[Safety and effectiveness of emergency stenting for acute anterior circulation large artery disease]

Objective: To explore the safety and effectiveness of early stent implantation in patients with acute anterior circulation large artery disease. Methods: Patients were recruited from the RESCUE-RE study (a registration study for Critical Care of Acute Ischemic Stroke After Recanalization). Patients who were diagnosed with acute ischemic stroke within 24 hours of onset and given endovascular treatment after consultation from July 2018 to May 2019 from 18 sub-centers nationwide were retrospectively enrolled. According to whether the stents were placed during the operation, the patients were divided into two groups: stenting group and non-stenting group. The baseline between the two groups was matched by propensity score. The matching variables included age, sex, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline Glasgow Coma Scale (GCS) score, history of stroke, smoking and onset to hospital time. The primary clinical outcome was 90-day good neurological outcome [defined as modified Rankin score (mRS) 0-2]. Secondary outcomes include 90-day mortality, 24-hour re-occlusion of the responsible artery, and symptomatic intracranial hemorrhage. The differences in clinical endpoints between the two groups were compared. Result: A total of 899 patients with acute anterior circulation artery stenosis or occlusion were included in the study, with a mean age of(66±12)years,and 532(59.18%) were male. There were 193 patients in the stenting group and 706 patients in the non-stenting group. After the baseline data between the two groups were matched by propensity score, 169 patients were enrolled in each of two groups respectively. After matching, the proportion of patients in the stenting group with etiological diagnosis of large atherosclerosis [82.53% (137/166) vs 55.69% (93/167)] and the proportion of patients with previous history of hypertension [63.31% (107/169) vs 47.93% (81/169)] in the stenting group were higher than those in the non-stenting group (both P<0.05). While the proportion of patients in the non-stenting group with cardiogenic embolism [37.73%(63/167) vs 11.45%(19/166)]and the proportion of patients with atrial fibrillation [18.93% (32/169) vs 10.65%(18/169)]was higher(all P<0.05). In the stenting group, the time from onset to recanalization was longer[519 (408, 620)min vs 469 (365, 690)min], and the proportion of general anesthesia [50.89% (86/169) vs 35.50% (60/169)] was higher in the stenting group(both P<0.05). In addition, in the stenting group, the proportion of patients receiving mechanical thrombectomy[67.46% (114/169) vs 88.76% (150/169)] and arterial thrombolysis [2.37% (4/169) vs 18.93% (32/169)] was lower than non-stenting group during the operation, while the proportion of patients receiving balloon dilation [53.85% (91/169) vs 13.61% (23/169)]was higher(both P<0.05). The proportion of patients in stent group receiving antiplatelet drugs before operation was higher [13.46% (21/169) vs 8.70% (14/169)](both P<0.05). In terms of clinical outcome, compared with the non-stenting group, the proportion of patients in the stenting group with good neurological function in 90 days was lower [44.79% (73/169) vs 56.36% (93/169)], and the proportion of death at 90 days was higher[15.98% (27/169) vs 8.88% (15/169)] (both P<0.05). There was no significant difference between the two groups in 24-hour re-occlusion[8.88% (15/169) vs 9.47% (16/169)] and symptomatic intracranial hemorrhage[5.92% (10/169) vs 4.76% (8/169)](both P>0.05). Conclusion: For patients with acute anterior circulation artery disease, early stent therapy may increase the proportion of patients with adverse neurological outcomes.

[The association between stress hyperglycemia ratio and outcome of patients with acute ischemic stroke undergoing endovascular treatment]

Objectives: To investigate the correlation between stress hyperglycemia ratio (SHR) and outcomes in patients with acute ischemic stroke treated with endovascular treatment. Methods: In a multicenter registration study for RESCUE-RE (a registration study for critical care of acute ischemic stroke after recanalization), eligible patients with large vessel occlusion stroke within 24 hours after onset who received endovascular treatment between July 2018 and May 2019 were enrolled. SHR was calculated as the fasting glucose concentration divided by the estimated average glucose concentration and then categorized into four groups according to the quartiles (group Q₁, group Q₂, group Q₃ and group Q₄). The primary outcome was poor neurological outcomeat day 90 fromstroke onset [defined as modified Rankin scale (mRS) of 3-6]. Secondary outcomes included early neurological deterioration (END), death within 3 months after stroke onset, and symptomatic intracranial hemorrhage.Multivariable logistic and Cox regression modelswere used to assess the correlation between quartiles of SHR and prognosis in patients with endovascular treatment. Results: A total of 592 patients were enrolled in the study, with a mean age of (63±12) years, and 68.07% were male.The median National Institute of Health stroke scale(NIHSS) score on admission was15(11, 20), and the median SHR was 1.23 (1.07, 1.47), with SHR<1.07 in group Q₁, 1.07≤SHR<1.23 in group Q₂, 1.23≤SHR<1.47 in group Q₃ and SHR≥1.47 in group Q₄, respectively. The rate of complete recanalization was lower in group Q₄ than that of group Q₁ (70.27% vs 83.67%, P=0.026). After fully adjusted for potential covariates, the risk of poor neurological outcome at day 90 from stroke onset in group Q₄ was 2.38 folds that of group Q₁(adjusted OR= 2.38, 95%CI: 1.57-3.57,P=0.003). The risk of death within 3 months of patients in group Q₄ was 1.80 times that of the patients in group Q₁, but the difference was not statistically significant(adjusted HR=1.80, 95%CI: 0.90-3.62, P=0.098). Conclusion: Higher SHR was correlated with poor neurological outcome at 3 months in large artery occlusion related acute ischemic stroke patients receiving endovascular therapy.

Platelet membrane-camouflaged silver metal-organic framework drug system against infections caused by methicillin-resistant Staphylococcus aureus

Background

Due to the intelligent survival strategy and self-preservation of methicillin-resistant Staphylococcus aureus (MRSA), many antibiotics are ineffective in treating MRSA infections. Nano-drug delivery systems have emerged as a new method to overcome this barrier. The aim of this study was to construct a novel nano-drug delivery system for the treatment of MRSA infection, and to evaluate the therapeutic effect and biotoxicity of this system. We prepared a nano silver metal-organic framework using 2-methylimidazole as ligand and silver nitrate as ion provider. Vancomycin (Vanc) was loaded with Ag-MOF, and nano-sized platelet vesicles were prepared to encapsulate Ag-MOF-Vanc, thus forming the novel platelet membrane-camouflaged nanoparticles PLT@Ag-MOF-Vanc.

Results

The synthesized Ag-MOF particles had uniform size and shape of radiating corona. The mean nanoparticle size and zeta potential of PLT@Ag-MOF-Vanc were 148 nm and − 25.6 mV, respectively. The encapsulation efficiency (EE) and loading efficiency (LE) of vancomycin were 81.0 and 64.7 %, respectively. PLT@Ag-MOF-Vanc was shown to be a pH-responsive nano-drug delivery system with good biocompatibility. Ag-MOF had a good inhibitory effect on the growth of three common clinical strains (Escherichia coli, Pseudomonas aeruginosa, and S. aureus). PLT@Ag-MOF-Vanc showed better antibacterial activity against common clinical strains in vitro than free vancomycin. PLT@Ag-MOF-Vanc killed MRSA through multiple approaches, including interfering with the metabolism of bacteria, catalyzing reactive oxygen species production, destroying the integrity of cell membrane, and inhibiting biofilm formation. Due to the encapsulation of the platelet membrane, PLT@Ag-MOF-Vanc can bind to the surface of the MRSA bacteria and the sites of MRSA infection. PLT@Ag-MOF-Vanc had a good anti-infective effect in mouse MRSA pneumonia model, which was significantly superior to free vancomycin, and has no obvious toxicity.

Conclusions

PLT@Ag-MOF-Vanc is a novel effective targeted drug delivery system, which is expected to be used safely in anti-infective therapy of MRSA.

Graphic abstract

[Expression of platelet miR-223 in coronary artery disease patients and its clinical significance]

Objective: To investigate the correlation of the expression of platelet microRNA-223 (miR-223) with the degree of platelet activation and the severity of coronary lesions in patients with coronary artery disease (CAD). Methods: A total of 204 consecutive patients underwent coronary artery angiography (CAG) at Beijing Anzhen Hospital between April and December 2016 were enrolled. According to CAG results, all the patients were divided into two groups: 112 patients in CAD group and 92 patients in control group. Real-time fluorescent quantitative PCR was used to detect the expression level of platelet miR-223 and mRNA of its target gene P2Y12. Flow cytometry was performed to detect the expression of platelet associated complement-1 (PAC-1). Results: Compared with control group, the expression level of platelet miR-223 in CAD group was higher [(1.27 (1.17, 1.32) vs 0.73 (0.64, 0.79), P<0.001], while the expression level of P2Y12 mRNA was lower [0.75 (0.51, 0.96) vs 1.00 (0.80, 1.64), P<0.001]. The positive expression rate of PAC-1 of CAD group was higher than that of control group (P<0.001). The expression level of platelet miR-223 was negatively correlated with the expression of P2Y12 (r=-0.39, P=0.02), but positively correlated with the expression of PAC-1 (r=0.50, P<0.001). The platelet miR-223 expression level had a positive correlation with the Gensini score in CAD group (r=0.90, P<0.001), but had no significant correlation with platelet aggregation (r=-0.06, P=0.36). Conclusion: The expression level of platelet miR-223 in patients with CAD may be an indicator for monitoring platelet activation and assessing the severity of CAD.

Initial empiric antibiotic therapy for community-acquired pneumonia in Chinese hospitals

OBJECTIVES

Studies on treatment of community-acquired pneumonia (CAP) in China are scarce. We performed a study to investigate empiric antibiotic practices for patients hospitalized with CAP in China and the risk factors for treatment failure.

METHODS

Data were collected from a national Chinese hospitalization database. Adult patients who were diagnosed with CAP between 1 October 2014 and 30 September 2015 were identified. We studied initial empiric antibiotic regimens, microbiologic sampling, treatment failure, in-hospital mortality and length of hospital stay.

RESULTS

We included 18 043 adult patients from 185 hospitals who met all the study inclusion criteria. The most common initial antibiotic regimen for CAP was monotherapy with a fluoroquinolone (14.8%, 2671/18 043). The most common initial antibiotic (used alone or in combination with other antibiotics) was levofloxacin (15.7%, 4597/29 278 (this denominator represents the total number of initial antibiotics)). The microbiologic sampling rate was 26.9% (4851/18 043). A total of 4050 (22.4%) of 18 043 patients experienced treatment failure. Multivariate logistic regression demonstrated that older age, male sex, coexisting lung cancer and use of regimens not covering atypical pathogens were risk factors for treatment failure. In-hospital mortality was 2.1% (380/18 043). The median hospital length of stay was 11 days (interquartile range, 8-15 days).

CONCLUSIONS

Patients receiving Chinese guideline-adherent regimens had better outcomes, and atypical pathogen active regimens were associated with a lower treatment failure rate and shorter length of hospital stay.

Meropenem-induced immune thrombocytopenia and the diagnostic process of laboratory testing

BACKGROUND

Drug-induced immune thrombocytopenia (DITP) is a serious, life-threatening clinical syndrome, the diagnosis of which is consistently difficult. In this report, we present a case of DITP caused by meropenem that was confirmed by laboratory tests.

CASE REPORT

A 59-year-old male patient developed severe thrombocytopenia 8 days after the administration of meropenem and cefoperazone-sulbactam. After other causes were ruled out, DITP was suspected. Drug-induced platelet (PLT) antibodies were detected by enzyme immunoassay, flow cytometry, and monoclonal antibody immobilization of PLT antigens (MAIPA). All these tests were performed in the presence and absence of the associated drugs.

RESULTS

PLT antibodies were detected in the patient's serum only in the presence of meropenem. MAIPA experiments demonstrated that glycoprotein IIb/IIIa was the binding site of the meropenem-induced PLT antibodies.

CONCLUSIONS

Drug-induced immune thrombocytopenia should be considered in cases of acute thrombocytopenia in patients undergoing meropenem treatment. Clinicians should be cognizant of DITP, and a definitive diagnosis should be pursued, if feasible.

Association between a point mutation at the -743-bp region of the transthyretin (TTR) gene and familial vitreous amyloidosis

The aim of this study was to identify changes in the base sequence of the upstream regulatory region of the transthyretin (TTR) gene. Whole-blood DNA was extracted from ten subjects belonging to a family with familial amyloidosis vitreoretinopathy; the upstream regulatory sequence was amplified by polymerase chain reaction, detected by gel electrophoresis, and sequenced. The DNA sequence of the upstream regulatory region of the TTR gene was successfully sequenced, and a point mutation (-743A→T) was identified in six of the ten blood samples: four patients and two family members without disease incidence. Therefore, a point mutation was identified in the upstream regulatory region of the TTR gene in a Han Chinese family with familial vitreous amyloidosis.

Oxidored-nitro domain-containing protein 1 expression is associated with the progression of hepatocellular carcinoma

Hepatocarcinogenesis is a stepwise process during which multiple genes are altered. Understanding the molecular mechanisms that induce hepatocarcinogenesis may improve the screening, prevention and treatment of patients with hepatocellular carcinoma (HCC). In recent years, the oxidored-nitro domain-containing protein 1 (NOR1) gene has been identified to have an important role in the development of HCC in vitro experiments. The current study aimed to examine the expression of NOR1 mRNA and protein expression in specimens of normal liver, hepatitis, cirrhosis and HCC, together representing the process of HCC development. Furthermore, the association between NOR1 expression and clinicopathological parameters of HCC patients was analyzed. Tissue microarrays containing the specimens of human normal liver, hepatitis, cirrhosis and HCC were purchased, and in situ hybridization and immunohistochemistry were used to detect the expression of NOR1 mRNA and protein expression, respectively. It was revealed that the positive rate of NOR1 protein and mRNA expression in the specimens of hepatitis and cirrhosis were not significantly different from that in the normal liver samples. However, the specimens of HCC exhibited an increased positive rate of NOR1 protein and mRNA expression in comparison with the normal liver samples. In addition, a higher positive rate of NOR1 protein expression was observed in HCC patients with a poor pathological differentiation grade and high tumor node metastasis (TNM) stage. In conclusion, the present study provides evidence, for the first time, of the increased expression of NOR1 in human HCC tissues, and its correlation with the pathological stage and TNM status. These findings indicate that NOR1 may be involved in the progression of HCC and it could be employed as a predictive biomarker in HCC development.

Therapeutic effects of acetylspiramycin and garlicin on cryptosporidiosis among drug users

Cryptosporidiosis affects humans of all ages, particularly malnourished children and those with compromised immune systems such as HIV/AIDS. This study investigated the therapeutic effects of acetylspiramycin and garlicin on Cryptosporidium infection in institutionalized male drug users receiving rehabilitative treatment. Examination of stool specimens from 903 drug users via modified acid-fast bacilli staining resulted in 172 positive cases. Among them 151 subjects consented to participate in a randomized trial of acetylspiramycin and garlicin in four groups: acetylspiramycin plus garlicin, acetylspiramycin only, garlicin only, and placebo control. The cryptosporidiosis rate was higher in younger subjects with longer drug use history than subjects who are older with shorter history of drug use. After two segments of treatments, 76.2% of the cases achieved negative test results, with the four groups achieving the rates of 92.1%, 76.7%, 72.2%, and 61.8%, respectively (χ(2) = 9.517, P = 0.023). These results indicate clinical potential of garlicin in conjunction with acetylspiramycin in treating cryptosporidiosis.

[Analysis on the effectiveness in 727 times of platelet transfusion]

This study was purposed to analyze the efficiency of platelet transfusion and to explore factors influencing platelet transfusion efficiency. 727 times of platelets transfusion in 254 patients in The Third Xiangya Hospital from September 2010 to May 2011 were analyzed retrospectively. Moreover, according to symptoms, times of platelet transfusion, blood types and splenomegaly, the corrected count of increment (CCI) and percentage of platelet recovery (PPR) were calculated for evaluation of platelet transfusion efficiency. The results showed that there were 456 effective transfusions out of 727 transfusions (62.72). Among them, the therapeutic effect of platelet transfusion for patients with acute blood loss anemia and chronic systemic diseases was relatively obvious, specially for chronic renal disease, the effective efficiency of them was 94.12. The patients with splenomegaly showed a significant impact on platelet transfusion efficiency (41.07). Analysis found that the frequency of platelet transfusion negatively correlated with transfusion efficiency. It is concluded that the transfusion frequency and splenomegaly are factors influencing the transfusion efficiency.

An analysis on the combination expression of HPV L1 capsid protein and p16INK4a in cervical lesions

Human papillomavirus (HPV) infection in cervix is the most important reason for cervical cancer, but only 2% cervical HPV infection will develop into cervical cancer. So how to identify patients at risk of progressive cervical lesions from those infected with HPV to avoid over treatment is a big issue in clinic. The aims of this study were to detect the expression of HPV L1 capsid protein and p16(INK4a) in cervical lesions and to investigate the combination expression of HPV L1 capsid protein and p16(INK4a) in cervical lesions and its diagnostic efficiency in clinic. Immunochemical method was used to detect the expression of HPV L1 capsid protein and p16(INK4a) in 169 cases of abnormal cytology. Histopathologic test was performed to identify cervical lesions of all the cases. chi(2) test and spearman's rank correlation were used for statistical analysis. The diagnostic sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), accuracy, and the area under the receive operating characteristic (ROC) curve (denoted by A(Z)) were calculated with SPSS 13.0. All the statistical tests were two sided at the 5% level of significance. L1 expression decreased (P < 0.001), but p16(INK4a) expression increased (P < 0.001) with histopathologic diagnosis increasing. The expression rates of HPV L1 capsid protein, p16(INK4a), and L1(-)/p16(+) in cervical intraepithelial neoplasia (CIN)2, CIN3, and squamous-cell carcinoma were statistically different from those in CIN1 (P < 0.001). The expressions of HPV L1 capsid protein, L1(+)/p16(+), L1(+)/p16(-), and L1(-)/p16(-) were negatively correlated with the severity of cervical lesions (P < 0.001), whereas the expressions of p16(INK4a) and L1(-)/p16(+) were positively correlated with the severity of cervical lesions (P < 0.001). The specificity and A(Z) of combining L1 with p16 (INK4a) were statistically higher than L1 or p16 (INK4a) alone (P < 0.05). L1 and p16(INK4a) are useful biomarkers for the early diagnosis of cervical lesions. The combination of L1 and p16(INK4a) has a higher diagnostic accuracy than L1 or p16(INK4a) alone in diagnosis of cervical lesions.

Analysis of the dose-response relationship between high-risk human papillomavirus viral load and cervical lesions

The aims of this study were to explore the dose-response relationship between high-risk human papillomavirus (hrHPV) load and cervical lesions; the relationship between hrHPV viral load and the severity of cervical lesions; and the clinical application of the hybrid capture II (HC-II) system in the secondary prevention of cervical cancer. HrHPV viral load was detected by the HC-II system and cervical lesions were diagnosed from biopsied tissue. Curve estimation and Mantel trend analysis were used to explore the dose-response relationship between hrHPV viral load and cervical lesions. Spearman's rank correlation analysis and ordinal regression model were used for the analysis of hrHPV viral load and the severity of cervical lesions. Curve estimation showed good correlation between cervical lesion rates and hrHPV viral load (r=0.775, P=0.008); the rate of cervical lesions increased with hrHPV viral load (chi(trend)=8.000, P<0.001). Medium intensity rank correlation was found between hrHPV viral load grades and the severity of cervical lesions (r(s)=0.321, P<0.001); a correlation appeared between hrHPV viral load and the severity of cervical lesions (P<0.001). These results suggest a dose-response relationship between hrHPV viral load and the severity of cervical lesions. This dependence has important clinical applications and shows the potential value of the HC-II system in cervical cancer prevention.

Electrochemical immunosensor of platelet-derived growth factor with aptamer-primed polymerase amplification

A new method for the determination of platelet-derived growth factor BB (PDGF-BB) was developed using an electrochemical immunosensor with an aptamer-primed, long-strand circular detection probe. Rabbit anti-human PDGF-B polyclonal antibody was immobilized on the electrode to serve as the capture antibody. The detection probe was synthesized via polymerase extension along a single-stranded circular plasmid DNA template with a primer headed by the anti-PDGF-B aptamer. In the presence of the analyte, the aptamer-primed circular probe was captured on the electrode via the formation of an antibody/PDGF-BB/aptamer sandwiched complex. The electroactivity indicator methylene blue was adsorbed on the electrode surface via the analyte-sandwiched complex with long-strand circular DNA, thus yielding a strong electrochemical signal for the quantification of PDGF-BB. This strategy allowed electrochemical detection with enormous signal amplification arising from the long-strand localized circular probe. The oxidation peak current of methylene blue in square wave voltammetric measurements showed a linear dependence on the concentration of PDGF-BB in the range from 50 to 500 ng mL(-1), with a detection limit as low as 18 pg mL(-1).

Poly(L-lysine)-modified silica nanoparticles for the delivery of antisense oligonucleotides

Silica nanoparticles were prepared in a microemulsion system, using polyoxyethylene nonylphenyl ether/cyclohexane/ammonium hydroxide. The surface charge of the particle was modified with PLL [poly(L-lysine)]. PAGE demonstrated the ability of PMS-NP (PLL-modified silica nanoparticles) to bind and protect antisense ODNs (oligonucleotides). The intracellular localization of FITC-labelled ODN was investigated by fluorescence microscopy. The results demonstrated that ODN could be delivered to cytoplasm. Flow-cytometry analysis showed a 20-fold enhancement of ODN delivered by PMS-NP compared with free ODN for a serum-free medium. Blocking efficacy of c- myc antisense ODN, delivered by PMS-NP, was examined in HNE1 and HeLa cell lines. Significant down-regulation of c- myc mRNA levels was observed in both the cell lines. However, the cellular uptake efficiency and antisense effects on target gene decreased in the presence of serum-containing medium. The analysis of the filtration assay showed that PMS-NP interacted with serum proteins. These results indicated that PMS-NP was a suitable delivery vector for antisense ODN, although its delivery efficiency decreased in the presence of a serum-containing medium.

IONP-PLL: a novel non-viral vector for efficient gene delivery

BACKGROUND

Non-viral methods of gene delivery have been an attractive alternative to virus-based gene therapy. However, the vectors that are currently available have drawbacks limiting their therapeutic application.

METHODS

We have developed a self-assembled non-viral gene carrier, poly-L-lysine modified iron oxide nanoparticles (IONP-PLL), which is formed by modifying poly-L-lysine to the surface of iron oxide nanoparticles. The ability of IONP-PLL to bind DNA was determined by ratio-dependent retardation of DNA in the agarose gel and co-sedimentation assay. In vitro cytotoxic effects were quantified by MTT assay. The transfection efficiency in vitro was evaluated by delivering exogenous DNA to different cell lines using IONP-PLL. Intravenous injection of IONP-PLL/DNA complexes into mice was evaluated as a gene delivery system for gene therapy. The PGL2-control gene encoding firefly luciferase and the EGFP-C2 gene encoding green fluorescent protein were used as marker genes.

RESULTS

IONP-PLL could bind and protect DNA. In contrast to PLL and cationic liposomes, IONP-PLL described here was less cytotoxic in a broad range of concentrations. In the current study, we have demonstrated that IONP-PLL can deliver exogenous gene to cells in vitro and in vivo. After intravenous injection, IONP-PLL transferred reporter gene EGFP-C2 to lung, brain, spleen and kidney. Furthermore, we have demonstrated that IONP-PLL transferred exogenous DNA across the blood-brain barrier to the glial cells and neuron of brain.

CONCLUSIONS

IONP-PLL, a low-toxicity vector, appears to have potential for fundamental research and genetic therapy in vitro and in vivo, especially for gene therapy of CNS disease.

[Analysis of splicing variants in NASG 3'UTR, down-regulated in nasopharyngeal carcinoma, and its expression in multiple cancer tissues]

BACKGROUND & OBJECTIVE

NASG gene, a tissue-specific gene of human nasopharyngeal epithelium was isolated by suppression subtractive hybridization. This study was designed to analyze splicing variants in NASG 3'untranslated region (UTR) and its expression profiling in multiple cancer tissues.

METHODS

The PCR primers were designed in NASG 3'UTR around the splicing variants and reverse transcription-polymerase chain reaction (RT-PCR) was performed. The PCR products were separated and sequenced. The expression patterns of NASG were detected by RT-PCR among nasopharyngeal carcinoma (NPC) cell line HNE1, primary human embryo nasopharyngeal epithelial cells, NPC biopsies, and normal adult nasopharyngeal epithelial tissues. Its expression profiling in multiple cancer tissues were tested by cancer profiling array hybridization.

RESULTS

There were three splicing variants in NASG 3'UTR. NASG was identified to be down-regulated in NPC cell line HNE1 and 71% of the NPC biopsies, but up-regulated in 25% lung of the cancer biopsies, and not express in other cancer tissues and normal tissues.

CONCLUSION

There were three splicing variants in NASG 3'UTR. Its abnormal expression may be an important molecular event in NPC and lung cancer.

[Expression of BRD7-interacting proteins,BRD2 and BRD3, in nasopharyngeal carcinoma tissues]

BACKGROUND & OBJECTIVE

BRD7 is a novel gene tightly associated with nasopharyngeal carcinoma(NPC) cloned by cDNA representational difference analysis (cDNA RDA). Two proteins,BRD2 and BRD3, including bromodomain and interacting with BRD7 protein had been screened from human fetal brain cDNA library by yeast two-hybrid system. This study was designed to further identify the interactions of BRD2 and BRD3 with BRD7 respectively and to investigate the expression and action pattern of BRD2 and BRD3 in NPC.

METHODS

BRD2 and BRD3 genes were respectively co-transformed to yeast Y187 with BRD7 gene, then the yeast cotransformers were blotted to nylon membrane. And then the expression of report gene Lac Z by beta-Gal was determined and the interactions of BRD2 and BRD3 proteins with BRD7 protein were identified. Besides,reverse transcription-polymerase chain reaction (RT- PCR) was used to examine the expression of BRD2 and BRD3 genes in normal nasopharyngeal epithelium and NPC biopsies, and to detect the effect of re-expression of BRD7 gene on the expression of BRD2 and BRD3 genes in HNE1 stably transfected BRD7 gene.

RESULTS

The yeast transformers showed all blue by yeast two-hybrid system, which further identified that BRD2 and BRD3 proteins could respectively interact with BRD7 protein. Down-expression or loss of BRD2 and BRD3 genes were detectable in NPC biopsies. The expression levels of BRD2 and BRD3 were increasing with the re-expression of BRD7 gene in HNE1 stably transfected with BRD7.

CONCLUSION

BRD7 protein could respectively interact with proteins, BRD2 and BRD3, and BRD7 could up-regulate the expression levels of BRD2 and BRD3 genes in mRNA level to some extent. Each of these three homolog proteins might be capable of forming heteromers with the others, which play important roles in the suppression of growth of NPC cells.

[Expression of a new cloned nitroreductase gene NOR1 and purification of expressed product]

BACKGROUND & OBJECTIVE

NOR(1)is a good candidate of tumor suppressor/susceptibility gene associated with nasopharyngeal carcinoma. This study was designed to construct the prokaryotic expression vector and to investigate the expression of nitroreductase gene NOR(1)in Escherichia coli and to purify expressed product.

METHODS

Total RNA was subtracted from normal nasopharyngeal carcinoma tissue. The full length of NOR(1)gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and digested with BamHIand XhoI restriction endonucleases. The plasmid pGEX-4T-2 was also digested with BamHI and XhoI,then the NOR(1)gene was inserted into vector pGEX-4T-2. The recombinant expression vector pGEX-4T-2/NOR(1)was identified by sequencing and digested with restriction enzymes. E.coli Jm105 transformed with the recombinant plasmid was induced by IPTG to express GST fusion protein. The result was confirmed by Western blot analysis and the purified targeted protein was obtained by affinity chromatography.

RESULTS

The 1.25kb NOR(1)gene was successfully isolated. After induction, a new anticipated protein of 74 kDa appeared on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). It existed not only in supernatant but also in precipitation of broken bacteria. The result was confirmed by Western blot analysis,and the purified targeted protein was obtained by affinity chromatography.

CONCLUSION

The successes in construction of expression vector of NOR(1), expression and purification of GST/NOR(1)fusion protein make it possible to prepare for the polyantibodies for NOR(1).