Circ_0000064 adsorption of microRNA-143 promotes malignant progression of hepatocellular carcinoma

OBJECTIVE

The aim of this study was to investigate the expression characteristics of circ_0000064 in hepatocellular carcinoma, and to further explore the underlying mechanism.

PATIENTS AND METHODS

Real time quantitative-Polymerase Chain Reaction (qPCR) was used to detect the expression of circ_0000064 in 42 hepatocellular carcinoma tissues and adjacent normal tissues. Meanwhile, the relationship between circ_0000064 expression and clinical indicators, as well as the prognosis of patients with hepatocellular carcinoma, were detected. QPCR was applied to measure circ_0000064 level in hepatocellular carcinoma cell lines as well. Subsequently, the circ_0000064 knockdown model was successfully constructed using lentivirus in hepatocellular carcinoma cell lines. Cell counting kit-8 (CCK-8), colony formation assay, and flow apoptosis were performed to analyze the influence of circ_0000064 on the biological functions of hepatocellular carcinoma cells. The potential mechanism was explored using cell recovery experiments. In addition, the relationship between circ_0000064 and microRNA-143 was finally explored.

RESULTS

QPCR results showed that the expression level of circ_0000064 in hepatocellular carcinoma tissues was remarkably higher than that of adjacent normal tissues, and the difference was statistically significant. Compared with patients with lower expression of circ_0000064, patients with higher expression of circ_0000064 exhibited remarkably higher pathological stage and lower overall survival rate. In vitro experiments demonstrated that the proliferation ability of the cells was remarkably reduced after the transfection of si-circ_0000064, while cell apoptosis ability significantly increased when compared with the NC group. Meanwhile, qPCR results indicated that microRNA-143 expression was negatively correlated with circ_0000064 expression in hepatocellular carcinoma. Luciferase reporter gene assay indicated that circ_0000064 could be targeted by microRNA-143 through their binding site. In addition, the cell recovery experiment confirmed that circ_0000064 and microRNA-143 could be mutually regulated, which affected the malignant progression of hepatocellular carcinoma together.

CONCLUSIONS

Circ_0000064 level was remarkably upregulated in hepatocellular carcinoma and was associated with high pathological stage and poor prognosis of patients. In addition, circ_0000064 significantly promoted proliferation and inhibited apoptosis of hepatocellular carcinoma cells via modulating microRNA-143.

RETRACTED: ORIENT-3: A randomized, open-label, phase III study of sintilimab versus docetaxel in previously treated advanced/metastatic squamous non-small cell lung cancer (sqNSCLC)

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article was retracted at the request of the authors. The authors of this abstract have advised that full agreement between authors and sponsors on publication of the abstract has not been reached and they are therefore unable to publish this data at present.

Antigenic load and peripheral chimeric levels in entire and partial liver allograft recipients

Orthotopic partial liver transplantation (PLT) models were developed in rats to explore the unique role of the liver in transplant tolerance. In PVG rats, syngeneic PLT established that surgical reduction to one-third of the liver and orthotopic transplantation permitted survival. Allogeneic PLT in the PVG to DA liver-tolerant model, both 50% and 33%, did not affect the tolerogeneic property of the liver, with all PLT recipients surviving indefinitely. Blood samples taken at various time points for detection of donor cells using flow cytometry showed a steady increase in donor cell chimerism in both PLT and whole liver transplantation (WLT) recipients that persisted throughout the 3-month observation period. At each time point, the level of donor cell chimerism in PLT was higher than that in WLT. We conclude that transplantation of one-third of the liver is compatible with survival in rats. Reduction of antigenic load by means of hepatectomy does not affect the tolerogenic effect of the liver in the PVG to DA LT model because of the remarkable regeneration capability of the liver. Peripheral chimeric levels increase progressively after WLT, suggesting that this is an ongoing immunological phenomenon. The earlier and increased chimerism after PLT may be associated with liver regeneration.

Multimodal data fusion of cortical-subcortical morphology and functional network connectivity in psychotic spectrum disorder

Multiple authors have noted overlapping symptoms and alterations across clinical, anatomical, and functional brain features in schizophrenia (SZ), schizoaffective disorder (SZA), and bipolar disorder (BPI). However, regarding brain features, few studies have approached this line of inquiry using analytical techniques optimally designed to extract the shared features across anatomical and functional information in a simultaneous manner. Univariate studies of anatomical or functional alterations across these disorders can be limited and run the risk of omitting small but potentially crucial overlapping or joint neuroanatomical (e.g., structural images) and functional features (e.g., fMRI-based features) which may serve as informative clinical indicators of across multiple diagnostic categories. To address this limitation, we paired an unsupervised multimodal canonical correlation analysis (mCCA) together with joint independent component analysis (jICA) to identify linked spatial gray matter (GM), resting-state functional network connectivity (FNC), and white matter fractional anisotropy (FA) features across these diagnostic categories. We then calculated associations between the identified linked features and trans-diagnostic behavioral measures (MATRICs Consensus Cognitive Battery, MCCB). Component number 4 of the 13 identified displayed a statistically significant relationship with overall MCCB scores across GM, resting-state FNC, and FA. These linked modalities of component 4 consisted primarily of positive correlations within subcortical structures including the caudate and putamen in the GM maps with overall MCCB, sparse negative correlations within subcortical and cortical connection tracts (e.g., corticospinal tract, superior longitudinal fasciculus) in the FA maps with overall MCCB, and negative relationships with MCCB values and loading parameters with FNC matrices displaying increased FNC in subcortical-cortical regions with auditory, somatomotor, and visual regions.

Altered selenium-binding protein levels associated with selenium resistance

Our previous studies have sought to elucidate the mechanism by which selenium inhibits cell growth since the mechanisms involved may be relevant to the chemopreventive properties of selenium. In a previous report, we described the isolation of a selenium-resistant cell line, B19, from a selenium-sensitive parental cell line, C57. In this report we identify biochemical changes that may be responsible for conferring selenium resistance. Altered selenium uptake and intracellular glutathione concentrations were eliminated as possible modes of resistance since these two parameters were similar between the two cell lines. However, when the selenium-containing protein complements of the two cell lines were compared by labelling with [75Se]selenite, both increases and decreases in a number of selenium-labelling proteins were found in the B19 cells. The most striking differences were the presence of two 72 kDa selenium-labelling proteins in B19 cells which could not be detected in C57 cells. The levels of a number of mRNAs encoding antioxidant or detoxification enzymes were also compared between the two cell lines but only minor changes were found. This work suggests that further analysis of the 72 kDa selenium-labelling proteins may reveal insights into the mechanisms of growth inhibition by selenium.

Alloy oxidation as a route to chemically active nanocomposites of gold atoms in a reducible oxide matrix

While nanoparticles are being pursued actively for a number of applications, dispersed atomic species have been explored far less in functional materials architectures, primarily because composites comprising dispersed atoms are challenging to synthesize and difficult to stabilize against sintering or coarsening. Here we show that room temperature oxidation of Au-Sn alloys produces nanostructures whose surface is terminated by a reducible amorphous oxide that contains atomically dispersed Au. Analysis of the oxidation process shows that the dispersal of Au in the oxide can be explained by predominant oxygen anion diffusion and kinetically limited metal mass transport, which restrict phase separation due to a preferential oxidation of Sn. Nanostructures prepared by oxidation of nanoscale Au-Sn alloys with intermediate Au content (30-50%) show high activity in a CO-oxidation probe reaction due to a cooperative mechanism involving Au atoms as sites for CO adsorption and reaction to CO₂ embedded in a reducible oxide that serves as a renewable oxygen reservoir. Our results demonstrate a reliable approach toward nanocomposites involving oxide-embedded, atomically dispersed noble metal species.

Regulation of herpes simplex virus type 1 gene expression in nonpermissive murine resident peritoneal macrophages

The restriction of herpes simplex virus type 1 (HSV-1) gene expression in nonpermissive murine resident peritoneal macrophages (ResPMO) was analyzed at the level of transcription. Using nuclear run-on assays, we established that transcription of a representative gene from each HSV-1 kinetic class was initiated in both ResPMO and permissive Vero cells. Using transient expression assays, we observed that the promoters of two early genes were activated by the immediate-early protein ICP4 in ResPMO. However, the level of transactivation of these promoters by another immediate-early protein, ICP0, was markedly reduced in ResPMO. Furthermore, the synergistic trans-activation normally observed between ICPs 4 and 0 in Vero cells was noticeably absent in ResPMO. The data indicate that the block in viral gene expression in ResPMO occurs after initiation of viral gene transcription and involves dysfunction of a viral immediate-early regulatory protein, ICP0.

Indicator microorganisms and pathogens removal function performed by copepods in constructed wetlands

Removal efficiency of indicator and pathogenic microorganisms in constructed wetlands were analyzed, and microorganisms removal function performed by copepods was determined. The results showed that the constructed wetlands effectively reduced Escherichia coli, fecal streptococci, total coliforms, and fecal coliforms, the Salmonella spp. removal efficiency was relatively low and the Clostridium perfringens removal was the least. At copepods concentrations of 3.0 x 10(2)/L, and 6.0 x 10(2)/L, high die-off rates were observed for indicator and pathogenic microorganisms compared to the control group, and indicator and pathogenic microorganisms in samples with higher concentration of copepods decreased much more rapidly than those in samples with lower concentration. These results suggest that predation by copepods is an important mechanism for the removal of bacteria in constructed wetlands.

The soma and proximal dendrites of sympathetic preganglionic neurons innervating the major pelvic ganglion in female rats receive predominantly inhibitory inputs

Sympathetic preganglionic neurons (SPNs) in the intermediolateral (IML) and dorsal commissural nucleus (DCN) of the thoracolumbar segments of the spinal cord contribute to the autonomic control of the pelvic visceral organs. We examined the morphology of these neurons at the light and electron microscopic level and quantified the boutons apposing the soma and proximal dendrites of the SPNs innervating the major pelvic ganglion (MPG) in female rats. The majority of these cells resided in the DCN (61.6±6.2%) and IML (33.2±4.4%) nuclei. Measurements of cell volume and shape revealed no differences between SPNs sampled from the DCN and IML populations. Ultrastructural studies of DCN and IML SPNs revealed that coverage of SPNs by synaptic inputs is sparse, with an average of 11.60±2.41% of the soma membrane and 16.33±6.18% of proximal dendrites apposed by boutons, though some somata exhibited no synaptic coverage. Three distinct types of boutons were found to appose the SPN somata and dendrites. The putatively inhibitory F-type bouton covered a significantly greater percentage of membrane on the soma (8.48±2.12%) and dendrites (12.65±4.34%), than the S-type bouton, a putatively excitatory bouton, which only covered 2.94±0.70% of the somatic and 3.68±2.98% of the dendritic membranes. Boutons with dense-core vesicles were rare. Our results demonstrate that SPNs of the DCN and IML of female rats are similar morphologically, and that synaptic input on these cells, though sparse, is predominantly inhibitory.

Circular RNA circ-PRKCI promotes cell proliferation and invasion by binding to microRNA-545 in gastric cancer

OBJECTIVE

The carcinogenic effects of circular RNA circ-PRKCI have been recognized in a variety of malignancies. However, the exact biological function of circ-PRKCI in gastric cancer has not been fully elucidated. Therefore, the aim of this study was to explore the expression of circ-PRKCI in gastric cancer (GC) and to investigate its potential regulation mechanism in the pathogenesis and progression of GC.

PATIENTS AND METHODS

The expression of circ-PRKCI in 50 GC tissues and cell lines was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Statistical methods were used to analyze the relation between circ-PRKCI expression and overall survival rate of patients. The effect of circ-PRKCI on GC cell proliferation was examined by cell counting kit-8 (CCK-8) and cell colony formation assays. Meanwhile, the effect of circ-PRKCI on the invasion ability of GC cells was determined by transwell invasion assay. Flow cytometry was used to detect the apoptosis of GC cells. Bioinformatics was used to search for miRNAs that might have direct effects with circ-PRKCI. In addition, the binding of circ-PRKCI to microRNA-545 was validated using Dual-Luciferase reporter gene assay.

RESULTS

Circ-PRKCI was significantly highly expressed in GC tissues, as well as cell lines. High expression of circ-PRKCI was positively associated with a poor prognosis of GC patients. Overexpression of circ-PRKCI significantly promoted the proliferation and invasion of GC cells, whereas reduced the proportion of apoptotic GC cells. Subsequent Dual-Luciferase reporter gene assay revealed that circ-PRKCI could bind to microRNA-545 and inhibit its expression in GC cells. These results indicated that circ-PRKCI might promote the development of GC by adsorbing microRNA-545 in a sponge manner.

CONCLUSIONS

Circ-PRKCI can be used as a potential prognostic indicator of GC, providing a new perspective for the potential bio-molecular mechanism in GC.

Effects of triethylene glycol dimethacrylate and hydroxyethyl methacrylate on macrophage polarization

AIM

To evaluate the effects of hydrophilic dental resin monomers, triethylene glycol dimethacrylate (TEGDMA) and hydroxyethyl methacrylate (HEMA), on the polarization of a human monocyte cell line (THP-1).

METHODOLOGY

THP-1 cells were treated with resin monomers at noncytotoxic concentrations for 48 h and were analysed for CD86 and CD206 expressions using flow cytometry. The cells were stimulated for polarization in the presence of resin monomers (co-treatment) or after treatment with monomers (pre-treatment). CD86 and CD206 mRNA in co-treated cells was evaluated using quantitative real-time polymerase chain reaction. The release of TNF-α and TGF-β by pre-treated and co-treated cells was assessed using enzyme-linked immunosorbent assay. Morphological changes of macrophages during polarization were observed using bright-field microscopy. One-way analysis of variance was used for statistical analysis.

RESULTS

TEGDMA (1 mmol L^-1 ) and HEMA (2 mmol L^-1 ) did not induce CD86 and CD206 expressions in THP-1 cells but rather inhibited their expressions in the co-treated cells. The inhibitory effects also appeared at the transcription level. However, the expression of surface markers was not affected by pre-treatment with resin monomers. The release of TNF-α and TGF-β by M1- and M2-stimulated cells, respectively, was suppressed by co-treatment (P < 0.05). Microscopic studies revealed that co-treatment with resin monomers suppressed polarization-associated morphological changes such as cell volume increase.

CONCLUSIONS

TEGDMA and HEMA inhibited macrophage polarization to both M1 and M2 at the transcription level, and the inhibitory effects disappeared upon the removal of resin monomers from the cell culture.

Effects of magnanimous therapy on coping, adjustment, and living function in advanced lung cancer

Objectives

We examined the effects of magnanimous therapy on psychological coping, adjustment, living function, and survival rate in patients with advanced lung cancer.

Methods

Patients with advanced lung cancer (n = 145) matched by demographics and medical variables were randomly assigned to an individual computer magnanimous therapy group (ic-mt), a group computer magnanimous therapy group (gc-mt), or a control group (ctrl). Over 2 weeks, the ic-mt and gc-mt groups received eight 40-minute sessions of ic-mt or gc-mt respectively, plus usual care; the ctrl group received only usual care. The Cancer Coping Modes Questionnaire (ccmq), the Psychological Adjustment Scale for Cancer Patients (pascp), and the Functional Living Index-Cancer (flic) were assessed at baseline and 2 weeks later. The relationships of changes in those indicators were analyzed, and survival rates were compared.

Results

The psychological coping style, adjustment, and living function of the ic-mt and gc-mt groups improved significantly after the intervention (p < 0.01). After 2 weeks, significant (p < 0.01) differences between the treatment groups and the ctrl group in coping style, adjustment, and living function suggested successful therapy. The changes in living function were correlated with changes in psychological coping and adjustment. No difference in efficacy between ic-mt and gc-mt was observed. The survival rate was 31.84% in the ic-mt group and 9.375% in the ctrl group at 2 years after the intervention.

Conclusions

In patients with advanced lung cancer, ic-mt and gc-mt were associated with positive short-term effects on psychological coping style, adjustment, and living function, although the magnitude of the effect did not differ significantly between the intervention approaches. The effects on living function are partly mediated by improvements in psychological coping and adjustment.

An automated computer system to support ultra high throughput SNP genotyping

Celera Genomics has constructed an automated computer system to support ultra high-throughput SNP genotyping that satisfies the increasing demand that disease association studies are placing on current genotyping facilities. This system consists of the seamless integration of target SNP selection, automated oligo design, in silico assay quality validation, laboratory management of samples, reagents and plates, automated allele calling, optional manual review of autocalls, regular status reports, and linkage disequilibrium analysis. Celera has proven the system by generating over 2.5 million genotypes from more than 10,000 SNPs, and is approaching the target capacity of over 10,000 genotypes per machine per hour using limited human intervention with state of the art laboratory hardware.

Chronic hyperglycemia inhibits vasoregression in a transgenic model of retinal degeneration

Vasoregression characterizes diabetic retinopathy in animal models and in humans. We have recently demonstrated that vasoregression is earlier initiated in a rat model of ciliopathy-induced retinal neurodegeneration (TGR rat). The aim was to assess the balance between vasoregressive effects of chronic hyperglycemia and photoreceptor degeneration on adult vascular remodelling. The retinas were analyzed at 4 and 9 months after streptozotocin-induced diabetes. Neurodegeneration was determined by quantitation of cell numbers and retinal layer thickness. Vasoregression was assessed by quantitative retinal morphometry in retinal digest preparations. Retinal VEGF levels were measured by ELISA. Glial activation, expression and location of HSP27 and phosphorylated HSP27 were evaluated by immunofluorescence staining. Unexpectedly, the numbers of acellular capillaries were reduced at both time points and led to fewer intraretinal microvascular abnormalities in late stage diabetic TGR. Concomitantly, inner nuclear layers (INLs) in diabetic TGR rats were protected from cell loss at both time points. Consequently, glial activation was reduced, but VEGF level was increased in diabetic TGR retinas. Expressions of HSP27 were upregulated in glia cells in the preserved INL of diabetic TGR. Chronic hyperglycemia preserves the microvasculature in the retinal model of neurodegeneration. Cell preservation in the retinal INL was associated with protective gene regulation. Together, these data indicate that diabetes can induce vasoprotection, in which retinal glia can play a particular role.

Interleukin-1β Regulates Lipid Homeostasis in Human Glomerular Mesangial Cells

BACKGROUND

Recent studies have shown that hyperlipidemia is closely related to the progression of kidney disease and glomerulosclerosis has similar pathophysiological mechanisms with atherosclerosis. Atherosclerosis is essentially a chronic inflammatory process and various kidney diseases are characterized by a micro-inflammatory state. Hyperlipidemia levels are not parallel to the degree of glomerulosclerosis, inflammatory factors together with lipids may contribute to the pathogenesis of glomerulosclerosis. Therefore, it is key to clarify lipid-mediated renal injury through studying the mechanism by which inflammation affects cholesterol homeostasis at the cellular level. Intracellular lipid homeostasis involves both lipid uptake and excretion, therefore in this study, we aimed to explore whether interleukin-1β (IL-1β) promotes the uptake of oxidized low-density lipoprotein (Ox-LDL) to increase in intracellular lipid levels, and to clarify the effect of IL-1β on the expression of lectin-like oxidized LDL receptor 1 (LOX-1) and ATP-binding cassette transporter A1 (ABCA1), which may regulate cholesterol homeostasis in human mesangial cells (HMCs).

METHODS

The effect of IL-1β on uptake of Ox-LDL labeled with fluorescent Dil (Dil-Ox-LDL) by HMCs was observed using laser confocal microscopy. The effect of IL-1β on LOX-1 and ABCA1 expression in HMCs was detected by polymerase chain reaction and western blotting.

RESULTS

Laser confocal microscopy revealed that HMCs took up Dil-Ox-LDL. Treatment of HMCs with 5 ng/ml IL-1β for 24 h significantly increased uptake of Dil-Ox-LDL. IL-1β also promoted LOX-1 mRNA and protein expression in a dose-dependent manner. Moreover, ABCA1 mRNA and protein expression were reduced by IL-1β in lipid-loaded HMCs in a dose-dependent manner.

CONCLUSIONS

IL-1β promotes the uptake of Ox-LDL and expression of LOX-1 in HMCs, whereas it inhibits expression of ABCA1 under lipid load. The imbalance in intracellular cholesterol resulted by IL-1β can in turn transform HMCs into foam cells and aggravate glomerulosclerosis.

Preliminary evidence for genetic determination of intraerythrocytic sodium concentration in Utah pedigrees

Intraerythrocytic sodium concentration has been reported to be increased in hypertensive individuals and some of their normotensive relatives. We investigated the "familiality" of this trait in 572 nonhypertensive subjects from 34 Utah kindreds. Most of these kindreds were selected because of a high incidence of hypertension, heart attack, or stroke. Intraerythrocytic sodium concentration was correlated with the sex of the subject and suprailiac skinfold thickness. Intraerythrocytic sodium concentration was adjusted by linear regression for these 2 factors. The residual values were positively correlated in parent-offspring pairs and among sibs, both those presumed to be living together and those presumed to be living apart. The spouse-spouse correlation was not significant. Pedigree analysis suggested a mixed major-gene/polygenic model of inheritance, but these data did not allow us to distinguish between dominant and recessive inheritance for the major gene component. Total heritability due to both major-gene and polygenic components was estimated to be 90-95%; the proportion of the total variance due to polygenes was estimated to be 60-75%. These results suggest that further study of the relationship between the inheritance of intraerythrocytic sodium and the pathophysiology of hypertension is warranted.

[The significance of pedigree genetic screening and rapid immunological parameters in the diagnosis of primary hemophagocytic lymphohistiocytosis]

目的

探讨家系基因筛查及快速免疫学指标检测在原发性噬血细胞综合征（HLH）诊断中的意义。

方法

通过对伴有PRF1、UNC13D及SH2D1A基因突变的4例原发性HLH患者展开家系调查，分别完成基因筛查及各项免疫学指标检测（包括NK细胞活性、CD107a检测及HLH相关缺陷蛋白表达测定），评价各项检测指标在原发性HLH诊断中的意义并探讨各项指标间的相关性。

结果

4个家系基因突变分别为PRF1基因错义突变c.T172C（p.S58P）和非框架移码突变c.1083_1094del (p.361_365del）；PRF1基因错义突变c.C1349T（p.T450M）和框架移码突变c.1090_1091delCT (p.T364fsX93）；UNC13D基因错义突变c.G2588A（p.G863D）；SH2D1A基因半合子错义突变c.32T>G (p.I11S）。先证者及家系成员分别存在不同程度的NK细胞活性降低，其中PRF1基因及SH2D1A基因突变家系HLH相关基因编码穿孔素蛋白、信号淋巴细胞活化分子相关蛋白（SAP）表达水平下降，UNC13D基因突变先证者及与其存在完全相同突变位点的家系成员细胞毒脱颗粒功能（CD107a表达）显著减低。

结论

开展家系基因筛查及快速免疫学指标检测对诊断原发性HLH具有重要意义，两者具有较好的一致性，其中快速免疫学指标检测作为一种高效的检测手段，可为原发性HLH的早期诊断提供可靠依据。

Antimicrobial susceptibility, multilocus sequence typing, and virulence of listeria isolated from a slaughterhouse in Jiangsu, China

Background

Listeria monocytogenes is one of the deadliest foodborne pathogens. The bacterium can tolerate severe environments through biofilm formation and antimicrobial resistance. This study aimed to investigate the antimicrobial susceptibility, resistance genes, virulence, and molecular epidemiology about Listeria from meat processing environments.

Methods

This study evaluated the antibiotic resistance and virulence of Listeria isolates from slaughtering and processing plants. All isolates were subjected to antimicrobial susceptibility testing using a standard microbroth dilution method. The harboring of resistant genes was identified by polymerase chain reaction. The multilocus sequence typing was used to determine the subtyping of the isolates and characterize possible routes of contamination from meat processing environments. The virulence of different STs of L. monocytogenes isolates was evaluated using a Caco-2 cell invasion assay.

Results

A total of 59 Listeria isolates were identified from 320 samples, including 37 L. monocytogenes isolates (62.71%). This study evaluated the virulence of L. monocytogenes and the antibiotic resistance of Listeria isolates from slaughtering and processing plants. The susceptibility of these 59 isolates against 8 antibiotics was analyzed, and the resistance levels to ceftazidime, ciprofloxacin, and lincomycin were as high as 98.31% (L. m 37; L. innocua 7; L. welshimeri 14), 96.61% (L. m 36; L. innocua 7; L. welshimeri 14), and 93.22% (L. m 35; L. innocua 7; L. welshimeri 13), respectively. More than 90% of the isolates were resistant to three to six antibiotics, indicating that Listeria isolated from meat processing environments had high antimicrobial resistance. Up to 60% of the isolates harbored the tetracycline-resistance genes tetA and tetM. The frequency of ermA, ermB, ermC, and aac(6′)-Ib was 16.95, 13.56, 15.25, and 6.78%, respectively. Notably, the resistant phenotype and genotype did not match exactly, suggesting that the mechanisms of antibiotic resistance of these isolates were likely related to the processing environment. Multilocus sequence typing (MLST) revealed that 59 Listeria isolates were grouped into 10 sequence types (STs). The dominant L. monocytogenes STs were ST5, ST9, and ST121 in the slaughtering and processing plant of Jiangsu province. Moreover, ST5 subtypes exhibited high invasion in Caco-2 cells compared with ST9 and ST121 cells.

Conclusion

The dominant L. monocytogenes ST5 persisted in the slaughtering and processing plant and had high antimicrobial resistance and invasion characteristics, illustrating a potential risk in food safety and human health.

Sequence and spatial requirements for the tissue- and species-independent 3'-end processing mechanism of plant mRNA

Two cis-regulatory regions are required for efficient mRNA 3'-end processing of the maize 27-kDa zein mRNA: a region containing a duplicated AAUGAA poly(A) signal and a region that is present upstream from it. Strict spatial positioning of these two regions is required for efficient mRNA 3'-end processing. Insertion of a stuffer sequence as short as 17 or 18 bp either between the upstream region and the two AAUGAA motifs or between the two AAUGAA motifs drastically reduced the efficiency of 3'-end processing. Mutational analyses of the nucleotide preference at the fourth position of the AAUGAA motif revealed the preference order G > A >> C or U, suggesting that AAUAAA is neither a defective nor an optimal poly(A) signal for the 27-kDa zein mRNA. As for the 3' control region of the cauliflower mosaic virus (CaMV) transcription unit, the mRNA 3'-end processing mechanism mediated by the 27-kDa zein 3' control sequence is neither tissue nor species specific. The 3' upstream sequence of the 27-kDa zein gene can functionally replace that of the CaMV transcription unit. Conversely, the CaMV upstream sequence can mediate mRNA polyadenylation in the presence of a duplicated 27-kDa zein poly(A) signal. However, instead of the proximal poly(A) signal normally used in the 27-kDa zein mRNA, the distal signal is utilized. These results suggest that a general mechanism controls the 3'-end processing of plant mRNAs and that the cis-regulatory functions mediated by their upstream regions are interchangeable.

Effect of RRS1 gene knockdown on BT549 cell line proliferation and apoptosis in breast cancer

The RRS1 regulator of ribosome synthesis has recently been reported a new target gene linked to cancer development. This study therefore investigates RRS1effectsb on BT549 cell proliferation and apoptosis in breast cancer. Western blot (WB) and real - time quantitative PCR (qPCR) were used to detect the relative expression of RRS1 in breast cancer cells BT-549 and the normal HMEC mammary gland epithelial cells. BT-549 cells were cultured and infected with retroviruses and RRS1 expression was detected by qPCR and WB. The MTT assay, Caspase-3/7 and flow cytometry (FCM) then detected growth and apoptosis in the BT549 breast cancer BT cell. WB detected the expression of Bcl-2 and Bax genes related to apoptosis at the protein level, and MTT assay confirmed that RRS1 knockdown significantly decreased cell viability (p<0.05) and induced apoptosis which was rescued by shRNA-RRS1 expression. The amount of caspase-3 increased significantly and apoptosis was obvious. The apoptotic cells amount analyzed by FCM was significantly increased and RRS1 knockdown also decreased the expression of apoptosis related protein bcl-2 and simultaneously increased the expression of Bax (p<0.05). Finally, the RRS1 gene was highly expressed in breast cancer cell line BT549 and its knockdown significantly reduced proliferation and apoptosis in BT549 cell. These results suggest that RRS1 is a novel gene related to breast cancer and has an important role in breast cancer proliferation and apoptosis.