High performance liquid chromatography with ultraviolet detection for the determination of SYUIQ-5, a novel telomerase inhibitor for cancer therapy: application to an enzyme kinetic study in rat liver microsomes

A sensitive assay for the determination of SYUIQ-5, a novel telomerase inhibitor and anti-tumor drug, in rat liver microsomes was developed by using high-performance liquid chromatography with ultraviolet detection. SYUIQ-5 was incubated in vitro with liver microsomes from rats pre-treated with control vehicle, beta-naphthofIavone, phenobarbital, 20% ethanol or dexamethasone. The analytes were extracted with diethyl ether and separated a C(18) 5-microm analytical column. Elution was conducted with 30 mM dipotassium hydrogen phosphate (pH 8.0)-methanol-triethylamine (30:70:0.05, v/v/v) at a flow-rate of 1.0 ml/min and the detection of UV absorbance was conducted at 278 nm. Intra-day and inter-day precision and accuracy of the method were within 10%. The mean analytical recoveries of SYUIQ-5 ranged from 78.8 to 95.3%. The linearity of the calibration curve was in the range of 1.0-80.0 microM. The lower limit of quantification (LOQ) was 1.0 microM. Kinetic analysis showed that beta-naphthofIavone and dexamethasone significantly induced SYUIQ-5 metabolism, suggesting that cytochrome P450 1A and 3A are the major contributor to SYUIQ-5 metabolism in rat liver microsomes.     

VEGF(165), but not VEGF(189), stimulates vasculogenesis and bone marrow cell migration into Ewing's sarcoma tumors in vivo

We previously showed that bone marrow stem cells participate in the tumor vessel expansion that supports the growth of Ewing's sarcoma tumors in vivo. The purpose of this study was to determine the relative importance of two isoforms of vascular endothelial growth factor (VEGF) in tumor vessel expansion and recruitment of bone marrow-derived cells during tumor growth. We injected VEGF(165)-siRNA-transfected cells (TCsi/7-1), control siRNA-transfected cells (TC/si-control), or TC71 parental Ewing's sarcoma cells into nude mice. The TCsi/7-1 tumors were then treated with adenoviral vectors expressing VEGF(165) (Ad-VEGF(165)), VEGF(189) (Ad-VEGF(189)), or beta-galactosidase (Ad-beta-gal). Bone marrow cells labeled with fluorescent tracker dye were injected into the mice 3 weeks later. The TCsi/7-1 tumors were significantly smaller (P < 0.05), had decreased vessel density, and showed significantly lower bone marrow cell migration than did TC71 parental and TC/si-control tumors. Treatment with Ad-VEGF(165), but not Ad-VEGF(189) or Ad-beta-gal, resulted in a significant increase in bone marrow cell infiltration, tumor vessel density, and tumor growth. Immunohistochemical staining revealed that the injected bone marrow cells migrated to and incorporated into the expanding CD31(+) tumor vessel network. Taken together, these data show that VEGF(165) is a chemoattractant that recruits bone marrow cells into the tumor area. These data provide a mechanism by which Ewing's sarcoma cells induce vasculogenesis.     

Fas-negative osteosarcoma tumor cells are selected during metastasis to the lungs: the role of the Fas pathway in the metastatic process of osteosarcoma

Low expression of Fas by different tumors including osteosarcoma, correlates with poor prognosis. We found that osteosarcoma lung metastases from patients expressed negligible amounts of Fas, but primary tumors often expressed high Fas levels. The reason for this discrepancy is unknown. We hypothesized that because FasL is constitutively expressed in the lungs, Fas-positive (Fas(+)) tumor cells entering the lungs would bind with FasL and die from Fas-induced apoptosis, resulting in the "selection" of Fas-negative (Fas(-)) cells, which would eventually form metastases. To test this hypothesis, we injected K7 osteosarcoma cells, which express functional Fas in vitro, into mice and confirmed that its bone tumors were Fas(+), but lung metastases were Fas(-). Next, to inhibit Fas signaling without affecting Fas expression, we transfected these cells with a FADD-dominant negative (FDN) plasmid and developed K7/FDN cells. Metastases formed by K7/FDN cells contained Fas(+) tumor cells. Moreover, K7/FDN cells were retained in the lungs longer and formed more lung metastases than K7 cells. In addition, the incidence of lung metastases in FasL-deficient mice injected with K7 cells was higher than that in wild-type mice. Metastases from FasL-deficient mice but not from wild-type mice contained Fas(+) tumor cells. Based on that, we conclude that Fas(-) osteosarcoma cells are selected during lung metastases formation and that inhibition of Fas signaling in tumors or lack of FasL in the host environment allows the proliferation of Fas(+) osteosarcoma cells in the lungs and promotes metastases growth. Therefore, Fas may be considered as a new therapeutic target for osteosarcoma treatment.     

中国生物多样性核心监测指标遥感产品体系构建与思考

生物多样性的稳定维持关乎人类生存发展与地球健康。生物多样性核心监测指标(Essential Biodiversity Variables, EBVs)旨在结合地面调查与遥感技术, 为大尺度、长时间序列的生物多样性监测提供新的解决方案。然而, 目前学界仍然缺乏一套国家尺度标准化EBVs遥感监测产品数据集, 以进行生物多样性评估。本研究旨在对中国生物多样性核心监测指标遥感产品进行体系构建与思考, 首先综述了目前EBVs的遥感研究概况, 并根据EBVs研究文献的数量进行调研分析; 同时, 本文在已有遥感生物多样性产品优先标准的基础上, 添加了“可重复性”的新标准, 并据此构建了中国EBVs遥感产品体系与监测数据集的指标清单, 最终对中国EBVs遥感研究存在的问题进行思考与讨论。本研究可为中国的生物多样性遥感监测提供科学依据, 有望为中国生物多样性政策的制定提供支撑。     

A study on the protective effects of CpG oligodeoxynucleotide-induced mucosal immunity against lung injury in a mouse acute respiratory distress syndrome model

This study aims to determine the feasibility of using oligodeoxynucleotides with unmethylated cytosine-guanine dinucleotide sequences (CpG ODN) as an immunity protection strategy for a mouse model of acute respiratory distress syndrome (ARDS). This is a prospective laboratory animal investigation. Twenty-week-old BALB/c mice in Animal research laboratory were randomized into groups. An ARDS model was induced in mice using lipopolysaccharides (LPSs). CpG ODN was intranasally and transrectally immunized before or after the 3rd and 7th days of establishing the ARDS model. Mice were euthanized on Day 7 after the second immunization. Then, retroorbital bleeding was carried out and the chest was rapidly opened to collect the trachea and tissues from both lungs for testing. CpG ODN significantly improved the pathologic impairment in mice lung, especially after the intranasal administration of 50 μg. This resulted in the least severe lung tissue injury. Furthermore, interleukin-6 (IL-6) and IL-8 concentrations were lower, which was second to mice treated with the rectal administration of 20 µg CpG ODN. In contrast, the nasal and rectal administration of CpG ODN in BALB/c mice before LPS immunization did not appear to exhibit any significant protective effects. The intranasal administration of CpG ODN may be a potential treatment approach to ARDS. More studies are needed to further determine the protective mechanism of CpG ODN.     

Retracted: Prelamin A overexpression promotes detrusor calcification/aging in urinary incontinence via prelamin A accumulation

Urinary incontinence (UI) is known as a distressing condition particularly among older adults, and negatively associated with health-related quality of life in both males and females. Prelamin A accumulation has been found in all progeroid laminopathies and is obviously linked to cell and organism aging. Therefore, this study was expected to investigate the effect of prelamin A on detrusor on UI. Prelamin A expression in clinical and animal samples was detected. To investigate the degree of prelamin A accumulation and detrusor calcification/aging, the detrusor cells were subcultured separately into low and high passage. The low-passage subculture cells were treated with transfection of overexpressed prelamin A plasmid, and transfection of overexpressed prelamin A plasmid and application of farnesyl transferase inhibitor (FTIs) H-9279, respectively. Zmpste24, Icmt and lamin A/C expression were detected to explore how prelamin A affected detrusor calcification/aging. Prelamin A was overexpressed in aged detrusor cells, indicating prelamin A expression was positively related to the age of subjects. The degree of prelamin A accumulation and detrusor calcification/aging was higher in aged rats and high passage subculture cells. Zmpste24, Icmt and lamin A/C were poorly expressed in cells transfected with overexpressed prelamin A, as well as cell proliferation activity decreased and calcium deposition and apoptotic rate increased. Furthermore, we also found that the effect of overexpressed prelamin A was lost when cells were treated with H-9279. These findings provide evidence that prelamin A overexpression impairs degradation of its farnesylated form, thus causing prelamin A accumulation which induces detrusor calcification/aging in UI.     

Augmentation of miR-202 in varicose veins modulates phenotypic transition of vascular smooth muscle cells by targeting proliferator–activated receptor-γ coactivator-1α

In varicose veins, vascular smooth muscle cells (VSMCs) often show abnormal proliferative and migratory rates and phenotypic transition. This study aimed to investigate whether microRNA (miR)-202 and its potential target, peroxisome proliferator–activated receptor-γ coactivator-1α (PGC-1α), were involved in VSMC phenotypic transition. miR-202 expression was analyzed in varicose veins and in VSMCs conditioned with platelet-derived growth factor. The effect of miR-202 on cell proliferation and migration was assessed. Furthermore, contractile marker SM-22α, synthetic markers vimentin and collagen I, and PGC-1α were analyzed by Western blot analysis. The modulation of PGC-1α expression by miR-202 was also evaluated. In varicose veins and proliferative VSMCs, miR-202 expression was upregulated, with decreased SM-22α expression and increased vimentin and collagen I expression. Transfection with a miR-202 mimic induced VSMC proliferation and migration, whereas a miR-202 inhibitor reduced cell proliferation and migration. miR-202 mimic constrained luciferase activity in HEK293 cells that were cotransfected with the PGC-1α 3′-untranslated region (3′-UTR) but not those with mutated 3′-UTR. miR-202 suppressed PGC-1α protein expression, with no influence on its messenger RNA expression. PGC-1α mediated VSMC phenotypic transition and was correlated with reactive oxygen species production. In conclusion, miR-202 affects VSMC phenotypic transition by targeting PGC-1α expression, providing a novel target for varicose vein therapy.     

Design,synthesis and biological evaluation of 1-Aryl-5-(4-arylpiperazine-1-carbonyl)-1H-tetrazols as novel microtubule destabilizers

A series of 1-aryl-5-(4-arylpiperazine-1-carbonyl)-1H-tetrazols as microtubule destabilizers were designed, synthesised and evaluated for anticancer activity. Based on bioisosterism, we introduced the tetrazole moiety containing the hydrogen-bond acceptors as B-ring of XRP44X analogues. The key intermediates ethyl 1-aryl-1H-tetrazole-5-carboxylates 10 can be simply and efficiently prepared via a microwave-assisted continuous operation process. Among the compounds synthesised, compound 6–31 showed noteworthy potency against SGC-7901, A549 and HeLa cell lines. In mechanism studies, compound 6–31 inhibited tubulin polymerisation and disorganised microtubule in SGC-7901 cells by binding to tubulin. Moreover, compound 6–31 arrested SGC-7901cells in G2/M phase. This study provided a new perspective for development of antitumor agents that target tubulin.