pubmed > ABL1 > b-all

IL-10 as an Indicator for Predicting Clinical Progression in Acute Lymphoblastic Leukemia Patients.
The aim of this research was to estimate the expression of interleukin-10 in acute lymphoblastic leukemia (ALL) patients before and after chemotherapy in order to evaluate its role as a marker of disease progression. Flow cytometry was used to detect the serum IL-10 levels in ALL patients before and during chemotherapy. Patients were divided into either complete remission (CR) group and non-remission (NR) group, before chemotherapy group and during chemotherapy group, B-ALL group and T-ALL group, WT-1 positive group and BCR-ABL1 positive group. The changes in serum IL-10 concentration before and during the chemotherapy were analyzed. IL-10 serum levels were significantly elevated in ALL patients at the onset of disease, and it was also more elevated in the NR group compared to the CR group. There is a significant reduction in IL-10 serum levels in ALL patients after effective chemotherapy. There was no significant difference between the before chemotherapy group and during chemotherapy group. Regardless of chemotherapy, the IL-10 levels of patients whose bone marrow achieved complete remission were lower than the patients who have not (p < 0.05). The same result can be seen in B or T-ALL groups. There was no significant difference in IL-10 serum levels between the group with WT-1(+) or BCR-ABL1(+) and the group with WT-1(-) or BCR-ABL1(-) (p > 0.05). In some ALL patients, increased IL-10 concentrations may be correlated to the number of peripheral blood leukemic cells. The increase of serum IL-10 level may be a possible marker of disease progression in ALL.
Publication Date: 2021-10-17
Journal: Clinical laboratory

IKZF1 alterations are not associated with outcome in 498 adults with B-precursor ALL enrolled in the UKALL14 trial.
IKZF1 deletions (ΔIKZF1) are commonly detected in B-precursor acute lymphoblastic leukemia (ALL; B-ALL) and are widely assumed to have a significant impact on outcome. We compared the ability of multiplex ligand-dependent probe amplification (MLPA) and polymerase chain reaction (PCR) to detect ΔIKZF1 and to determine the impact on event-free survival of patients with precursor B-ALL aged 23 to 65 years recruited to the completed trial UKALL14 (ISRCTN 66541317). From 655 recruits with BCR-ABL1+ and BCR-ABL1- B-ALL, all available diagnostic DNA samples (76% of the recruited population) were screened by multiplex end point PCR covering 4 deletions: dominant-negative (DN) Δ4-7 or the loss of function Δ2-7, Δ4-8, and Δ2-8 (n = 498), MLPA (n = 436), or by both (n = 420). Although patients with BCR-ABL1- ΔIKZF1 were more likely to have minimal residual disease at the end of induction, we did not find any impact of ΔIKZF1 (including subgroup analysis for DN or loss-of-function lesions) or the IKZF1plus genotype on event-free, overall survival, or relapse risk by univariable or multivariable analyses. Consistent with the technical approach, MLPA not only detected a wider range of deletions than PCR but also failed to detect some PCR-detected lesions. The main difference between our study and others reporting an association between ΔIKZF1 and outcome is the older age of participants in our population. The impact of ΔIKZF1 in ALL may be less marked in an older population of patients. Our study underscores the need for analyses in large, harmonized data sets. This trial was registered at www.clinicaltrials.gov as #NCT01085617.
Publication Date: 2021-09-04
Journal: Blood advances

Proposal and clinical application of molecular genetic risk scoring system, "MRplus", for BCR-ABL1 negative pediatric B-cell acute lymphoblastic leukemia- report from a single centre.
We propose "MRplus", a molecular genetic risk score and check its clinical application in the risk-stratification of pediatric B-ALL. The genomic DNA of untreated pediatricBCR-ABL1 negative B-ALL patients was analyzed for deletions of IKZF1, PAX5, CDKN2A/B, BTG1, RB1, ETV6, EBF1, ERG, pseudoautosomal region(PAR) genes using multiplex ligation-dependent probe amplification, along with the routine genetic work-up. The patients were assigned an 'M'score- 0 (M0) for low and 1 (M1) for high genetic-risk as per the criteria by Moorman et al., and another score "IKplus"-1 (IKplus1) for IKZF1plus as per the criteria by Stanulla et al., and 0 (IKplus0) for other patients. The final "MRplus" risk-score of 0 (MRplus0), 1 (MRplus1) or 2 (MRplus2) was obtained by adding both these scores. The association of risk scores with overall survival (OS) and event free survival(EFS) was seen using Cox proportion hazard model. The overall goodness of fit of the model was done using Cox-Snell residuals. The median age of 320 patients was 6 years (1-18 years). The patients with score M1 were 139 (43.4 %), M0-181 (56.6 %); IKplus1-32 (10 %) and IKplus0-288 (90 %). The final "MRplus" score of 0,1,or 2 was obtained in 181(56.6 %), 107(33.4 %) and 32(10 %) patients respectively. The post-induction remission rate was 90.7 %, 77.8 %, 73.9 % (p = 0.004); 4-year OS 67 %, 48 %, 27 % (p < 0.001); and 4-year EFS 56 %, 34 %, 19 %(p < 0.001) in patients with "MRplus" score 0,1,and 2 respectively. The proposed "MRplus" scoring at baseline could identify three distinct risk groups-good (MRplus0), intermediate (MRplus1) and poor (MRplus2), with different outcomes; in pediatricBCR-ABL1 negative B-ALL. This may help in better risk-stratification and selection of patients for alternative treatment approaches.
Publication Date: 2021-08-10
Journal: Leukemia research

From the archives of MD Anderson Cancer Center: Concurrent BCR-ABL1 and CRLF2 rearrangements in B-lymphoblast phase of chronic myeloid leukemia.
The t(9;22)(q34;q11.2), also known as the Philadelphia (Ph) chromosome, results in BCR-ABL1 fusion residing on the derivative chromosome 22. This translocation is characteristic of chronic myeloid leukemia, but also can occur in a substantial subset of B acute lymphoblastic leukemia (B-ALL) cases. Ph-like B-ALL has a gene expression profile similar to that of BCR-ABL1 positive/Ph-positive B-ALL, but by definition Ph-like B-ALL does not have the sentinel BCR-ABL1 or the Ph chromosome. About half of Ph-like B-ALL cases carry CRLF2 rearrangements. Rare cases of de novo B-ALL with co-occurrence of BCR-ABL1 and CRLF2 rearrangements have been described. To our knowledge, this is the first report of concurrent BCR-ABL1 and CRLF2 rearrangements in blast phase of chronic myeloid leukemia. In this patient, CRLF2 rearrangement was acquired at the time of disease progression to B-lymphoblast phase of chronic myeloid leukemia. We also review the literature and discuss the distinct clinicopathologic, and genomic characteristics of CRLF2 rearranged B-ALL.
Publication Date: 2021-06-13
Journal: Annals of diagnostic pathology

Systematic application of fluorescence in situ hybridization and immunophenotype profile for the identification of ZNF384 gene rearrangements in B cell acute lymphoblastic leukemia.
ZNF384 gene fusions resulting from translocations with several partner genes have been described in B cell acute lymphoblastic leukemia (B-ALL) with a characteristic immunophenotype (aberrant CD13 and or CD33 with dim CD10). The prognosis of patients with this rearrangement appears to depend on the fusion partner. ZNF384 rearrangements have been identified by high through put technologies such as RNA sequencing in most of the studies published. We tested the feasibility of using the characteristic immunophenotype as a tool to screen for patients with ZNF384 translocations which can be subsequently confirmed by cytogenetic / molecular methodologies. ZNF384 rearrangements in B-ALL patients at diagnosis with CD10 <80% and were negative for the BCR-ABL1 fusion (n = 109) were identified by fluorescence in situ hybridization followed by confirmation by reverse transcriptase-polymerase chain reaction and Sanger sequencing. The end of induction measurable residual disease evaluated by flow cytometry for these patients was obtained from patient records. ZNF384 translocations were identified in 14 patients and were cytogenetically cryptic in 13. EP300-ZNF384 was the most common fusion partner (n = 12), while TAF15-ZNF384 and TCF3-ZNF384 were identified in 1 patient each. End of induction MRD by flow cytometry was positive in 5 of 8 patients with the EP300-ZNF384 fusion treated at our center. Our findings show a practical approach for the identification of ZNF384 gene rearrangements by widely available technologies and indicate that the response to therapy may be heterogeneous even in this subset, which has been reported as having a favorable prognosis.
Publication Date: 2021-05-15
Journal: International journal of laboratory hematology

IKZF1 Deletion Subtyping and Outcome Analysis in BCR-ABL1-Negative Pediatric B-Cell Acute Lymphoblastic Leukemia: A Single-Institution Experience from North India.
IKZF1 deletions are associated with adverse outcomes in B-cell acute lymphoblastic leukemia (B-ALL). We assessed the prevalence and clinical impact of functional subtypes of IKZF1 deletions in pediatric BCR-ABL1-negative B-ALL. This retrospective study of IKZF1 deletions was done in cases of pediatric BCR-ABL1-negative B-ALL. The genomic DNA of cases, over a 53-month period, was analyzed using multiplex ligation-dependent probe amplification and multiplex fluorescent polymerase chain reaction. The deletions were divided into functional subgroups: (1) loss-of-function/haploinsufficiency, (2) dominant-negative, and (3) a combination of both types of deletion. The post-induction remission status, event-free survival (EFS), and overall survival (OS) were noted. Out of 320 cases, 47 (14.7%) had IKZF1 deletions. Thirty-six of the 47 (77%) had loss-of-function deletions, 10 (21%) had dominant-negative deletions, and one (2%) had a combination of both types. The post-induction remission rates in cases with loss-of-function deletions (22/30, 73%; P = .060) and dominant-negative deletions (4/5, 80%; P = .517) were lower compared with those without deletions (215/248, 86.7%). These cases also had worse median EFS: 21.1 months (P = .006) for loss-of-function and 15.4 months (P = .156) for dominant-negative deletions, compared with 46.4 months in cases without IKZF1 deletions. They also had worse median OS: 23.4 months (P = .012) for loss-of-function deletions and 15.7 months (P = .233) for dominant-negative deletions, compared with median not reached in cases without IKZF1 deletions. The IKZF1 deletions were seen in 14.7% of BCR-ABL1-negative pediatric B-ALL. Most of these deletions (77%) were loss-of-function type. The cases with loss-of-function deletions had lower remission rates and poor EFS and OS compared with cases without IKZF1 deletions. A similar trend of poor outcome was seen in the few cases with dominant-negative IKZF1 deletions.
Publication Date: 2021-04-29
Journal: Clinical lymphoma, myeloma & leukemia

Molecular classification improves risk assessment in adult BCR-ABL1-negative B-ALL.
Genomic classification has improved risk assignment of pediatric, but not adult B-lineage acute lymphoblastic leukemia (B-ALL). The international UKALLXII/ECOG-ACRIN E2993 (#NCT00002514) trial accrued 1229 adolescent/adult patients with BCR-ABL1- B-ALL (aged 14 to 65 years). Although 93% of patients achieved remission, 41% relapsed at a median of 13 months (range, 28 days to 12 years). Five-year overall survival (OS) was 42% (95% confidence interval, 39, 44). Transcriptome sequencing, gene expression profiling, cytogenetics, and fusion polymerase chain reaction enabled genomic subtyping of 282 patient samples, of which 264 were eligible for trial, accounting for 64.5% of E2993 patients. Among patients with outcome data, 29.5% with favorable outcomes (5-year OS 65% to 80%) were deemed standard risk (DUX4-rearranged [9.2%], ETV6-RUNX1/-like [2.3%], TCF3-PBX1 [6.9%], PAX5 P80R [4.1%], high-hyperdiploid [6.9%]); 50.2% had high-risk genotypes with 5-year OS of 0% to 27% (Ph-like [21.2%], KMT2A-AFF1 [12%], low-hypodiploid/near-haploid [14.3%], BCL2/MYC-rearranged [2.8%]); 20.3% had intermediate-risk genotypes with 5-year OS of 33% to 45% (PAX5alt [12.4%], ZNF384/-like [5.1%], MEF2D-rearranged [2.8%]). IKZF1 alterations occurred in 86% of Ph-like, and TP53 mutations in patients who were low-hypodiploid (54%) and BCL2/MYC-rearranged (33%) but were not independently associated with outcome. Of patients considered high risk based on presenting age and white blood cell count, 40% harbored subtype-defining genetic alterations associated with standard- or intermediate-risk outcomes. We identified distinct immunophenotypic features for DUX4-rearranged, PAX5 P80R, ZNF384-R/-like, and Ph-like genotypes. These data in a large adult B-ALL cohort treated with a non-risk-adapted approach on a single trial show the prognostic importance of genomic analyses, which may translate into future therapeutic benefits.
Publication Date: 2021-04-26
Journal: Blood

CRLF2 and IKZF1 abnormalities in Mexican children with acute lymphoblastic leukemia and recurrent gene fusions: exploring surrogate markers of signaling pathways.
The gene fusions BCR-ABL1, TCF3-PBX1, and ETV6-RUNX1 are recurrent in B-cell acute lymphoblastic leukemia (B-ALL) and are found with low frequency in coexistence with CRLF2 (cytokine receptor-like factor 2) rearrangements and overexpression. There is limited information regarding the CRLF2 abnormalities and dominant-negative IKZF1 isoforms associated with surrogate markers of Jak2, ABL, and Ras signaling pathways. To assess this, we evaluated 24 Mexican children with B-ALL positive for recurrent gene fusions at diagnosis. We found CRLF2 rearrangements and/or overexpression, dominant-negative IKZF1 isoforms, and surrogate phosphorylated markers of signaling pathways coexisting with recurrent gene fusions. All the BCR-ABL1 patients expressed CRLF2 and were positive for pCrkl (ABL); most of them were also positive for pStat5 (Jak2/Stat5) and negative for pErk (Ras). TCF3-PBX1 patients with CRLF2 abnormalities were positive for pStat5, most of them were also positive for pCrkl, and two patients were also positive for pErk. One patient with ETV6-RUNX1 and intracellular CRLF2 protein expressed pCrkl. In some cases, the activated signaling pathways were reverted in vitro by specific inhibitors. We further analyzed a TCF3-PBX1 patient at relapse, identifying a clone with the recurrent gene fusion, P2RY8-CRLF2, rearrangement, and phosphorylation of the three surrogate markers that we studied. These results agree with the previous reports regarding resistance to treatment observed in patients with recurrent gene fusions and coexisting CRLF2 gene abnormalities. A marker phosphorylation signature was identified in BCR-ABL1 and TCF3-PBX1 patients. To obtain useful information for the assessment of treatment in B-ALL patients with recurrent gene fusions, we suggest that they should be evaluated at diagnosis for CRLF2 gene abnormalities and dominant-negative IKZF1 isoforms, in addition to the analyses of activation and inhibition of signaling pathways.
Publication Date: 2021-04-24
Journal: The journal of pathology. Clinical research

Low incidence of ABL-class and JAK-STAT signaling pathway alterations in uniformly treated pediatric and adult B-cell acute lymphoblastic leukemia patients using MRD risk-directed approach - a population-based study.
ABL-class and JAK-STAT signaling pathway activating alterations have been associated with both a poor post-induction minimal residual disease (MRD) response and an inferior outcome in B-cell acute lymphoblastic leukemia (B-ALL). However, in most of the studies patients received non-uniform treatment. We performed a population-based analysis of 160 (122 pediatric and 38 adult) Lithuanian BCR-ABL1-negative B-ALL patients who had been uniformly treated according to MRD-directed NOPHO ALL-2008 protocol. Targeted RNA sequencing and FISH analysis were performed in cases without canonical B-ALL genomic alterations (high hyperdiploids and low hypodiploids included). We identified ABL-class fusions in 3/160 (1.9%) B-ALL patients, and exclusively in adults (p = 0.003). JAK-STAT pathway fusions were present in 4/160 (2.5%) cases. Of note, P2RY8-CRLF2 fusion was absent in both pediatric and adult B-ALL cases. Patients with ABL-class or JAK-STAT pathway fusions had a poor MRD response and were assigned to the higher risk groups, and had an inferior event-free survival (EFS) / overall survival (OS) compared to patients without these fusions. In a multivariate analysis, positivity for ABL-class and JAK-STAT fusions was a risk factor for worse EFS (p = 0.046) but not for OS (p = 0.278) in adults. We report a low overall frequency of ABL-class and JAK-STAT fusions and the absence of P2RY8-CRLF2 gene fusion in the Lithuanian BCR-ABL1 negative B-ALL cohort. Future (larger) studies are warranted to confirm an inferior event-free survival of ABL-class/JAK-STAT fusion-positive adult patients in MRD-directed protocols.
Publication Date: 2021-03-31
Journal: BMC cancer

Prognostic factors for CNS control in children with acute lymphoblastic leukemia treated without cranial irradiation.
To identify the prognostic factors that are useful to improve central nervous system (CNS) control in children with acute lymphoblastic leukemia (ALL), we analyzed the outcome of 7640 consecutive patients treated on Chinese Children's Cancer Group ALL-2015 protocol between 2015 and 2019. This protocol featured prephase dexamethasone treatment before conventional remission induction and subsequent risk-directed therapy, including 16 to 22 triple intrathecal treatments, without prophylactic cranial irradiation. The 5-year event-free survival was 80.3% (95% confidence interval [CI], 78.9-81.7), and overall survival 91.1% (95% CI, 90.1-92.1). The cumulative risk of isolated CNS relapse was 1.9% (95% CI, 1.5-2.3), and any CNS relapse 2.7% (95% CI, 2.2-3.2). The isolated CNS relapse rate was significantly lower in patients with B-cell ALL (B-ALL) than in those with T-cell ALL (T-ALL) (1.6%; 95% CI, 1.2-2.0 vs 4.6%; 95% CI, 2.9-6.3; P < .001). Independent risk factors for isolated CNS relapse included male sex (hazard ratio [HR], 1.8; 95% CI, 1.1-3.0; P = .03), the presence of BCR-ABL1 fusion (HR, 3.8; 95% CI, 2.0-7.3; P < .001) in B-ALL, and presenting leukocyte count ≥50×109/L (HR, 4.3; 95% CI, 1.5-12.2; P = .007) in T-ALL. Significantly lower isolated CNS relapse was associated with the use of total intravenous anesthesia during intrathecal therapy (HR, 0.2; 95% CI, 0.04-0.7; P = .02) and flow cytometry examination of diagnostic cerebrospinal fluid (CSF) (HR, 0.2; 95% CI, 0.06-0.6; P = .006) among patients with B-ALL. Prephase dexamethasone treatment, delayed intrathecal therapy, use of total intravenous anesthesia during intrathecal therapy, and flow cytometry examination of diagnostic CSF may improve CNS control in childhood ALL. This trial was registered with the Chinese Clinical Trial Registry (ChiCTR-IPR-14005706).
Publication Date: 2021-03-09
Journal: Blood

Precursor B-lineage acute lymphoblastic leukemia patients with aberrant natural killer cell and T cell - lineage antigen expression: experience from a tertiary cancer care center.
Flow cytometric immunophenotyping (FCI) plays a major role in diagnosing hematologic malignancies. In patients diagnosed with precursor B-lineage acute lymphoblastic leukemia (B-ALL), expression of certain non-lineage/cross lineage antigens is of prognostic and cytogenetic relevance. There is a paucity of studies that have comprehensively analyzed the clinical and laboratory profiles of B-ALL patients showing aberrant T/natural killer (NK) cell antigen expression. This is a prospective study where 152 consecutive B-ALL patients were analyzed for aberrant expression of T/NK cell antigens (CD1a, CD5, CD4, CD7, CD8 and CD56) by FCI. The clinical and laboratory profile of these T/NK-cell antigen-expressing B-ALL patients was statistically analyzed against conventional B-ALL patients. In our B-ALL cohort, CD5, CD7 and CD56 expression were observed in one, six and nine patients, respectively. CD56-expressing B-ALL patients were predominantly children (89%) and presented as standard clinical risk (p=0.010) disease with frequent ETV6-RUNX1 fusion (p=0.021) positivity. On the contrary, CD7-expressing B-ALL patients were adolescent-young adult/adult-age skewed (83%) and had an adverse cytogenetic profile (p=0.001), especially for the frequent presence of BCR-ABL1 fusion (p=0.004) and KMT2A rearrangement (p=0.045). CD7-expressing B-ALL patients had inferior event-free survival (p=0.040) than their CD56-expressing counterparts, but there was no significant difference in the overall survival (p=0.317). In comparison to conventional B-ALL patients, there are significant differences in the age, cytogenetic profile and event-free survival of T/NK-cell antigen-expressing B-ALL patients.
Publication Date: 2021-02-03
Journal: Hematology, transfusion and cell therapy

[Detection of activating mutations in RAS/RAF/MEK/ERK and JAK/STAT signaling pathways].
The study of activating mutations (NRAS,KRAS,FLT3,JAK2,CRLF2genes) of RAS/RAF/MEK/ERK and JAK/STAT signaling pathways in B-cell acute lymphoblastic leukemia (B-ALL) in adult patients which are included in Russian multicenter clinical trials. Within the multicenter study there were 119 adult patients included withde novoB-ALL. The study was considered as prospective and retrospective. The group withBCR-ABL1-negative B-ALL consisted of up to 93 patients (45 male and 48 female, at the age of 17 to 59, the median age 31), they were treated according to the protocols ALL-2009, ALL-2016. The median follow-up lasted for 19 months (1119). The group withBCR-ABL1-positive B-ALL with up to 26 patients (10 male and 16 female, at the age of 23 to 78, the median age 34 years) was included in the study as well. The treatment was carried out according to the protocols ALL-2009 and ALL-2012 in combination with tyrosine kinase inhibitors. The median follow-up lasted for 23 months (4120). The molecular analysis of activating mutations inNRAS,KRASgenes (RAS/RAF/MEK/ERK signaling pathway) andJAK2,CRLF2genes (JAK/STAT signaling cascade) was performed via Sanger sequencing. The internal tandem duplications (ITDs) inFLT3gene were studied by fragment analysis. The evaluation of CRLF2 expression was fulfilled via flow cytometry. Activating mutations inNRAS,KRAS,FLT3genes were found in 22 (23.6%) patients withBCR-ABL1-negative B-ALL. In total, 23 mutations were revealed in theNRAS(n=9),KRAS(n=12), andFLT3(n=2) genes, according to statistics that was significantly more frequent than withBCR-ABL1-positive B-ALL, these genes mutations were not identified in patients (p=0.007). The frequency of mutations detection inKRASandNRASgenes in patients withBCR-ABL1-negative B-ALL was comparable as 12.9% (12 of 93) to 9.7% (9 of 93), respectively (p=0.488). One patient was simultaneously revealed 2 mutations in theKRASgene (in codons 13 and 61).FLT3-ITD mutations were detected in 3.5% (2 of 57) cases ofBCR-ABL1-negative B-ALL. In patients withBCR-ABL1-positive B-ALLFLT3-ITD mutations were not assessed. Violations in the JAK/STAT signaling cascade were detected in 4 (4.3%) patients withBCR-ABL1-negative B-ALL. They were represented by the missense mutations ofJAK2gene (n=3) and the overexpression of CRLF2 (n=2); in one patient were detected the overexpression of CRLF2 and a mutation inJAK2gene simultaneously. No mutations were found inCRLF2gene. In patients withBCR-ABL1-positive B-ALL noJAK2mutations were detected. As long as analyzing demographic and clinical laboratory parameters between groups of patients with and without mutations, there were no statistically significant differences obtained. In the analyzed groups of patients, long-term therapy results did not differentiate according to the mutations presence inNRAS,KRAS,FLT3,JAK2genes. Also, substantive differences were not shown in the rate of the negative status achievement of the minimum residual disease between patients with and without activating mutations in the control points of the protocol (on the 70th, 133rd and 190th days). NRAS,KRAS,FLT3,JAK2activating mutations do not affect the long-term results of the therapy and the rate of the negative status achievement of the minimum residual disease in patients withBCR-ABL1-negative B-ALL treated by the Russian multicenter clinical trials. Цель.Изучение активирующих мутаций генов (NRAS,KRAS,FLT3,JAK2,CRLF2) сигнальных каскадов RAS/RAF/MEK/ERK и JAK/STAT при В-клеточном остром лимфобластном лейкозе (В-ОЛЛ) у взрослых больных, включенных в российские многоцентровые исследования. Материалы и методы.В многоцентровое исследование включены 119 взрослых пациентов с впервые установленным В-ОЛЛ. Исследование носило проспективный и ретроспективный характер. Группа сBCR-ABL1-негативным В-ОЛЛ составила 93 больных (48 женщин и 45 мужчин от 17 до 59 лет, медиана возраста 31 год), им проводили терапию по протоколам ОЛЛ-2009, ОЛЛ-2016. Медиана наблюдения составила 19 мес (1119). В группу сBCR-ABL1-позитивным В-ОЛЛ включены 26 пациентов (16 женщин и 10 мужчин от 23 до 78 лет, медиана возраста 34 года). Лечение проводили по протоколам ОЛЛ-2009 и ОЛЛ-2012 в сочетании с ингибиторами тирозинкиназ. Медиана наблюдения составила 23 мес (4120). Молекулярный анализ активирующих мутаций для геновNRAS,KRAS(сигнальный путь RAS/RAF/MEK/ERK) и геновJAK2,CRLF2(сигнальный путь JAK/STAT) проводился методом секвенирования по Сэнгеру. Внутренние тандемные повторы (ITD) генаFLT3 рецепторной внутриклеточной тирозинкиназы, приводящие к запуску целого каскада реакций, относящихся к различным сигнальным путям, включая RAS/RAF/MEK/ERK и JAK/STAT, исследованы методом фрагментного анализа. Экспрессию белка CRLF2 оценивали методом проточной цитофлуориметрии. Результаты.Активирующие мутации в генахNRAS,KRAS,FLT3обнаружены у 22 (23,6%) больныхBCR-ABL1-негативным В-ОЛЛ. В общей сложности выявлено 23 мутации в генахNRAS(n=9),KRAS(n=12),FLT3(n=2), что статистически значимо чаще, чем приBCR-ABL1-позитивном В-ОЛЛ, где мутации этих генов не выявлены ни у одного больного (р=0,007). Частота обнаружения мутаций в генахKRASиNRASу больныхBCR-ABL1-негативным В-ОЛЛ сопоставима 12,9% (12 из 93) и 9,7% (9 из 93) соответственно (р=0,488). У одного больного выявлено одновременно 2 мутации в генеKRAS(в кодонах 13 и 61). МутациюFLT3-ITD детектировали в 3,5% (2 из 57) случаевBCR-ABL1-негативных В-ОЛЛ. У больныхBCR-ABL1-позитивным В-ОЛЛ мутациюFLT3-ITD не оценивали. Нарушения в сигнальном каскаде JAK/STAT обнаружены у 4 (4,3%) больныхBCR-ABL1-негативным В-ОЛЛ. Они представлены миссенс-мутациями генаJAK2(n=3) и гиперэкспрессией CRLF2 (n=2), у одного больного обнаружены одновременно гиперэкспрессия CRLF2 и мутация в генеJAK2. В генеCRLF2мутации не выявлены. У больныхBCR-ABL1-позитивным В-ОЛЛ мутаций генаJAK2не выявлено. При анализе демографических и клинико-лабораторных показателей между группами больных с мутациями и без таковых статистически значимых различий не получено. В анализируемых группах больных долгосрочные результаты терапии в зависимости от наличия мутаций в генахNRAS,KRAS,FLT3,JAK2не различались. Также не показано значимых отличий в скорости достижения негативного статуса минимальной остаточной болезни между пациентами с активирующими мутациями и без в контрольные сроки протокола (на 70, 133 и 190-й день). Заключение.Активирующие мутации геновNRAS,KRAS,FLT3,JAK2не влияют на долгосрочные результаты терапии и скорость достижения негативного статуса минимальной остаточной болезни у больныхBCR-ABL1-негативным В-ОЛЛ при применении протоколов российского многоцентрового исследования.
Publication Date: 2020-12-22
Journal: Terapevticheskii arkhiv

Clinical and laboratory features associated with myeloperoxidase expression in pediatric B-lymphoblastic leukemia.
B-lymphoblastic leukemia (B-ALL) is the most common childhood malignancy, and its diagnosis requires immunophenotypically demonstrating blast B cell lineage differentiation. Expression of myeloperoxidase (MPO) in B-ALL is well-described and it has been recognized that a diagnosis of mixed phenotype acute leukemia should be made cautiously if MPO expression is the sole myeloid feature in these cases. We sought to determine whether MPO expression in pediatric B-ALL was associated with differences in laboratory, immunophenotypic, or clinical features. We reviewed clinical, diagnostic bone marrow flow cytometry, and laboratory data for all new B-ALL diagnoses at our pediatric institution in 5 years. Cases were categorized as MPO positive (MPO+) or negative (MPO-) using a threshold of ≥20% blasts expressing MPO at intensity greater than the upper limit of normal lymphocytes on diagnostic bone marrow flow cytometry. A total of 148 cases were reviewed, 32 of which (22%) were MPO+. MPO+ B-ALL was more frequently hyperdiploid and less frequently harbored ETV6-RUNX1; no MPO+ cases had KMT2A rearrangements or BCR-ABL1. Although not significantly so, MPO+ B-ALL was less likely than MPO- B-ALL to have positive end-of-induction minimal residual disease studies (9.4 and 24%, respectively), but relapse rates and stem cell transplantation rates were similar between groups. Aberrant expression of other more typically myeloid markers was similar between these groups. In our study cohort, MPO+ B-ALL showed minimal residual disease persistence less often after induction chemotherapy but otherwise had similar clinical outcomes to MPO- B-ALL, with similar rates of additional myeloid antigen aberrancy.
Publication Date: 2020-10-14
Journal: Cytometry. Part B, Clinical cytometry

New monoclonal antibodies and tyrosine kinase inhibitors in B-cell acute lymphoblastic leukemia.
Patients with acute lymphoblastic leukemia (ALL) are characterized by an unfavorable outcome in the majority of adult cases. Several clinical trials have confirmed the usefulness of a pediatric-type therapy applied to adult patients. Adults present with higher risk features at diagnosis that predispose them to chemotherapy resistance and disease relapse after an initial achievement of complete remission. The recent introduction of novel immune-targeted therapies, including monoclonal antibodies (MoAbs) targeting B cell-associated antigens such as CD19 (blinatumumab) and CD22 (inotuzumab), tyrosine kinase inhibitors targeting BCR-ABL1 tyrosine kinase, bispecific antibodies and chimeric antigen receptor T- cell therapy (CAR-T), circumvent B-ALL cell chemo-refractoriness through novel mechanisms of action, potentially eradicating minimal residual disease (MRD) and enabling more patients to receive allogeneic hematopoietic stem cell transplantation and to achieve a better clinical outcome.
Publication Date: 2020-09-22
Journal: Minerva medica

A small molecular compound CC1007 induces cross-lineage differentiation by inhibiting HDAC7 expression and HDAC7/MEF2C interaction in BCR-ABL1
Histone deacetylase 7 (HDAC7), a member of class IIa HDACs, has been described to be an important regulator for B cell development and has a potential role in B cell acute lymphoblastic leukemia (B-ALL). CC1007, a BML-210 analog, is designed to indirectly inhibit class IIa HDACs by binding to myocyte enhancer factor-2 (MEF2) and blocking the recruitment of class IIa HDACs to MEF2-targeted genes to enhance the expression of these targets. In this study, we investigated the anticancer effects of CC1007 in breakpoint cluster region-Abelson 1 fusion gene-negative (BCR-ABL1
Publication Date: 2020-09-12
Journal: Cell death & disease

Entire ABL1 Gene Deletion Without BCR/ABL1 Rearrangement in a Female Patient with B-Cell Precursor Acute Lymphoblastic Leukemia.
Acute lymphoblastic leukemia (ALL) is a malignant disease characterized by lymphocytic B-line or T-line cells abnormally proliferating in the bone marrow or extramedullary sites. BCR/ABL1 fusion protein in patients with ALL accounts for acts in 15-30% of B-lineage ALL cases, usually in adolescence. However, entire ABL1 gene deletion without BCR/ABL1 rearrangement is a rare phenomenon in ALL patients. Here we describe the first case of entire ABL1 gene deletion without BCR/ABL1 rearrangement in a female B-ALL patient. Relevant literature is reviewed to explain the association between ABL1 deletion and the pathogenesis/prognosis of this disease. ABL gene deletion can repress the activation of p53 and p73, and disrupt TGF-β signaling pathway to allow malignant cells to invade the normal tissue. The clinical significance of ABL gene deletion needs to be further explored.
Publication Date: 2020-03-12
Journal: OncoTargets and therapy

The application of RNA sequencing for the diagnosis and genomic classification of pediatric acute lymphoblastic leukemia.
Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, and implementation of risk-adapted therapy has been instrumental in the dramatic improvements in clinical outcomes. A key to risk-adapted therapies includes the identification of genomic features of individual tumors, including chromosome number (for hyper- and hypodiploidy) and gene fusions, notably ETV6-RUNX1, TCF3-PBX1, and BCR-ABL1 in B-cell ALL (B-ALL). RNA-sequencing (RNA-seq) of large ALL cohorts has expanded the number of recurrent gene fusions recognized as drivers in ALL, and identification of these new entities will contribute to refining ALL risk stratification. We used RNA-seq on 126 ALL patients from our clinical service to test the utility of including RNA-seq in standard-of-care diagnostic pipelines to detect gene rearrangements and IKZF1 deletions. RNA-seq identified 86% of rearrangements detected by standard-of-care diagnostics. KMT2A (MLL) rearrangements, although usually identified, were the most commonly missed by RNA-seq as a result of low expression. RNA-seq identified rearrangements that were not detected by standard-of-care testing in 9 patients. These were found in patients who were not classifiable using standard molecular assessment. We developed an approach to detect the most common IKZF1 deletion from RNA-seq data and validated this using an RQ-PCR assay. We applied an expression classifier to identify Philadelphia chromosome-like B-ALL patients. T-ALL proved a rich source of novel gene fusions, which have clinical implications or provide insights into disease biology. Our experience shows that RNA-seq can be implemented within an individual clinical service to enhance the current molecular diagnostic risk classification of ALL.
Publication Date: 2020-03-10
Journal: Blood advances

Bone marrow niche-derived extracellular matrix-degrading enzymes influence the progression of B-cell acute lymphoblastic leukemia.
Specific and reciprocal interactions with the bone marrow microenvironment (BMM) govern the course of hematological malignancies. Matrix metalloproteinase-9 (MMP-9), secreted by leukemia cells, facilitates tumor progression via remodeling of the extracellular matrix (ECM) of the BMM. Hypothesizing that leukemias may instruct the BMM to degrade the ECM, we show, that MMP-9-deficiency in the BMM prolongs survival of mice with BCR-ABL1-induced B-cell acute lymphoblastic leukemia (B-ALL) compared with controls and reduces leukemia-initiating cells. MMP-9-deficiency in the BMM leads to reduced degradation of proteins of the ECM and reduced invasion of B-ALL. Using various in vivo and in vitro assays, as well as recipient mice deficient for the receptor for tumor necrosis factor (TNF) α (TNFR1) we demonstrate that B-ALL cells induce MMP-9-expression in mesenchymal stem cells (MSC) and possibly other cells of the BMM via a release of TNFα. MMP-9-expression in MSC is mediated by activation of nuclear factor kappa B (NF-κB) downstream of TNFR1. Consistently, knockdown of TNF-α in B-ALL-initiating cells or pharmacological inhibition of MMP-9 led to significant prolongation of survival in mice with B-ALL. In summary, leukemia cell-derived Tnfα induced MMP-9-expression by the BMM promoting B-ALL progression. Inhibition of MMP-9 may act as an adjunct to existing therapies.
Publication Date: 2020-01-11
Journal: Leukemia

Identification of RNPC3 as a novel JAK2 fusion partner gene in B-acute lymphoblastic leukemia refractory to combination therapy including ruxolitinib.
Hematopoietic neoplasms with chromosomal translocations involving JAK2 are rare, and most of them show myeloproliferative neoplasm-associated features, followed by B-acute lymphoblastic leukemia (B-ALL). De novo B-ALL cases with JAK2 rearrangements are suggested to be appropriately considered as BCR-ABL1-like B-ALL, but its partners varied. Fluorescence in situ hybridization (FISH), RNA sequencing (RNA-Seq), whole-genome sequencing, and reverse transcription polymerase chain reaction (RT-PCR) were performed to identify the pathogenic fusion gene in a 29-year-old woman with relapsed B-ALL and rare t(1;9)(p13;p22) translocation. We identified RNPC3 as a new JAK2 fusion partner in the patient. She was treated with a combination of chemotherapy and targeted drug ruxolitinib and chimeric antigen receptor T-cell therapy, but failed to achieve complete remission. She had no chance to undergo allogeneic hematopoietic stem cell transplantation and died of disease progression 7 months after the initial diagnosis. Her clinical course demonstrated that this novel RNPC3-JAK2 fusion might portend an unfavorable prognosis. This finding adds to the expanding compendium of JAK2 fusions found in B-ALL and suggests the potential need for a diagnostic FISH analysis as well as RNA-Seq in the appropriate clinical setting.
Publication Date: 2019-12-31
Journal: Molecular genetics & genomic medicine

Clinical implications of cytogenetic heterogeneity in Philadelphia chromosome positive (Ph+) adult B cell acute lymphoblastic leukemia following tyrosine kinase inhibitors and chemotherapy regimens.
We retrospectively studied a cohort of 144 adults with Philadelphia chromosome/BCR-ABL1 positive B acute lymphoblastic leukemia (Ph + B-ALL) to assess the clinical implications of cytogenetic heterogeneity in this disease. The study group included 85 men and 59 women that were sorted into 6 subgroups based on karyotypic findings in the stemline as follows: 32 patients with t(9;22) as a sole aberration, 23 with t(9;22) plus 1 additional chromosomal abnormality (ACA), 26 with t(9;22) as part of a complex karyotype, 18 showing a variant-/complex- t(9;22), 30 with t(9;22) as the stemline with ACAs in the sideline(s), and 15 patients who had the t(9;22) and hyperdiploidy. In 89 patients 1 clone was identified; 41 had 2 clones and 14 had ≥ 3 clone(s). The median overall survival (OS) was 25.6 months and the median relapse-free survival (RFS) was 20.6 months. Patients with variant-/complex- t(9;22) had poorer OS and RFS when compared with all other subgroups combined (P = 0.0018 and P = 0.0049, respectively). In addition, patients with ≥ 2 clones had worse OS and RFS than patients with 1 clone (P = 0.0179 and P = 0.0429, respectively). Multivariate analysis confirmed that variant-/complex-t(9;22) and clone number are independent risk factors. We suggest that conventional chromosomal analysis is of clinical importance for risk stratification of B-ALL patients.
Publication Date: 2019-07-07
Journal: Leukemia research