33 research outputs found

    Antioxidant oils and Salmonella enterica Typhimurium reduce tumor in an experimental model of hepatic metastasis

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    Fruit seeds high in antioxidants have been shown to have anticancer properties and enhance host protection against microbial infection. Recently we showed that a single oral dose of Salmonella enterica serovar Typhimurium expressing a truncated human interleukin-2 gene (SalpIL2) is avirulent, immunogenic, and reduces hepatic metastases through increased natural killer cell populations in mice. To determine whether antioxidant compounds enhance the antitumor effect seen in SalpIL2-treated animals, we assayed black cumin (BC), black raspberry (BR), and milk thistle (MT) seed oils for the ability to reduce experimental hepatic metastases in mice. In animals without tumor, BC and BR oil diets altered the kinetics of the splenic lymphocyte response to SalpIL2. Consistent with previous reports, BR and BC seed oils demonstrated independent antitumor properties and moderate adjuvant potential with SalpIL2. MT oil, however, inhibited the efficacy of SalpIL2 in our model. Based on these data, we conclude that a diet high in antioxidant oils promoted a more robust immune response to SalpIL2, thus enhancing its antitumor efficacy

    Inhibition of angiogenesis and suppression of colorectal cancer metastatic to the liver using the Sleeping Beauty Transposon System

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    <p>Abstract</p> <p>Background</p> <p>Metastatic colon cancer is one of the leading causes of cancer-related death worldwide, with disease progression and metastatic spread being closely associated with angiogenesis. We investigated whether an antiangiogenic gene transfer approach using the <it>Sleeping Beauty </it>(SB) transposon system could be used to inhibit growth of colorectal tumors metastatic to the liver.</p> <p>Results</p> <p>Liver CT26 tumor-bearing mice were hydrodynamically injected with different doses of a plasmid containing a transposon encoding an angiostatin-endostatin fusion gene (Statin AE) along with varying amounts of SB transposase-encoding plasmid. Animals that were injected with a low dose (10 μg) of Statin AE transposon plasmid showed a significant decrease in tumor formation only when co-injected with SB transposase-encoding plasmid, while for animals injected with a higher dose (25 μg) of Statin AE transposon, co-injection of SB transposase-encoding plasmid did not significantly affect tumor load. For animals injected with 10 μg Statin AE transposon plasmid, the number of tumor nodules was inversely proportional to the amount of co-injected SB plasmid. Suppression of metastases was further evident in histological analyses, in which untreated animals showed higher levels of tumor cell proliferation and tumor vascularization than animals treated with low dose transposon plasmid.</p> <p>Conclusion</p> <p>These results demonstrate that hepatic colorectal metastases can be reduced using antiangiogenic transposons, and provide evidence for the importance of the transposition process in mediating suppression of these tumors.</p

    Who uses firearms as a means of suicide? A population study exploring firearm accessibility and method choice

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    <p>Abstract</p> <p>Background</p> <p>The 1996 Australian National Firearms Agreement introduced strict access limitations. However, reports on the effectiveness of the new legislation are conflicting. This study, accessing all cases of suicide 1997-2004, explores factors which may impact on the choice of firearms as a suicide method, including current licence possession and previous history of legal access.</p> <p>Methods</p> <p>Detailed information on all Queensland suicides (1997-2004) was obtained from the Queensland Suicide Register, with additional details of firearm licence history accessed from the Firearm Registry (Queensland Police Service). Cases were compared against licence history and method choice (firearms or other method). Odds ratios (OR) assessed the risk of firearms suicide and suicide by any method against licence history. A logistic regression was undertaken identifying factors significant in those most likely to use firearms in suicide.</p> <p>Results</p> <p>The rate of suicide using firearms in those with a current license (10.92 per 100,000) far exceeded the rate in those with no license history (1.03 per 100,000). Those with a license history had a far higher rate of suicide (30.41 per 100,000) compared to that of all suicides (15.39 per 100,000). Additionally, a history of firearms licence (current or present) was found to more than double the risk of suicide by any means (OR = 2.09, <it>P </it>< 0.001). The group with the highest risk of selecting firearms to suicide were older males from rural locations.</p> <p>Conclusion</p> <p>Accessibility and familiarity with firearms represent critical elements in determining the choice of method. Further licensing restrictions and the implementation of more stringent secure storage requirements are likely to reduce the overall familiarity with firearms in the community and contribute to reductions in rates of suicide.</p

    AI is a viable alternative to high throughput screening: a 318-target study

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    : High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

    S100A8/A9 (calprotectin) negatively regulates G2/M cell cycle progression and growth of squamous cell carcinoma.

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    Malignant transformation results in abnormal cell cycle regulation and uncontrolled growth in head and neck squamous cell carcinoma (HNSCC) and other cancers. S100A8/A9 (calprotectin) is a calcium-binding heterodimeric protein complex implicated in cell cycle regulation, but the specific mechanism and role in cell cycle control and carcinoma growth are not well understood. In HNSCC, S100A8/A9 is downregulated at both mRNA and protein levels. We now report that downregulation of S100A8/A9 correlates strongly with a loss of cell cycle control and increased growth of carcinoma cells. To show its role in carcinogenesis in an in vitro model, S100A8/A9 was stably expressed in an S100A8/A9-negative human carcinoma cell line (KB cells, HeLa-like). S100A8/A9 expression increases PP2A phosphatase activity and p-Chk1 (Ser345) phosphorylation, which appears to signal inhibitory phosphorylation of mitotic p-Cdc25C (Ser216) and p-Cdc2 (Thr14/Tyr15) to inactivate the G2/M Cdc2/cyclin B1 complex. Cyclin B1 expression then downregulates and the cell cycle arrests at the G2/M checkpoint, reducing cell division. As expected, S100A8/A9-expressing cells show both decreased anchorage-dependent and -independent growth and mitotic progression. Using shRNA, silencing of S100A8/A9 expression in the TR146 human HNSCC cell line increases growth and survival and reduces Cdc2 inhibitory phosphorylation at Thr14/Tyr15. The level of S100A8/A9 endogenous expression correlates strongly with the reduced p-Cdc2 (Thr14/Tyr14) level in HNSCC cell lines, SCC-58, OSCC-3 and UMSCC-17B. S100A8/A9-mediated control of the G2/M cell cycle checkpoint is, therefore, a likely suppressive mechanism in human squamous cell carcinomas and may suggest new therapeutic approaches

    Expression of S100A8 and S100A9 in human head and neck tissues and carcinoma cell lines.

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    <p>The mRNA expression levels of S100A8 and S100A9 in (A) normal adjacent (NAT) and HNSCC tissues and (B) TR146 HNSCC and KB cells were measured by qRT-PCR and normalized to GAPDH; dotted line shown as a threshold for detection. Total RNA extracted from matching NAT and HNSCC tissues from each of three patients was pooled separately for gene expression analysis. Cell lines cultured under standard conditions were harvested and analyzed at approximately 70% confluency. Data presented as mean ±SD (n = 2). Representative immunoblots of (C) S100A8 and S100A9 in KB-S100A8/A9 transfected cells and (D) TR146-shRNA-S100A8/A9 knockdown cells compared to wild type and negative transfection controls. β-actin was used as loading control for immunoblotting analysis separated in 10% SDS-PAGE gels.</p
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