The promyelocytic leukemia (PML) was originally identified and named as acute promyelocytic leukaemia (APL) . The PML, encoded by PML gene, locates in the nuclear body (NB) and shuttles in the cell nucleus-cytoplasm, so that PML completes many regulation functions. There are many research on the function of nuclear PML, but in recent years the foreign data indicate that cytoplasmic PML gene plays an important role in hematologic malignancies and solid tumors. In this article, the biological functions of PML gene in cytoplasm are reviewed.
Cytoplasm ; genetics ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; Nuclear Proteins ; genetics ; Promyelocytic Leukemia Protein ; Transcription Factors ; genetics ; Tumor Suppressor Proteins ; genetics

Acute myeloid leukemia (AML) is a rare type of childhood acute leukemia, which has a worse prognosis than childhood acute lymphoblastic leukemia. Over the past decade, significant progress has been made in the treatment of childhood AML and the 5-year event-free survival rate may be as high as 70% in developed countries. This survival improvement is largely attributable to risk-stratified treatments, therapies tailored to individual patients based on the biological characteristics of the disease, and continuously improving supportive care. An accurate diagnosis is the prerequisite for risk stratification, prognostic evaluation and therapeutic decision making. How to reduce early mortality and thus improve overall survival, how to implement appropriate supportive treatment to reduce treatment-associated complications, and how to reduce treatment-related mortality are the key to the improvement of therapies for childhood acute myeloid leukemia.
Child ; Humans ; Leukemia, Myeloid, Acute ; diagnosis ; drug therapy ; genetics ; mortality ; Leukemia, Promyelocytic, Acute ; drug therapy ; genetics

Humans ; Blast Crisis/genetics* ; Leukemia, Promyelocytic, Acute/genetics* ; Oncogene Proteins, Fusion/genetics* ; Tretinoin

Human acute premyeloid leukemia cell cDNA expression library was constructed to screen acute premyeloid leukemia tumor antigen. Total RNA and purified mRNA were extracted from human premyeloid cell line NB4. First and second strands of cDNA were synthesized by reverse transcription. After blunting, the cDNA fragments were ligated with EcoR I adapters. Then the cDNAs were digested with Xho I, and less than 400 bp cDNA fragment was removed by Sephacryl-S400 spin column, the remaining were ligated with lambdaZAP vector. The recombinants were packaged in vitro, and a small portion of packaged phage was used to infect E. coli XL1-Blue-MRF' for titration. The recombinants were examined by color selection. In order to evaluate the size of cDNA inserts and the diversity of library, the pBK-CMV phagemid was excised from the ZAP express vector by using ExAssist helper phage with XLOLR strain, and then the pBK-CMV phagemid was digested by Xho I and EcoR I. The results showed that the NB4 cell line cDNA library consisting of 1.65 x 10(6) recombinant bacteriophages was constructed with the recombinant ratio of 99.6%. The average length of the recombinant exogenous inserts was about 1.7 kb. It was concluded that the constructed cDNA library are deserved to screen target clones.
Bacteriophages/genetics ; DNA, Complementary/*biosynthesis ; *DNA, Neoplasm/biosynthesis ; DNA, Recombinant/biosynthesis ; *Gene Library ; Genetic Vectors ; Leukemia, Promyelocytic, Acute/*genetics ; Leukemia, Promyelocytic, Acute/metabolism ; Leukemia, Promyelocytic, Acute/pathology ; RNA-Directed DNA Polymerase/metabolism ; Transcription, Genetic/genetics

Objective: Most acute promyelocytic leukemia cases are characterized by the PML-RARa fusion oncogene and low white cell counts in peripheral blood. Methods: Based on the frequent overexpression of miR-125-family miRNAs in acute promyelocytic leukemia, we examined the consequence of this phenomenon by using an inducible mouse model overexpressing human miR-125b. Results: MiR-125b expression significantly accelerates PML-RARa-induced leukemogenesis, with the resultant induced leukemia being partially dependent on continued miR-125b overexpression. Interestingly, miR-125b expression led to low peripheral white cell counts to bone marrow blast percentage ratio, confirming the clinical observation in acute promyelocytic leukemia patients. Conclusion This study suggests that dysregulated miR-125b expression is actively involved in disease progression and pathophysiology of acute promyelocytic leukemia, indicating that targeting miR-125b may represent a new therapeutic option for acute promyelocytic leukemia.
Animals ; Humans ; Leukemia, Promyelocytic, Acute/metabolism* ; Mice ; MicroRNAs/genetics* ; Oncogene Proteins, Fusion/therapeutic use*

OBJECTIVETo optimize the calculation of quantitative real time RT-PCR (Q-RT-PCR) of PML-RARalpha in patients with acute promyelocytic leukemia (APL) for molecular monitoring of minimal residual disease (MRD).

METHODSBy using both regular reverse transcription polymerase chain reaction (RT-PCR) and Q-RT-PCR, the expression levels of PML-RARalpha transcripts were measured before and after treatment. The conventional Q-RT-PCR calculation was directly compared the post-treatment transcript level with the respective pre-treatment one (DoseN) in the individual patient while the standardized calculation was based on the calculation of standardized pre-treatment DoseN of all patients.

RESULTSIn 181 samples from 31 patients, the results of log-reduction of PML-RARa after induction, at the end of consolidation and during maintenance by conventional method were (1.9 +/- 1.9), (4.8 +/- 1.3) and (5.7 +/- 0.4), respectively, while by standardized method were (2.0 +/- 1.9), (4.9 +/- 1.4) and (5.7 +/- 0.1), respectively. Of notice, the result was with significant less variation of the latter methods during maintenance therapy. Moreover, with defined criteria of molecular response (3.0-4.9 log-reduction as minor and > or = 5.0 log-reduction as major molecular response), the standardized method was validated in clinical settings.

CONCLUSIONThe standardized method is superior to the conventional method for calculation of Q-RT-PCR results. The new method can reduce the individual variation in monitoring the MRD and is feasible even for patients with unavailable pre-treatment samples.

Follow-Up Studies ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; Oncogene Proteins, Fusion ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; methods

The high expression of tissue factor (TF) is related to the coagulation disorder in acute leukemia. TF in blood circulation is mainly expressed in cells, microparticles (MP) and alternatively spliced human tissue factor (asHTF). To elucidate the role of TF in the coagulation disorder of acute myeloid leukemia (AML), RT-PCR was performed on 6 common AML cell lines NB4, HL-60, Kasumi-1, U937, K562 and THP-1. The results showed that only NB4 and U937 cells expressed baseline full-length TF and asHTF which were proved by sequencing. The flow cytometric detection, TF activity and TF antigen tests in NB4 and U937 cells revealed that the asHTF was expressed in trace amount and almost had no activity, while the TF antigen and activity in microparticles were significantly higher than that in asHTF. It is concluded that asHTF may play an unimportant role in the coagulation disorder of AML. Microparticle associated tissue factor (MP-TF) is the predominant source of TF activity released from AML cells.
Alternative Splicing ; HL-60 Cells ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; metabolism ; Thromboplastin ; genetics ; metabolism ; Tumor Cells, Cultured ; U937 Cells

OBJECTIVETo explore the relationship between long (L) type PML-RAR alpha fusion gene and the prognosis of patients with acute promyelocytic leukemia (APL).

METHODSPML-RAR alpha fusion gene was detected by RT-PCR in 33 APL patients. The optical density of three bands including E5 (+) E6 (+) 636 bp (no deletion), E5 (-) E6 (+) 492 bp (exon 5 deleted) and E5 (-) E6 (-) 232 bp (both exon 5 and exon 6 deleted) was measured by a UVP analysis system and their relative proportions were calculated. The relative expression level of each splicing band, initial WBC count and age were statistically (for single and multi-factor analysis) analyzed with prognosis.

RESULTSThe relative expressions of E5 (-) E6 (+) and E5 (-) E6 (-) in death group were obviously different from that in first complete remission (CR1) group (P < 0.01), but do not for E5 (+) E6 (+) (P > 0.05). The relative expression levels of E5 (-) E6 (+), E5 (-) E6 (-) and E5 (+) E6 (+) were 0.23 +/- 0.12, 0.58 +/- 0.18, 0.20 +/- 0.09 in death group, and 0.45 +/- 0.16, 0.23 +/- 0.12, 0.31 +/- 0.16 in CR1 group, respectively. Initial WBC count and age was no difference between the two groups (P > 0.05). Logistic regression analysis showed that the expression of E5 (-) E6 (+) had no effect on the prognosis (B = 3.475, P = 0.492), but the expression of E5 (-) E6 (-) showed a negative correlation with prognosis (B = -19.660, P = 0.046).

CONCLUSIONSThe high expression of E5 (-) E6 (-) is correlated with the poor prognosis for patients with APL.

Adolescent ; Adult ; Alternative Splicing ; Female ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; Male ; Middle Aged ; Oncogene Proteins, Fusion ; genetics ; Prognosis ; Young Adult

In order to analyze the distribution and clonal expansion of TCR Vbeta subfamily T cells in patients with acute promyelocytic leukemia (APL) in vivo and in vitro after T cell culture, the peripheral blood mononuclear cells from 3 APL patients were expanded by rhIL-2 and anti-CD3 antibody using liquid T lymphocytes culture technique. The complementary determining region 3 (CDR3) of TCR beta with variable region genes was amplified in T cells from 3 APL cases before and after T cell culture by using RT-PCR. The positive products were further analyzed to identify the clonality of T cells by genescan. The results showed that only a part of 24 Vbeta subfamilies was detected in T cells from the patients, and some Vbeta subfamily T cells could be identified after T cells culture. The clonal expansion T cells in some TCR Vbeta subfamilies could be found in all patients. The similar oligoclonal expansion of Vbeta1, Vbeta3, Vbeta7, Vbeta16 and Vbeta20 T cells was detected in two cases at different time points after T cell culture. It is concluded that the restricted expression of TCR Vbeta subfamily in T cells from patients might be the common feature in leukemia. Some Vbeta subfamily T cells could be induced after T cells culture in vitro. The continual clonal expansion of TCR Vbeta subfamily T cells at different time points after T cells culture could be a specific immune response of patients T cells related to the specific APL cell associated antigen.
Humans ; Leukemia, Promyelocytic, Acute ; genetics ; immunology ; Lymphocyte Activation ; Receptors, Antigen, T-Cell, alpha-beta ; genetics ; T-Lymphocytes ; immunology

OBJECTIVERecent studies have suggested that there is a close relation between microRNA and acute leukemia (AL). The aim of this study was to investigate and better understand the classification and diagnosis of AL as well as pathogenesis and prognosis of this disease.

METHODSA total of 93 children with AL and and 12 cases of idiopathic thrombocytopenic purpura (as control group) were enrolled in this study. Microarray chip analysis of their bone marrow samples was conducted to evaluate the microRNA profiles. Quantitative real-time PCR was performed for validating the abnormal expression of microRNA.

RESULTSThe microRNA expression profiles were different between acute granulocytic leukemia and acute lymphoblastic leukemia and also between the three subtypes (M1, M2 and M3) of acute granulocytic leukemia according to FAB classification based on leukemic cell differentiation. These three subtypes of leukemia could be identified by unsupervised hierarchical cluster analysis of microRNA expression and had specific up-regulation of miR-335, miR-126 and miR-125b, respectively. However, in the M2 and M3 subtypes with positive AML1-ETO and PML-RARα, respectively, which have a better prognosis, the expressions of miR-126 and miR-125b were significantly higher than those with negative AML1-ETO and PML-RARα. Further more, miR-335 and miR-146 were up-regulated in acute granulocytic leukemia observed in this study, which are different from those reported for adult patients.

CONCLUSIONSmicroRNA cascade may serve as new biomarkers for the classification and diagnosis of pediatric AL. It is also suggested that there might be different pathogenesis and prognosis between AL types related to specific expression and regulation of microRNA.

Adolescent ; Child ; Child, Preschool ; Female ; Gene Expression Profiling ; Humans ; Infant ; Leukemia, Myeloid ; classification ; genetics ; metabolism ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Leukemia, Promyelocytic, Acute ; genetics ; metabolism ; Male ; MicroRNAs ; genetics ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; metabolism