Indole-3-carbinol synergistically sensitises ovarian cancer cells to bortezomib treatment

BACKGROUND

Bortezomib is a proteasome inhibitor with minimal clinical activity as a monotherapy in solid tumours, but its combination with other targeted therapies is being actively investigated as a way to increase its anticarcinogenic properties. Here, we evaluate the therapeutic potential of co-treatment with bortezomib and indole-3-carbinol (I3C), a natural compound found in cruciferous vegetables, in human ovarian cancer.

METHODS

We examined the effects of I3C, bortezomib and cisplatin in several human ovarian cancer cell lines. Synergy was determined using proliferation assays and isobologram analysis. Cell cycle and apoptotic effects were assessed by flow cytometry. The mechanism of I3C and bortezomib action was determined by RNA microarray studies, quantitative RT-PCR and western blotting. Antitumour activity of I3C and bortezomib was evaluated using an OVCAR5 xenograft mouse model.

RESULTS

I3C sensitised ovarian cancer cell lines to bortezomib treatment through potent synergistic mechanisms. Combination treatment with bortezomib and I3C led to profound cell cycle arrest and apoptosis as well as disruptions to multiple pathways, including those regulating endoplasmic reticulum stress, cytoskeleton, chemoresistance and carcinogen metabolism. Moreover, I3C and bortezomib co-treatment sensitised ovarian cancer cells to the standard chemotherapeutic agents, cisplatin and carboplatin. Importantly, in vivo studies demonstrated that co-treatment with I3C and bortezomib significantly inhibited tumour growth and reduced tumour weight compared with either drug alone.

CONCLUSION

Together, these data provide a novel rationale for the clinical application of I3C and bortezomib in the treatment of ovarian cancer.

A U-shaped relationship between ankle-brachial index and carotid intima-media thickness in a Chinese population of Inner Mongolia

AIM

The study was designed to investigate the relationship between ankle-brachial index (ABI) and carotid intima-media thickness (IMT), and provide scientific basis for primary and secondary prevention of atherosclerotic diseases.

METHODS

Participants were recruited for this investigation from Inner Mongolia in China through cluster multistage and random sampling. ABI and carotid-IMT were measured for each subject. Periphery arterial disease (PAD) was defined as an ABI≤0.9 in either leg. ABI values were divided into eight groups at every 0.05, and three carotid-IMT measures were compared among groups separately using analysis of variance (ANOVA) and multivariate linear regression analyses.

RESULTS

The results indicated that the prevalence of PAD among 1236 participants was 1.9%. The average common carotid IMT was 0.70±0.21 mm, internal carotid IMT 0.77±0.24 mm, and carotid artery bifurcation IMT 0.78±0.25 mm. A U-shaped relationship was observed that the values of common carotid, carotid artery bifurcation, and internal carotid arteries IMT were decreased at first then increased as ABI values increased. The U-shaped relationship between ABI and three carotid-IMT measures were remained after adjusting for covariates.

CONCLUSION

The data suggests that carotid IMT values are correlated with ABI values in a U-shaped curve. Increased carotid IMT is correlated with the high prevalence of PAD in population of Inner Mongolia in China.

Genetic diversity analyses of class 1 integrons and their associated antimicrobial resistance genes in Enterobacteriaceae strains recovered from aquatic habitats in China

AIMS

To characterize the molecular diversity of class 1 integrons and antibiotic resistance (AR) genes of Enterobacteriaceae strains recovered from aquatic habitats in Jinan, Shandong Province, China.

METHODS AND RESULTS

Six hundred and thirty-eight antimicrobial-resistant Enterobacteriaceae isolated from wastewater were examined for class 1 integron. Of these, 293 were positive for the class 1 integrase gene intI1; among these, 34 gene cassettes and 29 AR genes were detected. Twenty-nine distinct gene cassette arrays were identified by restriction fragment length polymorphism (RFLP). Seven strains harboring novel gene cassette arrays were subjected to further study, in which antimicrobial susceptibility profiles were determined, and the presence of other AR genes outside of the integrons was assayed. Several of the resistance determinants were found to be transferable by conjugation or transformation.

CONCLUSIONS

This study established the assessment of class 1 integron and antimicrobial resistance gene patterns among environmental Enterobacteriaceae. Also, a restriction enzyme EcoRII was employed to develop a rapid and simple method for characterizing gene cassette arrays by RFLP analysis, which facilitated further study of novel gene cassette arrays.

SIGNIFICANCE AND IMPACT OF STUDY

These data not only illustrated the diversity of class 1 integron gene cassettes but also provided direct evidence that integrons mobilized gene cassettes, generating new linkages of resistance genes, and they could be integrated in gene transfer units such as conjugative plasmids to contribute to the dissemination of AR genes by horizontal gene transfer (HGT) in aquatic environments.

The expression of histone demethylase JMJD1A in renal cell carcinoma

BACKGROUND

Hypoxia-inducible factor 1α has been shown to play a central role in RCC tumorigenesis by acting as a transcription factor. Histone demethylase JMJD1A is an iron- and 2-oxoglutarate-dependent dioxygenase which catalyze the demethylation of mono- and dimethylated H3K9. JMJD1A can be upregulated by hypoxia via HIF-1 and associated with cancer. The expression of JMJD1A was determined in 10 kidney cancer tissue and adjacent tissue by quantitative polymerase chain reaction, western blotting and immunohistochemistry. Furthermore, the expression of JMJD1A was investigated in cell line 786-0 through adding nickle or cobalt ion to mimic hypoxic environment. The expression of JMJD1A was higher in cancer tissue than adjacent tissue, and in hypoxic environment than normal environment. In cancer tissue, the JMJD1A mainly located around blood vessels which indicated that JMJD1A is involved tumor angiogenesis.

CONCLUSION

the increased expression of JMJD1A might be associated with the progression of kidney cancer.

KEYWORDS

renal cell carcinoma, histone demethylase, JMJD1A, hypoxia-inducible factor, iron.

Molecular cloning and characterization of a thioredoxin peroxidase gene from Apis cerana cerana

Thioredoxin peroxidases (Tpxs) play important roles in protecting organisms against the toxicity of reactive oxygen species (ROS) and regulating intracellular signal transduction. In the present study, we cloned the full cDNA of Tpx1 encoding a 195-amino acid protein from Apis cerana cerana (Acc). Based on the genomic DNA sequence, a 1442-bp 5'-flanking region was obtained, and the putative transcription factor binding sites were predicted. Quantitative PCR analysis showed that AccTpx1 was highly expressed in thorax and that the AccTpx1 transcript reached its highest level in two-week-old adult worker honeybees. Moreover, expression of the AccTpx1 transcript was increased by various abiotic stresses, such as ultraviolet light, HgCl(2) , and insecticide treatments. In addition, the recombinant AccTpx1 protein exhibited antioxidant activity; it removed hydrogen peroxide and protected DNA. These results suggest that AccTpx1 plays an important role in protecting honeybees from oxidative injury and may act in extending the lifespan of them.

A population-based study on the influence of brain atrophy on 20-year survival after age 85

BACKGROUND

Individuals aged 80 years and older is the fastest growing segment of the population worldwide. To understand the biology behind increasing longevity, it is important to examine factors related to survival in this age group. The relationship between brain atrophy and survival after age 85 remains unclear.

METHODS

A population-based sample (n = 239) had head CT scans at age 85 and was then followed until death. Cortical atrophy and ventricular size were assessed. Statistical analyses included Cox proportional hazards models with time to death as the outcome and considering a large number of possible confounders, including baseline cognitive function, incident dementia, and somatic disorders.

RESULTS

Mean survival time (±SD) was 5.0 ± 3.6 years (range 0.10-19.8 years). Decreased survival was associated with temporal, and frontal atrophy, sylvian fissure width and a number of ventricular measures after adjustment for potential confounders. In participants without dementia at baseline (n = 135), decreased survival was associated with temporal lobe atrophy and bifrontal ratio. In those with dementia (n = 104), decreased survival was associated with third ventricle width, cella media ratio, and ventricle-to-brain and ventricle-to-cranial ratio.

CONCLUSIONS

Several indices of brain atrophy were related to decreased survival after age 85, regardless of dementia status. Brain atrophy is rarely mentioned as a significant indicator of survival in the elderly, independent of traditional predictors such as cardiovascular disease or cancer. The biology behind the influence of brain atrophy on survival needs to be further scrutinized.

Pharmacokinetics of dexmedetomidine in Chinese post-surgical intensive care unit patients

BACKGROUND

Dexmedetomidine is a rather new drug in China. We sought to describe the pharmacokinetics of dexmedetomidine in patients requiring post-operative sedation and ventilation in our surgical intensive care unit.

METHODS

Twenty-two patients received post-operative infusions of dexmedetomidine at 6 μg/kg/h for 10 min, followed by 0.4 μg/kg/h for 350 min. Venous blood samples were drawn and assayed for plasma concentration. The pharmacokinetics were analysed using a nonlinear mixed-effect model with an interindividual and intraindividual error model. An initial estimation was performed to determine which of the one-, two- or three-compartment models is best to describe the concentration-time data. The covariates age, gender, weight, height, lean body mass (LBM), body surface area (BSA) and body mass index (BMI) were tested for significant effects on parameters using a stepwise forward addition and backward elimination approach. Covariate effects were judged based on changes in the objective function value (OFV).

RESULTS

The pharmacokinetics of dexmedetomidine were best described by a three-compartment model. The model was further improved when height was a covariate of systemic clearance (Cl1), with a decrease in OFV by -13.56 (P<0.01). From the heights of 155-178 cm, Cl1 increased by approximately 143%. The final pharmacokinetic parameter values were as follows: V1 =63.4 l, V2=41.3 l, V3 =284.3 l, Cl1=0.47×(height/160 cm)(6.42) l/min, Cl2=2.43 l/min and Cl3=0.086 l/min.

CONCLUSIONS

This study identified (i) the effect of height on the pharmacokinetics of dexmedetomidine; (ii) that there is no influence of age, gender, weight, LBM, BSA and BMI on pharmacokinetic parameters; and (iii) it established a preliminary population pharmacokinetic model for Chinese patients.

Highly efficient virus resistance mediated by artificial microRNAs that target the suppressor of PVX and PVY in plants

MicroRNAs (miRNAs) processed from nuclear-encoded transcripts control expression of target transcripts by directing cleavage or translational inhibition. Artificial miRNAs (amiRNAs) that exploit this endogenous gene silencing mechanism can be designed to target any gene of interest and provide a highly specific approach for effective post-transcriptional gene silencing (PTGS) in plants. Here, using Arabidopsis thaliana miR159a, miR167b and miR171a precursors as backbones, we designed two types of amiRNA targeting sequence that encode the silencing suppressor HC-Pro of Potato virus Y (PVY) and the TGBp1/p25 (p25) of Potato virus X (PVX). The detected amiRNAs efficiently inhibited HC-Pro and p25 gene expression and conferred highly specific resistance against PVY or PVX infection in transgenic Nicotiana tabacum; this resistance was also maintained under conditions of increased viral pressure. Moreover, resistance was strongly influenced by the complementarity between the target sequence and amiRNA, and was well correlated to amiRNA expression level; the expression level of amiRNAs was also well related to the precursor backbones. We further showed that transgenic N. tabacum developed highly effective resistance to both PVY and PVX through expression of a dimeric amiRNA precursor. Together, our findings indicate that transgenic plants with multiple virus-specific resistance can be obtained through co-expression of several amiRNAs targeting multiple viruses.

The CKLF1-C19 peptide attenuates allergic lung inflammation by inhibiting CCR3- and CCR4-mediated chemotaxis in a mouse model of asthma

BACKGROUND

  Human chemokine-like factor 1 (CKLF1) is a functional ligand for human CCR4, which is highly expressed on Th2 lymphocytes and plays an important role in the pathogenesis of asthma. The expression and function of CKLF1 are associated with asthma. The CKLF1 C-terminal peptides C19 and C27 also interact with human CCR4. Albeit with weaker chemotactic activity, C19 can inhibit chemotaxis induced by both CKLF1 and CCL17. Here, we explore whether C19 can act as an antagonist in the development of asthma.

METHODS

  A mouse model of asthma and in vitro and in vivo chemotaxis assays were used.

RESULTS

  Using a mouse model of asthma, we demonstrate here that C19 reduces airway eosinophilia, lung inflammation and airway hyperresponsiveness; in contrast, C27 has little effect on these parameters. The inhibitory effects of C19 on CCR4-mediated chemotaxis could be observed in human Th2 lymphocytes and in the splenocytes from ovalbumin-sensitized mice. Furthermore, we show that C19 can inhibit CCL11-induced chemotaxis of mouse eosinophils and human CCR3-transfected or mouse Ccr3-transfected HEK293 cells. In vivo chemotaxis assays revealed that C19 and C27 can reduce CCL11-mediated recruitment of eosinophils into the peritoneal cavity and that this inhibitory effect is stronger for C19 than for C27.

CONCLUSIONS

  Thus, C19 can attenuate airway eosinophilia and lung inflammation by inhibiting CCR3- and CCR4-mediated chemotaxis in a mouse model of asthma. Given its ability to inhibit human CCR3- and CCR4-meditated chemotaxis, C19 has great therapeutic potential for use in the treatment and control of allergic asthma.

Distribution and dynamics of Bemisia tabaci invasive biotypes in central China

The tobacco whitefly, Bemisia tabaci (Gennadius), causes severe crop losses in many agricultural systems. The worst of these losses are often associated with the invasion and establishment of specific whitefly biotypes. In a comprehensive survey of biotypes present in central China between 2005 and 2007, we obtained 191 samples of B. tabaci from 19 districts in Hubei province and its surrounds. Biotypes were identified by RAPD-PCR and by sequencing the mitochondrial cytochrome oxidase I gene (mtCO1). We determined that these central Chinese haplotypes included the world's two most invasive B. tabaci biotypes (B and Q) and two indigenous biotypes (ZHJ1 and ZHJ3). The B biotype shared >99.7% identity with other Chinese B biotypes and the Q biotype shared >99.5% of its identity with Q samples from the Mediterranean, USA, Africa and East Asia. By 2007, the Q biotype was dominant over much of Hubei province and appeared to be supplanting all other biotypes, although both the invasive and indigenous biotypes existed in sympatry in some regions. The invasion and rapid establishment of the Q biotype in China mirrors events elsewhere in the world, and we suggest that this is a consequence of its reproductive isolation, its polyphagous nature and its broad-spectrum resistance to insecticides. Its dominance has severe implications for the sustainability of some insecticide groups and for the production of a number of crops.

Kashin-Beck disease and Sayiwak disease in China: prevalence and a comparison of the clinical manifestations, familial aggregation, and heritability

OBJECTIVE

To compare the prevalence, the clinical manifestations, familial aggregation and heritability of Kashin-Beck disease (KBD) and Sayiwak disease (SD) in China.

METHODS

10,823 people from 1361 families in 14 villages in Linyou County, Shaanxi Province, were examined for KBD, and 2264 people from 552 families in Sayiwak village, Kashi city, Xinjiang, were examined for SD. The investigation included documentation of individual information and clinical manifestations. Patients were subject to radiographic imaging of the right hand. t-Tests and chi-square tests were used to examine correlations of the diseases with age and gender in each of the two groups. Analysis of familial aggregation was conducted with the chi-square distribution analysis of goodness of fit using the SAS8.0 program. The Li-Mantel-Gart method was employed for the segregation analysis. The Falconer regression method11 was employed to estimate heritability (h²).

RESULTS

The prevalence of KBD in Linyou County was 10.90%, and of SD in Sayiwak village was 0.57%. Of the 21 clinical signs examined, KBD cases exhibited 19 signs (90.48%) and SD cases exhibited 18 signs (85.71%), which indicate similarities between the two diseases. However, different clinical signs were evident between the KBD and SD cases, with different impairment rates among joints of limbs in KBD and similar rates in SD. A comparison of radiological features of limb arthropathy between the two diseases showed differences in several characteristics between the two diseases. In addition, measurements of stature and sitting height showed significant differences in bone development between the two diseases. For KBD cases, the values of h² in the first-degree and the second-degree relatives were 41.76% and 37.20% (P<0.05). The CI of h² was 31.17-52.38 and 19.86-54.55, with a segregation ratio of P=0.12, SE(P)=0.014, 95%CI 0.09-0.15, less than 0.25(χ²=42.36, df=1, P<0.001). For SD cases, the values of h² were 155.61%, 273.63% and 236.83%. The 95% CIs of h² were 133.20-178.12, 229.83-317.42 and 145.83-327.81, respectively, with a segregation ratio of P=0.34, SE(P)=0.059, and CIs between 0.22 and 0.45(χ²=4.9817, df=1, P>0.05).

CONCLUSION

The results indicate both similarities and differences in the clinical manifestations of KBD and SD. However, environmental factors appear to play a major role in KBD, while hereditability is a major factor in SD.

Reactive oxygen species cause endothelial dysfunction in chronic flow overload

Although elevation of shear stress increases production of vascular reactive oxygen species (ROS), the role of ROS in chronic flow overload (CFO) has not been well investigated. We hypothesize that CFO increases ROS production mediated in part by NADPH oxidase, which leads to endothelial dysfunction. In six swine, CFO in carotid arteries was induced by contralateral ligation for 1 wk. In an additional group, six swine received apocynin (NADPH oxidase blocker and anti-oxidant) treatment in conjunction with CFO for 1 wk. The blood flow in carotid arteries increased from 189.2 ± 25.3 ml/min (control) to 369.6 ± 61.9 ml/min (CFO), and the arterial diameter increased by 8.6%. The expressions of endothelial nitric oxide synthase (eNOS), p22/p47(phox), and NOX2/NOX4 were upregulated. ROS production increased threefold in response to CFO. The endothelium-dependent vasorelaxation was compromised in the CFO group. Treatment with apocynin significantly reduced ROS production in the vessel wall, preserved endothelial function, and inhibited expressions of p22/p47phox and NOX2/NOX4. Although the process of CFO remodeling to restore the wall shear stress has been thought of as a physiological response, the present data implicate NADPH oxidase-produced ROS and eNOS uncoupling in endothelial dysfunction at 1 wk of CFO.

A recombinant rabies virus expressing luciferase

A recombinant Rabies virus (RV) expressing firefly luciferase (rRV-luc) was generated by an improved reverse genetics system. Its biological properties were compared with those of the parental RV. The rRV-luc grew in BHK-21 cells similarly to RV, but its virulence for mice was weaker as shown by the lower infectious titers in brain. Rising infectious titers of rRV-luc during its passaging in BHK-21 cells indicated a virus adaptation, while the luciferase (luc) expression was stable. These results suggest that the recombinant RV carrying luc gene might prove a useful tool for further analysis of pathogenesis of RV in small animal models.