a combination of Bcl-2 inhibitor and a panel of 378 protein kinase inhibitors and identified polo-like kinase inhibitor as a promising candidate. We thus aimed to study the combined effect of Bcl-2 and PLK1 inhibition in a panel of T-ALL cell lines and in a PDX model of chemo-resistant childhood T-ALL. We also investigated the underlying mechanism of drug synergy by various biochemical assays. Results: Cell viability of 14 T-ALL cell lines was determined after being subjected to Bcl-2 inhibitor (ABT-199) and PLK1 inhibitor (BI-6727). All cell lines responded well to BI6727 with an EC50 of less than 70nM. However, they showed differential response to ABT199 with only 3 cell lines being sensitive with an EC50 of less than 40nM. The mRNA levels of Bcl-2, Bcl-xL and PLK 1, 2, 3 and 4 were determined by qRT-PCR. PLK1 was found to be highly expressed in all the cell lines as compared to the rest of the 3 PLK family proteins. ABT-199-sensitive cell lines showed lower Bcl-xL mRNA levels irrespective of their Bcl-2 expression, and displayed synergy with BI-6727. A higher degree of apoptosis was also observed in the combination treatment as compared to a single drug. Immunoblot analysis revealed cleavage of PARP1 and lower levels of c-Myc and MCL1 expression in the presence of both ABT-199 and BI-6727. Conclusions: Upregulation of the anti-apoptotic BCL2 family members is one of the canonical ways for cancer cells to escape apoptosis. In the past years, several highly selective and potent BCL2 inhibitors have been developed and showed promising efficacy in various cancers. We found that the sensitivity of T-ALL cell lines to ABT-199 is largely determined by the lower levels of Bcl-xL expression. Furthermore, ABT-199 displays synergy with the PLK inhibitor. T-ALL cell lines predominantly express PLK1 and thus the combinatorial effect of ABT-199 and BI-6727 is mediated through the pharmacological inhibition of both BCL2 and PLK1. Currently, we are generating iRFP-expressing T-ALL cell lines which will be used to check drug efficacy in vivo. Furthermore, we have collected chemo-resistant PDX cell lines which will be used to verify the cell line data. Besides its role in cell cycle control, we still have very limited knowledge about the function of PLK1 in leukemia. Thus, studying its role in T-ALL cell lines by knocking down PLK1 with CRISPR/Cas9 technology will provide an important insight. Disclosures No relevant conflicts of interest to declare.


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