Association of nuclear annexin A1 with prognosis of patients with esophageal squamous cell carcinoma

Although recent progress has been made in the diagnosis and treatment of cancer, the prognosis of esophageal squamous cell carcinoma (ESCC) remains poor. The identification of biomarkers for ESCC prognosis is important for treatment decisions. The aim of this study was to evaluate the relationship between the expressions of Annexin A1 (ANXA1), three prime repair exonuclease 1 (TREX1) and apurinic/apyrimidinic endonuclease-1 (APE1) and clinical outcome of patients with ESCC. The expressions of ANXA1, TREX1 and APE1 in 93 pairs of ESCC and paracancerous tissues were tested using immunohistochemistry. ANX1, TREX1 and APE1 were dysregulated in ESCC. Nuclear expressions of ANXA1 and APE1 were significantly associated with pathologic type (P = 0.004 and 0.040, respectively). Patients with low expression of nuclear ANXA1 had a better prognosis than those with high expression of nuclear ANXA1 (HR = 0. 448, 95% CI 0.236-0.849, P = 0.014), especially for those with histologic grade 1 and 2 (HR = 0.303, 95% CI: 0.155-0.593, P < 0.001). In conclusion, nuclear ANXA1 may be potentially used as a prognostic biomarker for ESCC.     

Microgravity inhibition of lipopolysaccharide-induced tumor necrosis factor-α expression in macrophage cells

Objective and design

Microgravity environments in space can cause major abnormalities in human physiology, including decreased immunity. The underlying mechanisms of microgravity-induced inflammatory defects in macrophages are unclear.

Material or subjects

RAW264.7 cells and primary mouse macrophages were used in the present study. Lipopolysaccharide (LPS)-induced cytokine expression in mouse macrophages was detected under either simulated microgravity or 1g control.

Methods

Freshly isolated primary mouse macrophages and RAW264.7 cells were cultured in a standard simulated microgravity situation using a rotary cell culture system (RCCS-1) and 1g control conditions. The cytokine expression was determined by real-time PCR and ELISA assays. Western blots were used to investigate the related intracellular signals.

Results

LPS-induced tumor necrosis factor-α (TNF-α) expression, but not interleukin-1β expression, in mouse macrophages was significantly suppressed under simulated microgravity. The molecular mechanism studies showed that LPS-induced intracellular signal transduction including phosphorylation of IKK and JNK and nuclear translocation of NF-κB in macrophages was identical under normal gravity and simulated microgravity. Furthermore, TNF-α mRNA stability did not decrease under simulated microgravity. Finally, we found that heat shock factor-1 (HSF1), a known repressor of TNF-α promoter, was markedly activated under simulated microgravity.

Conclusions

Short-term treatment with microgravity caused significantly decreased TNF-α production. Microgravity-activated HSF1 may contribute to the decreased TNF-α expression in macrophages directly caused by microgravity, while the LPS-induced NF-κB pathway is resistant to microgravity.     

Leukotrienes in pulmonary arterial hypertension

Leukotrienes (LTs) are lipid mediators derived from the 5-lipoxygenase (5-LO) pathway of arachidonic acid metabolism and are markers and mediators of pulmonary inflammation. Research over the past two decades has established that LTs modulate inflammation in pulmonary arterial hypertension (PAH). The purpose of this review was to summarize the current knowledge of LTs in the pathophysiology of PAH and to highlight a recent study that advances our understanding of how leukotriene B₄ (LTB₄) specifically contributes to pulmonary vascular remodeling. The results of these studies suggest that pharmacological inhibition of LT pathways, especially LTB₄, has high potential for the treatment of PAH.     

二甲双胍对人肝癌细胞Bel-7402增殖与凋亡的影响

目的:研究二甲双胍抑制人肝癌细胞Bel-7402增殖及调亡的影响,并初步探讨其机制。方法:体外培养人肝癌细胞株Bel-7402,以不同浓度的二甲双胍(10mM、20mM、40mM)干预细胞48h。采用MTT法检测药物对细胞增殖的影响;采用Hoechst 33258荧光染色法和流式细胞术检测细胞凋亡;Real-time PCR检测caspase-3、bax和bcl-2的mRNA水平表达。结果:与对照组相比,不同浓度的二甲双胍作用于Bel-7402细胞48h后,MTT结果显示对细胞增殖有明显抑制作用(P0.05);Hoechst 33258荧光染色法显示凋亡细胞明显增多;流式细胞术分析显示二甲双胍可明显诱导Bel-7402细胞凋亡,晚期凋亡率分别为3.76%,8.96%和18.67%;caspase-3、bax和bcl-2的mRNA表达水平均上调(P0.05);以上结果均具有浓度依赖性。结论:二甲双胍能抑制Bel-7402细胞增殖并诱导其凋亡,其机制可能与caspase-3、bax和bcl-2的mRNA表达水平改变有关。     

Antimycobacterial activity of Pichia pastoris-derived mature bovine neutrophil β-defensins 5

Tuberculosis (TB) is an ongoing threat to global health, and the lack of effective therapies for treating it is also a global problem. Previous studies have shown that human cathelicidin and defensins have effective antimicrobial activity against Mycobacterium spp. To our knowledge, there are no reports on the antimycobacterial effects of bovine neutrophil β-defensins so far. Here, we identified the antimicrobial effect of mature bovine neutrophil β-defensins (mBNBD) 5 against Mycobacterium infection both in vitro and in vivo. The mBNBD5 protein was expressed in Pichia pastoris. To increase the yield of β-defensins, a purification method was employed by adding a 6-His·tag to the C-terminus of the mBNBD5 gene. Our results indicated that recombinant mBNBD5 protein was successfully expressed and purified from Pichia pastoris with intact antimicrobial activity. The recombinant protein exhibited potent bactericidal activity in vitro against M. smegmatis and M. bovis, with a dose-dependent manner and a time-dependent manner. The electron microscope results showed that the bacterial cell wall of M. bovis was disrupted when incubated with mBNBD5 for 72 h. Our data also indicated that the exogenous addition of mBNBD5 could reduce the survival of Mycobacterium spp., especially M. tuberculosis and M. bovis in RAW 264.7 macrophages. These results provide foundations for the development of mBNBD5 as a potential new therapeutic agent for TB treatment.     

Clinicopathological characteristics of four cases of EBV positive T-cell lymphoproliferative disorders of childhood in China

A new category, “EBV positive T-cell lymphoproliferative disorders (LPD) of childhood”, was proposed in the 2008 World Health Organization’s (WHO) classifications of lymphoma. This series of lymphoproliferative disorders is rare. There are two major types of this series of disorders: systemic EBV positive T-cell LPD of childhood and hydroa vacciniforme-like lymphoma (HVLL). In this study, we describe the distinct features of four cases of EBV positive T-cell LPD of childhood in China. Two were systemic EBV positive T-cell LPD of childhood, one was HVLL and one was chronic active EBV (CAEBV). The main manifestations were lymphadenopathy, fever, hepatosplenomegaly and skin rashes. The structure of the lymph nodes in the patients ranged from preserved to partially or totally destroyed. Small- to medium-sized, atypical T cells had infiltrated the lymph nodes. In HVLL, the neoplastic cells had infiltrated the dermis and subcutaneous region surrounding sweat glands and nerves. All of the cases tested positive for CD8, other T cells, cytotoxic markers and EBV-encoded RNA (EBER) without CD56 expression. Molecular analysis was performed in three cases. All of the three analyses showed a TCRγ rearrangement and one case also had an IGH rearrangement. One of the patients with systemic EBV positive T-cell LPD of childhood experienced rapid evolved and died within five months of onset. CAEBV, systemic EBV-positive T-cell LPD of childhood and HVLL are distinct but overlapping diseases within the category of EBV-positive T-cell LPD of childhood. They constitute a continuous spectrum of EBV-infected associated disorders.     

Influence of anchoring ligands and particle size on the colloidal stability and in vivo biodistribution of polyethylene glycol-coated gold nanoparticles in tumor-xenografted mice

Polyethylene glycol (PEG)-coated (pegylated) gold nanoparticles (AuNPs) have been proposed as drug carriers and diagnostic contrast agents. However, the impact of particle characteristics on the biodistribution and pharmacokinetics of pegylated AuNPs is not clear. We investigated the effects of PEG molecular weight, type of anchoring ligand, and particle size on the assembly properties and colloidal stability of PEG-coated AuNPs. The pharmacokinetics and biodistribution of the most stable PEG-coated AuNPs in nude mice bearing subcutaneous A431 squamous tumors were further studied using ¹¹¹In-labeled AuNPs. AuNPs coated with thioctic acid (TA)-anchored PEG exhibited higher colloidal stability in phosphate-buffered saline in the presence of dithiothreitol than did AuNPs coated with monothiol-anchored PEG. AuNPs coated with high-molecular-weight (5000 Da) PEG were more stable than AuNPs coated with low-molecular-weight (2000 Da) PEG. Of the 20-nm, 40-nm, and 80-nm AuNPs coated with TA-terminated PEG₅₀₀₀, the 20-nm AuNPs exhibited the lowest uptake by reticuloendothelial cells and the slowest clearance from the body. Moreover, the 20-nm AuNPs coated with TA-terminated PEG₅₀₀₀ showed significantly higher tumor uptake and extravasation from the tumor blood vessels than did the 40- and 80-nm AuNPs. Thus, 20-nm AuNPs coated with TA-terminated PEG₅₀₀₀ are promising potential drug delivery vehicles and diagnostic imaging agents.