Single-cell analysis of anti-BCMA CAR T cell therapy in patients with central nervous system autoimmunity.

Chimeric antigen receptor (CAR) T cell immunotherapy for the treatment of neurological autoimmune diseases is promising, but CAR T cell kinetics and immune alterations after treatment are poorly understood. Here, we performed single-cell multi-omics sequencing of paired cerebrospinal fluid (CSF) and blood samples from patients with neuromyelitis optica spectrum disorder (NMOSD) treated with anti-B cell maturation antigen (BCMA) CAR T cells. Proliferating cytotoxic-like CD8+ CAR T cell clones were identified as the main effectors in autoimmunity. Anti-BCMA CAR T cells with enhanced features of chemotaxis efficiently crossed the blood-CSF barrier, eliminated plasmablasts and plasma cells in the CSF, and suppressed neuroinflammation. The CD44-expressing early memory phenotype in infusion products was potentially associated with CAR T cell persistence in autoimmunity. Moreover, CAR T cells from patients with NMOSD displayed distinctive features of suppressed cytotoxicity compared with those from hematological malignancies. Thus, we provide mechanistic insights into CAR T cell function in patients with neurological autoimmune disease.

B cell lineage reconstitution underlies CAR-T cell therapeutic efficacy in patients with refractory myasthenia gravis.

B-cell maturation antigen (BCMA), expressed in plasmablasts and plasma cells, could serve as a promising therapeutic target for autoimmune diseases. We reported here chimeric antigen receptor (CAR) T cells targeting BCMA in two patients with highly relapsed and refractory myasthenia gravis (one with AChR-IgG, and one with MuSk-IgG). Both patients exhibited favorable safety profiles and persistent clinical improvements over 18 months. Reconstitution of B-cell lineages with sustained reduced pathogenic autoantibodies might underlie the therapeutic efficacy. To identify the possible mechanisms underlying the therapeutic efficacy of CAR-T cells in these patients, longitudinal single-cell RNA and TCR sequencing was conducted on serial blood samples post infusion as well as their matching infusion products. By tracking the temporal evolution of CAR-T phenotypes, we demonstrated that proliferating cytotoxic-like CD8 clones were the main effectors in autoimmunity, whereas compromised cytotoxic and proliferation signature and profound mitochondrial dysfunction in CD8+ Te cells before infusion and subsequently defect CAR-T cells after manufacture might explain their characteristics in these patients. Our findings may guide future studies to improve CAR T-cell immunotherapy in autoimmune diseases.

Single-cell analysis of refractory anti-SRP necrotizing myopathy treated with anti-BCMA CAR-T cell therapy.

Immune-mediated necrotizing myopathy (IMNM) is an autoimmune disorder associated with the presence of autoantibodies, characterized by severe clinical presentation with rapidly progressive muscular weakness and elevated levels of creatine kinase, while traditional pharmacological approaches possess varying and often limited effects. Considering the pathogenic role of autoantibodies, chimeric antigen receptor (CAR)-T cells targeting B cell maturation antigen (BCMA) have emerged as a promising therapeutic strategy. We reported here a patient with anti-signal recognition particle IMNM refractory to multiple available therapies, who was treated with BCMA-targeting CAR-T cells, exhibited favorable safety profiles, sustained reduction in pathogenic autoantibodies, and persistent clinical improvements over 18 mo. Longitudinal single-cell RNA, B cell receptor, T cell receptor sequencing analysis presented the normalization of immune microenvironment after CAR-T cell infusion, including reconstitution of B cell lineages, replacement of T cell subclusters, and suppression of overactivated immune cells. Analysis on characteristics of CAR-T cells in IMNM demonstrated a more active expansion of CD8+ CAR-T cells, with a dynamic phenotype shifting pattern similar in CD4+ and CD8+ CAR-T cells. A comparison of CD8+ CAR-T cells in patients with IMNM and those with malignancies collected at different timepoints revealed a more NK-like phenotype with enhanced tendency of cell death and neuroinflammation and inhibited proliferating ability of CD8+ CAR-T cells in IMNM while neuroinflammation might be the distinct characteristics. Further studies are warranted to define the molecular features of CAR-T cells in autoimmunity and to seek higher efficiency and longer persistence of CAR-T cells in treating autoimmune disorders.

Anti-BCMA CAR T-cell therapy CT103A in relapsed or refractory AQP4-IgG seropositive neuromyelitis optica spectrum disorders: phase 1 trial interim results.

Chimeric antigen receptor (CAR) T-cell therapy that targets B-cell maturation antigen (BCMA) have great potentials in autoimmune diseases and could be novel therapeutics for relapsed/refractory neuromyelitis optica spectrum disorder (NMOSD). To evaluate the safety and efficacy of the CT103A, a self-developed BCMA-targeting CAR construct against BCMA, in patients with AQP4-IgG seropositive NMOSD, an ongoing, investigator-initiated, open-label, single-arm, phase 1 clinical trial is conducted at our center. In total, 12 patients were administered with a CAR-BCMA infusion. Ten of the 12 patients dosed were women (83.3%), with a median age of 49.5 years (range, 30-67). were The most common events of grade 3 or higher were hematologic toxic effects. Seven patients (58%) developed infections, but no grade 4 infections occurred. Cytokine release syndrome was reported in all patients with only events of grade 1 or 2 observed. During the follow-up of a median 5.5 months, 11 patients had no relapse; all patients generally reported improvement in disabilities and quality-of-life outcomes; 11 patients' AQP-4 antibodies in serum showed a downward trend by the cutoff date. CAR T-cell expansion was associated with responses, and persisted more than 6 months post-infusion in 17% of the patients. In summary, CAR T-cell therapy shows a manageable safety profile and therapeutic potentials for patients with relapsed/refractory AQP4-IgG seropositive NMOSD. Another expansion phase is currently underway to determine the safety and efficacy of CAR T-BCMA infusion in patients with other neuro-inflammatory diseases.

Quorum sensing signals improve the power performance and chlortetracycline degradation efficiency of mixed-culture electroactive biofilms.

Electroactive biofilms (EABs) play an important role in bioelectrochemical systems due to their abilities to generate electrons and perform extracellular electron transfer (EET). Here, we investigated the effects of quorum sensing (QS) signals on power output, chlortetracycline degradation, and structure of EABs in MFCs treating antibiotic wastewater. The voltage output of MFCs with C4-HSL and PQS increased by 21.57% and 13.73%, respectively, compared with that without QS signals. The chlortetracycline degradation efficiency in closed-circuit MFCs with C4-HSL and PQS increased by 56.53% and 50.04%, respectively, which resulted from the thicker biofilms, higher biomass, and stronger activities. Additionally, QS signals induced the heterogeneous distribution of EPS for a balance between self-protection and EET under environmental pressure. Geobacter prevailed by the addition of QS signals to resist high chlortetracycline concentration. Our results provided a broader understanding on regulating EABs within electrode interface to improve their performance for environmental remediation and clean energy development.

Doxycycline Combined With Bortezomib-Cyclophosphamide-Dexamethasone Chemotherapy for Newly Diagnosed Cardiac Light-Chain Amyloidosis: A Multicenter Randomized Controlled Trial.

BACKGROUND: Doxycycline was demonstrated in a retrospective study to be associated with greater survival in patients with light chain amyloidosis. Therefore, we prospectively compared the efficacy of bortezomib-cyclophosphamide-dexamethasone (CyBorD) and CyBorD combined with doxycycline for cardiac light chain amyloidosis. METHODS: This was a multicenter, open-label, randomized controlled trial. Patients with Mayo 2004 stage II to III light chain amyloidosis were included. Patients were randomized to doxycycline 100 mg twice daily along with 9 cycles of CyBorD (doxycycline group) or to 9 cycles of CyBorD alone (control group). The primary outcome was 2-year progression-free survival (PFS). PFS was defined as the time from randomization to death, hematologic progression, or organ progression (heart, kidney or liver). Hematologic progression was defined on the basis of a substantial increase in free light chain. An increase in either NT-proBNP (N-terminal pro B-type natriuretic peptide) or cardiac troponin was the main criterion for defining cardiac progression. Cardiac PFS, defined as the time from randomization to cardiac progression or death, was compared between groups in an exploratory analysis. The corresponding treatment hazard ratio was estimated with a Cox regression model. RESULTS: One hundred forty patients underwent randomization, with 70 in each group. The median age was 61 years (range, 33-78 years) with a male:female ratio of 1.75:1. Stage II disease was present in 34 (48.6%) and 33 (47.1%) patients in the doxycycline and control groups, respectively. After a median follow-up duration of 24.4 months, 32 of 70 (45.7%) patients in the doxycycline group and 30 of 70 (42.9%) patients in the control group experienced progression. PFS was not significantly different between groups (hazard ratio, 0.97 [95% CI, 0.59-1.60]; P=0.91). Cardiac progression occurred in 29 of 70 (41.4%) patients in the doxycycline group and 26 of 70 (37.1%) patients in the control group. The death rates for both groups by the end of follow-up was the same, 25 of 70 (35.7%). No significant differences were observed for either cardiac PFS (hazard ratio, 0.91 [95% CI, 0.54-1.55]; P=0.74) or overall survival (hazard ratio, 1.04 [95% CI, 0.60-1.81]; P=0.89). CONCLUSIONS: Our trial demonstrated that doxycycline combined with CyBorD failed to prolong PFS or cardiac PFS compared with CyBorD alone in cardiac light chain amyloidosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03401372.

Wuzi-Yanzong prescription alleviates spermatogenesis disorder induced by heat stress dependent on Akt, NF-κB signaling pathway.

Akt and nuclear factor kappa B (NF-κB) signaling pathways are involved in germ cell apoptosis and inflammation after testicular heat stress (THS). We observed that after THS induced by the exposure of rat testes to 43 °C for 20 min, their weight decreased, the fraction of apoptotic testicular germ cells significantly increased, and the proliferation of germ cells was inhibited. In addition, THS lowered serum testosterone (T) level, whereas the levels of follicle stimulating hormone and luteinizing hormone were not significantly changed. The ultrastructure of the seminiferous tubules became abnormal after THS, the structure of the blood-testis barrier (BTB) became loose, and the Sertoli cells showed a trend of differentiation. The level of phosphorylated Akt was reduced, whereas the amount of phosphorylated NF-κB p65 was augmented by THS. Wuzi-Yanzong (WZYZ), a classic Chinese medicine prescription for the treatment of male reproductive dysfunctions, alleviated the changes induced by THS. In order to determine the mechanism of action of WZYZ, we investigated how this preparation modulated the levels of T, androgen receptor (AR), erythropoietin (EPO), EPO receptor, and Tyro-3, Axl, and Mer (TAM) family of tyrosine kinase receptors. We found that WZYZ activated the Akt pathway, inhibited the Toll-like receptor/MyD88/NF-κB pathway, and repaired the structure of BTB by regulating the levels of T, AR, TAM receptors, and EPO. In conclusion, these results suggest that WZYZ activates the Akt pathway and inhibits the NF-κB pathway by acting on the upstream regulators, thereby improving spermatogenesis deficit induced by THS.

Effect of Wuzi Yanzong Pills on Sertoli cells and blood-testis barrier in heat-stressed rats based on Akt signalling pathway.

The blood-testis barrier (BTB) of Sertoli cells (SCs) is an important biological barrier that maintains spermatogenesis and provides a favourable microenvironment for spermatogenesis. However, heat stress can directly damage the BTB structural proteins of testicular SCs, leading to dyszoospermia. Wuzi Yanzong Pills (WYP) is a traditional Chinese medicine formula used to treat male reproductive diseases. However, whether WYP could ameliorate heat stress injury in primary SCs extracted from rat testes and BTB proteins remains unknown. Here, treatment with WYP (low, medium and high dose) increased the SC viability and the proliferation of cell antigen Ki67 significantly. Additionally, it promoted SC maturation, which presented in the form of increased androgen receptors (ARs) and decreased cytokeratin 18 (CK-18) in three WYP dose groups. WYP upregulated BTB proteins such as zonula occludens 1 (ZO-1) and occludin across all WYP groups and decreased phosphorylated Akt (p-Akt) in the middle and high-dose groups; however, ZO-1 and occludin recovery were reduced with the presence of Akt inhibitor in WYP groups. WYP improved SC viability and proliferation, and ameliorated dedifferentiation and BTB-proteins damaged by heat stress via Akt signalling. The findings present theoretical support for the effects of WYP in the management of dyszoospermia and male infertility.

Treatment and outcome patterns of patients with Waldenström's macroglobulinemia: a large, multicenter retrospective review in China.

In this study, we aimed to investigate treatment options and the prognosis of patients with WM in China. This retrospective study included 1141 patients diagnosed with symptomatic WM between January 2003 and December 2019 at 35 tertiary hospitals in 22 provinces of China. Fifty-four patients (7.3%) received monotherapy, 264 (36.0%) received chemoimmunotherapy, 395 (53.8%) received other combination regimens without rituximab, and 21 (2.9%) received ibrutinib. Using a multivariable Cox regression model, age > 65 years old, platelets <100 × 109/L, serum albumin <3.5 g/dl, ß2 microglobulin concentration ≥4 mg/L and LDH ≥250 IU/L predicted poor OS. In summary, our study showed that frontline treatment choices for WM are widely heterogeneous. We validated most of the established prognostic factors in the rIPSS (age >65 years, LDH ≥250 IU/L, ALB <3.5 g/dl and ß2 microglobulin ≥4 mg/L) together with PLT ≤ 100 × 109/L indicate a poor prognosis for patients with WM.

Anti-BCMA CAR-T Cell Therapy in Relapsed or Refractory Multiple Myeloma Patients with Impaired Renal Function.

Anti-B cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell therapy is effective and well-tolerated for refractory or relapsed multiple myeloma (RRMM). The purpose of the present study was to analyze efficacy in RRMM patients with renal impairment treated by anti-BCMA CAR-T cell therapy. A total of 59 RRMM patients were selected, and divided into impaired renal function (IRF) group [baseline estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m2 (n=18)] and normal renal function (NRF) group (baseline eGFR ≥ 90 mL/min/1.73 m2, n=41). For patients with IRF, eGFR at the 6th month post-CAR-T cells infusion was significantly higher than the baseline (P<0.05). The multivariate analysis showed that light chain type and beta-2 micro-globulin (beta-2M) were associated factors with the decrease of serum creatinine. Median progression-free survival (PFS) in the NRF group and IRF group was 266 days and 181 days respectively. Overall survival (OS) in the NRF group and IRF group was 877 days and 238 days respectively. There was no significant difference in the objective response rate (ORR) between the IRF group and the NRF group. It is suggested that CAR-T cells therapy could improve the renal function during the treatment of RRMM. The renal function could be more significantly improved in RRMM patients with light chain type than with other types.

[Extracellular vesicles and male reproduction: Advances in studies].

The transportation of extracellular vesicles (EV) is a newly discovered mechanism of cellular communication, which plays a biological role by interacting with cell surface receptors, endocytosis and direct fusion with target cell membranes. In the field of reproduction, experimental studies have found that EVs can influence the phenotypes and functions of receptor cells related to male reproduction and affect male reproductive health via transferring biological information carriers such as functional proteins and non-coding RNAs. This review focuses on the relationship between EVs and male reproduction from the perspectives of the testis, epididymis, semen, seminal vesicle and prostate, which are closely related to male reproduction, and discusses the new mechanisms affecting male reproductive health from the perspective of EVs.

Machine learning based early warning system enables accurate mortality risk prediction for COVID-19.

Soaring cases of coronavirus disease (COVID-19) are pummeling the global health system. Overwhelmed health facilities have endeavored to mitigate the pandemic, but mortality of COVID-19 continues to increase. Here, we present a mortality risk prediction model for COVID-19 (MRPMC) that uses patients' clinical data on admission to stratify patients by mortality risk, which enables prediction of physiological deterioration and death up to 20 days in advance. This ensemble model is built using four machine learning methods including Logistic Regression, Support Vector Machine, Gradient Boosted Decision Tree, and Neural Network. We validate MRPMC in an internal validation cohort and two external validation cohorts, where it achieves an AUC of 0.9621 (95% CI: 0.9464-0.9778), 0.9760 (0.9613-0.9906), and 0.9246 (0.8763-0.9729), respectively. This model enables expeditious and accurate mortality risk stratification of patients with COVID-19, and potentially facilitates more responsive health systems that are conducive to high risk COVID-19 patients.

[Construction of IK6 recombinant lentiviral vector and its expression and biologic feature in THP1 cells].

The purpose of this study was to construct a lentiviral vector carrying IK6 gene and to observe the expression of IK6 as well as related biologic feature in THP1 cells, so as to provide an effective method to further investigate the role of this gene in leukemia. The IK6 gene was obtained by using reverse transcription polymerase chain reaction (RT-PCR). Then IK6 was recombined with the pGC-FU vector to construct a recombinant lentiviral vector named pGC-FU-IK6 gene-GFP,which was confirmed by PCR and sequencing. The 293T cells were transfected with pGC-FU- IK6-GFP by using Lipofectamine 2000. After examining the titer of the virus, pGC-FU- IK6-GFP was used to transfect THP1 cells. The transfection efficiency was detected by flow cytometry, and the expression level of mRNA and IK6-GFP fusion protein were confirmed by RT-PCR and Western blot respectively. Then the impact of IK6 on apoptosis and cell cycle was analyzed. The results showed that the IK6 gene was obtained by RT-PCR and connected into the linearized lentiviral vector to successfully constructed target plasmid named pGC-FU-IK6-GFP with Amp resistant. The target plasmid was transfected into 293T cells and the virus titer was 2.0×10(9)TU/ml. Next, THP1 cells were transfected with pGC-FU-IK6-GFP and the efficiency was up to 90%. The detection of the IK6 mRNA and IK6-GFP fusion protein in target cells showed that IK6 could promote target cell clone formation and inhibit apoptosis, but had no significant effect on the cell cycle. It is concluded that virus vector carrying IK6 gene had been successfully constructed and expressed in THP1 stably. Biology studies of target THP1 cell shows that the IK6 is likely to interfere with the function of normal Ikaros protein as tumor suppressor, and it exerts a potential anti-apoptotic effect. Thus, IK6 can promote leukemia cell growth. However, there is no significant effect on the cell cycle. It provides an effective method for exploring the function of IK6 in acute myeloid leukemia.

[Mutation of isocitrate dehydrogenase 2 (IDH2) gene in Chinese AML patients and its clinical significance].

This study was purpose to analyze the frequency and of isocitrate dehydrogenase 2 (IDH2) gene mutation in acute myeloid leukemia (AML) and its clinic significance. The multiplex polymerase chain reaction (PCR) and sequencing were performed to screen 192 AML patients for exon 4 of the IDH2 gene. FLT3, NPM1, CEBPA, c-kit and WT1 mutations were also included in analysis. The results showed that IDH2 mutation was found in 14 (7.29%) of 192 patients. There were 9 AML patients with R140Q mutation, 1 patient with R140W mutation, and 1 patient with R172K mutation. IDH2 aberrations significantly more were detected in French-American-British (FAB) M5 (P < 0.005) than other types. There was no statistical difference in age, sex, WBC, platelet count, bone marrow blasts count, hemoglobin as compared with IDH2 wild-type. For immunotype analysis, IDH2 mutation patients were more likely to express CD34 and CD13, less CD36. IDH2 mutation combined with FLT3/ITD mutation was found in 7 cases, with CEBPA mutation in 4 cases, with NPM1 mutation in 4 cases, with Dnmt3a mutation in 5 cases, neither with c-kit, IDH1 or WT1 mutation for no one, which revealed a significant interaction between IDH2 mutation and the FLT3/ITD positive genotype, Dnmt3a mutated, and IDH1 wild-type. IDH2 mutation was detected in 5 (8.47%) of 59 CN-AML. There was no significant difference of IDH2 mutation incidence between the normal and abnormal karyotype. The CR rate was higher in IDH2 R140 mutated patients than wild-type ones, but there was no significant in the two group. It is concluded that the rate of IDH2 mutation is 7.29% in Chinese AML patients and 7.81% in CN-AML. IDH2 mutation is significantly associated with AML-M5, FLT3/ITD, Dnmt3a, IDH1 wild-type and fusion gene wild-type, but not with age, leucocyte and platelet counts in peripheral blood, karyotype, NPM1, CEBPA, c-kit or WT1 mutation. And IDH2 R140 mutation has no impact on CR rate.

[Effect of gambogic acid on proliferation of SKM-1 cells and its mechanism].

The aim of this study was to explore the effect of gambogic acid (GA) on MDS SKM-1 cell proliferation, apoptosis and their possible mechanism. Cell proliferation was determined by MTT method. The apoptosis percentage and cell cycle regulation of SKM-1 cells were analyzed by flow cytometry. Morphological features were observed by light microscopy. The mRNA expression of bcl-2 and bax were detected by RT-PCR. The results showed that GA could inhibit the proliferation of SKM-1 cells in a dose- and time-dependent manner (IC50 was 0.37 µg/ml at 48 h), increase the apoptotic percentage of SKM-1 cells, and arrest cell cycle at the G0/G1. The expression of bax mRNA was up-regulated while that of bcl-2 mRNA was down-regulated in SKM-1 cells treated with GA for 48 h. It is concluded that GA can induce apoptosis, which may be related to its effect of arresting cells at phase of G0/G1 and down-regulating bcl-2/bax ratio.

[Detection of isocitrate dehydrogenase 1 gene mutation in 205 AML patients and its clinical significance].

This study was purposed to detect the mutation of isocitrate dehydrogenase 1 (IDH-1) gene in patients with acute myeloid leukemia (AML) and to explore its clinical significance. The genomic DNA was extracted from mononuclear cells (MNC) of bone marrow or peripheral blood in 205 adult AML patients, the exon 4 of IDH1 gene was amplified by PCR, then the sequencing and comparison were performed. The results showed that IDH1 mutation was detected in 9 (4.39%) of 205 AML patients. There were 6 cases of R132H mutation, 1 of R132L mutation, 1 of R132G mutation and 1 of R132S mutation. Significantly more IDH1 aberrations were detected in AML-M2 (P = 0.002) than other types. And the 9 patients with IDH1 mutation were characterized by low platelet count which was lower than patients with wild type IDH1 (P = 0.003). IDH1 mutation combined with FLT3/ITD mutation was found in 5 cases, c-kit mutation in 1, NPM1 mutation in 2, and IDH1 mutation with CEBPA or WT1 mutation was not found, which revealed a significant interaction between IDH1 mutation and the FLT3/ITD positive genotype or the CEBPA wild-type. IDH1 mutation were detected in 4 of 71 (5.63%) CN-AML. There was no significant difference of IDH1 mutation incidence between the normal and abnormal karyotypes. It is concluded that the rate of IDH1 mutation was 4.39% in Chinese AML patients. IDH1 mutation is significantly associated with AML-M2, lower platelet counts in peripheral blood, FLT3/ITD mutation and CEBPA wild-type, but not with age, white blood cell count in peripheral blood, karyotype, NPM1, c-kit or WT1 mutation.

[Establishment of xenotransplated mouse model using primary multiple myeloma cells].

OBJECTIVE: To establish xenotransplated mouse model by non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice with primary myeloma cells. METHODS: The model of xenograft was established in NOD/SCID mice by tail vein injection of mononuclear cells from two end stage multiple myeloma patients, three mice were inoculated for each patient. Mice were monitored weekly for body weight. Two weeks later, the human CD45(+) cells from peripheral blood of mice were evaluated by flow cytometry (FCM). The experiment endpoint was body weight loss up to 20% or had pale, vertical hair and listlessness, then spleen and liver were studied by histologic analysis, the human CD45(+)CD38(+) cells from spleen, lymph node, peripheral blood and bone marrow were evaluated by FCM. RESULTS: Body weight of mice in group patient 1 and group patient 2 decreased seven and five weeks after inoculation respectively; the human CD45(+)CD38(+) cells appeared in the peripheral blood (26 ± 4) and (16 ± 4) days after inoculation in group patient 1 and group patient 2 respectively, and increased by time, reaching (16.2 ± 3.0)% and (31.3 ± 3.5)%, respectively at the endpoint; the spleen, liver and lymph node of both groups enlarged, the typical malignant plasma cells were observed in them. The human CD45(+)CD38(+) cells were detected in spleen, lymph node and bone marrow by FCM. CONCLUSION: Our study successfully established a NOD/SCID mouse model xenotransplated with human primary myeloma cells.

[Effect of 5-Aza-CdR on biological activity and inhibitor of DNA binding 4 gene expression in human erythroleukemia cell line K562].

This study was aimed to investigate the effect of 5-Aza-CdR on the biological activity of human erythroleukemia cell line K562 and the expression of inhibitor of DNA binding 4 (ID4). ID4 methylation in K562 cell line was detected by methylation-specific PCR. RQ-PCR was used to analyze the expression levels of ID4 mRNA in K562 cell line treated by different concentrations of 5-Aza-CdR. Cell apoptosis rate and cell cycle were analyzed by flow cytometry. The result showed that ID4 gene methylation existed in K562 cells, ID4 mRNA expression in K562 cells treated with 5-Aza-CdR increased in a concentration-dependent manner, the difference between experimental groups was statistical significant (p < 0.01). The 5-Aza-CdR could enhance the apoptotic rate of K562 cells in time and dose-dependent manner, the apoptotic rate of K562 cells highly correlated to relative expression level of ID4 mRNA (r = 0.95). After the K562 cells were treated by 5-Aza-CdR for 48 hours, cells in G(0)/G(1) phase increased, cells in G(2)/M phase decreased along with enhancement of drug concentration. It is concluded that methyltransferase inhibitor 5-Aza-CdR can re-express the silent ID4 gene in K562 cells. The upregulation of ID4 may be a key factor to give rise to cell apoptosis, and the cell cycle of K562 cells can be arrested by 5-Aza-CdR.

Negative regulation of cyclin D3 expression by transcription factor c-Ets1 in umbilical cord hematopoietic cells.

AIM: To investigate the role of transcription factor c-Ets1 in cyclin D3 expression and its effects on the proliferation of umbilical cord hematopoietic cells. METHODS: Cyclin D3 promoter deletion constructs were generated and transfected into CD34(+) cells. Dual luciferase reporter assays and TFSEARCH software were used to identify negative regulatory domains and to predict putative transcription factors involved in cyclin D3 downregulation. Expression of c-Ets1 in CD34(+) cells was detected using electrophoretic mobility shift and super shift assays. Point mutants of c-Ets1 binding sites were constructed. The wild-type c-Ets1 and the mutant promoter constructs were co-transfected into CD34(+) cells to determine the promoter activity. The impact of c-Ets1 expression on the proliferation of CD34(+) cells was assessed using MTT assay. RESULTS: Nine cyclin D3 promoter deletion constructs were generated. A negative regulatory domain containing c-Ets1 binding sites was identified between -439 bp and -362 bp. Transfection of the promoter deletion constructs containing mutant c-Ets1 binding sites enhanced cyclin D3 promoter activity. However, the opposite results were observed when CD34(+) cells were co-transfected with wildtype c-Ets1 and its promoter deletion constructs. The overexpression of c-Ets1 could suppress cyclin D3 mRNA and protein levels. In addition, it inhibits the proliferation of CD34(+) cells. CONCLUSION: c-Ets1 functions as a negative transcription factor, down-regulating the expression of cyclin D3, which leads to inhibition of CD34(+) cell proliferation.

[Analysis of IKAROS6 expression in 73 patients with chronic myelogenous leukemia].

This study was aimed to evaluate IKAROS6 expression in patients with chronic myelogenous leukemia (CML) and its clinical significance. cDNAs from 73 CML patients were amplified by PCR and sequenced for IKAROS expression to elucidate clinical characteristics in IKAROS6 positive patients. The results showed that there was no IKAROS6 gene expression in 8 healthy controls and 15 CML patients in chronic phase and accelerated phase, and 15 cases (35.71%) were IKAROS6 positive in lymphoblast crisis samples among 42 newly diagnosed CML; however, none was found in myeloblast crisis of 16 newly diagnosed CML. Among 42 lymphoblast crisis of CML, the complete remission (CR) rate of IKAROS6 expression positive patients reached 40% (6/15), which was obviously lower than that in IKAROS6 negative patients (85.19%, 23/27) (p < 0.01), IKAROS6 positive patients relapsed after CR for 15 (2 - 18) months with relapse rate 66.7% (4/6), which was higher than that in expressed wild type IKAROS gene patients (21.74%, 5/23) (p < 0.05). It is concluded that abnormal expression of IKAROS gene dominated by IKAROS6 isoforms can be detected in lymphoblast crisis samples of CML patients. Abnormal expression of IKAROS gene may be an important factor in lymphoblast crisis of CML. Therefore, detection of IKAROS gene expression may be important for target therapy and evaluation of clinical prognosis of CML patients.