Advance of neurodegeneration in diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

@#Diabetic retinopathy(DR), one of the most common complications of diabetes, has been widely reported as microangiopathy. However, retinal neurodegeneration was reported to occur early in DR and played a significant role in DR progression. Retinal neurodegeneration in DR was characterized as neuronal apoptosis and reactive gliosis. The mechanisms for its pathogenesis include hyperglycemia, oxidative stress, glutamate excitotoxicity, and inflammation <i>etc</i>. Furthermore, retinal neurodegeneration has a close relationship with the microangiopathy in the pathogenesis of DR.

Marsdeniae tenacissimae extract (MTE) suppresses cell proliferation by attenuating VEGF/VEGFR2 interactions and promotes apoptosis through regulating PKC pathway in human umbilical vein endothelial cells / 中国天然药物

Marsdeniae tenacissimae extract (MTE), commonly known as Xiao-Ai-Ping in China, is a traditional Chinese herb medicine capable of inhibiting proliferation and metastasis and boosting apoptosis in various cancer cells. However, little is known about the contribution of MTE towards tumor angiogenesis and the underlying mechanism. The present study aimed to evaluate the effects of MTE on the proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) and the molecular mechanism. 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium, inner salt (MTS) and PI-stained flow cytometry assays revealed that MTE dose-dependently reduced the proliferation of HUVECs by arresting cell cycle at S phase (P < 0.05). Annexin V-FITC/PI-stained flow cytometry confirmed that MTE (160 μL·L) enhanced the apoptosis of HUVECs significantly (P < 0.001). Real-time quantitative RT-PCR and Western blot analyses showed an increase in Bax expression and a sharply decline in Bcl-2 expression; caspase-3 was activated simultaneously in a dose-dependent manner (P < 0.05). Further study observed the dose-dependent down-regulation of vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2), P2Y6 receptor (P2Y6R), and chemokine (C-C motif) ligand 2 (CCL-2), along with the activation of PKC Δ and up-regulation of p53 in a dose-dependent manner in MTE-treated selected cells (P < 0.05). Collectively, the results from the present study suggested that MTE suppressed the proliferation by attenuating CCL-2-mediated VEGF/VEGFR2 interactions and promoted the apoptosis through PKCΔ-induced p53-dependent mitochondrial pathway in HUVECs, supporting that MTE may be developed as a potent anti-cancer medicine.

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 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Clinical observation of decitabine-treating patients with myelodysplastic syndrome and acute myeloid leukemia / 中国实验血液学杂志

This study was purposed to investigate the clinical efficiencies and adverse reactions of treating the myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) by using decitabine. The clinical data of 12 MDS and AML patients treated with decitabine were analyzed retrospectively. Among 12 patients there were 1 case of MDS-RA, 2 cases of MDS-RAEB-I, 3 cases of MDS-RAEB-II, 2 cases of AML-M4, 2 cases of AML-M5, 1 case of AML-M6 and 1 case of AML-M0. In decitabine chemotherapy program for 5 days (n = 8), decitabine 20 mg/(m(2)·d) × 5 days was applied, 4 weeks for 1 cycle; in program for 3 days (n = 2), decitabine 15 mg/m(2), once 8 h for 3 days, 6 weeks for 1 cycle; another program (n = 2), decitabine 20 mg/(m(2)·d) every other day for 5 times. For 1 patient achieved complete remission (CR) after treatment with decitabine, ID4 gene methylated level was detected by MS-PCR and ML-PCR before and after treatment. The results showed that 2 cases achieved CR, 1 case partial remission, 5 cases stable disease, 1 case progress of disease and 3 cases died. Disease control rate was 66.67% (8/12), the effective rate 25% (3/12). The average survival time was (11.5 ± 2.1) months. 1-year OS rate was 40%, 2-year OS rate was 16.7%. MS-PCR detection showed that the decitabine could significantly reduce the ID4 gene methylation level. It is concluded that decitabine can stabilize disease status of MDS patients, reduce blood transfusion dependence and improve the life quality of patients, and even some patients who transformed from MDS to leukemia achieved CR after treatment with decitabine. Decitabine can reduce the ID4 gene methylation level. The main adverse reaction of decitabine was myelosuppression, infection and so on. So the blood transfusions, antibiotics and other supportive treatments for these patients are needed. Most of patients well tolerate the adverse effects of decitabine after active symptomatic and supportive treatment. The efficacy and survival rate of patients in this study were similar to that of application of decitabine to treat MDS in other domestic studies.

Demethylating agent decitabine induces autologous cancer testis antigen specific cytotoxic T lymphocytes in vivo / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cancer testis antigens (CTAs) are a novel group of tumor associated antigens. Demethylating agent decitabine was reported to be able to up-regulate CTAs through its hypomethylation mechanism, thus enhance the immunogenicity of leukemia cells. However, few researches have ever focused on the questions that whether this immunostimulatory effect of decitabine could induce autologous CTA specific cytotoxic T lymphocytes (CTLs) in vivo, and if so, whether this effect contributes to disease control. In this study, we aimed to show that decitabine could induce specific autologous CTLs against some mouse CTAs in leukemia cells in vitro and in vivo.</p><p><b>METHODS</b>Several mouse CTAs were screened by RT-PCR. CTL specific to one of the CTAs named P1A was detected and sorted by P1A specific dimer by flow cytometry. The activity of specific CTLs was measured by real time RT-PCR.</p><p><b>RESULTS</b>We firstly screened expression of some CTAs in mouse leukemia cells before and after decitabine treatment and found that decitabine treatment did up-regulate expression of many CTAs. Then we measured the CTLs' activity specific to a mouse CTA P1A in vivo and showed that this activity increased after decitabine treatment. Finally, we sorted these in vivo induced P1A specific CTLs by flow cytometry and demonstrated their cytotoxicity against decitabine treated leukemia cells.</p><p><b>CONCLUSIONS</b>Our study showed the autologous immune response induced by decitabine in vivo. And more importantly, we firstly proved that this response may contribute to disease control. We believe that this immunostimulatory effect is another anti-cancer mechanism of decitabine, and this special effect would inspire new applications of decitabine in the field of leukemia treatment in the future.</p>

Rapid detection of AML1 associated fusion genes in patients with adult acute myeloid leukemia and its clinical significance / 中国实验血液学杂志

This study was aimed to detect the expression of AML1 fusion genes in the patients with adult acute myeloid leukemia (AML) and further to investigate their association with the progression and prognosis of AML. Bone marrow samples were collected from 168 patients with de novo adult AML, and the expression of AML1 ETO, AML1-EVI1, AML1-MDS1, AML1-MTG16, AML1-PRDM16, AML1-LRP16, AML1-CLCA2 and AML1-PRDX4 was analyzed by a novel multiplex nested RT-PCR. Positive samples and minimal residual disease were further examined by real-time fluorescent quantitative PCR. The results showed that the AML1 fusion genes were found in 10.7% (18/168) patients. Among them, AML1-ETO in 12 (7.1%) cases were detected, AML1-EVI1 in 2 cases (1.2%), and AML1-MDS1, AML1-MTG16, AML1-PRDM16, and AML1-CLCA2 in 1 case (0.6%) each were detected. Among the patients with AML1-ETO, 10 patients (10/12, 83.33%) achieved complete remission (CR) after one cycle of chemotherapy, while 2 patients achieved CR after 2 cycles of chemotherapy. The 2 patients with AML1-EVI1 failed to achieve CR after one cycle of chemotherapy. Patients with AML1-MDS1, AML1-MTG16, AML1-PRDM16, or AML1-CACL2 did not achieve CR after one cycle of chemotherapy. It is concluded that AML1 fusion genes are more frequent and can provide the molecular markers for diagnostics and prognosis evaluation of AML and for monitoring MRD.

Application of reverse transcription-multiplex nested PCR to detect PDGFRB gene rearrangement in myeloproliferative disorders / 中国实验血液学杂志

In order to explore the value of reverse transcription(RT)-multiplex nested PCR for detecting PDGFRB gene rearrangement in myeloproliferative disorders (MPD), the PDGFRB rearrangement was detected qualitatively in 146 MPD cases by reverse transcription multiplex nested PCR. The results showed that 8 cases with PDGFRB fusion gene were found in 146 cases, the positive rate was 5.5%. Out of 8 cases with PDGFRB fusion gene, TEL-PDGRB fusion gene was found in 3 cases; HIP1-PDGFRB fusion gene in 2 cases; GIT2-PDGFRB, TP53BP1-PDGFRB and WDP48-PDGFRB fusion gene in 1 case, respectively. It is concluded that RT-multiplex nested PCR is a powerful tool for the detection of PDGFRB rearrangement, which helps to tentatively diagnose MPD and to provide the clues for targeting therapy.

Application of multiplex nested RT-PCR for fast detection of PDGFRα fusion gene in myeloproliferative neoplasms / 中国实验血液学杂志

This study was aimed to explore the applicable value of multiplex nested reverse transcription-polymerase chain reaction (multiplex nested RT-PCR)for the detection of platelet-derived growth factor receptor alpha (PDGFRα) fusion gene in myeloproliferative neoplasms (MPN). Bone marrow or peripheral blood samples from 146 patients with MPN were analyzed by using a novel multiplex nested RT-PCR. The result showed that PDGFRα fusion gene was found in 6 out of the 146 bone marrow or peripheral blood samples, the positive rate was 4.11%, 4 from the 6 patients received treatment with imatinib and showed therapeutic effect. It is concluded that the multiplex nested RT-PCR has a series of advantages such as high sensitivity, specificity, and time-saving, and can be applied for determination of the molecular type of MPN, and also for the diagnosis and therapy of MPN.