Role of urokinase plasminogen activator receptor (CD87) as a prognostic marker in acute myeloid leukemia

Expression of uPAR (CD87) may play a relevant role in the diagnosis and pathophysiology and prognostic pattern of acute myeloid leukemia. The aims of this study were to find out the prognostic significance of pretreatment detection of CD87 and study the prevalence of CD87 expression and its value as a predictor for survival in AML patients. CD87 expression has been studied on blasts in 110 newly diagnosed AML patients. Immunophenotyping and cytogenetic analysis of these cases were performed. CD87 was positive in 80 (72.7%) cases of patients. The MFI categorized the expression of CD87 into CD87^High and CD87^Low expression. Blast cells show that monocytic differentiation has a significantly more CD87^High expression than CD87^Low expression. Cytogenetic abnormalities were found in 58.7% of patients with CD87^Low AML and 41.25% of patients with CD87^High AML. Cases with CD87^High expression cells were characterized by a significantly lower survival period especially when co-expressed with CD56, CD34, and/or CD64. There is a negative prognostic influence of the expression of CD87 on the surface of AML blasts, but more tests are necessary to explain the pathophysiological mechanisms behind these findings and to learn about the mechanism that influences the CD87 expression and function.     

Tryptase a novel biochemical marker of acute myeloid leukemia

Despite maturation arrest, blast cells in acute myeloid leukemia (AML) are often capable of expressing lineage-restricted (granulomonocytic or myelomastocytic) differentiation antigens. Tryptases are lineage-associated serine proteases primarily expressed in mast cells, and less abundantly in blood basophils. We have recently shown that myeloblasts in a group of patients with AML (approximately 40%) produce significant amounts of tryptase(s). In these patients, serum tryptase levels are elevated (> 15 ng/ml) and reflect the total burden of leukemic cells. In most cases, myeloblasts express alpha-tryptase mRNA in excess over beta-tryptase mRNA, and secrete the respective protein (= pro-alpha-tryptase) in a constitutive manner. It was also found that these AML blasts frequentlyco-express tryptase with additional mast cell lineage- and/or basophil-related differentiation antigens including KIT (CD117), histamine, and 2D7. We hypothesize that tryptase-positive AMLs arise from a leukemic progenitor that exhibits a limited potential to differentiate into mast cells and/or basophils.     

Early blast clearance by remission induction as a prognostic factor in acute myeloid leukemia

Conclusions Day 16 blasts are an important prognostic factor in newly diagnosed AML.     

Protein kinase CK2alpha as an unfavorable prognostic marker and novel therapeutic target in acute myeloid leukemia.

INTRODUCTION: Protein kinase CK2 is implicated in cellular proliferation and transformation. However, the clinical and biological significances of CK2 have not been elucidated in acute myeloid leukemia (AML). EXPERIMENTAL DESIGN: We evaluated the biological significances of catalytic subunit of CK2 (CK2alpha) expression in leukemia cell lines and primary leukemic blasts obtained from AML patients. RESULTS: In this study, the expression of CK2alpha was elevated in a substantial proportion of AML. In AML patients with normal karyotype, the disease-free survival and overall survival rates were significantly lower in the CK2alpha-high compared with the CK2alpha-low AML cases (P=0.0252 and P=0.0392, respectively). An induced overexpression of CK2alpha increased the levels of Ser473 phosphorylated (p)-Akt/protein kinase B (PKB), p-PDK1, pFKHR, p-BAD, Bcl-2, Bcl-xL, Mcl-1, and XIAP. Treatment of U937 cell line and primary AML blasts with selective CK2 inhibitor, tetrabromobenzotriazole or apigenin, reduced the levels of these molecules in a dose-dependent manner. CK2alpha small interfering RNA treatment also resulted in a down-regulation of p-Akt/PKB and Bcl-2 in U937 cells. Apigenin-induced cell death was preferentially observed in the CK2alpha-high leukemia cell lines, HL-60 and NB4, which was accompanied by cytoplasmic release of SMAC/DIABLO and proteolytic cleavage of procaspase-9, procaspase-3, procaspase-8, and poly(ADP)ribose polymerase. An induced overexpression of CK2alpha potentially enhanced the sensitivity of U937 cells to the apigenin-induced cell death. Apigenin-induced cell death was significantly higher in CK2alpha-high AML compared with CK2alpha-low AML (P<0.0001) or normal bone marrow samples (P<0.0001). CONCLUSION: These findings strongly suggest protein kinase CK2alpha as an unfavorable prognostic marker and novel therapeutic target in AML.     

急性髓系白血病预后相关因素分析

目的 探讨成年急性髓系白血病(AML)患者的预后影响因素.方法 回顾性分析182例初治AML患者临床资料,探讨患者性别、年龄(以60岁为界)、初治白细胞计数(≥30× 109/L)、骨髓细胞学免疫表型、细胞遗传学、异基因造血干细胞移植(allo-HSCT)和治疗1个疗程获得完全缓解(CR)等因素与总生存(OS)及无事件生存(EFS)的关系.结果 182例AML患者的中位年龄49岁(14～ 80岁),中位随访时间9.7个月(0.5～75.5个月),首次化疗达CR 107例,总有效率为65.9％(120/182),年龄≥60岁、CD64阴性、染色体高危组及首次诱导未达CR患者的总CR率低于无上述因素者.单因素生存分析提示年龄≥60岁、细胞遗传学高危组、CD19阴性、CD11b阳性、CD64阴性、未行allo-HSCT、首次诱导未达到CR的患者OS及EFS较短(P＜0.05),多因素分析显示年龄、细胞遗传学表达、CD11b、CD64、是否行allo-HSCT、首次诱导能否达CR是患者OS的独立预后因素,细胞遗传学表达、CD64表达、是否行allo-HSCT及首次诱导能否达CR是患者EFS的独立预后因素.结论 根据AML相关因素进行预后分析判断,有利于临床医生早期制订个体化治疗方案,对于延长患者生存期有重要意义.     

Telomerase activity is prognostic in pediatric patients with acute myeloid leukemia: comparison with adult acute myeloid leukemia

BACKGROUND: Significantly elevated telomerase activity (TA) has been found in samples from patients with almost all malignant hematologic diseases. The impact of elevated TA on the course of pediatric patients with acute myeloid leukemia (P-AML) is unknown. METHODS: Using a modified polymerase chain reaction-based, telomeric repeat-amplification protocol assay, the authors measured TA in bone marrow samples from 40 patients with P-AML and, for comparison, in 65 adult patients with AML (A-AML), excluding patients with French-American-British M3 disease. The results were correlated with patient characteristics and survival. RESULTS: TA in patients with P-AML was significantly lower compared with TA in patients with A-AML (P = 0.005). Patients who had P-AML with low TA had a projected 5-year survival rate of 88%, whereas patients who had P-AML with high TA had a projected 5-year survival rate of 43% (P = 0.009). Conversely, patients who had A-AML with very high TA (upper quartile) had significantly longer survival compared with patients who had A-AML with lower TA (P = 0.03). There was no correlation between complete remission rate or disease free survival and TA in P-AML or A-AML. In the A-AML group, when patients were separated by cytogenetic findings (poor prognosis vs. others), it was found that TA was significantly lower in patients with a poor prognosis, but the prognostic value of TA was not independent of cytogenetic status. CONCLUSIONS: The current results suggest, that for patients with P-AML, bone marrow TA is a highly significant prognostic factor.     

CAMAL: a new prognostic marker for remission in acute nonlymphoblastic leukemia

A leukemia-associated antigen, CAMAL, shown to be present in bone marrow (BM) cells from patients with acute nonlymphoblastic leukemia (ANLL) even during remission, has been examined using indirect immunoperoxidase and a monoclonal antibody, CAMAL-1. We are ending the third year of an ongoing blind study designed to monitor the number of BM cells expressing the CAMAL protein (CAMAL BM value) in ANLL patients over the course of their disease. Results thus far have revealed that the CAMAL BM value in individual patients often changed significantly post-chemotherapy. This change appeared to be a useful prognostic marker in many instances. ANLL patients at initial presentation whose CAMAL BM values increased or stayed the same post-chemotherapy had significantly (p less than 0.025) shorter remission lengths (x = 6.8 months, n = 24) than those whose CAMAL BM values decreased (x = 19.2 months, n = 10). There are indications that increasing CAMAL BM values during remission occur prior to clinical relapse.     

Identification of LPCAT1 expression as a potential prognostic biomarker guiding treatment choice in acute myeloid leukemia

Changes in lipid metabolism affect numerous cellular processes that are relevant to cancer biology, including cell proliferation, death, differentiation and motility. In the phosphatidylcholine biosynthesis pathway, the conversion of lysophosphatidylcholine (LPC) to phosphatidylcholine is catalyzed by cytosolic enzymes of the LPC acyltransferase (LPCAT) family. A number of studies have demonstrated that LPCAT1 overexpression is a frequent event in diverse human cancer types, and that it is associated with unfavorable pathological characteristics and patient survival. The aim of the present study was to explore the prognostic role of the expression of LPCAT family members in acute myeloid leukemia (AML). Using Cox regression analysis, only LPCAT1 expression was identified as an independent prognostic biomarker in AML. In a cohort from The Cancer Genome Atlas, Kaplan-Meier analysis revealed that patients with AML and higher expression levels of LPCAT1 had shorter overall survival (OS) and leukemia-free survival (LFS) times compared with those with lower expression levels of LPCAT1. This was further confirmed using an independent cohort from the Gene Expression Omnibus. Using a third cohort comprising patients with AML and healthy volunteers, it was confirmed that LPCAT1 expression was significantly increased in newly diagnosed AML cases compared with healthy controls. Moreover, higher expression of LPCAT1 was associated with French-American-British subtype-M4/M5 and nucleophosmin 1 mutations. Notably, patients who underwent hematopoietic stem cell transplantation (HSCT) following induction therapy exhibited significantly longer OS and LFS times compared with patients who only received chemotherapy after induction therapy in the higher LPCAT1 expression group, whereas no significant differences in OS and LFS times were observed between the HSCT and chemotherapy groups among total cases of AML in the lower LPCAT1 expression group. These results suggest that patients with AML who exhibit higher LPCAT1 expression levels may benefit from HSCT. Collectively, the findings of the present study indicate that LPCAT1 expression may serve as an independent prognostic biomarker that can guide the choice between HSCT and chemotherapy in patients with AML.     

Management of extramedullary leukemia as a presentation of acute myeloid leukemia

Extramedullary involvement is considered to be an uncommon presentation of acute myeloid leukemia (AML), although some data suggest it may be present in up to 30% of patients. Extra-medullary involvement by AML can present in a variety of clinical manifestations, most notably in the form of myeloid sarcoma, leukemia cutis, and central nervous system involvement. Each presents a unique clinical scenario in terms of symptoms and management. Extramedullary disease in any form presenting without evidence of bone marrow disease is still considered evidence of systemic disease and is usually treated as such. Most commonly, extramedullary disease presents concurrently with bone marrow disease, and although it may require additional local therapy in the form of intrathecal chemotherapy or radiation, the principles of systemic treatment remain unchanged. The prognostic impact of extramedullary disease is unclear. Specifically, whether hematopoietic stem cell transplantation should be considered in first remission irrespective of other prognostic factors has not been established. Patients who undergo transplantation have similar outcomes as patients without extramedullary disease, although they do have a higher rate of extramedullary relapse. More research is needed to define the molecular basis for extramedullary disease, its prognostic impact, and optimal management.     

BAALC expression: a suitable marker for prognostic risk stratification and detection of residual disease in cytogenetically normal acute myeloid leukemia

High brain and acute leukemia, cytoplasmic (BAALC) expression defines an important risk factor in cytogenetically normal acute myeloid leukemia (CN-AML). The prognostic value of BAALC expression in relation to other molecular prognosticators was analyzed in 326 CN-AML patients (<65 years). At diagnosis, high BAALC expression was associated with prognostically adverse mutations: FLT3 internal tandem duplication (FLT3-ITD) with an FLT3-ITD/FLT3 wild-type (wt) ratio of ⩾0.5 (P=0.001), partial tandem duplications within the MLL gene (MLL-PTD) (P=0.002), RUNX1 mutations (mut) (P<0.001) and WT1mut (P=0.001), while it was negatively associated with NPM1mut (P<0.001). However, high BAALC expression was also associated with prognostically favorable biallelic CEBPA (P=0.001). Survival analysis revealed an independent adverse prognostic impact of high BAALC expression on overall survival (OS) and event-free survival (EFS), and also on OS when eliminating the effect of allogeneic stem cell transplantation (SCT) (OS^TXcens). Furthermore, we analyzed BAALC expression in 416 diagnostic and follow-up samples of 66 patients. During follow-up, BAALC expression correlated with mutational load or expression levels, respectively, of other minimal residual disease markers: FLT3-ITD (r=0.650, P<0.001), MLL-PTD (r=0.728, P<0.001), NPM1mut (r=0.599, P<0.001) and RUNX1mut (r=0.889, P<0.001). Moreover, a reduction in BAALC expression after the second cycle of induction chemotherapy was associated with improved EFS. Thus, our data underline the utility of BAALC expression as a marker for prognostic risk stratification and detection of residual disease in CN-AML.     

Circulating angiopoietin-2 is a strong prognostic factor in acute myeloid leukemia.

Angiogenesis plays an important role in solid tumors and hematologic malignancies. The angiopoietins act as essential regulators in this process. We investigated the impact of circulating angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2) and soluble Tie2 (sTie2) on overall survival in patients with acute myeloid leukemia (AML). Ang-1, Ang-2 and sTie2 were measured in plasma samples from 68 AML patients and 11 controls using enzyme-linked immunosorbent assay. Circulating levels of Ang-2 and sTie2 (median (range): 1098.0 (361.4-4147.6) pg/ml and 3.40 (1.21-10.00) ng/ml, respectively) were significantly elevated in AML patients as compared to controls (307.9 (199.7-1225.0) pg/ml and 2.88 (1.71-3.29) ng/ml; P<0.001 and P=0.014). In a univariate Cox proportional hazards model, higher levels of Ang-2 and sTie2 were predictive of poor survival. In multivariate analyses, Ang-2 and cytogenetics proved to be independent prognostic factors, with a relative risk of 4.07 (95% confidence interval (CI) 1.88-8.81) and 2.70 (95% CI 1.25-5.81), respectively. The 3-year survival rate for AML patients with Ang-2 levels>/=1495.6 pg/ml was only 14.7% compared to 64.7% for those with Ang-2 levels<1495.6 pg/ml. These data provide evidence that circulating Ang-2 represents an independent prognostic factor in AML and may be used as a prognostic tool in the risk-adapted management of AML.     

GPX3 hypermethylation serves as an independent prognostic biomarker in non-M3 acute myeloid leukemia

Hypermethylation of GPX3 (glutathione peroxidase 3) promoter has been identified in various solid tumors. However, the pattern of GPX3 promoter methylation in acute myeloid leukemia (AML) remains poorly known. The current study was intended to investigate the clinical significance of GPX3 promoter methylation in de novo AML patients and further determine its role in regulating GPX3 expression. GPX3 promoter methylation status in 181 de novo AML patients and 44 normal controls was detected by real-time quantitative methylation-specific PCR and bisulfite sequencing PCR. Real-time quantitative PCR was carried out to assess GPX3 expression. GPX3 promoter was significantly methylated in 181 AML patients compared with normal controls (P=0.022). The patients with GPX3 methylation presented significantly older age than those with GPX3 unmethylation (P=0.011). GPX3 methylated patients had significantly lower frequency of C/EBPA mutation and higher incidence of FLT3-ITD mutation (P=0.037 and 0.030). The non-M3 patients with GPX3 methylation had significantly lower overall survival than thoes with GPX3 unmethylation (P=0.036). No significant correlation was observed between GPX3 expression and its promoter methylation (R=0.110, P=0.284). However, GPX3 mRNA level was significantly increased after 5-aza-2’-deoxycytidine treatment in leukemic cell line THP1. GPX3 methylation predicts adverse clinical outcome in non-M3 AML patients. Moreover, GPX3 expression is regulated by its promoter methylation in leukemic cell line THP1.