Cyclin D1 expression in acute leukemia

Background: Disorders of the cell cycle regulatory machinery play a key role in the pathogenesis of cancer. Over expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the involvement of cyclin D1 in acute leukemia.

Patients and methods: In this study, we analyzed the expression of cyclin D1 at protein level in, 40 newly diagnosed patients with acute myeloid leukemia (AML), 10 patients with acute lymphoblastic leukemia (ALL), and 11 normal controls using flow cytometry.

Results: The expression of cyclin D1 was not significantly different in AML group as compared to normal controls. On the other hand, over expression of cyclin D1 was evident in ALL group (4/10) as compared to that in healthy control. The ALL cases with cyclin D1 over expression were significantly correlated to blast cell counts in the peripheral blood and bone marrow (BM) but not with hemoglobin level, WBC, and platelets count. The ALL group with lymphadenopathy and organomegaly express significantly higher cyclin D1 over expression as compared to those without.

Conclusion: The biological value of cyclin D1 over expression might be different in AML and ALL.     

Decreased PARP and procaspase-2 protein levels are associated with cellular drug resistance in childhood acute lymphoblastic leukemia

Drug resistance in childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) is associated with impaired ability to induce apoptosis. To elucidate causes of apoptotic defects, we studied the protein expression of Apaf-1, procaspases-2, -3, -6, -7, -8, -10, and poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) in cells from children with acute lymphoblastic leukemia (ALL; n = 43) and acute myeloid leukemia (AML; n = 10). PARP expression was present in all B-lineage samples, but absent in 4 of 15 T-lineage ALL samples and 3 of 10 AML cases, which was not caused by genomic deletions. PARP expression was a median 7-fold lower in T-lineage ALL (P < .001) and 10-fold lower in AML (P < .001) compared with B-lineage ALL. PARP expression was 4-fold lower in prednisolone, vincristine and L-asparaginase (PVA)-resistant compared with PVA-sensitive ALL patients (P < .001). Procaspase-2 expression was 3-fold lower in T-lineage ALL (P = .022) and AML (P = .014) compared with B-lineage ALL. In addition, procaspase-2 expression was 2-fold lower in PVA-resistant compared to PVA-sensitive ALL patients (P = .042). No relation between apoptotic protease-activating factor 1 (Apaf-1), procaspases-3, -6, -7, -8, -10, and drug resistance was found. In conclusion, low baseline expression of PARP and procaspase-2 is related to cellular drug resistance in childhood acute lymphoblastic leukemia.     

Predictive value of multidrug resistance proteins and cellular drug resistance in childhood relapsed acute lymphoblastic leukemia

Purpose Cellular resistance in childhood acute leukemias might be related to profile and function of multidrug resistance proteins and apoptosis regulating proteins. The aims of the study were: (1) analysis of expression of MRP1, PGP1, LRP, BCL-2 and p53 proteins; (2) correlation with ex vivo drug resistance, and (3) analysis of their prognostic impact on clinical outcome in childhood acute lymphoblastic (ALL) and acute myeloid (AML) leukemia. Methods Total number of 787 children diagnosed for initial ALL (n = 527), relapsed ALL (n = 104), initial AML (n = 133) and relapsed AML (n = 23) were included into the study. Mean follow-up period was 3.5 years. Drug resistance for up to 30 anticancer agents was performed by the MTT assay. Expression of all proteins was tested by flow cytometry. Results Both initial AML and relapsed ALL samples showed higher drug resistance than initial ALL samples. No significant differences were found in drug resistance between initial and relapsed AML samples. The presence of multidrug resistance and apoptosis proteins had no impact on pDFS in iALL and iAML, however strong trend towards adverse prognostic impact of MRP1, PGP and LRP on pDFS in rALL was observed. The same trend was observed for each of analyzed co-expressions of tested multidrug resistance proteins. Conclusions The phenomenon of cellular drug resistance in childhood acute leukemias is multifactorial and plays an important role in response to therapy. Expression of MRP1, PGP and LRP proteins, as well as their co-expression play possible role in childhood relapsed ALL. An erratum to this article can be found at     

Gene Expression Profiling in Childhood Acute Leukemia: Progress and Perspectives

Recent advances in treatment have transformed childhood acute leukemias into curable diseases. However, 20% to 40% of acute leukemia patients still experience a relapse. Microarrays typically contain thousands of oligonucleotides or complementary DNAs and are rapidly becoming important research tools for the identification of novel classifications of leukemias and lymphomas. Microarray-based identification of several translocations has been performed in acute lymphoblastic leukemia (ALL), leading to the discovery of t(1;19), t(12;21), and 11q23 translocations, and in acute myeloid leukemia (AML), finding t(8;21), inv(16), and t(15;17). Correlations between gene expression profiles and clinical features have been reported in ALL and AML. Recently, it was reported that gene expression profiling can be used to predict the prognosis of childhood acute leukemia. In this report, the recent progress in microarray analysis of childhood acute leukemia is reviewed. Gene expression profiling provides new insights into the biological mechanisms of leukemogenesis and the prognosis of childhood acute leukemia.     

C-kit receptor tyrosine kinase (CD117) expression and its positive predictive value for the diagnosis of Thai adult acute myeloid leukemia

We examined the expression of c-kit receptor tyrosine kinase in 195 Thai adult patients with acute leukemia and determined its specificity and predictive values for the diagnosis of adult acute myeloid leukemia (AML). CD117 was used to detect c-kit expression on CD45 and side-scatter-gated blast cells by flow cytometry. Of 163 AML cases, 67% expressed CD117. None of acute lymphoid leukemia (ALL) had CD117 expression, except one case of T-ALL. The majority of AML patients carrying t(8;21), inv(16), and t(15;17) had high CD117 expression. High proportion of AML cases without c-kit expressed monocytic markers. Significant associations between CD117 and CD34 (P<0.001), CD13 (P=0.006), CD7 (P=0.034), and CD19 (P<0.001) were found in AML cases. The calculated specificity of CD117 for the diagnosis of AML was 0.97, which was higher than CD13 (0.78) and CD33 (0.75) but comparable to MPO (0.97). The positive predictive value (PPV) of CD117 for AML was 0.99, with the negative predictive value of 0.35. In conclusion, the majority of Thai adult AML cases expressed c-kit. C-kit is infrequently expressed in ALL and appeared to be specific for AML with high PPV. Future targeting therapy using c-kit as a therapeutic target should benefit the majority of Thai AML patients who had high c-kit expression.     

Demonstration of antibodies binding to autologous and allogeneic leukemic cells in childhood ALL

Summary The humoral immune response to autologous leukemic cells was investigated in childhood ALL using a ¹²⁵I protein A binding assay. In 5/7 patients antibodies were demonstrated at diagnosis and in 3/7 cases also after chemotherapy. Sera from 2/3 patients, which bound significantly to autologous leukemic cells, did not bind significantly to autologous remission cells. In allogeneic experiments sera bound significantly to ALL leukemic cells (6/7 positive combinations), but not to AML leukemic cells (8/8 negative combinations). We propose that ALL sera contain antibodies binding to autologous leukemic cells and that they are directed against a common ALL antigen(s).Abbreviations ALL acute lymphoblastic leukemia - AML acute myeloid leukemia - CALLA common ALL antigen - CPM counts per minute - HTLV 1 human T cell leukemia/lymphoma virus, type 1 - I a immune-associated antigens - SE standard error     

Bone marrow necrosis in acute leukemia: Clinical characteristic and outcome

Bone marrow necrosis (BMN) is characterized by infarction of the medullary stroma, leading to marrow necrosis with preserved cortical bone. In reported small series, BMN in hematological malignancies is associated with poor prognosis. We sought to find the impact of BMN on clinical outcome in a relatively larger cohort of patients with acute leukemias. Overall we evaluated 1,691 patients; 1,051 with acute myeloid leukemia (AML) and 640 with acute lymphocytic leukemia referred to our institution between 2002 and 2013. Patients with AML and acute lymphoblastic leukemia (ALL) were evaluated separately to determine the incidence of BMN, associated clinical features and its prognostic significance. At initial diagnosis, BMN was observed in 25 (2.4%) patients with AML and 20 (3.2%) patients with ALL. In AML, BMN was significantly associated with French–American–British AML M5 morphology (32% vs. 10%, P = 0.002). The complete remission (CR) rate in AML with and without BMN was 32% and 59% respectively (P = 0.008). Likewise, CR rate in ALL with BMN was also inferior, 70% vs. 92% (P = 0.005). The median overall survival (OS) in AML with BMN was significantly poorer, 3.7 months compared to 14 months without BMN (P = 0.003). Similarly, the median OS in ALL with and without BMN was 61.7 and 72 months respectively (P = 0.33). BMN is not a rare entity in AML and ALL, but is infrequent. BMN in AML and in ALL is suggestive of inferior response and poor prognosis. Am. J. Hematol. 90:769–773, 2015. © 2015 Wiley Periodicals, Inc.     

Clinical features of adult acute leukemia with 11q23 abnormalities in Japan: a co-operative multicenter study

To clarify the clinical features of adult patients with acute leukemia (AL) with 11q23 abnormalities, we performed a retrospective analysis of data from 58 adult Japanese patients: 51 with acute myeloid leukemia (AML), and 7 with acute lymphoblastic leukemia (ALL). The incidences according to fusion partners in AML were: t(9;11), 31.3%; t(11;19), 27.4%; t(6;11), 21.5%. The incidence of patients with t(11;19) was higher than those in the US and Europe, and the incidence of t(4;11) was lower than that in childhood. The results indicated the poor prognosis of AML with 11q23 abnormalities regardless of the fusion partners. AML patients with 11q23 aged <60 years in the first CR who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) showed a more favorable outcome than those treated without allo-HSCT, although the differences were not statistically significant (P = 0.322 for DFS, P = 0.138 for OS). This result suggests that treatment strategies including allo-HSCT may be considered in the first CR in cases of AML with 11q23 abnormalities. However, further studies involving a large number of cases are required to assess the effect of allo-HSCT on adult AL with 11q23 abnormalities.     

Vascular Endothelial Growth Factor Levels in Childhood Acute Lymphoblastic and Myeloblastic Leukemia

Angiogenesis has been associated with the growth, dissemination and metastasis and has been shown to be a prognostic. Although there are some data suggesting that angiogenesis may have a role in the pathophysiology of leukemia, its role in patient prognosis is yet to be defined. We analyzed the expression level of vascular endothelial growth factor (VEGF), an angiogenesis promoter and its possible- prognostic value in bone marrow samples at the time of diagnosis and remission of acute childhood leukemia patients. Besides 46 patients diagnosed as ALL or AML, 16 children were also included as a control group in the study. Our data have demonstrated that VEGF levels of AML patients were found higher than the control group statistically (P = 0.022). However we could not find any significant difference between VEGF levels of diagnosis and remission in both AML and ALL groups by blastic VEGF expression (P > 0.05). In this study the higher levels of VEGF in AML patients is one of the main findings although we were not able to assess any role of VEGF in predicting prognosis in pediatric leukemia patients by evaluating blastic cell VEGF expression. These results have demonstrated that the relationship between angiogenesis or angiogenesis promoters and hematological malignancies is not clear and simple as different methods or different cells beside different angiogenesis promotors are involved to these studies. So that not only tumor cells and their cytokines but also surrounding cells and their cytokines must be taken into consideration with the standardized study methods in the further studies to obtain a promising treatment approach.     

Identification of new markers discriminating between myeloid and lymphoid acute leukemia

Abstract

Background: The heterogeneity of acute myeloid leukemia (AML) with respect to biology and clinical course resides in the fact that patients belonging to the same group show marked differences in their response to chemotherapy, necessitating a refinement of AML classification.

Methods: In order to define molecular markers for AML, we performed microarray analysis on peripheral blood cells from two M5 AML patients, and selected four differentially expressed genes to validate their expression by real-time quantitative PCR (RT-PCR).

Results: We have shown that two downregulated genes in AML, those encoding guanine nucleotide-binding protein γ11 (GNG11) and amphiregulin (AREG), are also downregulated in B-lineage acute lymphoblastic leukemia (B-ALL) and T-lineage acute lymphoblastic leukemia (T-ALL) patients. A second gene, that encoding ceruloplasmin (CP), is upregulated in AML but not in B-ALL and T-ALL. The level of expression of these genes varies from one patient to another.

Conclusion: Since the number of patients studied is limited, further studies are needed with a larger series of patients to evaluate the potential utility of GNG11, AREG and CP as molecular markers for AML subtype classification. Our study is the first to analyze these genes in AML, B-ALL, T-ALL and chronic leukemia (myeloid and lymphoid) patients by RT-PCR. This rapid and sensitive method could be used to screen these genes in different types of leukemia.     

P-glycoprotein (P-170) expression in acute leukemias

Multidrug resistance (MDR) is still a major obstacle to chemotherapy success in acute myeloid leukemia (AML) and to a less extent acute lymphoblastic leukemia (ALL). Recent studies have shown that the expression of certain gene products mediate the development of resistance to chemotherapeutic agents. The most well characterized of these genes is the multidrug resistance gene MDR-1. This study was planned to study the expression of P-glycoprotein/170 in patients with acute leukemia and the effect of Cyclosporin A (CSA) as a modulator of P-glycoprotein functional activity. The study was carried out on 20 patients with acute leukemia (14 AML cases and 6 ALL cases). In addition, 6 normal individuals served as a reference group. Flow cytometric analysis of P-gp/170 surface expression was performed using UIC-2 MoAb together with the functional assay using Rhodamine 123 (Rh 123) and Cyclosporin A as a modulator.P-gp/170 was expressed on the leukemic cells of 37.5% of relapsed patients (40.0% of AML and 33.3% of ALL cases), whereas 27.2% of de novo patients expressed P-gp/170 (33.3% of AML cases and 0% of ALL cases). The functional activity of MDR-1 gp was 71.4% in AML and 33.3% in ALL patients compared with16.6% in normal lymphocytes. From this study, it is clear that P-gp/170 is expressed to a higher degree in leukemic cells and this is greater in relapsed compared to de novo cases and more in AML than ALL blasts. Functional activity is a more sensitive predictor of chemoresistance than P-gp/170 surface expression.     

Repetitive genomic elements and overall DNA methylation changes in acute myeloid and childhood B-cell lymphoblastic leukemia patients

Aberrant epigenetic regulation is a hallmark of neoplastic cells. Increased DNA methylation of individual genes’ promoter regions and decreases in overall DNA methylation level are both generally observed in cancer. In solid tumors, this global DNA hypomethylation is related to reduced methylation of repeated DNA elements (REs) and contributes to genome instability. The aim of the present study was to assess methylation level of LINE-1 and ALU REs and total 5-methylcytosine (5metC) content in adult acute myeloid leukemia (AML) (n = 58), childhood B-cell acute lymphoblastic leukemia (ALL) (n = 32), as the most frequent acute leukemias in two age categories and in normal adult bone marrow and children’s blood samples. DNA pyrosequencing and ELISA assays were used, respectively. Global DNA hypomethylation was not observed in leukemia patients. Results revealed higher DNA methylation of LINE-1 in AML and ALL samples compared to corresponding normal controls. Elevated methylation of ALU and overall 5metC level were also observed in B-cell ALL patients. Differences of REs and global DNA methylation between AML cytogenetic-risk groups were observed, with the lowest methylation levels in intermediate-risk/cytogenetically normal patients. B-cell ALL is characterized by the highest DNA methylation level compared to AML and controls and overall DNA methylation is correlated with leukocyte count.     

Interphase FISH on TEL/AML1 positive acute lymphoblastic leukemia relapses – analysis of clinical relevance of additional TEL and AML1 copy number changes

Objectives: TEL/AML1 (ETV6/RUNX1) fusion resulting from the translocation t(12;21)(p13;q22) constitutes the most common chimeric fusion gene in initial childhood B‐cell precursor (BCP) acute lymphoblastic leukemia (ALL) (19–27%) and has been associated with good prognosis. Three secondary aberrations in TEL/AML1 positive ALL have been suspected to negatively influence outcome: deletion of the second TEL allele (T), gain of the second AML1 allele (A) and duplication of the derivative chromosome 21 (der(21), TA). Many studies have explored such aberrations in initial disease, while only few reports have investigated them in relapses. Methods: In this study, bone marrow samples from 38 children with relapsed TEL/AML1 RT‐PCR positive and negative BCP‐ALL were analyzed for these mutations by interphase fluorescence in situ hybridization and results were compared with published data. Results: In children with TEL/AML1 positive ALL relapse, additional (a) TEL loss, (b) combined AML1 and der(21) gain, (c) combined TEL loss and AML1 gain as well as (d) the occurrence of a subpopulation with the signal pattern 1T/3A/1TA appear to be related to higher peripheral blast counts (PBCs) at relapse diagnosis (a and d) or a tendency towards the occurrence of a subsequent relapse (b and c) (P‐values <0.05). Conclusions: Our data together with published results on TEL/AML1 positive ALL suggest that frequencies of additional TEL and AML1 mutations are, with the exception of loss of untranslocated TEL, higher in first relapses than in initial disease. They also show that it is important to consider combined mutations in the analysis of this leukemia entity.     

Heterogeneity in the breakpoints of chromosome 19 among acute leukemia patients with the t(11;19)(q23;p13) translocation

Gene probes for insulin receptor (INSR) and c-ets-1 were hybridized to metaphase cells from three leukemic patients with the t(11;19)(q23;p13) translocation. Patients 1 and 2 were diagnosed as acute lymphocytic leukemia (ALL) (L2), and patient 3, as acute myelogenous leukemia (AML) (M4). The c-ets-1 gene was demonstrated to have translocated from chromosome 11 to the short arm of the rearranged chromosome 19 (19p+) in all three patients. On the other hand, the INSR gene translocated from chromosome 19 to the rearranged chromosome 11 (11q-) in the AML case, but remained on the rearranged chromosome 19 in the two ALL cases. Thus, the breakpoints of chromosome 19 are different among the patients studied, proximal to the INSR gene locus in the AML case and distal in the two ALL cases. Consequently, the c-ets-1 gene and the INSR gene remain separated in the AML case, whereas they become close to each other in the two ALL cases. Rearrangement of these two genes was studied in the two ALL patients, with no positive data being obtained. The results suggest that there may be heterogeneity in the breakpoints of chromosome 19 among the t(11;19)-associated acute leukemias.     

Wnt inhibition leads to improved chemosensitivity in paediatric acute lymphoblastic leukaemia

While childhood acute lymphoblastic leukaemia (ALL) is now highly curable, the dismal prognosis for children who relapse warrants novel therapeutic approaches. Previously, using an integrated genomic analysis of matched diagnosis‐relapse paired samples, we identified overactivation of the Wnt pathway as a possible mechanism of recurrence. To validate these findings and document whether Wnt inhibition may sensitize cells to chemotherapy, we analysed the expression of activated β‐catenin (and its downstream target BIRC5) using multiparameter phosphoflow cytometry and tested the efficacy of a recently developed Wnt inhibitor, iCRT14, in ALL cell lines and patient samples. We observed increased activation of β‐catenin at relapse in 6/10 patients. Furthermore, treatment of leukaemic cell lines with iCRT14 led to significant downregulation of Wnt target genes and combination with traditional chemotherapeutic drugs resulted in a synergistic decrease in viability as well as a significant increase in apoptotic cell death. Finally, pre‐treatment of purified blasts from patients with relapsed leukaemia with the Wnt inhibitor followed by exposure to prednisolone, restored chemosensitivity in these cells. Our results demonstrate that overactivation of the Wnt pathway may contribute to chemoresistance in relapsed childhood ALL and that Wnt‐inhibition may be a promising therapeutic approach.     

MicroRNA expression signatures accurately discriminate acute lymphoblastic leukemia from acute myeloid leukemia

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer, whereas acute myeloid leukemia (AML) is the most common acute leukemia in adults. In general, ALL has a better prognosis than AML. To understand the distinct mechanisms in leukemogenesis between ALL and AML and to identify markers for diagnosis and treatment, we performed a large-scale genome-wide microRNA (miRNA, miR) expression profiling assay and identified 27 miRNAs that are differentially expressed between ALL and AML. Among them, miR-128a and -128b are significantly overexpressed, whereas let-7b and miR-223 are significantly down-regulated in ALL compared with AML. They are the most discriminatory miRNAs between ALL and AML. Using the expression signatures of a minimum of two of these miRNAs resulted in an accuracy rate of >95% in the diagnosis of ALL and AML. The differential expression patterns of these four miRNAs were validated further through large-scale real-time PCR on 98 acute leukemia samples covering most of the common cytogenetic subtypes, along with 10 normal control samples. Furthermore, we found that overexpression of miR-128 in ALL was at least partly associated with promoter hypomethylation and not with an amplification of its genomic locus. Taken together, we showed that expression signatures of as few as two miRNAs could accurately discriminate ALL from AML, and that epigenetic regulation might play an important role in the regulation of expression of miRNAs in acute leukemias.     

BAALC overexpression retains its negative prognostic role across all cytogenetic risk groups in acute myeloid leukemia patients

Overexpression of brain and acute leukemia cytoplasmic (BAALC) gene confers poor prognosis in cytogenetically normal acute myeloid leukemia (AML) patients, while less defined is its role in AML with abnormal karyotype. We evaluated the effect of BAALC overexpression on outcome of 175 adult AML patients with different cytogenetic risks. Karyotype was favorable in 13, intermediate in 117 and unfavorable in 45 patients, respectively. Quantitative BAALC expression was determined by real‐time PCR, with cut off value set at 50th percentile. BAALC was overexpressed in 87/175 (50%) patients, without association with cytogenetic status. High BAALC was associated with unmutated NPM (P = 0.006) and CD34 positivity (P < 0.0001). Complete remission (CR) was attained in 111 patients (63%), and was maintained at 5 years in 52 ± 7%. BAALC overexpression had a negative impact on CR achievement (P = 0.04), while did not influence relapse probability. Median survival was 22 months with a 5‐years overall survival (OS) of 35%. Factors with a negative impact on OS were older age (P = 0.0001), unfavorable cytogenetic (P = 0.005), ABCG2 overexpression (P = 0.03) and high BAALC levels (P = 0.01). We observed a worse outcome in patients with high BAALC expression through all cytogenetic risk categories: 5‐years OS was 100% vs. 71% in patients with favorable cytogenetics (P = 0.05), 55% vs. 40% in cases with intermediate karyotype (P = 0.04) and 34% vs. 23% in unfavorable cytogenetic subgroup (P = 0.02). BAALC overexpression identified AML patients with poor prognosis in all cytogenetic groups. Though relatively rare, BAALC positivity in patients with favorable or unfavorable karyotype significantly worsened survival. Am. J. Hematol. 88:848–852, 2013. © 2013 Wiley Periodicals, Inc.