Sandwich-type electrochemical immunosensing of CA125 by using nanoribbon-like Ti3C2Tx MXenes and toluidine blue/UIO-66-NH2.

CA125 (carbohydrate antigen 125) is an important biomarker of ovarian cancer, so developing effective method for its detection is of great significance. In the present work, a novel sandwich-like electrochemical immunosensor (STEM) of CA125 was constructed by preparing nanoribbon-like Ti3C2Tx MXenes (Ti3C2TxNR) to immobilize primary antibody (PAb) of CA125 and UIO-66-NH2 MOFs structure to immobilize second antibody (SAb) and electroactive toluidine blue (Tb) probe. In this designed STEM assay, the as-prepared Ti3C2TxNR nanohybrid offers the advantages in large surface area and conductivity as carrier, and UIO-66-NH2 provided an ideal platform to accommodate SAb and a large number of Tb molecules as signal amplifier. In the presence of CA125, the peak currents of Tb from the formed STEM structure increase with the increase of CA125 level. After optimizing the related control conditions, a wide linear range (0.2-150.0 U mL-1) and a very low detection limit (0.05 U mL-1) of CA125 were achieved. It's thus expected the developed STEM strategy has important applications for the detection of CA125.

Tumor-associated macrophage-derived exosomes promote EGFR-TKI resistance in non-small cell lung cancer by regulating the AKT, ERK1/2 and STAT3 signaling pathways.

The evolutionary properties of organisms lead to the issue of targeted drug resistance. Numerous clinical trials have shown that tumor-associated macrophages (TAMs) in patients with lung cancer adversely affect the clinical efficacy of epithelial growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). However, the mechanism by which TAMs influence the tumor cell response to TKIs remains unclear. The aim of the present study was to investigate the influence of TAM-derived exosomes on the sensitivity of PC9 and HCC827 lung adenocarcinoma cells to the EGFR inhibitor gefitinib. Multiple cytokines were used to induce the differentiation of THP-1 human leukemia monocytes into macrophages in vitro. The obtained cells were identified as TAMs by cytomorphology and flow cytometry. Exosomes were extracted from the TAM culture supernatants and identified using electron microscopy and nanoparticle tracking analysis. Flow cytometry was used to examine the apoptosis of lung adenocarcinoma cells when treated with gefitinib and/or TAM-derived exosomes. In addition, western blotting was used to detect the expression of the key proteins of the AKT, ERK1/2 and STAT3 signaling pathways. TAM-derived exosomes were successfully obtained. The TAM-derived exosomes were shown to affect the proliferation and apoptosis of lung adenocarcinoma cells. Furthermore, the killing effect of gefitinib on the tumor cells was attenuated. The mechanism underlying the effects of the TAM-derived exosomes may be associated with reactivation of the AKT, ERK1/2 and STAT3 signaling pathways. In conclusion, the findings indicate that TAM-derived exosomes promote resistance to gefitinib in non-small cell lung cancer (NSCLC), and the mechanism may be associated with reactivation of the AKT, ERK1/2 and STAT3 signaling pathways. This study may serve as a reference in the exploration of alternative strategies for NSCLC following the development of resistance to EGFR-targeted drugs.

[Analysis of Immunophenotypes in 329 Patients with B-ALL at Different Ages].

OBJECTIVE: To investigate the immunophenotypes of B cell acute lymphoblastic leukemia (B-ALL) in patients at different age and to explore its clinical application in prognosis prediction and individualized treatment. METHOD: The immunophenotyping in 329 patients with B-ALL at different ages was performed by CD45/SSC gate four-color fluorescence flow cytometry. RESULTS: In all patients detected the highest incidence of lymphoid-associated antigens was CD19, HLA-DR, CyCD79a and cTdT, followed by CD10, CD22, CD34, CD38, CD20 and CyIg. B-ALL showed a higher concomitant expression rate of myeloid antigens CD13 and CD33; the CD11b, CD15, CD117 and T antigens (CD4, CD7 and CD56) were rarely expressed. CD10⁻ pro-B acute lymphoblastic leukemia (Pro - B-ALL) was predo-minant in infantile group (60%) with CD117 higher expression (40%). Subtype Pro-B-ALL was rarely expressed in childhood and adolescent group, but the incidence of disease increased as the age increase, the incidence of youth group (22.7%) and middle-aged' group (14.8%) were significantly higher than childhood group (4.4%). The influence of age on immunophenotypic characteristics of the adult B-ALL was not significant, the heterogeneity of antigen expression was less in the adult patients at different ages. The expression of CD10 and CD38 was lower, while expression of CD34, CD13 and CD33 were higher in adult patients than those in children patients. There was no significant difference in incidence of precursor-B-ALL (Pre-B-ALL) among different age groups (P > 0.05), but its incidence increased along with age increasing, and the expression of CD20 was higher in Pre - B-ALL than that in Pro - B-ALL and common B-ALL. CONCLUSION: The immunophenotype characteristics of B-ALL in the patients at different ages is of great value in prediction for disease prognosis and guidence of individualized treatment.

The Transcriptome Study of Subtype M2 Acute Myeloblastic Leukemia.

Our objective is to explore the tumor-specific mutated genes by transcriptome sequencing of patients with acute myeloblastic leukemia. 96 patients with subtype M2 acute myeloid leukemia (AML), admitted during January 2007 to January 2012, were selected. Bone marrow and peripheral blood samples from the patients after the first visit and the patients who were improved or alleviated, were subjected to high-throughput sequencing to compare the gene expression. The single nucleotide mutation related to subtype M2 AML was detected. Meanwhile, real-time fluorescent quantitation RT-PCR was used to detect the AML1/ETO fusion gene and its correlation with prognosis after treatment. Among 96 patients, AML1-ETO fusion gene was positive in 52 cases, the positive rate was 54.17 %. The complete relief (CR) rate of AML1-ETO fusion gene positive patients was 84.62 %, and the CR rate of AML1/ETO fusion gene negative patients was 77.27 %; the CR rate of AML1-ETO positive patients was higher than that of patients without the fusion gene, however there was no statistical difference. In the analysis of recurrent gene mutation in AML-M2 patients, IDH2, ASXL1, TET2, JAK1 and JAK2 gene expressions were not significantly different before treatment and after CR, however, IDHI, JAK3, ABL1 and BCR gene expressions were significantly different. In the study of transcriptome in AML-M2 patients, high-throughput sequencing could effectively detect the difference of the gene expression before treatment and after CR. Furthermore, positive expression of AML1-ETO fusion gene had effect on the prognosis of patients.

Lower number of plasmacytoid dendritic cells in peripheral blood of children with bronchiolitis following respiratory syncytial virus infection.

OBJECTIVES: Dendritic cells (DCs) are key mediators of allergic airway inflammation. Thus, it is important to understand the relationship between respiratory syncytial virus (RSV) infection and DCs, especially in children with RSV bronchiolitis. METHODS: We collected peripheral blood from 71 children with RSV bronchiolitis at the time of admission and 28 children who were followed up 3 months following admission. Flow cytometry was performed to detect dendritic cell immunophenotypes. RESULTS: Patients with RSV bronchiolitis exhibited significantly higher number of myeloid DCs and lower number of plasmacytoid DCs at the time of admission and 3 months following discharge, compared with healthy controls. These children had a significantly higher myeloid/plasmacytoid ratio 3 months after discharge compared with healthy controls. CONCLUSIONS: Among children with RSV bronchiolitis, there is an imbalance in peripheral blood myeloid/plasmacytoid ratio. The low number of plasmacytoid DCs in peripheral blood indicates the development of bronchiolitis due to RSV infection.

[Correlation between the numbers of peripheral blood dendritic cells and the clinical manifestations in children with respiratory syncytial virus bronchiolitis].

OBJECTIVE: To detect the quantity of peripheral blood myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) in children with bronchiolitis infected by respiratory syncytial virus (RSV) and analyze the correlation with the severity of the disease. METHODS: PCR was used to detect RSV in nasopharyngeal secretions. Flow cytometry was performed on the peripheral blood to detect the quantity of mDCs and pDCs in 71 children with bronchiolitis by RSV infection (including mild, moderate and severe infection) and 48 healthy control infants. RESULTS: The quantity of peripheral blood mDCs in the children with bronchiolitis by RSV infection was significantly higher than that of healthy controls (P<0.01), while the number of pDCs was significantly lower than that of healthy controls (P<0.01). The children with severe bronchiolitis by RSV infection had significantly lower quantity of peripheral blood mDCs and pDCs as compared with the mild group (P<0.05). CONCLUSION: The number of mDCs in peripheral blood of the children with RSV bronchiolitis significantly increased at the early stage, and in contrast pDCs were reduced. The increased number of mDCs indicates that the clinical manifestations are slighter, and the decreased number of pDCs suggests more wheezing of the children.

[Investigation on the mechanisms of p15INK4B gene demethylation by valproate in Molt-4 cells].

OBJECTIVE: To study the antitumour effects of sodium valproate (VPA) on the proliferation, differentiation and cell cycle of Molt-4 cell and to investigate its demethylation mechanisms. METHODS: After Molt-4 cells trated with VPA at different concentrations, cell viability and growth curve were assessed by MTT assay. Cell cycle changes were analyzed by flow cytometry. The expression level of p15, DNA methyltransferase 1 (DNMT-1), DNMT3A and 3B mRNA were detected by RT-PCR and the methylation level was detected by hn-MSPCR. RESULTS: VPA significantly inhibited the proliferation of Molt-4 cells. After 48 h culture with 5.0 mmol/L VPA, the percentages of Molt-4 cells in G(0)/G(1) phase was (66.87 ± 3.31)% and in S phase was (8.47 ± 2.56)%, while in control group, the cells in G(0)/G(1) phase increased and in S phase decreased significantly. The p15 gene in Molt-4 cells failed to express due to its hypermethylation. The expression level of p15 gene mRNA increased significantly after exposure to VPA for 48 h. As compared with control group, the expression of DNMT-1 was down-regulated in a dose-dependent manner. The expression level of DNMT3B decreased at 10.0 mmol/L concentration. CONCLUSION: VPA has a demethylation effect on p15 INK4B gene by inhibiting the DNMT-1 and DNMT3B gene activities to recover p15 gene activity, which arrests Molt-4 cell in G(0)/G(1) phase.