32 research outputs found

    Newcastle disease virus degrades HIF-1a through proteasomal pathways independent of VHL and p53

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    Newcastle disease virus (NDV) is a candidate agent for oncolytic virotherapy. Despite its potential, the exact mechanism of its oncolysis is still not known. Recently, we reported that NDV exhibited an increased oncolytic activity in hypoxic cancer cells. These types of cells negatively affect therapeutic outcome by overexpressing pro-survival genes under the control of the hypoxia-inducible factor (HIF). HIF-1 is a heterodimeric transcriptional factor consisting of a regulated α (HIF-1α) and a constitutive β subunit (HIF-1β). To investigate the effects of NDV infection on HIF-1α in cancer cells, the osteosarcoma (Saos-2), breast carcinoma (MCF-7), colon carcinoma (HCT116) and fibrosarcoma (HT1080) cell lines were used in the present study. Data obtained showed that a velogenic NDV infection diminished hypoxia-induced HIF-1α accumulation, leading to a decreased activation of its downstream target gene, carbonic anhydrase 9. This NDV-induced downregulation of HIF-1α occurred post-translationally and was partially abrogated by proteasomal inhibition. The process appeared to be independent of the tumour suppressor protein p53. These data revealed a correlation between NDV infection and HIF-1α downregulation, which highlights NDV as a promising agent to eliminate hypoxic cancer cells

    Bortezomib attenuates HIF-1- but not HIF-2-mediated transcriptional activation

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    Bortezomib is the first proteasomal inhibitor (PI) to be used therapeutically for treating relapse cases of multiple myeloma and mantle cell lymphoma. A proposed mechanism for its action is that it prevents the proteasomal degradation of proapoptotic proteins, leading to enhanced apoptosis. Although the α subunit of hypoxia‑inducible factor (HIF)‑1 is not degraded with bortezomib treatment, the heterodimeric HIF‑1 fails to transactivate target genes. HIF‑1 and HIF‑2 are related hypoxia‑inducible transcription factors that are important for the survival of hypoxic tumor cells. The majority of reports have focused on the effects of bortezomib on the transcriptional activities of HIF‑1, but not HIF‑2. The present study investigated the effects of bortezomib on HIF‑2 activity in cancer cells with different levels of HIF‑1α and HIF‑2α subunits. HIF‑α subunit levels were detected using specific antibodies, while HIF transcriptional activities were evaluated using immunodetection, reverse transcription‑polymerase chain reaction and luciferase reporter assay. Bortezomib treatment was found to suppress the transcription and expression of CA9, a HIF‑1‑specific target gene; however, it had minimal effects on EPO and GLUT‑1, which are target genes of both HIF‑1 and HIF‑2. These data suggest that bortezomib attenuates the transcriptional activity only of HIF‑1, and not HIF‑2. This novel finding on the lack of an inhibitory effect of bortezomib on HIF‑2 transcriptional activity has implications for the improvement of design and treatment modalities of bortezomib and other PI drugs

    Role of microRNAs in antiviral responses to dengue infection

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    Dengue virus (DENV) is the etiological agent of dengue fever. Severe dengue could be fatal and there is currently no effective antiviral agent or vaccine. The only licensed vaccine, Dengvaxia, has low efficacy against serotypes 1 and 2. Cellular miRNAs are post-transcriptional regulators that could play a role in direct regulation of viral genes. Host miRNA expressions could either promote or repress viral replications. Induction of some cellular miRNAs could help the virus to evade the host immune response by suppressing the IFN-α/β signaling pathway while others could upregulate IFN-α/β production and inhibit the viral infection. Understanding miRNA expressions and functions during dengue infections would provide insights into the development of miRNA-based therapeutics which could be strategized to act either as miRNA antagonists or miRNA mimics. The known mechanisms of how miRNAs impact DENV replication are diverse. They could suppress DENV multiplication by directly binding to the viral genome, resulting in translational repression. Other miRNA actions include modulation of host factors. In addition, miRNAs that could modulate immunopathogenesis are discussed. Major hurdles lie in the development of chemical modifications and delivery systems for in vivo delivery. Nevertheless, advancement in miRNA formulations and delivery systems hold great promise for the therapeutic potential of miRNA-based therapy, as supported by Miravirsen for treatment of Hepatitis C infection which has successfully completed phase II clinical trial

    Indirect method for quantification of cell biomass during solid-state fermentation of palm kernel cake based on protein content.

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    Solid-State Fermentation (SSF) of Aspergillus niger FTCC 5003 on Palm Kernel Cake (PKC) is a practical approach to upgrade PKC into value added product. Present study was conducted on Aspergillus niger FTCC 5003 growth profile and models that are able to describe the growth in SSF using PKC substrate. Due to the difficulties of separating cell biomass quantitatively from the substrate for SSF systems, indirect method for measurement of cell growth during SSF of PKC by Aspergillus niger FTCC 5003 was studied based on the estimation of glucosamine and protein content. Preliminary relationships between glucosamine and protein contents to fungal dry cell weight (Dw) were developed using simulated homogenous SSF data using glass beads as support materials. Both glucosamine and protein contents were well correlated to the fungal dry cell weight in SSF on support materials for protein and glucosamine, respectively. The equations obtained were used for the estimation of cell biomass profile during SSF of PKC from the data of glucosamine and protein as growth indicator study. The estimated fungal dry cell weight based on protein concentration and β-mannanase activity as metabolic activity for microbial growth were well correlated to PKC dry weight which, indicating that both were suitable marker in describing the growth of A. niger FTCC 5003 in this system. In contrast, estimated fungal dry cell weight based on glucosamine concentration was not suitable to describe the growth of A. niger FTCC 5003

    Oncogenic signaling in tumorigenesis and applications of siRNA nanotherapeutics in breast cancer

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    Overexpression of oncogenes and cross-talks of the oncoproteins-regulated signaling cascades with other intracellular pathways in breast cancer could lead to massive abnormal signaling with the consequence of tumorigenesis. The ability to identify the genes having vital roles in cancer development would give a promising therapeutics strategy in combating the disease. Genetic manipulations through siRNAs targeting the complementary sequence of the oncogenic mRNA in breast cancer is one of the promising approaches that can be harnessed to develop more efficient treatments for breast cancer. In this review, we highlighted the effects of major signaling pathways stimulated by oncogene products on breast tumorigenesis and discussed the potential therapeutic strategies for targeted delivery of siRNAs with nanoparticles in suppressing the stimulated signaling pathways

    Human renal carcinoma cells respond to Newcastle disease virus infection through activation of the p38 MAPK/NF-κB/IκBα pathway

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    Purpose: Newcastle disease virus (NDV) is an oncolytic virus that is known to have a higher preference to cancer cells than to normal cells. It has been proposed that this higher preference may be due to defects in the interferon (IFN) responses of cancer cells. The exact mechanism underlying this process, however, remains to be resolved. In the present study, we examined the antiviral response towards NDV infection of clear cell renal cell carcinoma (ccRCC) cells. ccRCC is associated with mutations of the von Hippel-Lindau tumor suppressor gene VHL, whose protein product is important for eliciting cellular responses to changes in oxygen levels. The most common first line treatment strategy of ccRCC includes IFN. Unfortunately, most ccRCC cases are diagnosed at a late stage and often are resistant to IFN-based therapies. Alternative treatment approaches, including virotherapy using oncolytic viruses, are currently being investigated. The present study was designed to investigate the mechanistic pathways underlying the response of ccRCC cells to oncolytic NDV infection. Methods and results: We found that NDV induces activation of NF-κB in ccRCC cells by inducing phosphorylation and subsequent degradation of IκBα. IκBα was found to be phosphorylated as early as 1 hour post-infection and to result in rapid NF-κB nuclear translocation and activation. Importantly, p38 MAPK phosphorylation was found to occur upstream of the NDV-induced NF-κB activation. Restoration of VHL in ccRCC cells did not result in a reduction of this phosphorylation. A similar phenomenon was also observed in several other cancer-derived cell lines. Conclusion: Our data provide evidence for involvement of the p38 MAPK/NF-κB/IκBα pathway in NDV infection and subsequent induction of apoptosis in ccRCC cells

    Immunosensor development formatting for tungro disease detection using nano-gold antibody particles application

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    The plant disease such as Rice tungro disease (RTD) becomes a major problem in rice production and also will effect in the economy loss in the country. Therefore, to tackle this problem at early stages, the immunosensor application is a most reliable sensor nowadays because of advantages towards detecting biological molecule. Thus, in order to deal with immunosensor development, it can be done by undergoing the formation of immunosensor format on screen-printed carbon electrode (SPCE). Results can be elaborated with the potential applications to detect the viruses

    Determination of fixed-potential selection using chronoamperometry analysis by screen-printed carbon electrode for rice tungro bacilliform virus (RTBV) detection

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    This paper describes the analysis for the determination of fixed-potential selection using chronoamperometry technique for the detection of rice tungro bacilliform virus (RTBV). RTBV is one of the viruses that cause Tungro disease in rice plantation where the epidemic has been reported since the mid-1960s. Thus immuno-biosensor developed here can replace traditional and conventional analytical systems. One of the important steps to develop immunosensor is to determine the best potential to use in this system to indicate high percentage of active area in conducting electron and it can be used as the best potential for future immunosensor development

    Immunosensor development formatting for tungro disease detection using nano-gold antibody particles application

    Get PDF
    The plant disease such as Rice tungro disease (RTD) becomes a major problem in rice production and also will effect in the economy loss in the country. Therefore, to tackle this problem at early stages, the immunosensor application is a most reliable sensor nowadays because of advantages towards detecting biological molecule. Thus, in order to deal with immunosensor development, it can be done by undergoing the formation of immunosensor format on screen-printed carbon electrode (SPCE). Results can be elaborated with the potential applications to detect the viruses

    Stress and deformation of optimally shaped silicon microneedles for transdermal drug delivery

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    In this study, we demonstrated the fabrication of the concave conic shape microneedle with the aid of COMSOL Multiphysics simulation. The stress and buckling of the microneedle structure were simulated by applying various loads ranging from 50 to 800 g perpendiculars to the tip in order to predict the occurrence of microneedles structure deformation. The simulation study indicated that the surface buckling deformation does not occur to the microneedle structure with the increment of the load. The microneedles with dimensions of height and diameter tip ranging from 60 to 100 μm and 1 to 4 μm, respectively had been fabricated via an etching process in a mixture of hydrofluoric acid, nitric acid, and acetic acid. Three optimized microneedles but different in the structures were fabricated via the acidic etching process. The reproducibility of three different microneedle structures was 15, 20, and 60%, respectively. Stress and buckling analyses of the fabricated microneedles were further carried out on the rat skin. The obtained experimental results show promising applications for the deep dermis, stratum corneum to epidermis layer penetration
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