[Effect of Hemoglobin on Efficacy of CAR-T Therapy in Patients with Multiple Myeloma].

OBJECTIVE: To investigate the effect of hemoglobin (Hb) on the efficacy of chimeric antigen receptor T cell therapy (CAR-T) in patients with multiple myeloma (MM). METHODS: From June 2017 to December 2020, 76 MM patients who received CAR-T therapy in the Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, with complete clinical data and evaluable efficacy, were selected as the research objects. According to the receiver operating characteristic (ROC) curve, the best cut-off value was obtained. The patients were divided into groups on the basis of Hb 105.5 g/L as the cut-off value. The age, sex, serum calcium, ß2-microglobulin, serum creatinine, lactate dehydrogenase (LDH), and the influencing factors of CAR-T treatment efficacy in MM patients were analyzed. RESULTS: Hb was an influencing factor of efficacy. Univariate analysis showed that Hb, LDH, and albumin affected the efficacy of CAR-T therapy. Multivariate analysis showed that Hb ( OR=1.039, 95% CI: 1.002-1.078) and LDH ( OR=1.014, 95% CI: 1.000-1.027) were the influencing factors for the efficacy of CAR-T therapy. CONCLUSION: The efficacy of CAR-T therapy in MM patients with low Hb is poor, and Hb is a factor affecting the efficacy of CAR-T therapy.

Using colloidal AFM probe technique and XDLVO theory to predict the transport of nanoplastics in porous media.

The plastic concentration in terrestrial systems is orders of magnitude higher than that found in marine ecosystems, which has raised global concerns about their potential risk to agricultural sustainability. Previous research on the transport of nanoplastics in soil relied heavily on the qualitative prediction of the mean-field extended Derjaguin-Landau-Verwey-Overbeek theory (XDLVO), but direct and quantitative measurements of the interfacial forces between single nanoplastics and porous media are lacking. In this study, we conducted multiscale investigations ranging from column transport experiments to single particle measurements. The maximum effluent concentration (C/C0) of amino-modified nanoplastics (PS-NH2) was 0.94, whereas that of the carboxyl-modified nanoplastics (PS-COOH) was only 0.33, indicating PS-NH2 were more mobile than PS-COOH at different ionic strengths (1-50 mM) and pH values (5-9). This phenomenon was mainly attributed to the homogeneous aggregation of PS-COOH. In addition, the transport of PS-NH2 in the quartz sand column was inhibited with the increase of ionic strength and pH, and pH was the major factor governing their mobility. The transport of PS-COOH was inhibited with increasing ionic strength and decreasing pH. Hydrophilicity/hydrophobicity-mediated interactions and particle heterogeneity strongly interfered with interfacial forces, leading to the qualitative prediction of XDLVO, contrary to experimental observations. Through the combination of XDLVO and colloidal atomic force microscopy, accurate and quantitative interfacial forces can provide compelling insight into the fate of nanoparticles in the soil environment.

Efficacy of median nerve electrical stimulation on the recovery of patients with consciousness disorders: a systematic review and meta-analysis.

OBJECTIVE: To identify whether median nerve stimulation (MNS) may be a potential candidate for the treatment of consciousness disorders via a systematic review and meta-analysis. METHODS: PubMed, Cochrane Library, China National Knowledge Infrastructure, Chinese VIP Information, Wanfang, and SinoMed databases were searched. Risk of bias was assessed using the Cochrane Collaboration's tool. The Glasgow Coma Scale (GCS), Disability Rating Scale (DRS), electroencephalogram (EEG), days in the Intensive Care Unit (ICU), and cerebral blood flow measures were compared between the median nerve stimulation and control groups. The meta-analysis was conducted using Review Manager software. RESULTS: We identified 2244 studies, of which 23 (with data from 1856 patients) qualified for the analysis. MNS improved GCS scores (mean difference [MD] = 2.15), EEG scores (MD = 1.61), cerebral mean blood flow velocity (MD = 4.23), and cerebral systolic blood flow velocity (MD = 10.51). Furthermore, it decreased DRS scores (MD = -1.77) and days in the ICU (MD = -2.02). The effects of MNS on GCS scores increased with longer treatments (1 week, MD = 1.03; 1 month, MD = 2.35) and were better with right MNS (right, MD = 2.36; bilateral, MD = 1.72). CONCLUSIONS: MNS may promote recovery from consciousness disorders.

The complete mitochondrial genome of Mactra quadrangularis (Mactridae).

The whole mitochondrial genome sequence of Mactra quadrangularis (Reeve, 1854) was determined. It had a total length of 16,848 bp and it contained 12 protein coding genes, 2 ribosome RNA genes, and 22 transfer RNA genes. The base composition was 25.75% A, 20.82% G, 11.53% C, and 41.90% T, respectively. Furthermore, state codon of ND4 was ATT; ND1 and CYTB were ATA; COX1 was GTG; ND5, COX2, ND4L, ND6, ND2, COX3, ATP6, and ND3 were ATG. Phylogenetic analysis demonstrated that M. quadrangularis was most closely related to Mactra chinensis. The mitochondrial genome will provide reference for the further investigation and research of M. quadrangularis.

[Curative Efficacy of Rituximab for ITP Patients with Different Sensitivity to Hormone].

OBJECTIVE: To investigatc the curative efficacy of low dose rituximab for glucocorticoid ineffective on dependent ITP patients and its relation with sensitivity to glucocorticoid so as to provide reference basis for rational use of drugs in clinical treatmant. METHODS: Seventy-ninth ITP patients enrolled in this study included the glucocorticoid-ineffective patients (19 cases) and glucocorticoid-dependent patients (60 cases). All ITP patients were treated with regimen consisted of high dose dexamethasone plus low dose rituximab (dexal-methasone 40 mg/d for 4 days per os, ritaximab 100 mg by intravenous infusion at D7, 14, 21 and 28 respectively). The patients after treatment were followed-up for 12 month, and the relation of patients sensitivity to glucocorticoid with therapentic response of rituximab was analyzed. The changes of Treg cell ratio and BAFF, IL-2 and sCD40L levels before and after treatment were detected by flow cytometry and ELISA respectively. RESULTS: The overall response rate (ORR) of patients treated with above- mentioned regemen at 1, 3, 6 and 12 months after treatment was 79.7% (63/79), 69.6% (55/79), 63.3% (50/79) and 60.8% (48/79) respectivcly, out of which the ORR of glucocorticoid ineffective and glucocorticoid-dependent ITP patients treated with above-mentioned regimen at 1, 3, 6 and 12 months after treatment was 47.4% (9/19) vs 90.0% (54/60), 36.8% (7/19) vs 80.0% (48/60), 21.1% (4/19) vs 76.7% (46/60), 21.1% (4/19) vs 73.3% (44/60), and the difference between 2 groups was statistically significant. The detection of T reg cell showed that the T reg cell ratio in glucocorticoid- ineffective and dependent patients at 1, 3, 6 and 12 months after treatment was (1.70±0.43)% vs (3.47±0.72)%, (1.66±0.33)% vs (4.29±0.91)%, (1.71±0.37)% vs (4.44±0.97)%, (3.36±0.54)% vs (4.29±1.04)%, respectively. The detection of cytokines showed that the levels of BAFF, IL-2 and sCD40L in plasma of glucocorticoid-dependent patients at 1 month after treatment significanlly decreased (P＜0.05), the levels of BAFF, IL-2 and sCD40L in plasma of glucocorticoid-ineffective patients although decreased at 1 mouth after treatment, but there was no statistical difference as compared with glucocosticoid-depenment patients. CONCLUSION: The treatment of glucocorticoid-dependent ITP patients with rituximab is more effective. The regulatory effect of rituximab on the T-reg cells, BAFF, IL-2 and sCD40L may be one of its mechanisms.

One-Pot Asymmetric Synthesis of Spiropyrazolone-Linked Cyclopropanes and Benzofurans through a General Michael Addition/Chlorination/Nucleophilic Substitution Sequence.

A sequential and general strategy has been successfully developed for the synthesis of spiropyrazolone scaffolds. This intriguing transformation of the asymmetric multicomponent catalysis process was realized with the combination of Michael addition/chlorination/nucleophilic substitution in a one-pot sequence, giving rise to a series of spiropyrazolones with fully substituted cyclopropanes and spiro-dihydrobenzofurans containing continuous stereogenic centers in good yields with excellent stereoselectivities.

[Prognostic Significance of CD45dimCD117+ Cells in Patients with Acute Myeloid Leukemia after Complete Remission].

OBJECTIVE: To investigate the predictive value of CD45dimCD117+ phenotype-abnormal cells (hereinafter referred to as "abnormal cells") for relapse and prognosis in adult patients with acute myeloid leukemia (AML) within 2 weeks after the first complete remission (CR1). METHODS: The clinical data of patients with newly diagnosed AML (non-acute promyelocytic leukemia) admitted in our department from July 1, 2014 to June 30, 2017 were analyzed retrospectively, and the relationship between clinical features at the initial diagnosis and the abnormal phenotype cells of CD45dimCD117+ within 2 weeks after CR1 with the prognosis were analyzed. RESULTS: A total of 91 patients with CD45dimCD117+ abnormal cells were detected. The median age was 51 years old, the median WBC count was 11.60×109/L, and the median ratio of bone marrow blast cells was 0.35 at initial diagnosis. According to the FAB classification, 1 (1.1%), 7 (7.7%), 38 (41.7%), 20 (22.0%), 21 (23.1%) and 4 (4.4%) patients were classifice as M0, M1, M2, M4, M5, and M6, respectively. According to the NCCN risk stratification, 30 (33.0%), 51 (56.0%), and 10 (11.0%) patients were determined as good, moderate, and poor prognosis, respectively. The median ratio of abnormal cells within 2 weeks after CR1 was 1.8500 (0.0236-8.0000)%. The median time from initiation of induction therapy to the acquisition of CR was 46 days, median recurrence-free survival time was 319 days, and median overall survival time was 352 days. A total of 45 patients relapsed, of which 14 died; 46 patients did not relapse, of which 3 died. The cutoff of abnormal cells by receiver operating characteristic curve (ROC) analysis was 2.055% (Se=0.733，Sp=0.761). The abnormal cell ratio was＞2.055% in 44 patients, the median ratio of abnormal cells was 3.075%, among which 33 patients relapsed and 12 patients died; the abnormal cell ratio was ＜2.055% in 47 patients, the median ratio of abnormal cells was 1.150%, 12 patients relapsed and 5 patients died. Regression analysis showed that WBC count＞50×109/L and abnormal cell ratio＞2.055% were independent risk factors for recurrence. The abnormal cell ratio＞2.055% group had a 2-year RFS rate of 54.3% and a 2-year OS rate of 52.8%. The abnormal cell ratio＜2.055% group had a 2-year RFS rate of 86.6% (P=0.018), and a 2-year OS rate of 85.3% (P＜0.05). CONCLUSION: For adult AML patients, CD45dimCD117+ phenotypical abnormal cells ratio＞2.055% within 2 weeks after CR1 is an independent risk factor for recurrence, which also is an dverse factor for RFS and OS.

[Effect of Stably Down-regulating FMI Expression of K562 Cells on Sensitivity of K562 cells to Imatinib Mesylate].

OBJECTIVE: To investigate the effect of stably down-regulating the FMI expression of K562 cells on the sensitivity of K562 cells to Imatinib (IM) and its possible mechanism. METHODS: Western-blot was used to detect the expression of FMI protein in K562 cells and peripheral blood mononuclear cells from the patients with chronic myelogenous leukemia, chronic myeloid blast crisis and healthy volunteers. The specific interference sequences targeting at the human FMI gene were designed and ligated into the lentiviral vector LV3; the three plasmid system-packaged lentivirus particles were used to transfect K562 cells to screen K562 cells that stably down-regulated FMI. CCK-8 assay and flow cytometry were used to determine effect of IM on cell proliferation and apoptosis. The transcription level of FMI and Fz8 in leukemia cells was detected by fluorescent quantitative PCR. The protein expression levels of FMI, Fz8, NFAT1, BCR-ABL and ß-catenin in leukemia cells were detected by Western-blot. RESULTS: The expression of FMI protein could be detected in peripheral blood mononuclear cells of the patients with CML-BC and K562 cells, the FMI expression could not be detected in all the patients with CML-CP and healthy volunteers. The recombinant lentiviral vector LV3/FMI had been successfully constructed the lentivirus was packaged, and the K562 cells stably down-regulating the FMI protein were screened. After stable down-regulation of FMI expression in K562 cells, the proliferation rate of leukemia cells decreased and the apoptosis rate was increased under the same drug concentration. Both the transcription and protein expression levels of Fz8 decreased. The NFAT1 total protein level increased, as well as the nuclear translocation of protein was enhanced. There was no significant change in the expression level of BCR-ABL fusion protein. The expression level of ß-catenin protein decreased. CONCLUSION: After the stable down-regulation of FMI expression, the sensitivity of K562 cells to IM and apoptosis of cells increase, which are performed possibly by inhibiting the FMI-Fz8 signaling pathway and activating the Ca2+-NFAT and Wnt/ß-catenin signaling pathway.

[Role of Ca2+-NFAT Signaling Pathway in Ph+ ALL Drug-resistance Mediated by Bone Marrow Stromal Cells].

OBJECTIVE: To explore the role of Ca2+-NFAT signaling pathway in Ph+-ALL drug resistance mediated by bone marrow stromal cells. METHODS: The transcription level of NFAT mRNA in Sup-B15 cells and Ph+ ALL primary cells was detected by polymerase chain reaction. The expression of P-glycoprotein in Sup-B15 cells was detected by flow cytometry. The change of NFAT protein in Sup-B15 cells was detected by Western blot. AnnexinV/7-AAD was used to label cells. Flow cytometry was used to detect cell apoptosis; Fluo 3-AM dye was used to label cells, and flow cytometry used to detect changes of Ca2+ concentration in leukemia cells. RESULTS: NFAT expression could be detected in both Sup-B15 and Ph+ ALL primary cells; P-glycoprotein could not be detected by flow cytometry; CAS could significantly inhibit NFAT protein expression in clinically applied drug concentrations (2.5, 5 µmol/L); Clinically applied concentration of CAS (2.5, 5 µmol / L) has no significant effect on the apoptosis of Sup-B15 cells, while higher concentration of CAS (10 µmol / L) could induce apoptosis of Sup-B15 cells. Bone marrow stromal cells OP9 could, decrease the sensitivity of Sup-B15 cells and Ph+ ALL primary cells to imatinib (IM); After co-culture with bone were marrow stromal cells, the Ca2+ concentration in Sup-B15 cells was enhanced, the levels of NFAT protein and nullear protein in sup-B15 cells also were enhanced. The addition of CAS in co-culture system could inlibit the Ca2+-NFAT signaling pathway, reduce the protective effect of OP9 on Sup-B15 cells.Conclution:The Ca2+-NFAT sigualing pathway, contributes to the survival of Ph+ ALL cells. Bone marrow stromal cells can mediate the resistance of Ph+ ALL cells to IM by activating Ca2+-NFAT signaling pathway.

[Multivariate Analysis of Factors Influencing Recovery from Hemorrhagic Cystitis after Allo-HSCT].

OBJECTIVE: To analyze the incidence of hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation and the factors affecting HC, so as to provide clinical evidence for further treatment of HC. METHODS: The HC of 113 patients after allogeneic hematopoietic stem cell transplantation in Affiliated Hospital of Xuzhou Medical University between the years 2014-2016 was analyzed respectively. All cases of HC were divided into HC group and non-HC(control) group. The follow-up time: from preeonditionig day to 180 d after transplantation. The 10 clinical parameters were selected for univariate analysis with COX regression analysis: sex, age (＜25 years and 25 years), primary disease, conditioning regimen with anti-thymoglobulin(ATG), sex-mismatch in recipients, haploidential HSCT, cytomegalovirus (CMV) viremia, EB viremia, graft-versus-host disease (GVHD), and primary disease relapse, the factors significant at the 0.1 level in univariate analysis should be further evaluated by multivariate analysis using a COX regression analysis. The difference was significant at P＜0.05 in multivariate analysis. RESULTS: The HC occured in 31 of 113 patients (27.4%), with 5 cases of grade I (5.5%), 19 of grade II (16.8%), 5 of grade III (4.4%), and 2 of grade IV (1.8%). The median time of HC onset was 37 days (26-70 d) after transplantation. The median duration of HC was 14 days (5-55d). Univariate analysis showed that conditioning with anti-thymoglobulin (ATG) (RR=6.170, 95%CI: 1.875-20.306, P＜0.01), CMV viremia (RR=7.633, 95%CI：2.318-25.133) (P＜0.01), haploidentical HSCT (RR=0.307, 95%CI：0.137-0.686, P＜0.01), GVHD (RR=1.891, 95%CI：0.918-3.898, P＞0.05) were the risk factors for recovery from HC. The multivatiate analysis of above-mentioned risk factors with statistical significance showed that only CMV viremia (RR=4.770, 95%CI: 1.394-16.326, P＜0.05) was the indentified risk factor affecting the recovery from HC. CONCLUSION: Monitoring CMV viremia and antivirotic treatment are effective measurs to prevent the occurrence of HC and promote the recovery from HC.

Participation of ß-Ketothioamides in N-Heterocyclic Carbene-Catalyzed [3 + 3] Spiroannulation: Asymmetric Synthesis of Functionalized Spiro-piperidinone Derivatives.

An N-heterocyclic carbene-catalyzed asymmetric [3 + 3] spiroannulation of ß-ketothioamide was successfully developed. ß-Ketothioamides exhibit an unusual reactivity to undergo a previously challenging lactamization reaction, and the desired spiro-piperidinone derivatives containing two vicinal stereogenic centers were synthesized in good to high yields with high stereoselectivities, whose structure can be converted to the corresponding imide and δ-lactam derivatives smoothly.

[Relationship between BCR-ABLIS and Prognosis and Affecting Factors for Prognosis in CML Patients Treated with TKI for 12 Months].

OBJECTIVE: To evaluate the long-term prognosis of CML patients whose BCR-ABL transcript level was warning and best response at 12 months of treatment with tyrosine kinase inhititor (TKI), and to investigate the factors affecting therapeutic efficacy and prognosis. METHODS: The clinical data of patients with newly diagnosed CML were analyzed retrospectively. According to BCR-ABL transcript level, the 80 patients were divided into group A and group B, the patients with BCR-ABLIS >0.1% and ≤ 1% (warning response) were entolled in group A, and the patients with BCR-ABLIS ≤ 0.1% (best response) were enrolled in group B as control. The ratio of patients with main molecular response (MMR) and deep molecular response (DMR), as well as aquistation rate and cummulative rate of MR4 (DMR) at specified fine points in 2 groups were compared, the independent risk factors affecting the therapeutic efficacy and prognosis were analyzed. RESULTS: The MMR and MR4 of the B group at 15, 18 and 24 months after TKI treatment were significantly higher than those of the A group, and the patients in the B group reached MR4 faster. In the 3 months, 6 months and 12 months after the demarcation point (TKI 12 months), the A group was much less easy to obtain MR4 (P<0.05) than the B group. Through survival analysis, there were more patients in the B group than the A group at different time points to reach MR4, and the difference was statistically significant (P<0.01). The single factor analysis showed that the splenomegaly (below rib edge)> 10cm (P<0.01) and lactate dehydrogenase > 400 U/L (P<0.05) were the long-term warning factors for patients. Multivariate analysis showed that the size of the spleen was an independent factor (P<0.01) to affect the prognosis of the patients who had been warned for 12 months. CONCLUSION: Patients at 12 months warning effect are slower and less easier to get DMR, which has a poor long-term prognosis. The size of the spleen in the patient at warning for 12 months of treatment effect can predict the relatively poor long-term prognosis. For a patient with a 12 months response to the warning, an early replacement therapy is available on the basis of combining other factors..

[Risk Factors and Prognosis of Hepatic cGVHD after Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To analyze the risk factors and prognosis of hepatic chronic GVHD after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The clinical data of 147 patients undergoing allo-HSCT from January 2013 to December 2016 were analyzed, the correlation between recipient age and sex, disease state, matched degree of HLA, donor sex, stem cell sources, ATG in GVHD prophylaxis, liver dysfunction during conditioning period, pre-transplant HBsAg, prior aGVHD and hepatic cGVHD were studied, and the correlation between hepatic cGVHD and prognosis were analysed. RESULTS: Thirty-two patients had hepatic cGVHD, cumulative incidence of 26.4%. In univariate analysis, pre-transplant HBsAg+and liver dysfunction during conditioning period were not significantly related with hepatic cGVHD (P>0.05). In multivariate analysis, prior acute GVHD (HR=2.087, P=0.045) was the independent risk factor for hepatic cGVHD, ATG (HR=0.231, P=0.000) was significantly related with a lower incidence of hepatic cGVHD. In univariate analysis, patients with hepatic cGVHD had a lower 2 years relapse rate (P=0.038). CONCLUSION: Prior acute GVHD is the independent risk factor for hepatic cGVHD, the ATG can significantly reduce the incidence of hepatic cGVHD. Hepatic cGVHD has been found to relate with a lower 2 years relapse rate.

[Effect of Steadily Down-regulating VE-Cadherin Expression on Susceptibitity of K562 Cells to Chemotherapy].

OBJECTIVE: To investigate the effect of steadily down-regulating the expression of VE-cadherin on the chemotheraputic sensitivity of K562 cells, and explore its possible mechanism. METHODS: Specifically targeting interference sequences carrying human VE-cadherin were designed, the recombinant lentiviral vector containing the IRES-GFP and NEO segment was constructed; recombinant lentivirus was generated by three-plasmids packing system, and transfected into K562 cells, then the cells steadily down-regulated were sorted. CCK-8 assay was performed to evaluate the VE-cadherin of chemotherapeutic (Imatinib) sensitivity of K562 cells. The apoptosis was analyzed by flow cytometry with Annexin V/7-AAD double labeling. The expressions of CD133 and ALDH1 mRNA were determined by real time PCR. The protein expressions of VE-cadherin, BCR-ABL and ß-catenin were analyzed by Western blot. RESULTS: The recombinant lentiviral vector pLB-shVEC-NEO-IRES-GFP was successfully constructed, packed into the lentivirus, then the K562 cells steadily down-regulating VE-cadherin expression was obtained. When VE-cadherin was down-rengulated in K562 cells, the proliferation rate was reduced while the the apoptosis rate was increased; the mRNA levels of CD133 and ALDH1 also were reduced; BCR-ABL fusion protein was not obviously changed; the total ß-catenin protein, as well as the nuclear ß-catenin protein were decreased in the K562/shVEC cells. Conclution: K562 cells are more susceptible to chemotherapy when VE-cadherin is down-regulated, that may be realized via reducing the stability and the nuclear transfer of ß-catenin protein.

Twenty-four-hour blood pressure variability plays a detrimental role in the neurological outcome of hemorrhagic stroke.

Background Blood pressure variability (BPV) is a modifiable risk factor for stroke. This study was performed to determine the prognostic role of BPV in patients with acute hemorrhagic stroke. Methods The data of 131 hospitalized hypertensive patients with spontaneous intracerebral hemorrhage (sICH) were collected. All patients underwent examinations using several neurological scales (Glasgow Coma Scale, National Institutes of Health Stroke Scale, and modified Rankin scale [mRS]) and BP measurements at different time points. Results Sex, age, hematoma volume, and neurological scores were not significantly different between patients with a favorable and unfavorable prognosis for sICH. However, significant differences were found in hypertension, diabetes, metabolic syndrome, atrial fibrillation, smoking, and stroke history. The standard deviation (SD), coefficient of variation (CV), and maximum-minimum range (Max-Min) of diastolic BP and the mean, SD, CV, and Max-Min of systolic BP significantly differed between the groups. Statistical analysis also demonstrated correlations between the 90-day mRS score and BPV and between systolic BPV and the 90-day mRS score. Conclusion High systolic or diastolic BPV within 24 hours of hemorrhagic stroke onset is associated with the 90-day neurological prognosis. The 24-hour BPV plays a critical role in the neurological outcome of hemorrhagic stroke.

Stromal cells attenuate the cytotoxicity of imatinib on Philadelphia chromosome-positive leukemia cells by up-regulating the VE-cadherin/ß-catenin signal.

ß-Catenin is a key regulator of leukemia stem cell maintenance and drug resistance. Herein, we investigated the protective effects of the stromal cell-mediated VE-cadherin-ß-catenin signal on Ph+ leukemia cells during imatinib treatment. We found stromal cells could desensitize imatinib and up-regulate VE-cadherin expression on Ph+ leukemia cells (K562 and SUP-B15 cells), which further stabilized and activated ß-catenin. Knockdown of VE-cadherin with shRNA diminished the ß-catenin protein and partly resensitized Ph+ leukemia cells to imatinib despite the presence of stromal cells, suggesting VE-cadherin is a potential target in the treatment of Ph+ leukemia.

[Establishment of a high efficient human coagulation factor VIII eukaryotic expression system using lentiviral vector].

OBJECTIVE: To establish a high efficient human coagulation factor VIII (FVIII) eukaryotic stable expression system using lentiviral vector, and determine its biosafety. METHODS: Lentiviral transfer plasmid carrying human B-domain-deleted FVIII(BDDhFVIII)-IRES-GFP(BDDhFVIII/pXZ9)or IRES-GFP(pXZ9) was constructed. Lentivirus particles were produced by transiently co-transfected 3-plasmids into 293FT cells and further concentrated via ultracentrifugation. CHO cells were infected, 72h later, the FVIII antigen (FVIII:Ag) concentration in the medium was examined by ELISA, the activity was detected via one stage coagulation,and the transcription of FVIII in the infected CHO cells was determined by RT-PCR.Virus infection ability in the medium and the gag gene in CHO cells were determined to evaluate the model's biosafety. RESULTS: Lentiviral transfer plasmid BDDhFVIII-IRES-GFP(BDDhFVIII/pXZ9)carrying human B-domain-deleted FVIII or IRES-GFP (pXZ9) was successfully constructed, and high titer lentiviruses has been prepared. The lentivirus could infect CHO cells efficiently, after an additional 72 h, the FVIII:Ag concentration had up to (1724.9±283.7) mU/ml, the FVIII:C level increased to (10.58±1.55)%, and transcripts of BDDhFVIII mRNA could be measured by RT-PCR. Neither the gag gene nor the virus in the supernatant was detected. CONCLUSION: Lentivirus-mediated human coagulation factor VIII could be expressed efficiently in CHO cells. The system couldn't produce offspring virus, proving a good biosafety.

[Effect of VE-cadherin on sensitivity to Imatinib in Sup-B15 Philadelphia chromosome positive acute lymphoblastic leukemia cells].

OBJECTIVE: To investigate the sensitivity of imatinib mesylate (IM) on Sup-B15 Ph⁺ acute lymphoblastic leukemia (ALL) cells knockdown of VE-cadherin (CD144), and to further explore its mechanism. METHODS: CD144 in Sup-B15 leukemia cells was stably knock downed via lentivirus-mediated RNA interference (named as Sup-B15/shVEC). The inhibitory effects of IM on Sup-B15/shVEC and Sup-B15 leukemia cells were measured by CCK-8 test, and the apoptosis of those cells was determined by AnnexinV/7-AAD dyeing using flow cytometry, the percentage of CD34⁺CD38⁻ leukemia cells also by flow cytometry. ALDH1 mRNA levels were detected by real-time RT-PCR, and protein levels of CD144, CD133, Bcr-abl and ß-catenin by Western blot. RESULTS: IM treatment presented inhibitory effects on Sup-B15/shVEC and Sup-B15 leukemia cells at multiple concentrations of IM. The IC50 of IM on Sup-B15/shVEC and Sup-B15 leukemia cells were 25.1µmol/L and 18.7µmol/L, respectively (P<0.05). After 48h of 20 µmol/L IM treatment, the percentages of apoptosis cell in Sup-B15/shVEC cells and Sup-B15 cell were (13.52±2.06)% and (3.03±0.72) %, respectively (P<0.05). The percentage of CD34⁺CD38⁻ cells in Sup-B15 cells was significantly higher than in Sup-B15/shVEC cells [(2.39±0.28)% vs (0.96±0.07)%, P<0.05). As compared to Sup-B15 cells, the transcription of ALDH1 in Sup-B15/shVEC was remarkably downregulated, and the CD133 protein level was also downregulated in Sup-B15/shVEC cells. Both cytoplasmic and nucleic ß-catenin protein levels (but not for Bcr-abl levels) decreased in Sup-B15/shVEC cells as compare to Sup-B15 cells. CONCLUSION: Knockdown of CD144 sensitized Sup-B15 Ph+ ALL cells to IM. The possible mechanisms underlying this phenomenon might be via inhibiting ß-catenin nucleic translocation and facilitating ß-catenin degradation.

[Cloning of mouse adam10 gene promoter and construction and identification of dual luciferase reporter system].

This study was aimed to clone mouse adam10 gene promoter and construct its dual luciferase report vector, and to investigate its transcriptional activity. Total DNA was extracted from mouse brain and used for amplifying the fragment containing adam10 gene promoter by PCR. The amplified product was inserted into pGL-4.10 vector to construct pGL4.10-adam10. The pGL4.10-adam10 and control plasmid pGL4.74 were co-transfected into HEK293 FT cells by lipofectamine 2000. The activity of adam10 gene promoter was assayed by luciferase system. The results showed that the recombinant plasmid pGL4.10-adam10 containing promoter of mouse adam10 was correctly constructed. The method was optimized by changing ratio of two plasmids. Moreover, the transcriptional activity of pGL4.10-adam10 stimulated by ionomycin increased. It is concluded that the dual luciferase reporter system is successfully established, which is useful in bioluminescence imaging technology in vitro. The effect of ionomycin can enhance the transcriptional activity of adam10 gene promoter.

[Construction of lentiviral vector for truncated mouse fibroblast growth factor receptor-1 gene and its expression in eukaryotic cells].

This study was aimed to clone the gene coding mouse fibroblast growth factor receptor-1 (fgfr1), to construct the recombinant lentiviral vector of truncated form fgfr-1 (Δfgfr1) carrying enhanced green fluorescence protein (EGFP) and to investigate its expression in eukaryotic cells (293FT cells). The full length fgfr1 gene was cloned by RT-PCR using brain tissue of BALB/c fetal mouse as template and inserted into PCR-Blunt vector, a truncated fgfr1 fragment was produced by site-directed mutagenesis for deleting intracellular phosphorylated domain, then was subcloned into a lentiviral vector and cotransfected into 293FT packaging cells together with envelope plasmid and packaging plasmid by lipofectamine 2000. Viruses were gathered and concentrated using ultracentrifuge, and then transfected into 293FT cells. Expression of EGFP was detected by fluorescent microscopy and flow cytometry (FCM), and the truncated FGFR1 protein was detected by Western blot. The results demonstrated that mouse fgfr1 gene was cloned and the lentiviral expression vector LV-IRES-EGFP-Δfgfr1 and control vector LV-IRES-EGFP were successfully constructed. The lentiviral particles were correctly packaged, and the virus titers were above 10(8) TU/ml in the supernatant after concentration. Expression of EGFP was detected by fluorescent microscopy in 293FT cells post transfection, and the transfection efficacy was > 95% determined by FCM. Expression of FGFR1 protein detected by Western blot was significantly higher than that in control group. It is concluded that the truncated gene fgfr1 along with the gene coding EGFP is successfully inserted into a lentiviral vector to construct a recombinant lentiviral vector, which can be expressed in eukaryotic cells.