Lijing Shen

MYCN Transgenic Zebrafish Model with the Characterization of Acute Myeloid Leukemia and Altered Hematopoiesis

Background Amplification of MYCN (N-Myc) oncogene has been reported as a frequent event and a poor prognostic marker in human acute myeloid leukemia (AML). The molecular mechanisms and transcriptional networks by which MYCN exerts its influence in AML are largely unknown. Methodology/Principal Findings We introduced murine MYCN gene into embryonic zebrafish through a heat-shock promoter and established the stable germline Tg(MYCN:HSE:EGFP) zebrafish. N-Myc downstream regulated gene 1 (NDRG1), negatively controlled by MYCN in human and functionally involved in neutrophil maturation, was significantly under-expressed in this model. Using peripheral blood smear detection, histological section and flow cytometric analysis of single cell suspension from kidney and spleen, we found that MYCN overexpression promoted cell proliferation, enhanced the repopulating activity of myeloid cells and the accumulation of immature hematopoietic blast cells. MYCN enhanced primitive hematopoiesis by upregulating scl and lmo2 expression and promoted myelopoiesis by inhibiting gata1 expression and inducing pu.1, mpo expression. Microarray analysis identified that cell cycle, glycolysis/gluconeogenesis, MAPK/Ras, and p53-mediated apoptosis pathways were upregulated. In addition, mismatch repair, transforming and growth factor β (TGFβ) were downregulated in MYCN-overexpressing blood cells (p<0.01). All of these signaling pathways are critical in the proliferation and malignant transformation of blood cells. Conclusion/Significance The above results induced by overexpression of MYCN closely resemble the main aspects of human AML, suggesting that MYCN plays a role in the etiology of AML. MYCN reprograms hematopoietic cell fate by regulating NDRG1 and several lineage-specific hematopoietic transcription factors. Therefore, this MYCN transgenic zebrafish model facilitates dissection of MYCN-mediated signaling in vivo, and enables high-throughput scale screens to identify the potential therapeutic targets.

Co-Existent de novo Myelodysplastic Syndrome and T-cell Non-Hodgkin Lymphoma: a Common Origin or Not?

The co-existence of de novo myelodysplastic syndrome (MDS) and non-Hodgkin lymphoma (NHL) prior to therapy is an extremely unusual finding. We report here a case of co-existent de novo MDS-refractory cytopenia with multilineage dysplasia and T-cell NHL, including clinical features, histopathological findings, molecular assessment, treatment course and outcomes. Other cases from the literature showing co-existence of both disorders are also reviewed; to date 19 similar cases have been reported. Among all cases (including the present patient), eight cases were diagnosed with de novo MDS and NHL simultaneously, which were considered to be true coincidences. The mechanisms responsible for the appearance of co-existence have not yet been ascertained, however in the present case a common chromosomal abnormality (20q deletion) was found in bone marrow and lymph node preparations. We conclude, therefore, that the co-existent de novo MDS and T-cell NHL seen in the present case may have a common origin.

Using modified whole-mount in situ hybridization to study mpo expression in zebrafish

In this study, we cloned the myeloperoxidase (mpo) gene of zebrafish and prepared a digoxigenin-labeled mpo RNA probe to investigate mpo gene expression in zebrafish during embryonic development by whole-mount in situ hybridization (WISH). The earliest mpo expression was detected in cells of the intermediate cell mass (ICM) at 18 h post-fertilization (hpf). It was detected 1 to 2 h later in cells in the rostral blood island (RBI) and strong signals were observed in the anterior ICM. Then, it spread over the yolk sac. By 72 hpf these mpo-expressing cells were in the circulation and distributed throughout the embryo. We identified that the level of mpo expression detected by WISH at an early stage was consistent with the data of cytological analyses of adult fish. The use of this method enabled us to track the gene changes that took place before morphological phenotypes were detected, as well to as investigate the hematopoietic cell fate in mutational or transgenic models in vivo. In this study, we modified several steps of WISH. The improved hybridization results demonstrated high specificity, distinct coloration and low background figures.

miR-146a Expression Level as a Novel Putative Prognostic Marker for Acute Promyelocytic Leukemia

Background. Although the curative rate for acute promyelocytic leukemia (APL) has been improved over decades, long-term prognosis is still poor. The genetic pathways that regulated cell lineage fate during the development of APL remain unclear. Methods. We investigated the correlations of miR-146a expression with its target gene Smad4 and the biological behaviors of NB4 cells. We also analyzed their expression in clinical samples from APL patients. Results. miR-146a influenced apoptosis and proliferation in NB4 cells. miR-146a influenced endogenous Smad4 protein levels in APL cells. miR-146a expression levels were positively correlated with white cell counts and PML/RARα fusion protein expression. miR-146a expression levels were negatively correlated with Smad4 protein and the helper T cell (Th)/the suppressor T cell (Ts) ratio in these patients. Conclusions. These findings indicated that miR-146a played an important role in the development of APL in part through the repression on Smad4 protein expression. miR-146a functioned as an oncogene and may be a novel prognostic biomarker in APL.

Hyperfibrinolysis after parapelvic cyst surgery: A case report

The present study describes the diagnosis and treatment of hyperfibrinolysis following surgery in a 25-year-old female patient. An examination revealed that the left kidney had been affected by severe hydronephrosis for two weeks prior to hospitalization. The diagnosis of a parapelvic cyst was obtained by preoperative intravenous pyelogram (IVP), computed tomography (CT) and upper left urinary tract retrograde pyelography. Unroofing of the left parapelvic cyst was performed by open surgery. The patient exhibited symptoms of shock 48 h later, and her hemoglobin (Hb) levels dropped to only 62.2 g/l. To treat this, 400 ml erythrocyte suspension transfusion was administered 3 times every other day. The patient’s Hb levels remained between 50 and 60 g/l. The D-dimer assay index rose from 0.3 to 16 mg/l and the fibrin degradation product (FDP) levels progressively increased following the hemorrhage, while the platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (Fg) index were all within normal levels. p-Aminomethylbenzoic acid (PAMBA; 0.5 g) was administered to the patient every day, and as a consequence the Hb levels rose steadily from the next day onwards. After a one week course of PAMBA treatment, the patient’s condition became stable. Blood coagulation and fibrinolytic function measurements were all within the normal ranges in the three months following the surgery. Delayed hemorrhage following surgery should be considered as a possible cause of hyperfibrinolysis. Monitoring FDP and D-dimer levels may aid a rapid and clear diagnosis. Anti-fibrinolytic therapy, such as PAMBA treatment, is safe and effective for use against the type of hemorrhage caused by hyperfibrinolysis.

Correlation of pretreatment 18F-FDG uptake with clinicopathological factors and prognosis in patients with newly diagnosed diffuse large B-cell lymphoma

ObjectivesThe aim of this study is to determine the correlation of pretreatment fluorine-18 fluorodeoxyglucose uptake with clinicopathological factors and its prognostic value in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). Patients and methodsA cohort of 162 patients with newly diagnosed DLBCL who had undergone pretreatment PET/computed tomography was retrospectively reviewed. The relationship of pretreatment maximum standard uptake value (SUVmax) with clinical factors, molecular markers, and efficacy was evaluated. The value of SUVmax in predicting progression-free survival (PFS) and overall survival was analyzed. ResultsIn all, 72.9% of the patients received R-CHOP treatment; the rest received CHOP chemotherapy. The median follow-up duration was 30 months (range, 4–124 months). The median SUVmax was 12.2 (range, 1.7–42.7). SUVmax between groups differed significantly with respect to each of International Prognostic Index (IPI) factors, except for age and performance status. High SUVmax was associated with high Ki-67 and Glut-3 protein expression, but not with Glut-1. Complete remission rate differed significantly between the low (SUVmax⩽9.0) and the high SUVmax (SUVmax>9.0) groups (91.7 vs. 61.1%, P=0.000). Patients with low SUVmax showed favorable survival (3-year PFS: 92.2 vs. 63.6%, P=0.000; 3-year overall survival: 95.5 vs. 78.3%, P=0.003). On multivariate analyses, SUVmax predicted PFS independent of revised-IPI (SUVmax: P=0.011, hazard ratio 4.784; revised-IPI: P=0.004, hazard ratio 2.551). ConclusionPretreatment SUVmax was associated with clinicopathological factors, efficacy, and survival outcome. A novel prognostic model on the basis of IPI score/pretreatment SUVmax might be useful for risk stratification of patients with newly diagnosed DLBCL Video abstract: http://links.lww.com/NMC/A55.