Preliminary study on the function of TMEM50A and its correlation with the RH genes.

OBJECTIVES: The purpose of this study was to investigate the association and impact of TMEM50A on RH genes activity and function. BACKGROUND: SMP1 is located on chromosome 1p36.11 in the RH gene locus, between the RHD and RHCE gene, where its position may be linked to RH haplotypes and contribute to selective pressures regarding certain RH haplotypes. TMEM50A is encoded by the SMP1 located in the intergenic region of RH, its influence on the function of the RH genes remains unclear. METHODS: The expression of TMEM50A was regulated by transfection of plasmid and siRNA in K562 cell model. Western blot and real-time PCR were used to detect possible expression changes in the RH. The ammonium transport function of cells was monitored using pH-sensitive dye, while transcriptome sequencing was used to predict the potential function of TMEM50A. RESULTS: The overexpression of TMEM50A significantly up-regulated RHCE gene activity (63.56%). The inhibition of TMEM50A resulted in significantly decreased RHCE (41.82%) and RHD expression (27.35%). Compared to control group, there was no significant change in the NH4 + transport function of cells in the overexpressed TMEM50A group. Transcriptome analysis showed that TMEM50A not only affected the transcription of target gene through splicing activities, but also played a role in the development of embryonic nervous system. CONCLUSIONS: TMEM50A may regulate the expression of RH gene by affecting the stability of RH mRNA through splicing function. It speculates that TMEM50A may play an important role in the development of embryonic nervous system.

Indirect purification method provides high yield and quality ssDNA sublibrary for potential aptamer selection.

The quality and yield of single-stranded DNA (ssDNA) play key roles in ssDNA aptamer selection. However, current methods for generating and purifying ssDNA provides either low yield due to ssDNA loss during the gel purification process or low specificity due to tertiary structural damage of ssDNA by alkaline or exonuclease treatment in removing dsDNA and by-products. This study developed an indirect purification method that provides a high yield and quality ssDNA sublibrary. Symmetric PCR was applied to generate a sufficient template, while asymmetric PCR using an excessive nonbiotinylated forward primer and an insufficient biotinylated reverse primer combined with a biotin-strepavidin system was applied to eliminate dsDNA, hence, leading to ssDNA purification. However, no alkaline or exonuclease were involved in treating dsDNA, so as to warrant the tertiary structure of ssDNA for potential aptamer SELEX selection. Agarose gel imaging indicated that no dsDNA or by-product contamination was detected in the ssDNA sublibrary generated by the indirect purification method. Purified ssDNA concentration reached 1020±210nM, which was much greater than previous methods. In conclusion, this novel method provided a simple and fast tool for generating and purifying a high yield and quality ssDNA sublibrary.

A novel pyrosequencing strategy for RHD zygosity for predicting risk of hemolytic disease of the fetus and newborn.

OBJECTIVE: The aim of this study was the development of an accurate and quantitative pyrosequence (PSQ) method for paternal RHD zygosity detection to help risk management of hemolytic disease of the fetus and newborn (HDFN). METHODS: Blood samples from 96 individuals were genotyped for RHD zygosity using pyrosequencing assay. To validate the accuracy of pyrosequencing results, all the samples were then detected by the mismatch polymerase chain reaction with sequence-specific primers (PCR-SSP) method and Sanger DNA sequencing. Serological tests were performed to assess RhD phenotypes. RESULTS: Serological results revealed that 36 cases were RhD-positive and 60 cases were RhD-negative. The concordance rate between pyrosequencing assay and mismatch PCR-SSP assay was 94.8% (91/96). There were 5 discordant results between pyrosequencing and the mismatch PCR-SSP assay. Sanger sequencing confirmed that the pyrosequencing assay correctly assigned zygosity for the 5 samples. CONCLUSION: This DNA pyrosequencing method accurately detect RHD zygosity and will help risk management of pregnancies that are at risk of HDFN.

Expression patterns of E2Fs identify tumor microenvironment features in human gastric cancer.

Objective: E2F transcription factors are associated with tumor development, but their underlying mechanisms in gastric cancer (GC) remain unclear. This study explored whether E2Fs determine the prognosis or immune and therapy responses of GC patients. Methods: E2F regulation patterns from The Cancer Genome Atlas (TCGA) were systematically investigated and E2F patterns were correlated with the characteristics of cellular infiltration in the tumor microenvironment (TME). A principal component analysis was used to construct an E2F scoring model based on prognosis-related differential genes to quantify the E2F regulation of a single tumor. This scoring model was then tested in patient cohorts to predict effects of immunotherapy. Results: Based on the expression profiles of E2F transcription factors in GC, two different regulatory patterns of E2F were identified. TME and survival differences emerged between the two clusters. Lower survival rates in the Cluster2 group were attributed to limited immune function due to stromal activation. The E2F scoring model was then constructed based on the E2F-related prognostic genes. Evidence supported the E2F score as an independent and effective prognostic factor and predictor of immunotherapy response. A gene-set analysis correlated E2F score with the characteristics of immune cell infiltration within the TME. The immunotherapy cohort database showed that patients with a higher E2F score demonstrated better survival and immune responses. Conclusions: This study found that differences in GC prognosis might be related to the E2F patterns in the TME. The E2F scoring system developed in this study has practical value as a predictor of survival and treatment response in GC patients.

Immune microenvironment-related gene mapping predicts immunochemotherapy response and prognosis in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma (NHL). The R-CHOP immunochemotherapy regimen is the first-line treatment option for DLBCL patients and has greatly improved the prognosis of DLBCL, making it a curable disease. However, drug resistance or relapse is the main challenge for current DLBCL treatment. Studies have shown that the tumor microenvironment plays an important role in the onset, development, and responsiveness to drugs in DLBCL. Here, we used the CIBERSORT algorithm to resolve the composition of the immune microenvironment of 471 DLBCL patients from the GEO database. We found that activated memory CD4+ T cells and γδ T cells were significantly associated with immunochemotherapy response. Weighted gene co-expression networks (WGCNA) were constructed using differentially expressed genes from immunochemotherapy responders and non-responders. The module most associated with these two types of T cells was defined as hub module. Enrichment analysis of the hub module showed that baseline immune status was significantly stronger in responders than in non-responders. A protein-protein interaction (PPI) network was constructed for hub module to identify hub genes. After survival analysis, five prognosis-related genes (CD3G, CD3D, GNB4, FCHO2, GPR183) were identified and all these genes were significantly negatively associated with PD1. Using our own patient cohort, we validated the efficacy of CD3G and CD3D in predicting immunochemotherapy response. Our study showed that CD3G, CD3D, GNB4, FCHO2, and GPR183 are involved in the regulation of the immune microenvironment of DLBCL. They can be used as biomarkers for predicting immunochemotherapy response and potential therapeutic targets in DLBCL.

Clinical role of M. pneumoniae typing antibody detected by chemiluminescent immunoassay in the diagnosis of Mycoplasma pneumoniae pneumonia in children.

OBJECTIVE: The levels of serum M. pneumoniae typing antibodies in children with community-acquired pneumonia (CAP) were detected by chemiluminescent immunoassay (CLIA) to explore the clinical role of M. pneumoniae typing antibody (MP-IgM, MP-IgG) in M. pneumoniae pneumonia. METHODS: A total of 387 Child patients with CAP diagnosed at the Pediatric outpatient department of Zengcheng Branch, Nanfang Hospital, Southern Medical University, were enrolled between January 2020 to December 2021 and divided into M. pneumoniae pneumonia (MPP) group (n = 210) and non-M. pneumoniae pneumonia (NMPP) group (n = 177). Firstly, Clinical data, full blood count (WBC, NEU%, LYM%, MONO%, EOS%, BASO%, RBC, HGB, PLT) and biochemical tests (AST, LDH, ɑ-HBDH, CK, CKMB, CRP, PCT, IL-6) as well as laboratory diagnostic tests (MP-IgM, MP-IgG) were compared between the two groups. Secondly, we assessed the correlation between the average level of M. pneumoniae typing antibody detected by CLIA and the titer of anti-M. pneumoniae antibody (MP-Ab) tested by passive agglutination (PA) method. Thirdly, receiver operating characteristic (ROC) curve for the MP-IgM and MP-IgG was examined to evaluate the value of diagnosing M. pneumoniae pneumonia. Finally, we follow-up 120 cases of MPP group and analysis medication results. RESULTS: (1) Mean age, runny nose, expectoration, LYM%, NEU%, HGB, AST, MP-IgM and MP-IgG were statistically significant in the MPP group and NMPP group (all P < 0.05). (2) Correlation analysis showed that MP-IgM average level was linearly associated with MP-Ab titer (R2 = 0.84) and MP-IgG average level was exponentially correlated with MP-Ab titer under 1:640 (R2 = 0.96). (3) The ROC curve of MP-IgM and MP-IgG were significantly different (both P < 0.001). A serum MP-IgM level above 1 S/CO and MP-IgG level above 14.15 AU/mL were significant predictors for M. pneumoniae pneumonia: area under the curve (AUC) of 0.810, 0.815; standard error (SE) of 0.021, 0.022; 95 % confidence interval (CI) of 0.768-0.852, 0.773-0.858; the diagnostic sensitivity of 74.3 %, 62.1 %; and specificity of 72.9 %, 87.0 %; respectively. (4) Of the 120 children with M. pneumoniae pneumonia followed up, 79 (65.8 %) cases took azithromycin and 68 (86.1 %) cases were recovered. CONCLUSIONS: A series of our studies shown that, CLIA, speedy and automated clinical examination method, has higher specificity and sensitivity for the quantitative detection of MP-IgM and MP-IgG, playing an important role of early diagnosis as well as prompt intervention to reduces macrolide-resistant strains and sequelae of children with M. pneumoniae pneumonia.

Design for a Multicentre Prospective Cohort for the Assessment of Platelet Function in Patients with Hepatitis-B-Virus-Related Acute-on-Chronic Liver Failure.

Background: Acute-on-chronic liver failure (ACLF) has high short-term mortality and lacks sufficient medical therapy. Available algorithms are unable to precisely predict short-term outcomes or safely stratify patients with ACLF as emergent liver transplantation candidates. Therefore, a personalized prognostic tool is urgently needed. Purpose: Platelet function and its clinical significance in ACLF patients with chronic hepatitis B virus (HBV) infection have not been investigated. This study aimed to assess changes in platelet function using thromboelastography (TEG) and platelet mapping (TEG-PM) in HBV-related ACLF patients. Methods: Chronic liver disease patients with acute decompensation or acute hepatic injury were recruited. The derivation cohort enrolled HBV-related patients at Nanfang Hospital. HBV-related and non-HBV-related patients were both enrolled in internal and external validation cohorts at seven university hospitals. TEG and TEG-PM were performed at baseline in the derivation cohort and baseline, day 7, and day 14 in the validation cohorts. The primary outcome was all-cause 28-day mortality. Status check and new-onset complications were recorded during the 3-month follow-up, but status check will extend to 5 years. Conclusion and Future Plans: In this study, 586 participants were enrolled, including 100 in derivation cohort, 133 in internal validation cohort, and 353 in external validation cohort. Biomaterials, including plasma, serum, urine, and some explanted liver tissues, were collected from these patients. A 3-month follow-up with survival status was completed. The baseline characteristics indicated that 51% of the patients had adenosine diphosphate (ADP)-hyporesponsive circulating platelets. The prognostic potential of platelet function will be explored in the derivation cohort (HBV-related ACLF patients) and further substantiated in the validation cohorts (HBV-related and non-HBV-related ACLF patients). Biosamples are currently used to explore the underlying mechanisms related to ADP-hyporesponsive platelets. The ongoing proteomic and metabolic analyses will provide new insights into the pathogenesis of extrahepatic organ failures in ACLF patients.

Effects of ex vivo Extracorporeal Membrane Oxygenation Circuits on Sequestration of Antimicrobial Agents.

Objectives: Our ex vivo study was designed to determine the sequestration of teicoplanin, tigecycline, micafungin, meropenem, polymyxin B, caspofungin, cefoperazone sulbactam, and voriconazole in extracorporeal membrane oxygenation (ECMO) circuits. Methods: Simulated closed-loop ECMO circuits were prepared using 2 types of blood-primed ECMO. After the circulation was stabilized, the study drugs were injected into the circuit. Blood samples were collected at 2, 5, 15, 30 min, 1, 3, 6, 12, and 24 h after injection. Drug concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry. Control groups were stored at 4°C after 3, 6, 12, and 24 h immersing in a water bath at 37°C to observe spontaneous drug degradation. Results: Twenty-six samples were analyzed. The average drug recoveries from the ECMO circuits and control groups at 24 h relative to baseline were 67 and 89% for teicoplanin, 100 and 145% for tigecycline, 67 and 99% for micafungin, 45 and 75% for meropenem, 62 and 60% for polymyxin B, 83 and 85% for caspofungin, 79 and 98% for cefoperazone, 75 and 87% for sulbactam, and 60 and 101% for voriconazole, respectively. Simple linear regression showed no significant correlation between lipophilicity (r 2 = 0.008, P = 0.225) or the protein binding rate (r 2 = 0.168, P = 0.479) of drugs and the extent of drug loss in the ECMO circuits. Conclusions: In the two ECMO circuits, meropenem and voriconazole were significantly lost, cefoperazone was slightly lost, while tigecycline and caspofungin were not lost. Drugs with high lipophilicity were lost more in the Maquet circuit than in the Sorin circuit. This study needs more in vivo studies with larger samples for further confirmation, and it suggests that therapeutic drug concentration monitoring should be strongly considered during ECMO.

Single­strained DNA aptamers mask RhD antigenic epitopes on human RhD+ red blood cells to escape alloanti­RhD immunological recognition.

Rhesus D­ (RhD­) individuals should receive Rh­matched blood to prevent hemolytic anemia. However, there is a shortage of RhD­ blood. This study aimed to generate RhD antigen­specific single­stranded DNA (ssDNA) aptamers, and test their efficacy in masking RhD antigens on RhD+ red blood cells (RBCs) to prevent their immunoreactivity in vitro. In the present study, ssDNA aptamer candidates were synthesized as a central randomized sequence of 40 nucleotides (nt) flanked by 21­nt primer hybridization sequences. The functional aptamers were screened using the cell­based systematic evolution of ligands by exponential enrichment technique and RhD+ RBCs. Two bioactive ssDNA aptamers significantly inhibited the binding of an anti­RhD antibody to RhD+ RBCs and bound to RhD antigens with high affinity (dissociation constant values of 580.5±142.0 and 737.7±161.8 nM, respectively). Furthermore, treatment with both ssDNA aptamers (500 pmol) effectively masked RhD antigens on 4,000,000 RhD+ RBCs to prevent human anti­RhD alloantibody­mediated binding, RBC agglutination and monocyte recognition in vitro. Collectively, such data suggested that these ssDNA aptamers may be feasible for masking RhD antigens on RBCs, and thus valuable for prevention or at least amelioration of RhD+­related hemolytic anemia in RhD­ individuals.

Changes in Coagulation and Fibrinolysis in Post-Cesarean Section Parturients Treated With Low Molecular Weight Heparin.

BACKGROUND: Cesarean section is an independent risk factor for Venous thromboembolism (VTE). Low molecular weight heparin (LMWH) is extensively used for VTE prophylaxis after cesarean section. In this study, the effects of LMWH on coagulation and fibrinolysis after cesarean section and its clinical value were explored by studying the changes in laboratory indicators. METHODS: Antepartum and postpartum peripheral blood of 44 pregnant women who underwent vaginal delivery and 44 pregnant women who underwent cesarean section treated per routine with LMWH thromboprophylaxis on the first day post-operatively were collected for the following tests: D-dimer; thrombotic markers such as thrombomodulin (TM), thrombin-antithrombin complex (TAT), α2-plasmin inhibitor-plasmin complex (PIC), and tissue plasminogen activator inhibitor complex (t-PAIC); thromboelastography. RESULTS: Compared to the antepartum levels, PIC increased, TM, TAT, and t-PAIC decreased significantly in the parturients after a spontaneous vaginal delivery. Compared to the antepartum levels, parturients routinely treated with LMWH after cesarean section had higher PIC levels and lower D-dimer, TAT, and t-PAIC levels. Compared with parturients after vaginal delivery, parturients treated with LMWH after cesarean section had higher levels of TM, R, and MA, while there was no significant differences in the levels of D-dimer, TAT, PIC, t-PAIC, K, angle, LY30, and CI. CONCLUSION: The coagulation and fibrinolytic systems in gravidas and parturients are in a high level of dynamic equilibrium. The levels of coagulation and fibrinolytic system activation were similar in parturients who were routinely treated with LMWH after cesarean section compared with parturients after a spontaneous vaginal delivery.

Ex vivo expansion of CD34+ and T and NK cells from umbilical cord blood for leukemic BALB/C nude mouse transplantation.

CBSCT with low incidence of GVHD is associated with higher rates of delayed engraftment and relapse compared with other stem cells transplants. The immune-mediated effect of NK and cytotoxic T cells against residual tumor cells was shown to prevent relapse and reinduce remission after bone marrow transplantation. We expanded CD34+ and T and NK cells ex vivo in cord blood with different cytokines combination and transplanted into leukemic BALB/C nude mouse. The results showed significant expansion of MNCs and CD34+ cells. The CD3+ T cells increased in the groups containing cytokines cocktail, especially in the group with IL-7 or IL-2. CD56+ NK cells number increased significantly only in a medium containing IL-2. Of the 20 engrafted BALB/C nude mice, 14 survived after 6 weeks transplantation, and the numbers in each group were from 3 to 4. Human CD3+ cells in the bone marrow of the survived mice were analyzed by flow cytometry and showed existing evidences. RT-PCR was used to detect leukemic fusion bcr/abl gene; all mice that experienced expanded cord blood transplantation could not be found to have expression of fusion bcr/abl gene. These suggest that T, NK cells as well as CD34+ cells could be expanded from CB MNCs in the same medium with the combination of cytokines. The expanded CB MNCs could reconstitute hematopoiesis and eliminate minimal residue leukemia disease in transplanted mice.

[Comparison between genotyping and serological phenotyping in RhCE blood group].

OBJECTIVE: To genotype the RHCE gene of Hans, Xinjiang's Uigurs and Kazakstans in China, and to compare the results of RHCE genotyping with that of RhCc/Ee phenotyping. METHODS: RHCE genes of 98 Hans with RhD positive and 230 Hans, 72 Uigurs and 18 Kazakstans with RhD/RHD negative were genotyped with PCR-sequence specific primer (SSP) technique. RESULTS: The results of RHE/RHe genotyping from samples with RhD positive and negative were in accord with that of phenotyping. It would result in 4.44% error using C-->G polymorphism at nt48 of RHCE gene to genotype RHCE, and 4.05% failure of detection using the 109 bp insertion to detectRHCE gene in Chinese Hans. The results of RHE/RHe genotyping in unrelated 72 Uigurs and 18 Kazakstans with RhD phenotype were consistent with that of phenotyping, and false positive and false negative were not found in genotyping in Uigurs and Kazakstans tested. CONCLUSION: The results of RHE/RHe and RHc genotyping were correct with PCR-SSP and accordant with that of phenotyping. Using the C48G polymorphism in exon 1 of RHCE to genotype RHC gene would result in false positive resulting from RHc mutation at this locus, and using the 109 bp insertion to genotype RHC gene would result in false negative because of the absence of the 109 bp. Therefore it is necessary to genotype RHC gene using more than two polymorphic loci.

Single-stranded DNA aptamer targeting and neutralization of anti-D alloantibody: a potential therapeutic strategy for haemolytic diseases caused by Rhesus alloantibody.

BACKGROUND: Rhesus (Rh) D antigen is the most important antigen in the Rh blood group system because of its strong immunogenicity. When RhD-negative individuals are exposed to RhD-positive blood, they may produce anti-D alloantibody, potentially resulting in delayed haemolytic transfusion reactions and Rh haemolytic disease of the foetus and newborn, which are difficult to treat. Inhibition of the binding of anti-D antibody with RhD antigens on the surface of red blood cells may effectively prevent immune haemolytic diseases. MATERIALS AND METHODS: In this study, single-stranded (ss) DNA aptamers, specifically binding to anti-D antibodies, were selected via systematic evolution of ligands by exponential enrichment (SELEX) technology. After 14 rounds of selection, the purified ssDNA was sequenced using a Personal Genome Machine system. Haemagglutination inhibition assays were performed to screen aptamers for biological activity in terms of blocking antigen-antibody reactions: the affinity and specificity of the aptamers were also determined. RESULTS: In addition to high specificity, the aptamers which were selected showed high affinity for anti-D antibodies with dissociation constant (Kd) values ranging from 51.46±14.90 to 543.30±92.59 nM. By the combined use of specific ssDNA aptamer 7 and auxiliary ssDNA aptamer 2, anti-D could be effectively neutralised at low concentrations of the aptamers. DISCUSSION: Our results demonstrate that ssDNA aptamers may be a novel, promising strategy for the treatment of delayed haemolytic transfusion reactions and Rh haemolytic disease of the foetus and newborn.

Effect of allogeneic blood transfusion on levels of IL-6 and sIL-R2 in peripheral blood of children with acute lymphocytic leukemia.

Effect of allogeneic blood transfusion on the expression of interleukin-6 (IL-6) and soluble interleukin-2 receptor (sIL-2R) in peripheral blood of children with acute lymphoblastic leukemia (ALL) was investigated. A total of 91 ALL children admitted to Nanfang Hospital from June 2014 to January 2017 were selected as the study group. Patients were randomly divided into allogeneic blood transfusion group (n=38) and non-transfusion group (n=53). In addition, a total of 64 healthy children were also selected from June 2014 to January 2017 as the control group. Patients in allogeneic blood transfusion group were transfused with red blood cell suspension and machine-collected platelets, while patients in non-transfusion group were not treated with blood transfusion. Peripheral venous blood was collected before and at 4, 8 and 12 weeks after blood transfusion to prepare serum. Serum IL-6 and sIL-2R levels were measured by enzyme-linked immunosorbent assay (ELISA). Before transfusion, serum levels of IL-6 and sIL-2R were significantly lower in the study group than those in control group (p<0.05), and no significant differences in serum levels of IL-6 and sIL-2R were found between the allogeneic blood transfusion and non-transfusion group. After transfusion, serum levels of IL-6 and sIL-2R were stable for 12 weeks in the non-transfusion group, while IL-6 and sIL-2R levels were significantly increased in the allogeneic blood transfusion group. The results showed that serum level of IL-6 and sIL-2R was increased in ALL patients with allogeneic blood transfusion, which resulted in reduced antibody production and decreased cellular immunity. The patients had low immunity, and attention should be paid on the pathogen infection prevention.

[A comparative research on RHD gene structures of Chinese Han and Uigur population].

OBJECTIVE: To research comparatively on the RHD gene structures in unrelated RhD negative individuals of Chinese Uigur and Han population. METHODS: The upstream, downstream, hybrid box and 10 exons of RHD gene were detected with sequence specific primer-PCR technique. RESULTS: The results showed the genotypes of RhD negative individuals to have the significant difference between Chinese Uigur and Han population, that 94.44% Uigur individuals were with RHD(-)/RHD(-) genotype but just 61.40% Han population were with this genotype(94.44% versus 61.40%, P<0.01); 2.78% Uigur individuals were with RHD(+)/RHD(-) genotype but 34.21% Han population were with this genotype(2.78% versus 34.21%, P<0.01). However, there was significantly no RHD(+)/RHD(+) genotype difference between Chinese Uigur and Han population(2.78% versus 4.39%, P>0.05). In 78 cases of RhD negative Chinese Hans with single RHD gene, of which the RHD gene structure showed that 53(67.95%) cases were RHD(1-10) allele(of 53 RHD(1-10) alleles, 14 alleles were unexpressed); 15(19.23%) were RHD-CE(2-9)-D(2) allele; 5(6.41%) cases were RHD-CE(2-7)-D(2) allele; 2(2.56%) were similar to RHD-CE(3-6)D allele; 1(1.28%) case was RHD-CE(5-6)-D allele; and 2(2.56%) were RHD-CE(6)-D or point mutation respectively. Of 2 RhD negative Chinese Uigurs with RhD(-)/RHD(+) genotype, one carried RHD(1-10) allele, another carried RHD-CE(2-9)-D(2) allele. CONCLUSION: The most frequently unexpressed RHD alleles were RHD-CE(2-9)-D(2), RHD(1-10) and RHD-CE(2-7)-D(2) respectively in Chinese Han population who carried single RHD allele with RHD(-) phenotype and RHD(+) genotype. It showed the confluent character of RH gene in Chinese Han and Uigur population that there existed unexpressed RHD-CE(2-9)-D(2) allele in Chinese Uigur nationality, which was infrequent in Chinese Uigur population but frequent in Chinese Han population.

MicroRNA-340 promotes the tumor growth of human gastric cancer by inhibiting cyclin G2.

Aberrant expression and function of microRNAs (miRNAs) play a critical role in the development and progression of various human cancers including gastric cancer. However, the clinical significance and underlying mechanisms of miR-340 remain largely unknown in gastric cancer. In the present study, we demonstrated that the expression of miR-340 was aberrantly elevated in both gastric cancer tissues and cells. Moreover clinical association analyses disclosed that the elevated level of miR-340 was significantly associated with unfavorable clinicopathological characteristics of the gastric cancer patients, such as poor differentiation, large tumor size and advanced tumor-node-metastasis (TNM) stage. Gastric cancer patients with high expression of miR-340 had prominently shorter overall survival and disease-free survival. Functionally, forced expression of miR-340 promoted cell viability, proliferation, colony formation and cell cycle progression in the SGC-7901 cells, while miR-340 silencing reduced cell viability, proliferation, colony formation and cell cycle progression in MGC-803 cells. Furthermore, in vivo experiments indicated that miR-340 knockdown suppressed the tumor growth of MGC-803 cells. Notably, alteration of miR-340 expression affected the luciferase activity of wild-type 3'-UTR of cyclin G2 (CCNG2) and regulated CCNG2 abundance in gastric cancer cells, indicating that CCNG2 is a direct target of miR-340. Moreover, CCNG2 knockdown eradicated the effects of miR-340 silencing on gastric cancer cells. In conclusion, our data suggest that miR-340 may potentially serve as a novel prognostic biomarker and therapeutic target for gastric cancer.

Intron 4 of the RH Gene in Han Chinese, Tibetan, and Mongol Populations.

AIMS: This study aimed to compare the intron 4 sequence of the RHD and RHCE genes from Han Chinese, Tibetans, and Mongols, and explore its polymorphisms. MATERIALS AND METHODS: To investigate the distinction in the RHD and RHCE intron 4, polymerase chain reaction (PCR) was performed by a set of primers: Intron4F and Intron4R. Primer Intron4F for a sequence located in exon 4 and primer Intron4R for a sequence located in exon 5, respectively. RHD and RHCE intron 4 of all the samples from 26 cases of random unrelated Hans (13 RhD-positive donors and 13 RhD-negative donors), 25 cases of random unrelated Tibetans (18 RhD-positive donors and 7 RhD-negative donors), and 4 cases of random unrelated Mongols (1 RhD-positive donor and 3 RhD-negative donors) were amplified with PCR. The PCR products were then sequenced. RESULTS: A 576-bp product was detected in all the Han, Tibetan, and Mongol RhD-positive donors, whereas a 1228-bp product was detected in RhD-negative donors. The sequences of RHCE gene intron 4 were identical to each other in all Han, Tibetan, and Mongol RhD-negative donors, including 335 bp of Alu element, with a whole length of 1078 bp. By contrast, a 426-bp product was detected in all Han, Tibetan, and Mongol RhD-positive donors. Compared with the RHCE gene, a 652-bp deletion was noted in the RHD gene of Chinese, including the whole Alu element. The results were similar to the findings of Caucasians, whereas the lengths of RHD gene deletion fragments of Japanese and French were 649 and 654 or 651 bp, respectively. CONCLUSIONS: The RHCE gene intron 4 of Han Chinese, Tibetans, and Mongols differs from the RHD gene intron 4 in the presence of a 652-bp fragment. The RHCE gene intron 4 in Chinese has its own structural characteristics and differs among various ethnicities and regions.

[Comparison of Rhesus boxes in Hans and Uighurs].

OBJECTIVE: To study the difference and similarity between Hans and Uighurs in regard to Rhesus box and its significance. METHODS: The sequence specific primers of upstream, downstream and hybrid Rhesus boxes were designed on the basis of RHD gene sequence. The upstream, downstream and hybrid Rhesus boxes were determined by polymerase chain reaction-sequence specific primer(PCP-SSP) and mismatched PCR. RESULTS: The percentage of RHD-/RHD-, RHD+/RHD- and RHD+/RHD+ genotypes ascertained in the unrelated Hans with RhD(-) were 61.40%, 34.21% and 4.39% respectively, while those in the unrelated Chinese Uighurs with RhD(-) were 94.44%, 2.78% and 2.78% respectively. Furthermore, all 6 cases of some other minorities were RHD-/RHD- types. The percentage of RHD-/RHD- and RHD+/RHD- genotypes ascertained in the unrelated Chinese Uighurs were significantly higher than those in Chinese Hans (P < 0.01), whereas no statistically significant difference in the percentage of RHD+/RDH+ genotype between the two groups was observed (P > 0.05). CONCLUSION: The Rh blood group of Uighurs in Xingjiang possesses both Oriental and Caucasian characteristics, which embodies a special ethnical aspect of the Chinese nation and is in accord with the anthropologic research results.

N-3-(oxododecanoyl)-L-homoserine lactone promotes the induction of regulatory T-cells by preventing human dendritic cell maturation.

N-3-(Oxododecanoyl)-L-homoserine lactone (C12) is a small bacterial signaling molecule secreted by Pseudomonas aeruginosa (PA), which activates mammalian cells through TLR4-independent mechanisms. C12 acts as an immunosuppressant and it has been shown to modulate murine bone marrow-derived dendritic cell-mediated T-helper 2 (Th2) cell polarizations in vitro. In the present study, we initially examined the impact of C12 on the maturation of human monocyte-derived dendritic cells (Mo-DCs) and the induction of regulatory T-cells (iTregs) in culture. Our findings demonstrate that C12-treated Mo-DCs failed to undergo lipopolysaccharide (LPS)-induced maturation. At the molecular level, C12 blocked the upregulation of surface molecules, including CD11c, HLA-DR, CD40, and CD80, and it switched to an interleukin (IL)-10(high), IL-12p70(low) phenotype. Moreover, C12 selectively inhibited the capacity of Mo-DCs to stimulate the proliferation of allogeneic CD4(+) T-cells. Otherwise, the C12-treated Mo-DCs promoted the generation of CD4(+)CD25(+)Foxp3(+)-induced regulatory T-cells (iTregs) and enhanced their IL-10 and transforming growth factor (TGF)-ß production associated with reduced interferon (IFN)-γ and IL-12p70 production. These findings provide new insights towards understanding the persistence of chronic inflammation in PA infection.

[Methoxypolyethylene glycol-modified HLA-A2 antigen on lymphocytes].

OBJECTIVE: To modify the HLA-A2 antigen on the lymphocytes with methoxypolyethylene glycol (mPEG) so as to block the specific binding site for antibody. METHOD: Different types of mPEG (all with final concentration of 12 mmol/L) were used at different temperatures in PBS with varied pH values for the modification of the HLA-A2 antigen. RESULT: The modification of the antigen was not obviously affected when it was carried out at 4 degrees Celsius or room temperature, but higher temperatures of 30 and 37 degrees Celsius significantly hampered the modification. Better antigen modification was observed with high-concentration mPEG in basic PBS, depending also on the type of mPEGs used for this purpose. CONCLUSION: The specific HLA-A2 binding on the lymphocytes is completely blocked by benzotriazole carbonate-mPEG(mPEG-BTC), which is superior to N-hydroxysuccinimidyl ester of mPEG(mPEG-SPA). Maleimide-mPEG(mPEG-MAL) is incapable of blocking the HLA-A2 ligand-binding site with antibody.