Hypoxia-Induced Aggressiveness of Pancreatic Cancer Cells Is Due to Increased Expression of VEGF,IL-6 and miR-21, Which Can Be Attenuated by CDF Treatment

Hypoxia is known to play critical roles in cell survival, angiogenesis, tumor invasion, and metastasis. Hypoxia mediated over-expression of hypoxia-inducible factor (HIF) has been shown to be associated with therapeutic resistance, and contributes to poor prognosis of cancer patients. Emerging evidence suggest that hypoxia and HIF pathways contributes to the acquisition of epithelial-to-mesenchymal transition (EMT), maintenance of cancer stem cell (CSC) functions, and also maintains the vicious cycle of inflammation-all which lead to therapeutic resistance. However, the precise molecular mechanism(s) by which hypoxia/HIF drives these events are not fully understood. Here, we show, for the first time, that hypoxia leads to increased expression of VEGF, IL-6, and CSC signature genes Nanog, Oct4 and EZH2 consistent with increased cell migration/invasion and angiogenesis, and the formation of pancreatospheres, concomitant with increased expression of miR-21 and miR-210 in human pancreatic cancer (PC) cells. The treatment of PC cells with CDF, a novel synthetic compound inhibited the production of VEGF and IL-6, and down-regulated the expression of Nanog, Oct4, EZH2 mRNAs, as well as miR-21 and miR-210 under hypoxia. CDF also led to decreased cell migration/invasion, angiogenesis, and formation of pancreatospheres under hypoxia. Moreover, CDF decreased gene expression of miR-21, miR-210, IL-6, HIF-1α, VEGF, and CSC signatures in vivo in a mouse orthotopic model of human PC. Collectively, these results suggest that the anti-tumor activity of CDF is in part mediated through deregulation of tumor hypoxic pathways, and thus CDF could become a novel, and effective anti-tumor agent for PC therapy.     

Kinetics study of invertase covalently linked to a new functional nanogel

Nanogels are promising materials as supports for enzyme immobilization. A new hydrogel comprising of methacrylic acid (MAAc) and N-vinyl pyrrolidone (N-VP) and ethyleneglycol dimethacrylate (EGDMA) was synthesized and converted to nanogel by an emulsification method. Nanogel was further functionalized by Curtius azide reaction for use as support for the covalent immobilization of invertase (Saccharomyces cerevisiae). As-prepared or invertase-immobilized nanogel was characterized by FTIR, XRD, TEM and nitrogen analysis. The characterization of both free and the immobilized-invertase were performed using a spectrophotometric method at 540 nm. The values of V_max, maximum reaction rate, (0.123 unit/mg), k_m, Michaelis constant (7.429 mol/L) and E_a, energy of activation (3.511 kj/mol) for the immobilized-invertase are comparable with those of the free invertase at optimum conditions (time 70 min, pH 6.0 and temperature 45 °C). The covalent immobilization enhanced the pH and thermal stability of invertase. The immobilized biocatalyst was efficiently reused up to eight cycles.     

Organotypic culture of human amnion cells in air-liquid interface as a potential substitute for skin regeneration

Background aimsThe aim of the present study was to evaluate the effects of air-liquid interface on the differentiation potential of human amnion epithelial cells (HAECs) to skin-like substitute in organotypic culture.MethodsHAECs at passage 1–2 were seeded onto a fibrin layer populated with human amnion mesenchymal cells to form the organotypic cultures. The organotypic HAECs were then cultured for 7, 14 and 21 d in two types of culture system: the submerged culture and the air-liquid interface culture. Cell morphogenesis was examined under the light and electron microscopes (transmission and scanning) and analyzed by immunohistochemistry.ResultsOrganotypic HAECs formed a single layer epithelium after 3 wk in submerged as well as air-liquid interface cultures. Ultrastructurally, desmosomes were observed in organotypic HAECs cultured in the air-liquid interface but not in the submerged culture. The presence of desmosomes marked the onset of early epidermal differentiation. Organotypic HAECs were positive against anti-CK18 and anti-CK14 in both the submerged and the air-liquid interface cultures. The co-expression of CK14 and CK18 suggested that differentiation of HAECs into skin may follow the process of embryonic skin development. However, weak expression of CK14 was observed after 2 and 3 wk of culture in air-liquid interface. CK10, involucrin, type IV collagen and laminin-5 expression was absent in organotypic HAECs. This observation reflects the initial process of embryonic epidermal differentiation and stratification.ConclusionsResults from the present study suggest that the air-liquid interface could stimulate early differentiation of organotypic HAECs to epidermal cells, with a potential use for skin regeneration.     

First-Time Detection of Mycobacterium bovis in Livestock Tissues and Milk in the West Bank,Palestinian Territories

Background

Bovine tuberculosis, bTB, is classified by the WHO as one of the seven neglected zoonontic diseases that cause animal health problems and has high potential to infect humans. In the West Bank, bTB was not studied among animals and the prevalence of human tuberculosis caused by M. bovis is unknown. Therefore, the aim of this study was to estimate the prevalence of bTB among cattle and goats and identify the molecular characteristics of bTB in our area.

Methodology/principal findings

A total of 208 tissue samples, representing 104 animals, and 150 raw milk samples, obtained from cows and goats were examined for the presence of mycobacteria. The tissue samples were collected during routine meat inspection from the Jericho abattoir. DNA was extracted from all samples, milk and tissue biopsies (n = 358), and screened for presence of TB DNA by amplifying a 123-bp segment of the insertion sequence IS6110. Eight out of 254 animals (3.1%) were found to be TB positive based on the IS6110-PCR. Identification of M. bovis among the positive TB samples was carried out via real time PCR followed by high resolution melt curve analysis, targeting the A/G transition along the oxyR gene. Spoligotyping analysis revealed a new genotype of M. bovis that was revealed from one tissue sample.

Significance

Detection of M. bovis in tissue and milk of livestock suggests that apparently healthy cattle and goats are a potential source of infection of bTB and may pose a risk to public health. Hence, appropriate measures including meat inspection at abattoirs in the region are required together with promotion of a health campaign emphasizing the importance of drinking pasteurized milk. In addition, further studies are essential at the farm level to determine the exact prevalence of bTB in goats and cattle herds in the West Bank and Israel.     

Pancreatic Cancer Stem-like Cells Display Aggressive Behavior Mediated via Activation of FoxQ1

Subpopulations of cancer stem cells (CSCs) or cancer stem-like cells (CSLCs) have been identified from most tumors, including pancreatic cancer (PC), and the existence of these cells is clinically relevant. Emerging evidence suggests that CSLCs participate in cell growth/proliferation, migration/invasion, metastasis, and chemo-radiotherapy resistance, ultimately contributing to poor clinical outcome. However, the pathogenesis and biological significance of CSLCs in PC has not been well characterized. In the present study, we found that isolated triple-marker-positive (CD44⁺/CD133⁺/EpCAM⁺) cells of human PC MiaPaCa-2 and L3.6pl cells behave as CSLCs. These CSLCs exhibit aggressive behavior, such as increased cell growth, migration, clonogenicity, and self-renewal capacity. The mRNA expression profiling analysis showed that CSLCs (CD44⁺/CD133⁺/EpCAM⁺) exhibit differential expression of more than 1,600 mRNAs, including FoxQ1, compared with the triple-marker-negative (CD44⁻/CD133⁻/EpCAM⁻) cells. The knockdown of FoxQ1 by its siRNA in CSLCs resulted in the inhibition of aggressive behavior, consistent with the inhibition of EpCAM and Snail expression. Mouse xenograft tumor studies showed that CSLCs have a 100-fold higher potential for tumor formation and rapid tumor growth, consistent with overexpression of CSC-associated markers/mediators, including FoxQ1, compared with its parental MiaPaCa-2 cells. The inhibition of FoxQ1 attenuated tumor formation and growth, and expression of CSC markers in the xenograft tumor derived from CSLCs of MiaPaCa-2 cells. These data clearly suggest the role of differentially expressed genes in the regulation of CSLC characteristics, further suggesting that targeting some of these genes could be important for the development of novel therapies for achieving better treatment outcome of PC.     

Larval Behaviours and Their Contribution to the Distribution of the Intertidal Coral Reef Sponge Carteriospongia foliascens

Sponges (Phylum Porifera) are an evolutionary and ecologically significant group; however information on processes influencing sponge population distributions is surprisingly limited. Carteriospongia foliascens is a common Indo-Pacific sponge, which has been reported from the intertidal to the mesophotic. Interestingly, the distribution of C. foliascens at inshore reefs of the Great Barrier Reef is restricted to the intertidal with no individuals evident in adjacent subtidal habitats. The abundance of C. foliascens and substrate availability was first quantified to investigate the influence of substrate limitation on adult distribution. Pre-settlement processes of larval spawning, swimming speeds, phototaxis, vertical migration, and settlement to intertidal and subtidal substrate cues were also quantified. Notably, suitable settlement substrate (coral rubble) was not limiting in subtidal habitats. C. foliascens released up to 765 brooded larvae sponge⁻¹ day⁻¹ during the day, with larvae (80%±5.77) being negatively phototactic and migrating to the bottom within 40 minutes from release. Subsequently, larvae (up to 58.67%±2.91) migrated to the surface after the loss of the daylight cue (nightfall), and after 34 h post-release >98.67% (±0.67) of larvae had adopted a benthic habit regardless of light conditions. Intertidal and subtidal biofilms initiated similar settlement responses, inducing faster (as early 6 h post-release) and more successful metamorphosis (>60%) than unconditioned surfaces. C. foliascens has a high larval supply and larval behaviours that support recruitment to the subtidal. The absence of C. foliascens in subtidal habitats at inshore reefs is therefore proposed to be a potential consequence of post-settlement mortalities.     

Orofacial findings in chronic granulomatous disease: report of twelve patients and review of the literature

Background

Chronic granulomatous disease is an extremely rare primary immunodeficiency syndrome that can be associated with various oral complications. This can affect high number of patients. However, data on oral complications is sparse. Here we will review the literature and describe the orofacial findings in 12 patients.

Findings

The age range was 5-31 years. Oral findings were variable, and reflected a low level of oral hygiene. They included periodontitis, rampant caries, gingivitis, aphthous-like ulcers, and geographic tongue. One patient had white patches on the buccal mucosa similar to lichen planus. Another patient had a nodular dorsum of the tongue associated with fissured and geographic tongue. Biopsies from the latter two lesions revealed chronic non-specific mucositis. Panoramic radiographs showed extensive periodontitis in one patient and periapical lesions in another patient.

Conclusion

Patients with chronic granulomatous disease may develop oral lesions reflecting susceptibility to infections and inflammation. It is also possible that social and genetic factors may influence the development of this complication. Therefore, oral hygiene must be kept at an optimum level to prevent infections that can be difficult to manage.

     

Prior exposure to restraint stress enhances 7,12-dimethylbenz(a)anthracene (DMBA) induced DNA damage in rats

Over the years, several lines of evidence have emerged supporting the role of stress in the development and progression of cancer. Stress can cause an increase in the production of reactive oxygen species (ROS) and decrease in the in vivo antioxidant defense systems. A ROS-induced DNA damage in peripheral lymphocytes, liver and skin cells may be revealed by Comet assay. To test whether DNA is damaged by stress/DMBA/stress and DMBA, rats were exposed to multiple doses of DMBA in the presence and absence of restraint stress, and DNA damage was evaluated. Insignificant differences were detected in all the three cells tested (peripheral lymphocytes, liver and skin cells) between control and stress treatment in terms of frequencies of damaged DNA. The extent of DNA migration was enhanced in DMBA treated rats in a dose dependent manner. Pre-stress DMBA treatment showed still higher frequencies of damage in comparison with control, stress alone or DMBA alone groups. Thus, prior exposure to stress clearly enhanced the DMBA induced DNA damage, especially so in the skin cells (target organ of the carcinogen application) than liver and peripheral lymphocytes as observed on the basis of the extent of DNA migration (tail DNA) during single cell gel electrophoresis.