Impact of a novel prognostic model on allogeneic hematopoietic stem cell transplantation outcomes in patients with CMML.

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell malignancy, and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curable treatment. The outcomes after transplant are influenced by both disease characteristics and patient comorbidities. To develop a novel prognostic model to predict the post-transplant survival of CMML patients, we identified risk factors by applying univariable and multivariable Cox proportional hazards regression to a derivation cohort. In multivariable analysis, advanced age (hazard ratio [HR] 3.583), leukocyte count (HR 3.499), anemia (HR 3.439), bone marrow blast cell count (HR 2.095), and no chronic graft versus host disease (cGVHD; HR 4.799) were independently associated with worse survival. A novel prognostic model termed ABLAG (Age, Blast, Leukocyte, Anemia, cGVHD) was developed and the points were assigned according to the regression equation. The patients were categorized into low risk (0-1), intermediate risk (2, 3), and high risk (4-6) three groups and the 3-year overall survival (OS) were 93.3% (95%CI, 61%-99%), 78.9% (95%CI, 60%-90%), and 51.6% (95%CI, 32%-68%; p < .001), respectively. In internal and external validation cohort, the area under the receiver operating characteristic (ROC) curves of the ABLAG model were 0.829 (95% CI, 0.776-0.902) and 0.749 (95% CI, 0.684-0.854). Compared with existing models designed for the nontransplant setting, calibration plots, and decision curve analysis showed that the ABLAG model revealed a high consistency between predicted and observed outcomes and patients could benefit from this model. In conclusion, combining disease and patient characteristic, the ABLAG model provides better survival stratification for CMML patients receiving allo-HSCT.

High-dose dexamethasone plus recombinant human thrombopoietin vs high-dose dexamethasone alone as frontline treatment for newly diagnosed adult primary immune thrombocytopenia: A prospective, multicenter, randomized trial.

We conducted a prospective, multicenter, randomized, controlled clinical trial to compare the efficacy and safety of high-dose dexamethasone (HD-DXM) plus recombinant human thrombopoietin (rhTPO), vs HD-DXM alone in newly diagnosed adult immune thrombocytopenia (ITP) patients. Enrolled patients were randomly assigned to receive DXM plus rhTPO or DXM monotherapy. Another 4-day course of DXM was repeated if response was not achieved by day 10 in both arms. One hundred patients in the HD-DXM plus rhTPO arm and 96 patients in the HD-DXM monotherapy arm were included in the full analysis set. So, HD-DXM plus rhTPO resulted in a higher incidence of initial response (89.0% vs 66.7%, P < .001) and complete response (CR, 75.0% vs 42.7%, P < .001) compared with HD-DXM monotherapy. Response rate at 6 months was also higher in the HD-DXM plus rhTPO arm than that in the HD-DXM monotherapy arm (51.0% vs 36.5%, P = .02; sustained CR: 46.0% vs 32.3%, P = .043). Throughout the follow-up period, the overall duration of response was greater in the HD-DXM plus rhTPO arm compared to the HD-DXM monotherapy arm (P = .04), as estimated by the Kaplan-Meier analysis. The study drugs were generally well tolerated. In conclusion, the combination of HD-DXM with rhTPO significantly improved the initial response and yielded favorable SR in newly diagnosed ITP patients, thus could be further validated as a frontline treatment for ITP. This study is registered as clinicaltrials.gov identifier: NCT01734044.

A multicenter randomized open-label study of rituximab plus rhTPO vs rituximab in corticosteroid-resistant or relapsed ITP.

This study aimed to compare the efficacy and safety of rituximab (RTX) plus recombinant human thrombopoietin (rhTPO) with RTX alone in patients with immune thrombocytopenia (ITP) who had failed to respond to corticosteroids or relapsed. Recruited patients were randomized at a ratio of 2:1 into 2 groups: the combination group (RTX + rhTPO, n = 77) and the monotherapy group (RTX, n = 38). Overall response was achieved in 79.2% of patients in the combination group vs 71.1% in the monotherapy group (P = .36), and the complete response (CR) rate was 45.4% in the combination group compared with 23.7% in the monotherapy group (P = .026). The combination group had significantly shorter time to response (TTR; median and range, 7 and 4-28 days) compared with the monotherapy group (28 and 4-90 days) (P < .01). There was no difference between these 2 groups in terms of the long-term response (P = .12). Our findings demonstrated that the combination of RTX and rhTPO significantly increased the CR rate and shortened TTR compared with RTX monotherapy in the treatment of corticosteroid-resistant or relapsed ITP but failed to show a beneficial effect on the long-lasting response. This study is registered at www.clinicaltrials.gov as #NCT01525836.

Arsenic trioxide inhibits DNA methyltransferase and restores TMS1 gene expression in K562 cells.

BACKGROUND: Gene silencing associated with aberrant methylation of promoter region CpG islands is an acquired epigenetic alteration that serves as an alternative to genetic defects in the inactivation of tumor suppressor genes in human cancers. The demethylating, dose-dependent effect of arsenic trioxide (As2O3) on several tumor-related genes has already been postulated. However, whether such a demethylating effect also applies to the TMS1 gene in chronic myeloid leukemia cell line K562 cells has not been studied so far. The aim of the present study was to detect the methylation status of the TMS1 gene in K562 cells and the demethylation effect of As2O3 on TMS1 as well as TMS1 apoptosis-associated protein Bcl-2/Bax and DNA methyltransferase (DNMT) expression. METHODS: TMS1 mRNA expression in K562 cells and normal bone marrow was determined by reverse transcription (RT) polymerase chain reaction (PCR), and the DNA methylation status of the TMS1 promoter in K562 cells treated with different concentrations of As2O3 for 48 h was determined by methylation-specific PCR. RT-PCR and Western blot were used to detect TMS1 and DNMT expression. We also assessed TMS1-associated apoptosis protein Bcl-2/Bax expression by Western blot and apoptosis rates by flow cytometry using annexin V/propidium iodide double staining. RESULTS: In K562 cells, TMS1 was completely methylated and both TMS1 mRNA and protein showed a low expression, but 2 µmol/l As2O3 could significantly restore the expression of the TMS1 gene both at mRNA and protein level (p < 0.01) by fully reversing DNA methylation. As2O3 decreased mRNA and protein expression of DNMT1 (p < 0.05) in a dose-dependent manner. Flow cytometry showed that in the experimental group (2 µmol/l As2O3), cell apoptosis was significantly increased compared with the control group (no As2O3; p < 0.05). In the experimental group, Western blot showed that the expression of the anti-apoptotic protein Bcl-2 was significantly decreased; however, the proapoptotic protein Bax was markedly increased and the Bcl-2/Bax ratio was markedly reduced (p < 0.01). CONCLUSIONS: As2O3 could restore the expression of TMS1 by inhibiting DNMT to reverse the hypermethylation and induced apoptosis of K562 cells by downregulation of Bcl-2/Bax expression.

Increased Th17 and Treg levels in peripheral blood positively correlate with minimal residual disease in acute myeloid leukaemia.

PURPOSE: Immune dysregulation plays a key role in acute myeloid leukemia (AML). We aimed to explore the correlation between T helper cell 17 (Th17) and the regulatory cells (Tregs) in the peripheral blood of patients with newly diagnosed (ND) AML and bone marrow blast cells, as well as minimal residual disease (MRD) before and after treatment. METHODS: Changes in Th17 and Treg cells in the peripheral blood of 32 patients with ND AML were observed before and after induction chemotherapy with cytarabine for seven days and anthracycline for three days. The levels of inflammatory cytokines were measured using an enzyme-linked immunosorbent assay. Correlation analysis between bone marrow blast cells and Th17 and Treg cell frequencies was performed using the Pearson's correlation test. Frequencies of Th17 and Treg cells and MRD were assessed using flow cytometry. RESULTS: IL-6, IL-10, IL-17A, and GM-CSF levels gradually increased in patients with ND AML and CR and NR patients. The percentages of Th17 and Treg cells positively correlated with those of blast cells. In addition, the frequencies of Th17 and Treg cells in MRD-positive patients were higher than those in MRD-negative patients at the initial induction and after three months of chemotherapy. The frequencies of Tregs and Th17 cells positively correlated with MRD onset. CONCLUSION: Increased Th17 and Treg cell levels were positively correlated with onset of AML, poor remission, and MRD.

Population pharmacokinetics of lenalidomide in Chinese patients with influence of genetic polymorphisms of ABCB1.

Affected by differences in the pharmacokinetics (PK) of lenalidomide, the toxicity of lenalidomide varies among different patients, with serious toxicity leading to dose reduction or discontinuation. The differences in the PK of lenalidomide may be related to factors such as patients' physiological characteristics, pathological characteristics and gene polymorphisms etc., which may also affect its toxicity. The aim of this study is to establish a population pharmacokinetic (PPK) model of lenalidomide and explore factors associated with the adverse events (AEs) of lenalidomide from a PK perspective. Blood samples were collected by opportunistic blood collection. Drug concentrations were determined by using HPLC/MS and genotype of ABCB1 3435 C > T (rs1045642), ABCB1 1236 A > G (rs1128503) and ABCB1 2677 A > C/T (rs2032582) was tested by the first-generation DNA sequencing technology. NONMEM software and SPSS 26.0 software were used respectively to establish PPK model of lenalidomide and explore the correlation between PK parameters and the incidence of serious AEs of lenalidomide. 51 patients were enrolled in the PPK study, and one-compartment model with first-order absorption and elimination agreed well with the observed data. The significant covariate affecting lenalidomide apparent volume of distribution (V/F) were the gene polymorphism of ABCB1 3435 C > T and diet. Safety studies could be conducted in 39 patients. The V/F value in patients suffering from serious AEs was significantly higher than that in others ( median = 67.04 L vs 37.17 L, P = 0.033). According to the covariates screened, the incidence of serious AEs was higher in patients with genotype CT or TT at ABCB1 3435 C > T locus than that in patients with genotype CC (P = 0.039). Additionally, V/F value was the highest in patients carrying genotype TT with postprandial medication, in whom the incidence of serious AEs was higher than others (P = 0.037). In conclusion, the genotype of ABCB1 3435 C > T locus and diet had pharmacokinetically relevant impact on lenalidomide, which may also be related to the incidence of serious AEs. Patients with gene variants of CT or TT at ABCB1 3435 C > T locus may be more susceptible to serious AEs, and monitoring of adverse reactions should be particularly strengthened in patients who carried genotype TT with postprandial medication.

Role of miR­let­7c­5p/c­myc signaling axis in the committed differentiation of leukemic THP­1 cells into monocytes/macrophages.

In a preliminary experiment, it was found that c-myc expression was decreased following the differentiation of THP-1 cells into monocytes/macrophages induced by phorbol 12-myristate 13 acetate (PMA) + lipopolysaccharide (LPS) + interferon (IFN)-γ. The expression of miR-let-7c-5p was then found to be elevated by cross-sectional analysis using TargetScan and PubMed and differential microarray analysis. The present study aimed to investigate the role of the miR-let-7c-5p/c-myc signaling axis in the committed differentiation of THP-1 leukemic cells into monocytes/macrophages induced by PMA + LPS + IFN-γ. Human THP-1 leukemic cells were induced to differentiate into monocytes/macrophages by PMA + LPS + IFN-γ. Following induction for 48 h, the growth density of the THP-1 cells was observed directly under an inverted microscope, cell proliferation was measured using Cell Counting Kit-8 assay and the cell cycle and the expression of differentiation-related antigens (CD11b and CD14) were measured using flow cytometry. The mRNA expression of miR-let-7c-5p and c-myc was detected using reverse transcription-quantitative PCR and the protein expression of c-myc was detected using western blot analysis. Dual luciferase reporter gene analysis was used to detect the targeted binding of miR-let-7c-5p on the 3'UTR of c-myc. The relative expression of miR-let-7c-5p and c-myc genes in THP-1 cells induced by PMA + LPS + IFN-γ was found to be up- and downregulated respectively, and expression of miR-let-7c-5p was negatively correlated with the expression of c-myc gene. Dual luciferase reporter gene assays confirmed that miR-let-7c-5p targeted the 3'UTR of c-myc and inhibited luciferase activity. Following transfection with miR-let-7c-5p mimics, the expression of c-myc was markedly downregulated and the proliferative ability of the THP-1 cells was decreased, while the expression rate of CD11b and CD14 was significantly increased. The rescue experiment revealed that the effects of miR-let-7c-5p mimics on the proliferation and differentiation of THP-1 cells were attenuated by transfection with c-myc overexpression vector. Together, the findings of the present study demonstrated that miR-let-7c-5p can target the 3'UTR region of c-myc and that the miR-let-7c-5p/c-myc signaling axis is one of the critical pathways involved in the directional differentiation of leukemic cells into monocytes/macrophages.

Coexistence of nodal marginal zone B-cell lymphoma and multiple myeloma: A case report and literature review.

RATIONALE: Nodal marginal zone B-cell lymphoma (NMZL) is a relatively rare indolent lymphoma that is the least common subtype of marginal zone B-cell lymphoma. Furthermore, coexistence of lymphoma and multiple myeloma (MM) is rare. Here, we report a case of the coexistence of NMZL and MM. PATIENT CONCERNS: The patient was a 66-year-old man with pain in the left rib and lower left back. Enlarged lymph nodes were palpable in the cervical and inguinal regions, the biggest of which was 4.0 × 2.0 cm in size in the left groin. DIAGNOSIS: Pathological and immunohistochemical findings of the left inguinal lymph node revealed NMZL. The patient met the diagnostic criteria for symptomatic MM. Therefore, the patient was diagnosed with NMZL and lambda-type MM. INTERVENTION: We adopted a bortezomib, liposomal adriamycin, and dexamethasone (PAD) chemotherapy regimen mainly for MM. OUTCOMES: After 3 cycles of treatment, the patient achieved complete remission of myeloma. A 50% decrease in enlarged lymph node size was observed. LESSON: To our knowledge, this is the first case report of the simultaneous occurrence of NMZL and MM. Further studies are required to explain the association between these 2 tumors and improve treatment selection.

MiR-140 Targets lncRNA DNAJC3-AS1 to Suppress Cell Proliferation in Acute Myeloid Leukemia.

OBJECTIVES: MiR-140 and DNAJC3-AS1 have been demonstrated to play critical roles in cancer biology, while their participation in acute myeloid leukemia (AML) is unclear. This study aimed to explore the role of miR-140 and DNAJC3-AS1 in AML. METHODS: The expression of DNAJC3-AS1 and miR-140 were detected by RT-qPCR. Then, the role of DNAJC3-AS1 and miR-140 in regulating each other was explored by overexpression assay. Next, the direct interaction between DNAJC3-AS1 and miR-140 was analyzed using an RNA pull-down assay. Next, the subcellular location of DNAJC3-AS1 was explored using cellular, subcellular fractionation assay. Finally, cell proliferation analysis was evaluated with BrdU assay. RESULTS: Increased expression levels of DNAJC3-AS1 and decreased expression levels of miR-140 were observed in AML patients. DNAJC3-AS1 was detected in nuclear and cytoplasm samples and direct interaction between DNAJC3-AS1 and miR-140 was observed. DISCUSSION: Reduced expression levels of DNAJC3-AS1 were observed after overexpression of miR-140 in AML cells. DNAJC3-AS1 increased cell proliferation and inhibited the role of miR-140 in suppressing cell proliferation. CONCLUSION: In conclusion, miR-140 may target DNAJC3-AS1 to suppress cell proliferation in AML.

CircRNA CircEHBP1 Regulates the Maturation of MiR-129 to Increase the Chemoresistance of Cancer Cells to Adriamycin in Acute Myeloid Leukaemia.

Background: MicroRNA-129 (miR-129) is known to promote chemosensitivity of many types of cancer cells. However, the role of miR-129 in acute myeloid leukaemia (AML) is unclear. We predicted that premature miR-129 might interact with circEHBP1, a well-characterized oncogene in bladder cancer, and analyzed the interaction between circEHBP1 and miR-129 in AML. Methods: Expression of circEHBP1 and miR-129 in AML patients before and after adriamycin (ADR) treatment was determined by RT-qPCR. CircEHBP1 distribution in nuclear and cytoplasm fractions of AML cells was determined using a cellular fractionation assay. The direct interaction of circEHBP1 with premature miR-129 was explored with an RNA-RNA pull-down assay. Finally, the role of circEHBP1 in regulating miR-129 maturation was analyzed in overexpression cells by RT-qPCRs. Results: Compared to the controls, AML patients exhibited increased circEHBP1 and premature miR-129 levels but decreased mature miR-129 levels. Altered gene expression was more obvious in ADR resistant group than in ADR sensitive group. CircEHBP1 was detected in both nuclear and cytoplasm fractions of AML cells and directly interacted with premature miR-129. CircEHBP1 overexpression increased premature miR-129 level but decreased mature miR-129 level. In AML cells, circEHBP1 suppressed ADR-induced cell apoptosis and attenuated the enhancing effects of miR-129 on cell apoptosis. More importantly, the role of circEHBP1 in regulating cell apoptosis was more obvious in ADR resistance cells. Conclusion: CircEHBP1 may suppress miR-129 maturation to increase the chemoresistance of cancer cells to ADR in AML.

[Study of WIF-1 promoter methylation with expressions of ß-catenin in acute leukemia].

OBJECTIVE: To explore the significance of WIF-1 gene promoter methylation and the expression of ß-catenin in acute leukemia (AL) patients. METHODS: The method of methylation specific polymerase chain reaction was employed to detect the status of WIF-1 gene methylation in 55 acute leukemia patients and normal controls from January 2009 to June 2010 in our hospital. The expression of ß-catenin was measured by flow cytometry. RESULTS: The methylation of WIF-1 gene promoter was found in 32.7% (18/55) AL patients. And the percentage was significantly higher than that of the controls (0). The patients with the methylation of WIF-1 gene had a lower complete remission rate (38.9%, 7/18) for the first chemotherapy than those without (81.1%, 30/37) (P < 0.05). The expressions of ß-catenin in methylation AL patients and those with non-methylation were 17.5% ± 3.3% and 15.4% ± 3.6% respectively. And they were significantly higher than the controls (10.5% ± 1.5%, P < 0.05). The expression of ß-catenin was higher in positive methylation patients than those negative ones (P < 0.05). CONCLUSION: The methylation of WIF-1 gene promoter and ß-catenin may be involved in the abnormal activation of Wnt/ß-catenin signal in acute leukemia.

[Retracted] In vitro and in vivo anticancer effects of marmesin in U937 human leukemia cells are mediated via mitochondrial­mediated apoptosis, cell cycle arrest, and inhibition of cancer cell migration.

Following the publication of the above paper, a concerned reader drew to the Editor's attention that a pair of tumors in Fig. 10 appeared to have been duplicated, although one of the tumors appeared at a larger size in the figure relative to the first one. Furthermore, the flow cytometric plots shown in Fig. 2B in the above paper appeared to be remarkably similar to data presented in a paper published in Phytomedicine [Sui C­G, Meng F­D and Jiang Y­H: Antiproliferative activity of rosamultic acid is associated with induction of apoptosis, cell cycle arrest, inhibition of cell migration and caspase activation in human gastric cancer (SGC­7901) cells. Phyomedicine 22: 796­806, 2015]. After having conducted an independent investigation in the Editorial Office, the Editor of Oncology Reports has determined that the above paper should be retracted from the Journal on account of a lack of confidence concerning the originality and the authenticity of the data. The authors were asked for an explanation to account for these concerns, but the Editorial Office never received any reply. The Editor regrets any inconvenience that has been caused to the readership of the Journal. [the original article was published in Oncology Reports 39: 597­602, 2018; DOI: 10.3892/or.2017.6147].

CircRNA circ_POLA2 is Upregulated in Acute Myeloid Leukemia (AML) and Promotes Cell Proliferation by Suppressing the Production of Mature miR-34a.

PURPOSE: CircRNA circ_POLA2 has been reported as an oncogene in lung cancer, while its role in other malignancies is unknown. This study aimed to explore the role of circ_POLA2 in acute myeloid leukemia (AML). METHODS: The expression levels of circ_POLA2, mature miR-34a and miR-34a precursor in bone marrow mononuclear cells (BMMNCs) from AML patients (n = 50) and healthy controls (n = 50) were determined by RT-qPCR. Correlations among them were analyzed by Pearson's correlation coefficient. Overexpression of circ_POLA2 was achieved in AML cell lines, followed by the measurement of the expression levels of mature miR-34a and miR-34a precursor. The role of circ_POLA2 and miR-34a in regulating AML cell proliferation was assessed by CCK-8 assay. RESULTS: Circ_POLA2 was upregulated in AML and inversely correlated with mature miR-34a, but not miR-34a precursor. In AML cells, overexpression of circ_POLA2 decreased the expression levels of mature miR-34a, but not miR-34a precursor. Cell proliferation analysis showed that the overexpression of miR-34a attenuated the effects of overexpression of circ_POLA2 on cell proliferation. CONCLUSION: Circ_POLA2 is upregulated in AML and promotes cell proliferation by suppressing the production of mature miR-34a.

IL13Rα1 protects against rheumatoid arthritis by combating the apoptotic resistance of fibroblast-like synoviocytes.

BACKGROUND: Endoplasmic reticulum (ER) stress is closely related with the pathological progression of rheumatoid arthritis (RA), and fibroblast-like synoviocytes (FLSs) are known as its resistance against ER stress-induced apoptosis. Studies on overcoming such resistance would provide a novel treatment strategy for RA in a clinical setting. METHODS: IL13Rα1 expression was assessed in the synovial tissue by RT-qPCR, immunohistology, and Western blot. Gain or loss of functional analysis was applied to evaluate the biological roles of IL13Rα1 in RA FLSs. Cell viability and apoptosis were assessed by MTS, Western blot, and flow cytometry. The therapeutic effects of IL13Rα1 on the severity of type II collagen-induced arthritis (CIA) in DBA-/1 mouse model were evaluated by scoring synovitis, hyperplasia, cartilage degradation, and bone destruction. RESULTS: IL13Rα1 expression was selectively downregulated when RA FLSs were stimulated by ER stress inducers. Functionally, IL13Rα1 overexpression could inhibit the viability, but induce the apoptosis of RA FLSs in the presence of ER stress inducers. Mechanistically, IL13Rα1 promotes cell apoptosis via transcriptionally activating trail expression. Besides, IL13Rα1 could interact and stabilize DR5 protein, thus forming a positive loop involving trail and DR5 to render RA FLSs more susceptible to apoptosis. Additionally, intraarticular injection of IL13Rα1 conferred therapeutic effects in CIA models and showed a limited degree of synovial proliferation and joint destruction. CONCLUSIONS: Together, our data establishes a regulatory role for IL13Rα1 to combat the apoptotic resistance of RA FLSs against ER stress. The inhibitory effects of IL13Rα1 on arthritis progression suggest the therapeutic potential in RA.

In vitro and in vivo anticancer effects of marmesin in U937 human leukemia cells are mediated via mitochondrial-mediated apoptosis, cell cycle arrest, and inhibition of cancer cell migration.

Leukemia is one of the highly lethal cancers among all pediatric cancers. With limited drug options and the severe side effects associated with the current chemotherapy, there is pressing need to look for new and novel anticancer agents. Against this backdrop, in the present study we evaluated the anticancer activity of a natural coumarin, marmesin against human leukemia cell line U937 and normal human monocytes It was observed that marmesin exhibited an IC50 value of 40 µM and exerted its cytotoxic effects in a dose-dependent manner. However, the cytotoxic effects of marmesin were comparatively lower for the normal human monocytes as evident from the IC50 of 125 µM. Our results indicated that marmesin inhibits colony formation and induces apoptosis dose-dependently. We also investigated the effect of marmesin on the expression of Bax and Bcl-2 proteins. It was observed that marmesin treatment triggered upregulation of Bax and downregulation of Bcl-2 causing significant increase in the Bax/Bcl-2 ratio, marmesin could also induce ROS mediated alterations in mitochondrial membrane potential. Additionally, marmesin induced G2/M cell cycle arrest and significantly inhibited cell migration potential of leukemia cells at the IC50. Remarkably, marmesin prevent tumor growth significantly in vivo at the dosage of 30 mg/kg in vivo. These results strongly indicate that marmesin may prove to be a novel anticancer lead for the management of leukemia.

Progression of primary myelofibrosis to polycythemia vera: A case report.

RATIONALE: This case report describes the progression of primary myelofibrosis (PMF) to polycythemia vera (PV), and discuss its potential mechanisms. PATIENT CONCERNS: The patient was admitted because of abdominal discomfort and enlarged spleen for 19 months. DIAGNOSIS: A case of PMF progressed to PV was retrospectively analyzed. There were 19 months between the diagnosis of PMF and PV. The JAK2 V617F mutation was positive before and after the diagnosis of PV; however, new chromosomal abnormalities were detected during the progression. INTERVENTIONS: For treatment of PMF, the danazol, calcitriol, and thalidomide were given. Then, the use of thalidomide and calcitriol was stopped, and hydroxyurea was started. For treatment of PV, interferon treatment was given, whereas hydroxyurea was continued. OUTCOMES: After 30 months of the progression (at the recent follow-up), this patient had no obvious symptoms or thrombosis. LESSONS: PMF rarely progresses to PV, however, the progression will significantly improve the quality of life and prognosis.

Arsenic trioxide increases expression of secreted frizzled-related protein 1 gene and inhibits the WNT/ß-catenin signaling pathway in Jurkat cells.

The aim of the present study was to investigate the demethylation effect of arsenic trioxide (As2O3) on the secreted frizzled-related protein 1 (SFRP1) gene and its ability to inhibit the Wingless-type MMTV integration site family (WNT) pathway in Jurkat cells. Methylation-specific polymerase chain reaction was used to examine the CpG island methylation status of the SFRP1 gene in leukemia cell lines. In addition, the effects on Jurkat cells of treatment with different concentrations of As2O3 for 48 h were investigated. Reverse transcription-quantitative polymerase chain reaction was employed to measure the expression of mRNAs, while western blot analysis was used to examine protein expression in cells. The SFRP1 gene was methylated in Jurkat cells. However, both methylated and unmethylated SFRP1 genes were detected in HL60 and K562 cells. In normal bone marrow mononuclear cells, the SFRP1 gene was unmethylated. Following treatment with As2O3 for 48 h, the SFRP1 gene was demethylated, and the mRNA and protein expression levels of the SFRP1 gene were increased. By contrast, the mRNA and protein expression levels of ß-catenin and cyclin Dl were downregulated. The protein expression of c-myc was also downregulated, but As2O3 exhibited no significant effect on the mRNA expression of c-myc. Abnormal methylation of the SFRP1 gene was detected in Jurkat cells. These results suggest that As2O3 activates SFRP1 gene expression at the mRNA and protein levels in Jurkat cells by demethylation of the SFRP1 gene. Furthermore, they indicate that As2O3 regulates WNT target genes and controls the growth of Jurkat cells through the WNT/ß-catenin signaling pathway.

Down-regulation of TRRAP-dependent hTERT and TRRAP-independent CAD activation by Myc/Max contributes to the differentiation of HL60 cells after exposure to DMSO.

Myc/Max/Mad often play pivotal roles in the proliferation, apoptosis, differentiation and cell cycle progress of leukemia cells. Myc and Mad are known to be unstable proteins and their expression is tightly regulated throughout cell cycle progression and differentiation. Usually, c-Myc expression is implicated in cell growth and proliferation, and the deregulated expression of c-Myc in both myeloid leukemia cells and normal myeloid cells not only blocks terminal differentiation but also its associated growth arrest. HL60 cells could be induced to differentiate into mature granulocytes by DMSO in vitro, but the mechanism of this effect has not been elucidated clearly. We proposed the hypothesis that down-regulation of c-Myc expression by DMSO contributed to the differentiation of HL60 cells by way of activating target genes hTert and CAD. The results showed that c-Myc expression was down-regulated in differentiated HL60 cells but not in exponentially-growing HL60 cells, without or with the target gene activation of hTert and CAD, respectively. Further study indicated that hTert activation is TRRAP-dependent while CAD activation is TRRAP-independent. On the other hand, up-regulation of P(21) and P(27) and down-regulation of cyclinA and cyclinE also play important roles in induction of the terminal differentiation of HL60 cells. Our results support the hypothesis that c-Myc expression and activation of target genes for hTert and CAD play critical roles in the proliferation of HL60 cells, while down-regulation of c-Myc expression and activation of target genes for hTert and CAD contributed to the terminal differentiation of HL60 cells after exposure to DMSO in vitro.

A novel PAD4/SOX4/PU.1 signaling pathway is involved in the committed differentiation of acute promyelocytic leukemia cells into granulocytic cells.

All-trans retinoic acid (ATRA) treatment yields cure rates > 80% through proteasomal degradation of the PML-RARα fusion protein that typically promotes acute promyelocytic leukemia (APL). However, recent evidence indicates that ATRA can also promote differentiation of leukemia cells that are PML-RARα negative, such as HL-60 cells. Here, gene expression profiling of HL-60 cells was used to investigate the alternative mechanism of impaired differentiation in APL. The expression of peptidylarginine deiminase 4 (PADI4), encoding PAD4, a protein that post-translationally converts arginine into citrulline, was restored during ATRA-induced differentiation. We further identified that hypermethylation in the PADI4 promoter was associated with its transcriptional repression in HL-60 and NB4 (PML-RARα positive) cells. Functionally, PAD4 translocated into the nucleus upon ATRA exposure and promoted ATRA-mediated differentiation. Mechanistic studies using RNAi knockdown or electroporation-mediated delivery of PADI4, along with chromatin immunoprecipitation, helped identify PU.1 as an indirect target and SOX4 as a direct target of PAD4 regulation. Indeed, PAD4 regulates SOX4-mediated PU.1 expression, and thereby the differentiation process, in a SOX4-dependent manner. Taken together, our results highlight an association between PAD4 and DNA hypermethylation in APL and demonstrate that targeting PAD4 or regulating its downstream effectors may be a promising strategy to control differentiation in the clinic.

The role of EVI-1 in normal hematopoiesis and myeloid malignancies (Review).

Ecotropic virus integration site-1 (EVI-1) gene, locus on chromosome 3 (3q26.2) in the human genome, was first found in the AKXD strain of mice, in a model of retrovirus-induced acute myeloid leukemia (AML) established twenty years ago. Since then, EVI-1 was regarded as one of the most invasive proto-oncogenes in human leukemia. EVI-1 can encode a unique zinc-finger protein of 145 kDa that can bind with DNA, and its overexpression was closely related to human hemopoietic diseases. Furthermore, accumulating research indicates that EVI-1 is involved in the differentiation, apoptosis and proliferation of leukemia cells. The present review focuses on the biochemical properties of EVI-1 which plays a role in myeloid malignancies.