35 research outputs found
Purine Nucleoside Phosphorylase mediated molecular chemotherapy and conventional chemotherapy: A tangible union against chemoresistant cancer
Background Late stage Ovarian Cancer is essentially incurable primarily due to late diagnosis and its inherent heterogeneity. Single agent treatments are inadequate and generally lead to severe side effects at therapeutic doses. It is crucial to develop clinically relevant novel combination regimens involving synergistic modalities that target a wider repertoire of cells and lead to lowered individual doses. Stemming from this premise, this is the first report of two- and three-way synergies between Adenovirus-mediated Purine Nucleoside Phosphorylase based gene directed enzyme prodrug therapy (PNP-GDEPT), docetaxel and/or carboplatin in multidrug-resistant ovarian cancer cells. Methods The effects of PNP-GDEPT on different cellular processes were determined using Shotgun Proteomics analyses. The in vitro cell growth inhibition in differentially treated drug resistant human ovarian cancer cell lines was established using a cell-viability assay. The extent of synergy, additivity, or antagonism between treatments was evaluated using CalcuSyn statistical analyses. The involvement of apoptosis and implicated proteins in effects of different treatments was established using flow cytometry based detection of M30 (an early marker of apoptosis), cell cycle analyses and finally western blot based analyses. Results Efficacy of the trimodal treatment was significantly greater than that achieved with bimodal- or individual treatments with potential for 10-50 fold dose reduction compared to that required for individual treatments. Of note was the marked enhancement in apoptosis that specifically accompanied the combinations that included PNP-GDEPT and accordingly correlated with a shift in the expression of anti- and pro-apoptotic proteins. PNP-GDEPT mediated enhancement of apoptosis was reinforced by cell cycle analyses. Proteomic analyses of PNP-GDEPT treated cells indicated a dowregulation of proteins involved in oncogenesis or cancer drug resistance in treated cells with accompanying upregulation of apoptotic- and tumour- suppressor proteins. Conclusion Inclusion of PNP-GDEPT in regular chemotherapy regimens can lead to significant enhancement of the cancer cell susceptibility to the combined treatment. Overall, these data will underpin the development of regimens that can benefit patients with late stage ovarian cancer leading to significantly improved efficacy and increased quality of life
Evidence for Widespread Genomic Methylation in the Migratory Locust, Locusta migratoria (Orthoptera: Acrididae)
The importance of DNA methylation in mammalian and plant systems is well established. In recent years there has been renewed interest in DNA methylation in insects. Accumulating evidence, both from mammals and insects, points towards an emerging role for DNA methylation in the regulation of phenotypic plasticity. The migratory locust (Locusta migratoria) is a model organism for the study of phenotypic plasticity. Despite this, there is little information available about the degree to which the genome is methylated in this species and genes encoding methylation machinery have not been previously identified. We therefore undertook an initial investigation to establish the presence of a functional DNA methylation system in L. migratoria. We found that the migratory locust possesses genes that putatively encode methylation machinery (DNA methyltransferases and a methyl-binding domain protein) and exhibits genomic methylation, some of which appears to be localised to repetitive regions of the genome. We have also identified a distinct group of genes within the L. migratoria genome that appear to have been historically methylated and show some possible functional differentiation. These results will facilitate more detailed research into the functional significance of DNA methylation in locusts
Italian guidelines for primary headaches: 2012 revised version
The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version
Reducing the efficiency–stability–cost gap of organic photovoltaics with highly efficient and stable small molecule acceptor ternary solar cells
Participative Leadership and Organizational Identification in SMEs in the MENA Region: Testing the Roles of CSR Perceptions and Pride in Membership
The aim of this research is to explore the process linking participative leadership to organizational identification. The study examines the relationship between participative leadership and internal CSR perceptions of employees and also investigates the role that pride in membership plays in the affiliation of CSR perceptions with organizational identification. By studying these relationships, the paper aspires to contemplate new presumed mediators in the association of participative leadership with organizational identification as well as determine a possible novel antecedent of employee CSR perceptions. Empirical evidence is provided from data that was collected through a survey distributed to employees working for small- and medium-sized enterprises in three countries in the Middle East and North Africa regions, particularly the United Arab Emirates, Lebanon, and Tunisia. Findings show that participative leadership leads to positive internal CSR perceptions of employees and that these CSR perceptions lead to pride in membership which, in turn, results in organizational identification. Implications of these findings are also discussed
Little evidence for association between the TGFBR1*6A variant and colorectal cancer: a family-based association study on non-syndromic family members from Australia and Spain
BACKGROUND: Genome-wide linkage studies have identified the 9q22 chromosomal region as linked with colorectal cancer (CRC) predisposition. A candidate gene in this region is transforming growth factor β receptor 1 (TGFBR1). Investigation of TGFBR1 has focused on the common genetic variant rs11466445, a short exonic deletion of nine base pairs which results in truncation of a stretch of nine alanine residues to six alanine residues in the gene product. While the six alanine (*6A) allele has been reported to be associated with increased risk of CRC in some population based study groups this association remains the subject of robust debate. To date, reports have been limited to population-based case-control association studies, or case-control studies of CRC families selecting one affected individual per family. No study has yet taken advantage of all the genetic information provided by multiplex CRC families. METHODS: We have tested for an association between rs11466445 and risk of CRC using several family-based statistical tests in a new study group comprising members of non-syndromic high risk CRC families sourced from three familial cancer centres, two in Australia and one in Spain. RESULTS: We report a finding of a nominally significant result using the pedigree-based association test approach (PBAT; p = 0.028), while other family-based tests were non-significant, but with a p-value <; 0.10 in each instance. These other tests included the Generalised Disequilibrium Test (GDT; p = 0.085), parent of origin GDT Generalised Disequilibrium Test (GDT-PO; p = 0.081) and empirical Family-Based Association Test (FBAT; p = 0.096, additive model). Related-person case-control testing using the "More Powerful" Quasi-Likelihood Score Test did not provide any evidence for association (MQLS; p = 0.41). CONCLUSIONS: After conservatively taking into account considerations for multiple hypothesis testing, we find little evidence for an association between the TGFBR1*6A allele and CRC risk in these families. The weak support for an increase in risk in CRC predisposed families is in agreement with recent meta-analyses of case-control studies, which estimate only a modest increase in sporadic CRC risk among 6*A allele carriers
Intratumoral generation of 2‐fluoroadenine to treat solid malignancies of the head and neck
Ovine atadenovirus, a novel and highly immunogenic vector in prime-boost studies of a candidate HIV-1 vaccine.
Ovine adenovirus type 7 (OAdV) is the prototype member of the genus Atadenovirus. No immunity to the virus has so far been detected in human sera. We describe the construction and evaluation of a candidate HIV-1 vaccine based on OAdV and its utilisation alone and in combination with plasmid-, human adenovirus type 5 (HAdV5; a Mastadenovirus)-, and modified vaccinia Ankara (MVA)-vectored vaccines. All vectors expressed HIVA, an immunogen consisting of HIV-1 clade A consensus Gag-derived protein coupled to a T cell polyepitope. OAdV.HIVA was genetically stable, grew well and expressed high levels of protein from the Rous sarcoma virus promoter. OAdV.HIVA was highly immunogenic in mice and efficiently primed and boosted HIV-1-specific T cell responses together with heterologous HIVA-expressing vectors. There were significant differences between OAdV and HAdV5 vectors in priming of naïve CD8(+) T cell responses to HIVA and in the persistence of MHC class I-restricted epitope presentation in the local draining lymph nodes. OAdV.HIVA primed T cells more rapidly but was less persistent than AdV5.HIVA and thus induced a qualitatively distinct T cell response. Nevertheless, both vectors primed a response in mice that reduced viral titres in a surrogate challenge model by three to four orders of magnitude. Thus, OAdV is a novel, underexplored vaccine vector with potential for further development for HIV-1 and other vaccines. The data are discussed in the context of the latest HIV-1 vaccine developments
In vivo gene therapy for prostate cancer: Preclinical evaluation of two different enzyme-directed prodrug therapy systems delivered by identical adenovirus vectors
Advanced prostate cancer is invariably lethal once it becomes androgen independent (AI). With the aim of developing a new treatment we have used the human androgen-independent prostate cancer cell line, PC-3, to evaluate the effectiveness of two enzyme-directed prodrug therapy (EPT) systems as a novel means for promoting tumor cell destruction in vivo. We have confined our study to the use of a PSA promoter, in a preliminary attempt to achieve prostate specificity. The two EPT systems used were the HSVTK/GCV and PNP/6MPDR systems. These were chosen for their differential dependence on DNA replication for their mechanism of action. In the present work, either the HSVTK or PNP gene, each controlled by a PSA promoter fragment, was delivered by an E1-, replication-deficient human adenovirus (Ad5) into PC-3 tumors growing subcutaneously in BALB/c nude mice. Tumors were injected with a single dose of recombinant Ad5 and mice were treated intraperitoneally with the appropriate prodrug, twice daily, for 6 days thereafter. The growth of established PC-3 tumors was significantly suppressed and host survival increased with a single course of HSVTK/GCV or PNP/6MPDR treatment. HSVTK/GCV-treated PC-3 tumor growth was 80% less than that of control treatments on day 33, while PNP/6MPDR-treated tumor growth was ~ 75% less than that of control treatments on day 52. Survival data showed that 20% of HSVTK/GCV- or PNP/6MPDR-treated animals lived > 45 and > 448 days, respectively, longer than control animals. These results demonstrate that both HSVTK/GCV and PNP/6MPDR therapies interrupt the growth of an aggressive human prostate cancer cell line in vivo