Genome-wide identification and expression analysis of CSLA gene family of Dendrobium catenatum / 中国中药杂志

Glucomannan is the key active ingredient of Dendrobium catenatum, and CSLA family is responsible for glucomannan biosynthesis. In order to systematically evaluate the CSLA family members of D. catenatum, the bioinformatics methods were performed for genome-wide identification of DcCSLA gene family members through the genomic data of D. catenatum downloaded from the NCBI database, and further analyses of their phylogenetic relationship, gene structure, protein conserved domains and motifs, promoter cis-elements and gene expression profiles in response to stresses. The results showed that D. catenatum contains 13 CSLA members, all of which contain 9-10 exons. In the evolutionary relationship, CSLA genes were clustered into 5 groups, DcCSLA genes were distributed in all branches. Among which the ancestral genes of groupI existed before the monocot-dicot divergence, and groupⅡ-Ⅴ only existed in the monocot plants, indicating that group Ⅰ represents the earliest origin group. CSLA proteins are characteristic of the signature CESA_CaSu_A2 domain. Their promoter regions contain cis elements related to stresses and hormones. Under different stress treatments, low temperature induces the expression of DcCSLA5 and inhibits the expression of DcCSLA3. Infection of Sclerotium delphinii inhibits DcCSLA3/4/6/8/9/10 expression. Under the treatment of jasmonic acid, DcCSLA11 expression was significantly up-regulated, and DcCSLA2/5/7/12/13 were significantly down-regulated. These results laid a foundation for further study on the function of DcCSLA genes in glucomannan biosynthesis and accumulation.

Preparation, in Vitro and in Vivo evaluation of pyridostigmine bromide-phospholipids complex nanoemulsion / 中国药学杂志

OBJECTIVE: To prepare pyridostigmine bromide-phospholipids complex nanoemulsion (PPNE) and carry out in vitro and in vivo evaluation. METHODS: The pyridostigmine bromide-phospholipids and PPNE were prepared by solvent evaporation method and pseudo-ternary phase diagram method, respectively. The morphology, particle size, Zeta potential, in vitro release and oral bioavailability of PPNE were evaluated. RESULTS: The PPNE was approximately circular. The particle size and Zeta potential were 26.16 nm and -3.88 mV, respectively. The in vitro release behavior of PPNE was similar to pyridostigmine bromide. The relative oral bioavailability of PPNE was 208.1% to pyridostigmine bromide. CONCLUSION: PPNE was successfully prepared with a simple and repeatable method, which may be a fundamental formulation for further research of pyridostigmine bromide.

Synergism between carnosic acid and arsenic trioxide on induction of acute myeloid leukemia cell apoptosis is associated with modulation of PTEN/Akt signaling pathway / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the synergistic effects of carnosic acid (CA) with arsenic trioxide (As₂O₃) on proliferation and apoptosis in HL-60 human myeloid leukemia cells, and the major cellular signaling pathway involved in these effects.</p><p><b>METHODS</b>HL-60 cellular proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. Cell cycle distribution and apoptosis were monitored by flow cytometry. The activation of casepase-9, Bcl-2-associated agonist of cell death (BAD), p-BAD, p27, phosphatase and tensin homolog deleted on chromosome ten (PTEN), Akt, p-Akt was assessed by Western blot analysis. The expression of PTEN mRNA was tested by reverse transcription polymerase chain reaction (RT-PCR) analysis.</p><p><b>RESULTS</b>CA reduced HL-60 cell viability in a dose- and time-dependent manner, and induced G1 arrest and apoptosis. Moreover, CA upregulated PTEN expression, blocked the Akt signaling pathway, subsequently inhibited phosphorylation of BAD, reactivated caspase-9, and elevated levels of p27. CA also augmented these effects of As₂O₃.</p><p><b>CONCLUSION</b>CA might be a novel candidate of the combination therapy for leukemia treatment; these effects were apparently associated with the modulation of PTEN/Akt signaling pathway.</p>

Study on reversing mechanism of multidrug resistance of K562/A02 cell line by carnosic acid / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of carnosic acid (CA) on reversal of the multidrug resistance (MDR) of human leukemia cell line K562/A02 and its mechanism.</p><p><b>METHODS</b>MTT assay was used to determine the sensitivity of K562/A02 cells to adriamycin (ADM) pre-and post-treated with CA. Flow cytometry (FCM) and laser scanning confocal microscopy (LSCM) were used to measure intracellular fluorescence intensity and concentration of ADM respectively. The expression level of mdr1 was detected by semi-quantitative RT-PCR. P-glycoprotein (P-gp) expression was detected by FCM and Western blot.</p><p><b>RESULTS</b>CA decreased IC(50) of ADM in K562/A02 cells from 16.31 µg/mL to 1.35 µg/mL, being a 12.08-fold decrease. The intracellular ADM fluorescence intensity of K562/A02 was increased from 17.05 to 60.53 after treated with CA (P < 0.01). In living K562/A02 cells, after treated with CA, the diffuse distribution of intracellular ADM was recovered in both nuclear and cytoplasm, and the concentration of intracellular ADM increased from 4.93µg/mL to 15.43µg/mL. RT-PCR assay showed that CA inhibited the expressions of mdr1 mRNA in K562/A02 cells (P < 0.01). Mean fluorescence intensity of P-gp detected by FCM in CA-treated K562/A02 was decreased to 22.80 as compared with that in untreated K562/A02 cells (44.40, P < 0.05).</p><p><b>CONCLUSION</b>CA can reverse the MDR of K562/A02 cells in vitro. The mechanism may be associated with down-regulation of mdr1 and inhibition of P-gp function.</p>

Killing effect of double suicide genes mediated by retroviral vector on k562 cells / 中国实验血液学杂志

The aim of study was to investigate the killing effect of double suicide gene system mediated by retroviral vector on K562 cells in vivo and ex vivo. CDglyTK gene was transfected into PA317 cells by using lipofectamine. K562 cells were infected with viral supernatant. K562/CDglyTK cells were treated with 5-fluorocytosine (5-FC) and/or ganciclovir (GCV). Mice were randomly divided into three groups: tumor formation, tumor inhibition and tumor therapy. Each mouse was implanted with K562/CDglyTK cells or K562 cells. The results indicated that the killing effect of 5-FC in combination with GCV on K562/CDglyTK was more significant than using 5-FC or GCV alone. In vivo study showed that after being injected subcutaneously with K562 cells and K562/CDglyTK cells, there was not obvious difference in tumor formation rate of mice, 5-FC + GCV could suppress tumor formation of the K562/CDglyTK cells. After being treated with 5-FC and GCV, the median tumor volume of mice implanted with K562/CDglyTK cells decreased obviously, compared with the control group. Their median survival was significantly prolonged. It is concluded that double suicide genes are more effective for killing effect on K562 cells in vivo and in ex vivo. It may be applicable to clinical gene therapy.

Experimental study on immunotherapy with dendritic cell in leukemic mice model / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility and efficiency of immunotherapy with dendritic cell (DC) in leukemic mice model after allogeneic bone marrow transplantation (allo-BMT).</p><p><b>METHODS</b>Mature DC were expanded from mice bone marrow mononuclear cells (MNC) by adding mouse granulocyte-macrophage colony stimulating factor (mGM-CSF) and interleukin-4 (mIL-4). Three days later they were pulsed with frozen thawing L7212 leukemia-related antigen. Mice bearing leukemia received allo-BMT at d 0, and then were divided into control group (A), T cells group (B) and DC + T cells group (C) to receive respective immune therapy at d 14. The survival rate, survival time, occurrence of graft-versus-host disease (GVHD), cytotoxicity of spleen cells and serum cytokine level were observed. The survivors in each group were rechallenged with L7212 cells to observe the immune response to the leukemia.</p><p><b>RESULTS</b>Mature DC were successfully induced from bone marrow MNC. In groups B and C, the relapse rates were 30% and 0%, while the long term survival rates after BMT was 30% and 70% respectively. Both of the differences were statistically significant (P < 0.05). However, the incidence of GVHD in these two groups were similar. The mean survival times were (32.95 +/- 13.29) days and (41.15 +/- 13.88) days, respectively (P < 0.01). MTT assay indicated that spleen cells from group C had specific killing activity to L7212 cells. Enzyme-labeled immunosorbent assay (ELISA) showed that the serum IL-2 level in group C was (419.75 +/- 26.66) pg/ml, being significantly higher than that in the other two groups (P < 0.01). When the survivors were rechallenged with L7212 cells, there was difference between the survival rates of groups C and B (85.7% vs 33.3%, P < 0.05).</p><p><b>CONCLUSION</b>Immunotherapy with leukemia related antigen-pulsed DC in combination with donor lymphocyte infusions is an effective approach to reinforce GVL effect and decrease relapse after allo-BMT.</p>

Special morphological changes of pathologic cells in two cases of Waldenström's macroglobulinemia / 中国实验血液学杂志

Waldenström's macroglobulinemia (WM) is one of malignant hematological disease on account of abnormal proliferation of B lymphocyte clone and the pathologic cells of WM possess ability to secrete monoclonal immunoglobulin M. In this study, the diagnosis and morphological characteristics of 2 patients with WM were analyzed. The results showed that a special kind of "foam cells" were found by cytochemical staining examinations in both cases, which displayed characteristics of lymphocytes, but neither monocyte-macrophage nor fatty cells. The periodic acid-Shiff's reaction (PAS) demonstrated strong positive, especially on the inclusion bodies in pathologic cell plasma while the acid phosphatase, and alpha-butanoic acetate esterase stainings, resulted both in negative. In conclusion, the cells found in the two cases reported may be described as gemmy ring-like lymphocyte in morphology, a special subtype of ring-like lymphocyte.

Application of pseudotyped lentivirus-mediated double suicide genes to allogeneic bone marrow transplantation in mice / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility and efficiency of cytosine deaminase (CD)/thymidine kinase (TK) gene-modified donor T cells used in allogeneic bone marrow transplantation (allo-BMT) as an approach to mitigate GVHD without compromising engraftment.</p><p><b>METHODS</b>The pseudotyped lentivirus vectors containing CD and TK double suicide genes were transfected with lipofectine to donor T cells. Lethally irradiated 615 leukemia mice were transplanted with BALB/c bone marrow plus CD(+)TK(+)T cells. GVHD prophylaxis was by administration of ganciclovir (GCV) and 5-Fluoride cytosine (5-FC).</p><p><b>RESULTS</b>The pseudotyped lentivirus-mediated gene transfer system could efficiently transfer CD and TK double suicide genes into donor T cells. Administration of GCV and 5-FC to the mice could markedly potentiate the CFU-S and CFU-GM yields and raise the number of peripheral white blood cells. 1 x 10(7) CD(+)TK(+) allogeneic T cells caused GVHD of a similar magnitude and time course to that of fresh, naive T cells after allo-BMT. Administration of GCV and 5-FC in mice received CD(+)TK(+)T cells reduced the severity of GVHD and resulted in significantly longer survival as compared with non-administration mice, and the effect was stronger than that of administration of GCV or 5-FC alone.</p><p><b>CONCLUSION</b>Administration of CD + TK gene-modified donor T cells to recipient in allo-BMT might be an approach to mitigate GVHD without compromising alloengraftment.</p>

Establishment of lentivirus-mediated system of double suicide genes and its killing effects on K562 cells / 中国实验血液学杂志

To establish lentivirus-mediated system of double suicide genes and explore its killing effects on K562 cells, lentivirus transfer vector for double suicide genes was constructed using molecular methods, three plasmids of lentivirus gene transfer vector system were transferred into packaging cell line 293T using lipofectine method, the transfer effect was observed through fluorescence microscopy, the lentivirus particles were observed by means of electron microscopy. High titer of lentivirus was harvested from the supernatant of virus-producing cell culture and concentrated by high-speed centrifugation with Poly-L-Lysine (PLL). The K562 cells were infected with the concentrated supernatant containing the virus with the double suicide genes. Fluorescence microscopy and RT- PCR confirmed the integration and expression of extraneous gene. The cytotoxicity to these transgenic cells treated with 5-FC and GCV was measured by MTT assays. The growth inhibition ratio (GIR) of cells and inhibition concentration 50 (IC(50)) were counted. After administration of GCV and 5-FC, the changes of those cells were observed through scanning electron microscope. The results showed that lentivirus transfer vector with double suicide genes was constructed successfully. The above-mentioned plasmids were effectively transferred into 293T cells. So much green fluorescence was observed through fluorescence microscope. A lot of lentivirus particles were observed through transmission electron microscope. Double suicide genes mediated by lentivirus were stably integrated and expressed in K562 cells after infection with the concentrated virus using fluorescence microscopy and RT-PCR. The GIR of K562 cells using GCV or 5-FC was 48.73% or 50.69% respectively and it was apparently higher than that of untransfected cells (P < 0.01). When using GCV and 5-FC together, the GIR was 87.69%, which was apparently higher than that of group using GCV or 5-FC alone (P < 0.01). In conclusion, lentivirus-mediated gene transfer system could transfer CD and TK double suicide genes into K562 cells with high efficiency and it had strong killing effects when giving 5-FC and/or GCV. The cytotoxic effects of double suicide genes were superior to that of single suicide gene. The lentivirus-mediated double suicide gene transfer system is a high-efficiency gene transfer vector.