[Molecular Features and Clinical Significance of Acute Myeloid Leukemia in Elderly Patients].

OBJECTIVE: To study the molecular characteristics and clinical significance of elderly patients with acute myeloid leukemia (AML). METHODS: Dideoxy sequencing was used to analyze the mutation spectrum and clinical significance of 51 hematopathy-related genes in 52 patients with newly diagnosed elderly AML. The efficacy of 39 patients receiving DCAG chemotherapy was also analyzed. RESULTS: The mutational frequency was high in elderly AML patients (98.1%, 51/52), and there were some coexistence or mutual exclusion between different mutations. Both the number of mutations and the incidence of epigenetic mutations DNMT3A, TET2 (P<0.01), as well as FLT3-ITD (P<0.05) increased with age. c-KIT mutations were most common in favorable-risk AML (P<0.01), while NPM1 and DNMT3A were common in intermediate-risk AML (P<0.05), especially in AML with normal karyotype. The complete remission rate of elderly AML patients receiving DCAG chemotherapy was 71.8% (28/39). CONCLUSION: Elderly AML patients have specific molecular characteristics, and the incidence of methylation-related gene mutations is very high, showing a certain significance for clinical diagnosis and treatment.

Characteristics and prognostic significance of genetic mutations in acute myeloid leukemia based on a targeted next-generation sequencing technique.

To explore the characteristics and prognostic significance of genetic mutations in acute myeloid leukemia (AML), we screened the gene mutation profile of 171 previously untreated AML patients using a next-generation sequencing technique targeting 127 genes with potential prognostic significance. A total of 390 genetic alterations were identified in 149 patients with a frequency of 87.1%. Younger age and high sensitivity to induction chemotherapy were associated with a lower number of mutations. NPM1 mutation was closely related to DNMT3A and FLT3-internal tandem duplication (FLT3-ITD) mutations, but mutually exclusive with ASXL1 mutation and CEBPAdouble mutation . In univariate analysis, ASXL1 or TET2 mutation predicted shorter overall survival (OS) or relapse-free survival (RFS), DNMT3A, FLT3-ITD, or RUNX1 mutation predicted a higher likelihood of remission-induction failure, whereas NRAS mutation or CEBPAdouble mutation predicted longer OS. Concurrent DNMT3A, FLT3-ITD, and NPM1 mutations predicted shorter OS. Hypomethylation agents could improve the OS in patients with DNA methylation-related mutations. According to multivariate analysis, TET2 mutation was recognized as an independent prognostic factors for RFS. In summary, our study provided a detailed pattern of gene mutations and their prognostic relevance in Chinese AML patients based on targeted next-generation sequencing screening.

[Clinical Characteristics and Prognosis of 21 Cases of Acute Lymphoblastic Leukemia with Central Nervous System Leukemia].

OBJECTIVE: To investigate the clinical characteristics, therapeutic efficacy survival and prognosis of patients with adult acute lymphoblastic leukemia (ALL) accompanied by central nervous system leukemia (CNSL). METHODS: The clinical and cerebrospinal fluid (CSF) features, diagnosis and treatment, therapeutic efficacy and survival rate of 21 cases of acute lymphoblastic leukemia (ALL) with central nervous system involvement (CNSL) were analyzed retrospectively. RESULTS: Out of 21 cases, 10 cases were B cell acute lymphoblastic leukemia(B-ALL), 6 cases were T cells acute lymphoblastic(T-ALL), 4 cases were determined as no clear typing, 1 case was Burkitt lymphoma/leukemia, 7 patients had CNSL at the time of diagnosis, and 14 patients were showed CNS relapse. Clinical manifestations included headache, facial paralysis, limb weakness and blurred vision, etc. Their median follow-up time was 19(6-40) months,from them 10 cases died, 7 cases survived, 4 cases were lost to follow up. Patients had CNSL at the time of diagnosis, their peripheral blood LDH≥600 U/L or not achieving complete remission (CR) after 1 course of treatment with poor prognosis, and the difference is significant (P< 0.05). Radiotherapy and allogeneic stem cell transplantation (allo-HSCT) could improve the patient's survival. Multivariate analysis showed that the LDH and allo-HSCT was significantly correlated with survival time (P=0.048, P=0.013). CONCLUSION: There are no specific clinical manifestations, CSF features and imaging manifestations of ALL accompanied by CNSL, and the diagnosis of CSF is needed to find the leukemia cells in CSF. The factors for poor prognosis include LDH≥600 U/L, no CR of patients after 1 course of treatment, existence of CNSL at the diagnosis. ALL patients with CNSL have a poor prognosis. Intrathecal injection combined with systemic chemotherapy, radiation therapy and allo-HSCT after CR is the feasible and effective treatment regimen.

[A New Goal for Tyrosine Kinase Inhibitor Therapy in Chronic Myeloid Leukemia: Treatment-free Remission -Review].

Tyrosine kinase inhibitor (TKI) therapy significantly improved the prognosis and outcome of patients with chronic myeloid leukemia(CML). Long-term therapy of TKI drugs was often accompanied with financial burden and the rise of chronic adverse effects. At present, the treatment-free remission (TFR) has been gradually regarded as the new ultimate aim to the patients with long-term CML. In clinical trials, the patients with the therapy of imatinib stopping TKI treatment after acquired deep molecular reaction still maintained remission. Here, the research progress on discontinuation of TKI therapy and how to better grasp the safety of drug withdrawal strategy are reviewed. However, the radical cure of CML needs more further research.

Epigenetic Silencing of Eyes Absent 4 Gene by Acute Myeloid Leukemia 1-Eight-twenty-one Oncoprotein Contributes to Leukemogenesis in t(8;21) Acute Myeloid Leukemia.

BACKGROUND: The acute myeloid leukemia 1 (AML1)-eight-twenty-one (ETO) fusion protein generated by the t(8;21)(q22;q22) translocation is considered to display a crucial role in leukemogenesis in AML. By focusing on the anti-leukemia effects of eyes absent 4 (EYA4) gene on AML cells, we investigated the biologic and molecular mechanism associated with AML1-ETO expressed in t(8;21) AML. METHODS: Qualitative polymerase chain reaction (PCR), quantitative reverse transcription PCR (RT-PCR), and Western blotting analysis were used to observe the mRNA and protein expression levels of EYA4 in cell lines. Different plasmids (including mutant plasmids) of dual luciferase reporter vector were built to study the binding status of AML1-ETO to the promoter region of EYA4. Chromatin immunoprecipitation assay was used to study the epigenetic silencing mechanism of EYA4. Bisulfite sequencing was applied to detect the methylation status in EYA4 promoter region. The influence of EYA4 gene in the cell proliferation, apoptosis, and cell clone-forming ability was detected by the technique of Cell Counting Kit-8, flow cytometry, and clonogenic assay. RESULTS: EYA4 gene was hypermethylated in AML1-ETO+ patients and its expression was down-regulated by 6-fold in Kasumi-1 and SKNO-1 cells, compared to HL-60 and SKNO-1-siA/E cells, respectively. We demonstrated that AML1-ETO triggered the epigenetic silencing of EYA4 gene by binding at AML1-binding sites and recruiting histone deacetylase 1 and DNA methyltransferases. Enhanced EYA4 expression levels inhibited cellular proliferation and suppressed cell colony formation in AML1-ETO+ cell lines. We also found EYA4 transfection increased apoptosis of Kasumi-1 and SKNO-1 cells by 1.6-fold and 1.4-fold compared to negative control, respectively. CONCLUSIONS: Our study identified EYA4 gene as targets for AML1-ETO and indicated it as a novel tumor suppressor gene. In addition, we provided evidence that EYA4 gene might be a novel therapeutic target and a potential candidate for treating AML1-ETO+ t (8;21) AML.

Genomics-based Approach and Prognostic Stratification Significance of Gene Mutations in Intermediate-risk Acute Myeloid Leukemia.

OBJECTIVE: Intermediate-risk acute myeloid leukemia (IR-AML), which accounts for a substantial number of AML cases, is highly heterogeneous. We systematically summarize the latest research progress on the significance of gene mutations for prognostic stratification of IR-AML. DATA SOURCES: We conducted a systemic search from the PubMed database up to October, 2014 using various search terms and their combinations including IR-AML, gene mutations, mutational analysis, prognosis, risk stratification, next generation sequencing (NGS). STUDY SELECTION: Clinical or basic research articles on NGS and the prognosis of gene mutations in IR-AML were included. RESULTS: The advent of the era of whole-genome sequencing has led to the discovery of an increasing number of molecular genetics aberrations that involved in leukemogenesis, and some of them have been used for prognostic risk stratification. Several studies have consistently identified that some gene mutations have prognostic relevance, however, there are still many controversies for some genes because of lacking sufficient evidence. In addition, tumor cells harbor hundreds of mutated genes and multiple mutations often coexist, therefore, single mutational analysis is not sufficient to make accurate prognostic predictions. The comprehensive analysis of multiple mutations based on sophisticated genomic technologies has raised increasing interest in recent years. CONCLUSIONS: NGS represents a pioneering and helpful approach to prognostic risk stratification of IR-AML patients. Further large-scale studies for comprehensive molecular analysis are needed to provide guidance and a theoretical basis for IR-AML prognostic stratification and clinical management.

[Expression and significance of matrix metalloproteinase and tissue inhibitor of matrix metalloproteinase in non-melanoma skin cancer].

OBJECTIVE: To investigate the expression and significance of matrix metalloproteinases (MMP-2, MMP-9) and tissue inhibitor of matrix metalloproteinase (TIMP-2, TIMP-1) in non-melanoma skin cancer (NMSC). METHODS: Thirty six patients with squamous cell carcinoma (SCC) and 32 patients with basal cell carcinoma (BCC), confirmed by pathology, were selected, and 30 cases of normal skin were selected as control. The expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 in all samples were examined by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). The expression rate, expression intensity and expression level of each factor were recorded. The results were compared between the groups. RESULTS: The expression rates of MMP-2 and MMP-9 in the control group were 30.0% and 36.7%, the expression levels of MMP-2 and MMP-9 in the control group were 57.216 ± 12.785 and 59.318 ± 13.262, all significantly lower than those in the tumor edge and center of the SCC and BCC groups (P < 0.01). The expression rates of TIMP-1 and TIMP-2 in the control group were 96.7% and 100%, their expression levels were 121.738 ± 25.516 and 122.612 ± 25.964, all significantly higher than those in the SCC and BCC groups (P < 0.01). The expression levels of MMP-2 and MMP-9 in the tumor center and edge of SCC group were significantly higher than those in the corresponding parts of the BCC group, while the expression levels of TIMP-1 and TIMP-2 were significantly lower than those in the BCC group (P < 0.01). The expression levels of MMP-2 and MMP-9 in the tumor edge of the SCC and BCC groups were significantly higher than those in the tumor centers (P < 0.01), while the expression levels of TIMP-1and TIMP-2 were significantly lower than those in the tumor centers (P < 0.01). CONCLUSION: MMP-2, MMP-9 and TIMP-2, TIMP-1 may play an important role in the development, progression, invasion and metastasis of non-melanoma skin cancer.

[Construction of a lentiviral vector carrying TRAIL gene and its infection efficiency to lymphoma cells in vitro].

This study was purposed to construct a lentiviral vector carrying the TNF-related apoptosis-inducing ligand (TRAIL) gene and investigate its infection efficiency to several lymphoma cells lines. A pGM-T-TRAIL vector was constructed by inserting the cDNA segment derived from TRAIL mRNA into the cloning vector pGM-T, which was then inserted into the lentiviral vector pWPI. The recombinant lentiviral vector plenti-TRAIL was produced by transfecting 293T cells with pWPI-TRAIL, packaging plasmid Δ8.2, and envelope plasmid pCMV-VSVG and then harvested from the culture supernatant. Infection efficiency was measured in several lymphoma cell lines by live cell GFP fluorescence, while TRAIL expression was assessed by RT-PCR and Western blot. The results showed that the enzyme cut identification and sequencing demonstrated the successful construction of both pGM-T-TRAIL and pWPI-TRAIL. The results of testing drop showed that the concentration of the restructured lentiviral plenti-TRAIL reached 10(9) IU/ml. Comparison of infection efficiency revealed that YTS cells were more likely to be infected than DOHH2 or Jurkat cells (P < 0.05). Finally, RT-PCR and Western blot showed that lymphoma cells infected with plenti-TRAIL were able to efficiently express the TRAIL mRNA and protein. It is concluded that the lentiviral vector pWPI-TRAIL is successfully constructed and the recombinant lentiviral plenti-TRAIL is manufactured. The plenti-TRAIL vector is able to infect several lymphoma cell lines, and the infected lymphoma cells can effectively express TRAIL genes.