SPINK2 Protein Expression Is an Independent Adverse Prognostic Marker in AML and Is Potentially Implicated in the Regulation of Ferroptosis and Immune Response.

There is an urgent need for the identification as well as clinicopathological and functional characterization of potent prognostic biomarkers and therapeutic targets in acute myeloid leukemia (AML). Using immunohistochemistry and next-generation sequencing, we investigated the protein expression as well as clinicopathological and prognostic associations of serine protease inhibitor Kazal type 2 (SPINK2) in AML and examined its potential biological functions. High SPINK2 protein expression was an independent adverse biomarker for survival and an indicator of elevated therapy resistance and relapse risk. SPINK2 expression was associated with AML with an NPM1 mutation and an intermediate risk by cytogenetics and European LeukemiaNet (ELN) 2022 criteria. Furthermore, SPINK2 expression could refine the ELN2022prognostic stratification. Functionally, an RNA sequencing analysis uncovered a potential link of SPINK2 with ferroptosis and immune response. SPINK2 regulated the expression of certain P53 targets and ferroptosis-related genes, including SLC7A11 and STEAP3, and affected cystine uptake, intracellular iron levels and sensitivity to erastin, a specific ferroptosis inducer. Furthermore, SPINK2 inhibition consistently increased the expression of ALCAM, an immune response enhancer and promoter of T-cell activity. Additionally, we identified a potential small-molecule inhibitor of SPINK2, which requires further characterization. In summary, high SPINK2 protein expression was a potent adverse prognostic marker in AML and might represent a druggable target.

Liver complications of haemoglobin H disease in adults.

Haemoglobin H (HbH) disease is a type of non-transfusion-dependent thalassaemia. This cross-sectional study aimed at determining the prevalence and severity of liver iron overload and liver fibrosis in patients with HbH disease. Risk factors for advanced liver fibrosis were also identified. A total of 80 patients were evaluated [median (range) age 53 (24-79) years, male 34%, non-deletional HbH disease 24%]. Patients underwent 'observed' T2-weighted magnetic resonance imaging examination for liver iron concentration (LIC) quantification, and transient elastography for liver stiffness measurement (LSM) and fibrosis staging. In all, 25 patients (31%) had moderate-to-severe liver iron overload (LIC ≥7 mg/g dry weight). The median LIC was higher in non-deletional than in deletional HbH disease (7·8 vs. 2.9 mg/g dry weight, P = 0·002). In all, 16 patients (20%) had advanced liver fibrosis (LSM >7.9 kPa) and seven (9%) out of them had probable cirrhosis (LSM >11.9 kPa). LSM positively correlated with age (R = 0·24, P = 0·03), serum ferritin (R = 0·36, P = 0·001) and LIC (R = 0·28, P = 0·01). In multivariable regression, age ≥65 years [odds ratio (OR) 4·97, 95% confidence interval (CI) 1·52-17·50; P = 0·047] and moderate-to-severe liver iron overload (OR 3·47, 95% CI 1·01-12·14; P = 0·01) were independently associated with advanced liver fibrosis. The findings suggest that regular screening for liver complications should be considered in the management of HbH disease.

t(1;22)(p13;q13) Acute Megakaryoblastic Leukemia Complicated by Hepatic Fibrosis: Antifibrosis Therapy?

BACKGROUND: There is no established effective treatment for patients with t(1;22)(p13;q13) acute megakaryoblastic leukemia (AMKL) and hepatic fibrosis. OBSERVATION: Here we report the outcomes of 2 t(1;22)(p13;q13) AMKL patients with hepatic fibrosis. One patient died from liver failure despite the control of leukemia. The other patient was successfully treated with reduced-intensity chemotherapy and antifibrosis therapy with tretinoin and α-tocopheryl acetate, the hepatic fibrosis resolved and leukemia was in remission for 3 years. CONCLUSIONS: Reduced-intensity chemotherapy plus antifibrosis therapy with tretinoin and α-tocopheryl acetate could be a treatment option for these patients with t(1;22)(p13;q13) AMKL and hepatic fibrosis.

An Evaluation for the Causes of Reduced Hb A2 and the Molecular Characterization of HBD Variants in Hong Kong.

Prenatal screening of ß-thalassemia (ß-thal) carriers is based on the hallmark phenotype of microcytosis and raised Hb A2. The unanticipated birth of ß-thal major (ß-TM) offspring to ß-thal carriers who were misdiagnosed during prenatal screening have been reported. A subset of these resulted from the masked phenotype due to the coinheritance of HBD variants. In a broader sense, the causes of reduced Hb A2 in thalassemia screening, the prevalence and spectrum of HBD variants in Hong Kong remain to be characterized. Over a 13-month period, a total of 2982 samples were referred for thalassemia screening. Surplus samples with reduced Hb A2 levels (2.0%) were evaluated. HBD variations were assessed by direct sequencing. Sixty-six samples were tested. Hb H disease, HBD variants, α-thalassemia (α-thal) trait and iron deficiency were detected in 40 (60.6%), 12 (18.2%), eight (12.1%) and seven (10.6%) samples, respectively. Seven samples carried more than one of the mentioned conditions. The cause remained elusive in seven samples. Thirteen HBD variants were detected and two were recurrent, including HBD: c.-127T>C [-77 (T>C)] and HBD: c.314G>A (Hb Chori-Burnaby). A novel nonsense variant HBD: c.262C>T [codon 87 (C>T)] was detected in cis with HBD: c.-127T>C. Overall, the prevalence of HBD variants was 0.4%. This study advanced our understanding of the causes of reduced Hb A2 in clinical practice and identified hereditary disorders of α- and δ-globin genes as the prevailing causes. It established the landscape of HBD variations in our locality and highlighted the pitfall of phenotypic screening of ß-thal carriers.

Distinct mutation spectrum, clinical outcome and therapeutic responses of typical complex/monosomy karyotype acute myeloid leukemia carrying TP53 mutations.

The present study aimed to define a subtype of complex/monosomal karyotype (CK/MK) acute myeloid leukemia (AML) by its distinct clinical features, p53 signaling and responses to p53 targeting agents. Ninety-eight young adults (range: 21-60 years; median: 49 years) with CK/MK AML were studied. They received standard induction, consolidation and allogeneic hematopoietic stem cell transplantation from siblings or matched unrelated donors if available. Chromosomal abnormalities most commonly affected chromosome 5 (30%), 7 (22%) and 17 (21%). Next generation sequencing of a 54-myeloid gene panel were available in 76 patients. Tumor protein 53 (TP53) mutations were most common (49%) and associated with the presence of -5/5q- (P < .001) and -17/17p- (P < .001), but not -7/7q- (P = .370). This "typical" CK/MK AML subtype was associated with significantly lower presenting white cell counts, higher number of karyotypic abnormalities, and inferior leukemia-free and overall survivals, compared with CK/MK AML without the typical features. Blood or bone marrow samples from typical CK/MK AML patients showed defective p53 signaling upon induction by etoposide. In vitro drug sensitivity analysis showed that they were sensitive to APR-246 that targeted mutant p53, but resistant to MDM2 antagonist MI-77301. Novel therapeutic strategies targeting TP53 mutations in CK/MK AML should be developed and tested in clinical trials.

RUNX1 upregulation via disruption of long-range transcriptional control by a novel t(5;21)(q13;q22) translocation in acute myeloid leukemia.

RUNX1 encodes a Runt-related transcription factor that is critical for hematopoiesis. In this study, through a combinatorial molecular approach, we characterized a novel t(5;21)(q13;q22) translocation involving RUNX1 that was acquired during the progression of myelodysplastic syndrome to acute myeloid leukemia (AML) in a pediatric patient. We found that this translocation did not generate RUNX1 fusion but aberrantly upregulated RUNX1. This upregulation was attributed to the disruption of long-range chromatin interactions between the RUNX1 P2 promoter and a silencer in the first intron of the gene. Characterization of the silencer revealed a role of SNAG repressors and their corepressor LSD1/KDM1A in mediating the effect. Our findings suggest that chromosomal rearrangements may activate RUNX1 by perturbing its transcriptional control to contribute to AML pathogenesis, in keeping with an emerging oncogenic role of RUNX1 in leukemia.

Outcome of children with newly diagnosed acute lymphoblastic leukemia treated with CCLG-ALL 2008: The first nation-wide prospective multicenter study in China.

Acute lymphoblastic leukemia (ALL) is the most common malignancy among children. The trial Chinese Children Leukemia Group (CCLG)-ALL 2008 was a prospective clinical trial designed to improve treatment outcome of childhood ALL through the first nation-wide collaborative study in China. Totally 2231 patients were recruited from ten tertiary hospitals in eight cities. The patients were stratified according to clinical-biological characteristics and early treatment response. Standard risk (SR) and intermediate risk (IR) groups were treated with a modified BFM based protocol, and there was 25%-50% dose reduction during intensification phases in the SR group. Patients in high risk (HR) group received a more intensive maintenance treatment. Minimal residual disease (MRD) monitoring with treatment adjustment was performed in two hospitals (the MRD group). Complete remission (CR) was achieved in 2100 patients (94.1%). At five years, the estimate for overall survival (OS) and event-free survival (EFS) of the whole group was 85.3% and 79.9%, respectively. The cumulative incidence of relapse (CIR) was 15.3% at five years. The OS, EFS and CIR for the SR group were 91.5%, 87.9%, and 9.7%, respectively. The outcome of the MRD group is better than the non-MRD group (5y-EFS: 82.4% vs 78.3%, P = .038; 5y-CIR: 10.7% vs 18.0%, P < .001). Our results demonstrated that the large-scale multicenter trial for pediatric ALL was feasible in China. Dose reduction in the SR group could achieve high EFS. MRD-based risk stratification might improve the treatment outcome for childhood ALL.

First Report of Hb Kent [ß37(C3)Trp→Cys (TGG>TGC) HBB: c.114G>C] in a Chinese Family.

We report a novel HBB: c.114G>C mutation in a Chinese family. This mutation resulted in a ß37(C3)Trp→Cys amino acid substitution and was synonymous with Hb Kent, a hemoglobin (Hb) variant that was reported exclusively in patients of European descent. Though Hb Kent has a normal oxygen affinity and molecular stability, it has a characteristic dual variant appearance on cellulose acetate electrophoresis (CAE) and high performance liquid chromatography (HPLC) caused by the posttranslational modification of cysteine. We also report the phenotypic expression of this variant when coinherited with the Southeast Asian (- -SEA) double α-globin gene deletion.

Helicase-like transcription factor is a RUNX1 target whose downregulation promotes genomic instability and correlates with complex cytogenetic features in acute myeloid leukemia.

Helicase-like transcription factor is a SWI/SNF chromatin remodeling factor involved in various biological processes. However, little is known about its role in hematopoiesis. In this study, we measured helicase-like transcription factor mRNA expression in the bone marrow of 204 adult patients with de novo acute myeloid leukemia. Patients were dichotomized into low and high expression groups at the median level for clinicopathological correlations. Helicase-like transcription factor levels were dramatically reduced in the low expression patient group compared to those in the normal controls (n=40) (P<0.0001). Low helicase-like transcription factor expression correlated positively with French-American-British M4/M5 subtypes (P<0.0001) and complex cytogenetic abnormalities (P=0.02 for ≥3 abnormalities;P=0.004 for ≥5 abnormalities) but negatively with CEBPA double mutations (P=0.012). Also, low expression correlated with poorer overall (P=0.005) and event-free (P=0.006) survival in the intermediate-risk cytogenetic subgroup. Consistent with the more aggressive disease associated with low expression, helicase-like transcription factor knockdown in leukemic cells promoted proliferation and chromosomal instability that was accompanied by downregulation of mitotic regulators and impaired DNA damage response. The significance of helicase-like transcription factor in genome maintenance was further indicated by its markedly elevated expression in normal human CD34(+)hematopoietic stem cells. We further demonstrated that helicase-like transcription factor was a RUNX1 target and transcriptionally repressed by RUNX1-ETO and site-specific DNA methylation through a duplicated RUNX1 binding site in its promoter. Taken together, our findings provide new mechanistic insights on genomic instability linked to helicase-like transcription factor deregulation, and strongly suggest a tumor suppressor function of the SWI/SNF protein in acute myeloid leukemia.

Hb Tarrant [α126(H9)Asp→Asn; HBA2: c.379G > A (or HBA1)] in a Chinese Family as a Cause of Familial Erythrocytosis.

Hb Tarrant [α126(H9)Asp→Asn; HBA2: c.379G > A (or HBA1)], is a rare high oxygen affinity hemoglobin (Hb) variant that causes erythrocytosis, previously described in a few Mexican-American families. Here we report the first Chinese family with this Hb variant presenting with unexplained familial erythrocytosis. No evidence of hemolysis was seen. A locally adapted approach to the diagnostic process in clinical laboratories is discussed. Molecular analysis has an important role in confirmation of the diagnosis. Proper identification of this rare but clinically significant Hb variant is helpful for family counseling and will help to guide appropriate management of absolute erythrocytosis.

A Multi-locus Approach to Characterization of Major Quantitative Trait Loci Influencing Hb F Regulation in Chinese ß-thalassemia Carriers.

Genetic association studies showed that Hb F is under the influence of major quantitative trait loci (QTL) in ß-thalassemia (ß-thal) carriers. Single nucleotide polymorphisms (SNPs) at three major QTLs, BCL11A, HBS1L-MYB intergenic region and XmnI-HBG2 were individually validated in univariate models. However, their relative effect sizes on Hb F regulation are unknown. We genotyped 99 Chinese ß-thal carriers for the three major QTLs and performed genetic association studies using three different statistical models, including mass univariate analysis, multivariate linear regression and partial least square regression structural equation modeling (PLS-SEM). Performances of the three models were compared and effect sizes of the three QTLs in a multivariate model were assessed. Traditional mass univariate analysis and multivariate linear regression showed limited statistical power in our small cohort and the latter was constrained by multicollinearity. Partial least structural equation modeling showed significant positive associations of each QTL (p <0.05) with Hb F regulation, together explained 34.4% of variance. The HBS1L-MYB intergenic region polymorphism (HMIP) demonstrated the highest effect on Hb F prediction with effect size f2 0.294. PLS-SEM offered a statistically powerful multivariate model for multi-locus genetic association studies. We reproduced findings of previous studies with a much smaller cohort and demonstrated HMIP as the strongest regulator of Hb F in Chinese ß-thal carriers.

Serotonin enhances megakaryopoiesis and proplatelet formation via p-Erk1/2 and F-actin reorganization.

Our previous studies have shown that serotonin (5-hydroxytryptamine; 5-HT) is a growth factor for hematopoietic stem/progenitor cells. In this study, we proposed a possible mechanism: 5-HT may enhance megakaryopoiesis and proplatelet formation via Erk1/2 pathway and cytoskeleton reorganization. Here, 5-HT(2B)R was first identified in megakaryocytic cells. 5-HT also promoted the megakaryocytes (MKs) proliferation and reduced the cell apoptosis via the activation of 5-HT(2B)R and Akt pathway. The effects were reduced by the 5-HT2B R inhibitor ketanserin. The effect of 5-HT on proplatelet formation in bone marrow MKs were further confirmed: the 5-HT treated group had more proplatelet bearing MKs compared with the control group. To determine whether 5-HT has effects on cytoskeleton reorganization of MKs, and whether these effects could be reduced by ketanserin or Erk1/2 inhibitor PD98059, MKs were stained with the F-actin specific binder rhodamine-phalloidin. The polymerized actin level was lower in the control group than the 5-HT group and was distributed throughout the cytoplasm with occasional aggregations. Our data demonstrated that Erk1/2 was activated in MKs treated with 5-HT. This study suggests that 5-HT has a potent effect on platelet formation and this effect is likely mediated via 5HT(2B)R with subsequent activation of p-Erk1/2 and consequent F-actin reorganization and proplatelet formation. We also demonstrated that melatonin, the metabolite of 5-HT, exerts a protective effect on MK and platelet recovery in the irradiated mouse model. This study suggested that 5-HT plays an important role in platelet formation via 5HT(2B)R, p-Erk1/2, and F-actin reorganization.

SIRT2 overexpression in hepatocellular carcinoma mediates epithelial to mesenchymal transition by protein kinase B/glycogen synthase kinase-3ß/ß-catenin signaling.

UNLABELLED: Sirtuin 1 (SIRT1) has been implicated in telomere maintenance and the growth of hepatocellular carcinoma (HCC). Nevertheless, the role of other sirtuins in the pathogenesis of HCC remains elusive. We found that sirtuin 2 (SIRT2), another member of the sirtuin family, also contributes to cell motility and invasiveness of HCC. SIRT2 is up-regulated in HCC cell lines and in a subset of human HCC tissues (23/45). Up-regulations of SIRT2 in primary HCC tumors were significantly correlated with the presence of microscopic vascular invasion (P = 0.001), a more advanced tumor stage (P = 0.004), and shorter overall survival (P = 0.0499). Functional studies by short hairpin RNA-mediated suppression of SIRT2 expression in HCC cell lines revealed significant inhibition of motility and invasiveness. Depletion of SIRT2 also led to the regression of epithelial-mesenchymal transition (EMT) phenotypes, whereas the ectopic expression of SIRT2 in the immortalized hepatocyte cell line L02 promoted cell motility and invasiveness. Mechanistic studies revealed that SIRT2 regulates the deacetylation and activation of protein kinase B, which subsequently impinges on the glycogen synthase kinase-3ß/ß-catenin signaling pathway to regulate EMT. CONCLUSIONS: Our findings have uncovered a novel role for SIRT2 in HCC metastasis, and provide a rationale to explore the use of sirtuin inhibitors in HCC therapy. (HEPATOLOGY 2013;).

Secreted-frizzled related protein 1 is a transcriptional repression target of the t(8;21) fusion protein in acute myeloid leukemia.

Secreted-frizzled related proteins (SFRPs) are modulators of the Wnt signaling pathway that is closely involved in normal and malignant hematopoiesis. Epigenetic deregulation of Wnt modulators leading to aberrant signaling has been reported in adult patients with acute myeloid leukemia (AML), but its occurrence in childhood patients with AML and the role of individual modulators are unclear. In this study, we examined SFRP1, SFRP2, SFRP4, and SFRP5 promoter methylation in 83 patients with AML (59 children and 24 adults) and found preferential SFRP1 methylation and mRNA down-regulation in the prognostically favorable subgroup of AML with t(8;21) translocation. Among the 4 genes, SFRP1 methylation independently predicted prolonged event-free and relapse-free survivals in childhood patients with nonacute promyelocytic leukemia with nonadverse cytogenetics. Mechanistically, we further demonstrated that RUNX1-ETO, the t(8;21) fusion product, specifically bound the SFRP1 promoter and repressed its transcription via a consensus RUNX binding site. In t(8;21)-leukemia cells, SFRP1 selectively inhibited canonical Wnt signaling and cellular proliferation that were associated with concomitant down-regulation of Wnt/ß-catenin target genes, including CCND1 and MYC. Taken together, we identified SFRP1 as a transcriptional repression target of the t(8;21) fusion protein and demonstrated a novel mechanism of Wnt activation in a specific subtype of AML.

Preclinical evaluation of the AKT inhibitor MK-2206 in nasopharyngeal carcinoma cell lines.

Nasopharyngeal carcinoma (NPC) is endemic to Asia and over 40 % of NPC tissues harbor PIK3CA amplifications. This study characterized the preclinical activity of MK-2206, an oral allosteric inhibitor of AKT in 6 NPC cell lines: C666-1, HK1, HONE-1-EBV, HONE-1, CNE-2 and HNE-1. Exposure to increasing concentrations of MK-2206 resulted in over 95 % of growth inhibition in all NPC cell lines with IC50 values in the low micromolar range. Further experiments were performed in 3 representative NPC cell lines: CNE-2 (harbor PIK3CA mutation and most sensitive to MK-2206), C666-1 (carries PIK3CA amplification), and HONE-1-EBV (least sensitive to MK-2206). MK-2206 induced G0/G1 cycle arrest in all 3 cell lines, but could induce apoptosis only in CNE-2 cells. MK-2206 significantly abrogated AKT signaling in all 3 cell lines by inhibiting the activation of AKT and its downstream effectors (FKHR, GSK3ß and BAD). MK-2206 also reduced mTOR signaling by reducing activation of mTOR and its downstream 4E-BP1 and p70S6 kinase. MAPK activation was observed in HONE-1 and C666-1 cells, but not in CNE-2 cells following exposure to MK-2206. The addition of MK-2206 to cisplatin (but not with paclitaxel) has a supra-additive inhibitory effect on growth in vitro. In summary, MK-2206 can inhibit growth and abrogate AKT and mTOR signaling in NPC cell lines. This agent is currently being evaluated in a phase II study in metastatic NPC.

Activity of the MEK inhibitor selumetinib (AZD6244; ARRY-142886) in nasopharyngeal cancer cell lines.

This study evaluated the preclinical activity of selumetinib (AZD6244, ARRY-142866), an inhibitor of the mitogen-activated protein kinase kinase (MAPKK or MEK1/2) in 6 nasopharyngeal cancer (NPC) cell lines. Selumetinib could achieve up to 90 % inhibition of cell growth with the respective IC(50) values in NPC cell lines as follow: HK1 = 0.04 µM, HK1-LMP1(B95.8) = 0.17 µM, HONE-1-EBV = 0.46 µM, HONE-1 = 1.79 µM, CNE-2 = 2.20 µM and C666-1 > 10 µM. The drug-sensitive cell lines HK1, HK1-LMP1(B95.8) and HONE-1-EBV have higher basal expression of phosphorylated (pi)-MAPK than the less sensitive cell lines. BRAF mutations were not detected in all 6 cell lines. Re-introduction of the EBV genome into HONE-1 cells, generating the HONE-1-EBV cell line, seemed to result in elevated expression of pi-MAPK and sensitivity to selumetinib when compared with the parental HONE-1 cells. At a concentration of 0.5 µM and 5 µM, selumetinib induced apoptosis (as indicated by cleaved PARP expression and caspase 3 induction), and G(0)/G(1) cycle arrest in HONE-1-EBV and HK1-LMP1(B95.8) cells. The combination of selumetinib (at IC(25) concentration) and the EGFR tyrosine kinase inhibitor, gefitinib (at concentrations of 0.1, 3 and 9 µM) resulted in synergistic growth inhibition in HK1-LMP1(B95.8) cells. The combination of selumetinib (at IC(25) concentration) and cisplatin (at concentrations of 0.1, 0.4, 0.8 and 2 µM) resulted in synergistic growth inhibition in HONE-1 and HONE-1-EBV cells. This result suggests that selumetinib alone or in combination with gefitinib or cisplatin maybe a promising strategy against NPC. Further studies are warranted.

Platelet factor 4 induces cell apoptosis by inhibition of STAT3 via up-regulation of SOCS3 expression in multiple myeloma.

Platelet factor 4 (PF4) is an angiostatic chemokine that suppresses tumor growth and metastasis. We previously revealed frequent transcriptional silencing of PF4 in multiple myeloma, but the functional roles of this chemokine are still unknown. We studied the apoptotic effects of PF4 on myeloma cell lines and primary myeloma in vitro, and investigated the involved signaling pathway. The in vivo effects were also studied using a mouse model. PF4 not only suppressed myeloma-associated angiogenesis, but also inhibited growth and induced apoptosis in myeloma cells. We found that PF4 negatively regulated STAT3 and concordantly inhibited constitutive and interleukin-6-induced phosphorylation of STAT3, and down-regulated the expression of STAT3 target genes (Mcl-1, survivin and VEGF). Overexpression of constitutively activated STAT3 could rescue PF4-induced apoptotic effects. Furthermore, we found that PF4 induced the expression of SOCS3, a STAT3 inhibitor, and gene silencing of SOCS3 abolished its ability to inhibit STAT3 activation, suggesting a critical role of SOCS3 in PF4-induced STAT3 inhibition. Knockdown of LRP1, a putative PF4 receptor, could also abolish PF4-induced apoptosis and STAT3 inhibition. Finally, the tumor growth inhibitory effect of PF4 was confirmed by in vivo mouse models. Immunostaining of rabbit bone xenografts from PF4-treated mice showed induction of apoptosis of myeloma cells and inhibition of angiogenesis, which was associated with suppression of STAT3 activity. Together, our preclinical data indicate that PF4 may be a potential new targeting agent for the treatment of myeloma.

A polymorphism in the 3'-untranslated region of the NPM1 gene causes illegitimate regulation by microRNA-337-5p and correlates with adverse outcome in acute myeloid leukemia.

Nucleophosmin, encoded by NPM1, is a haploinsufficient suppressor in hematologic malignancies. NPM1 mutations are mostly found in acute myeloid leukemia patients with normal karyotype and associated with favorable prognosis. A polymorphic nucleotide T deletion with unknown significance is present in the NPM1 3'-untranslated region. Here, we showed that the homozygous nucleotide T deletion was associated with adverse outcomes and could independently predict shortened survival in patients with de novo acute myeloid leukemia. Mechanistically, we demonstrated that the nucleotide T deletion created an illegitimate binding NPM1 for miR-337-5p, which was widely expressed in different acute myeloid leukemia subtypes and inhibited NPM1 expression. Accordingly, NPM1 levels were found to be significantly reduced and correlated with miR-337-5p levels in patients carrying a homozygous nucleotide T-deletion genotype. Together, our findings uncover a microRNA-mediated control of NPM1 expression that contributes to disease heterogeneity and suggest additional prognostic values of NPM1 in acute myeloid leukemia.

HLA-B alleles associated with severe cutaneous reactions to antiepileptic drugs in Han Chinese.

PURPOSE: HLA-B*15:02 screening is recommended before starting carbamazepine in Han Chinese and Southeast Asians because the allele is strongly predictive of Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) induced by the drug. We examined whether other HLA-B alleles are also involved and whether the association extends to other antiepileptic drugs (AEDs). METHODS: Cases of SJS/TEN induced by any AEDs were recruited and matched (1:5) with AED-tolerant controls. Carrier rates of HLA-B alleles, determined by direct sequencing, were compared between cases and controls. Results were meta-analyzed with previous studies to examine the associations between HLA-B*15:02 and SJS/TEN induced by phenytoin and lamotrigine. KEY FINDINGS: A total of 55 cases (27 carbamazepine, 15 phenytoin, 6 lamotrigine, 7 other AEDs) and 275 controls were recruited. In drug-specific analysis, the carrier rate of HLA-B*15:02 was significantly higher in carbamazepine-SJS/TEN cases compared with carbamazepine-tolerant controls (92.3% vs. 11.9%; p = 3.51 × 10(-18) ; odds ratio (OR) 89.25; 95% confidence interval (CI) 19.25-413.83), and also in phenytoin-SJS/TEN cases compared with phenytoin-tolerant controls (46.7% vs. 20.0%; p = 0.045; OR 3.50; 95% CI 1.10-11.18). Meta-analyses showed a strong association of HLA-B*15:02 with phenytoin-SJS/TEN (p < 3 × 10(-4) ; OR 4.26; 95% CI 1.93-9.39) and, to a lesser extent, lamotrigine-SJS/TEN (p = 0.03; OR 3.59; 95% CI 1.15-11.22). Compared with drug-tolerant controls, the carrier rates of HLA-B*40:01 and HLA-B*58:01 were lower in cases of SJS/TEN induced by carbamazepine (p = 0.004) and other AEDs (p = 0.009), respectively. SIGNIFICANCE: SJS/TEN induced by carbamazepine and phenytoin is strongly and moderately associated with HLA-B*15:02 in Han Chinese, respectively. Possible protective associations with HLA-B*40:01 and HLA-B*58:01 warrant further investigation.