Simultaneous detection of MDR1 and WT1 gene expression to predict the prognosis of adult acute lymphoblastic leukemia

Expression of interferon regulatory factor family and its prognostic value in acute myeloid leukemia

Aim: To elucidate the clinicopathological and prognostic values of interferon regulatory factor (IRF) family genes in acute myeloid leukemia (AML). Patients & methods: Differential expression analysis and survival analysis from several reliable databases were conducted and further validated using patients with AML. Results: The expression level of IRF1/2/4/5/7/8/9 in patients with AML was upregulated, while IRF3/6 expression was downregulated. High IRF1/7/9 expression indicated a worse overall survival rate. Conclusion: Overexpression of IRF1/7/9 may be associated with poor survival in patients with AML, suggesting that the IRF family may be a promising therapeutic target.

WT1 overexpression predicted good outcomes in adult B-cell acute lymphoblastic leukemia patients receiving chemotherapy

Objectives: The prognostic role of WT1 in acute lymphoblastic leukemia (ALL) is still controversial. No study has focused on the prognostic role of WT1 expression in adult B-ALL patients receiving chemotherapy only.Methods: Using TaqMan-based real time quantitative PCR (RQ-PCR), we detected the WT1 transcript levels of 162 de-novo adult B-ALL patients at the time of diagnosis and analysed their clinical features.Results: WT1 overexpression was defined as a transcript level higher than 0.50%, which is the upper limit in normal bone marrow. WT1 overexpression was identified in 66.0% of the patients and was an independent positive prognostic factor for CIR, RFS and OS in patients who received chemotherapy only (CIR: HR = 0.236 [95% confidence interval 0.094-0.592]; P = 0.002; RFS: HR = 0.223 [0.092-0.543]; P = 0.001; OS: HR = 0.409 [0.214-0.783]; P = 0.007) and in patients who did not have BCR-ABL fusion or KMT2A rearrangements (CIR: HR = 0.431 [0.201-0.921]; P = 0.030; RFS: HR = 0.449 [0.224-0.899]; P = 0.024; OS: HR = 0.521 [0.278-0.977]; P = 0.042). However, WT1 overexpression had no prognostic value in patients who received allogenic hematopoietic stem cell transplantation (allo-HSCT). Furthermore, allo-HSCT could improve the prognosis of patients with low WT1 expression.Conclusion: Therefore, testing for WT1 expression at the time of diagnosis may predict outcomes in adult B-ALL patients who receive only chemotherapy and who do not have the BCR-ABL fusion gene or KMT2A rearrangements. Allo-HSCT may improve the prognosis of patients with low WT1 transcript levels.

Identification of promising prognostic genes for relapsed acute lymphoblastic leukemia

PURPOSE

The present study aimed to identify the molecular mechanism of acute lymphoblastic leukemia (ALL), and explore valuable prognostic biomarkers for relapsed ALL.

METHODS

Gene expression dataset including 59 samples from ALL survivals without recurrence (good group) and 114 samples from dead ALL patients died of recurrence (poor group) was downloaded from TCGA database. The differentially expressed genes (DEGs) were identified between good and poor groups, followed by pathway and functional enrichment analyses. Subsequently, logistic regression model and survival analysis were performed.

RESULTS

In total, 637 up- and 578 down-regulated DEGs were revealed between good and poor groups. These DEGs were mainly enriched in functions including transcription and pathways like focal adhesion. Genes including alpha-protein kinase 1 (ALPK1), zinc finger protein 695 (ZNF695), actinin alpha 4 (ACTN4), calreticulin (CALR), and F-Box and leucine rich repeat protein 5 (FBXL5) were outstanding in survival analysis.

CONCLUSION

Transcription and focal adhesion might play important roles in ALL progression. Furthermore, genes including ALPK1, ZNF695, ACTN4, CALR, and FBXL5 might be novel prognostic genes for relapsed ALL.

Identification of interconnected markers for T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is a complex disease, resulting from proliferation of differentially arrested immature T cells. The molecular mechanisms and the genes involved in the generation of T-ALL remain largely undefined. In this study, we propose a set of genes to differentiate individuals with T-ALL from the nonleukemia/healthy ones and genes that are not differential themselves but interconnected with highly differentially expressed ones. We provide new suggestions for pathways involved in the cause of T-ALL and show that network-based classification techniques produce fewer genes with more meaningful and successful results than expression-based approaches. We have identified 19 significant subnetworks, containing 102 genes. The classification/prediction accuracies of subnetworks are considerably high, as high as 98%. Subnetworks contain 6 nondifferentially expressed genes, which could potentially participate in pathogenesis of T-ALL. Although these genes are not differential, they may serve as biomarkers if their loss/gain of function contributes to generation of T-ALL via SNPs. We conclude that transcription factors, zinc-ion-binding proteins, and tyrosine kinases are the important protein families to trigger T-ALL. These potential disease-causing genes in our subnetworks may serve as biomarkers, alternative to the traditional ones used for the diagnosis of T-ALL, and help understand the pathogenesis of the disease.

Idarubicin is superior to daunorubicin in remission induction of de novo acute myeloid leukemia patients with high MDR1 expression

Aim: To investigate whether idarubicin in a cytarabine-based induction regimen was superior to daunorubicin in de novo acute myeloid leukemia patients expressing high MDR1. Patients & methods: The clinicopathological data were analyzed in 125 patients receiving daunorubicin or idarubicin with cytarabine for remission induction. Median MDR1 mRNA expression in pretreated bone marrow cells was used as the cutoff point for high and low MDR1 expression. Results: A total of 59.7% high and 77.8% low MDR1 expressers achieved complete remission (CR; p = 0.029). Idarubicin yielded a higher CR rate than daunorubicin in high MDR1 expressers (82.1 vs 41.2%; p = 0.001), it also demonstrated a higher CR rate than daunorubicin (p < 0.05) in high MDR1 expressers exhibiting favorable or intermediate risk, while there was no difference between the two treatment arms in low MDR1 expressers exhibiting either favorable or intermediate risk. Conclusion: Idarubicin is associated with better remission induction of de novo acute myeloid leukemia patients with high MDR1 expression.

Original submitted 23 May 2012; Revision submitted 10 October 2012

Advances in acute lymphoblastic leukemia in adults

PURPOSE OF REVIEW

This review will be focused on the advances in adult acute lymphoblastic leukemia (ALL) based on recently published articles.

RECENT FINDINGS

Progress in the understanding of the molecular basis of ALL has contributed to a more precise definition of risk factors. The study of minimal residual disease has re-defined the baseline prognostic factors and has opened new strategies for postremission management. The use of pediatric-inspired therapies for young adults with standard-risk ALL, the broadening of the number of patients who are eligible for allogeneic stem cell transplantation, the increasing use of targeted therapies (monoclonal antibodies, tyrosine kinase inhibitors, and new purine analogs, etc.) in early phases of the disease, together with the improvements in supportive therapy explain the increased survival of young and middle-aged adult ALL.

SUMMARY

These changes are improving long-term outcome, which in ongoing studies is expected to be of close to 50%, and are opening the door for future therapeutic advances.

Upregulation of mdr1 gene is related to activation of the MAPK/ERK signal transduction pathway and YB-1 nuclear translocation in B-cell lymphoma

OBJECTIVE

Multidrug resistance (MDR) in human B-cell lymphoma constitutes a major obstacle to the effectiveness of chemotherapy. The aim of this study was to investigate the molecular mechanism of MDR in B-cell lymphoma.

MATERIALS AND METHODS

The B-cell lymphoma MDR sublines were developed by exposing the parental Daudi cells to stepwise increasing concentrations of doxorubicin. Interaction of Y-box binding protein-1 (YB-1) with the Y-box motif of the mdr1 gene promoters was studied by electrophoretic mobility shift assay. The effects of YB-1 on mdr1 promoter activity were examined by luciferase assay. After silencing of YB-1 gene by shRNA, the role of YB-1 nuclear translocation in the formation of induced MDR was examined. Expression of mdr1 and YB-1 was examined further after Daudi cells were pretreated with mitogen-activated protein kinase (MAPK) inhibitor PD98059 for 1 hour.

RESULTS

Doxorubicin-resistant sublines was generated from the Daudi cell line by stepwise selection in doxorubicin. We found that acquisition of MDR is associated with enhanced YB-1 nuclear translocation and MAPK/extracellular signal-regulated kinase (ERK) activity. Electrophoretic mobility shift assay revealed that doxorubicin increased binding of YB-1 to the Y-box of mdr1 promoter. Luciferase reporter assays demonstrated that the Y-box region is essential for YB-1 regulation of mdr1 expression. The introduction of exogenous YB-1 shRNA into Daudi cells resulted in decreased levels of the expression of mdr1 gene and P-glycoprotein induced by doxorubicin. When Daudi cells were pretreated with MAPK inhibitor PD98059, the phosphorylation of ERK was effectively inhibited as well as the nuclear translocation of YB-1 and the expression of mdr1 gene.

CONCLUSION

Doxorubicin can increase expression of mdr1/P-glycoprotein through activating MAPK/ERK transduction pathway, then increasing expression of YB-1, inducing YB-1 nuclear translocation, and enhancing DNA-binding activity of YB-1.