Phenotypic Evolution of Therapeutic Salmonella enterica Serovar Typhimurium after Invasion of TRAMP Mouse Prostate Tumor

Salmonella has been of interest in cancer research due to its intrinsic ability to selectively target and colonize within tumors, leading to tumor cell death. Current research indicates promising use of Salmonella in regular administrations to remove tumors in mouse models while minimizing toxic side effects. However, selection of mutants during such long-term tumor colonization is a safety concern, and understanding selection of certain phenotypes within a tumor is an important consideration in predicting the long-term success of bacterium-based cancer treatment strategies. Thus, we have made an initial examination of selected phenotypes in a therapeutic Salmonella enterica serovar Typhimurium population developed from an archival wild-type LT2 strain and intraperitoneally injected into a 6-month-old TRAMP (transgenic adenocarcinoma of mouse prostate) mouse. We compared the original injected strain to isolates recovered from prostate tumors and those recovered from the spleen and liver of non-tumor-bearing TRAMP mice through phenotypic assessments of bacteriophage susceptibility, motility, growth rates, morphology, and metabolic activity. Tumor isolate traits, particularly the loss of wild-type motility and flagella, reflect the selective pressure of the tumor, while the maintenance of bacteriophage resistance indicates no active selection to remove this robust trait. We posit that the Salmonella population adopts certain strategies to minimize energy consumption and maximize survival and proliferation once within the tumor. We find these insights to be nonnegligible considerations in the development of cancer therapies involving bacteria and suggest further examinations into the evolution of therapeutic strains during passage through tumors.Center for Cancer Research (National Cancer Institute (U.S.)

Lipoxygenases and Poly(ADP-Ribose) Polymerase in Amyloid Beta Cytotoxicity

The 12/15-lipoxygenase(s) (LOX), poly(ADP-ribose) polymerase (PARP-1) activity and mitochondrial apoptosis inducing factor (AIF) protein in the amyloid β (Aβ) toxicity were investigated in PC12 cells that express either wild-type (APPwt) or double Swedish mutation (APPsw) forms of human Aβ precursor protein. Different levels of Aβ secretion and free radicals formation characterize these cells. The results demonstrated a relationship between the Aβ levels and LOX protein expression and activity. High Aβ concentration in APPsw cells correlated with a significant increase in free radicals and LOX activation, which leads to translocation of p65/NF-κB into the nucleus. An increase in AIF expression in mitochondria was observed concurrently with inhibition of PARP-1 activity in the nuclear fraction of APPsw cells. We suggested that AIF accumulation in mitochondria may be involved in adaptive/protective processes. However, inhibition of PARP-1 may be responsible for the disturbances in transcription and DNA repair as well as the degeneration of APP cells. Under conditions of increased nitrosative stress, evoked by the nitric oxide donor, sodium nitroprusside (SNP, 0.5 mM), 70–80% of all cells types died after 24 h, significantly more in APPsw cells. There was no further significant change in mitochondrial AIF level and PARP-1 activity compared to corresponding non-treated cells. Only one exception was observed in PC12 control, where SNP significantly inhibits PARP-1 activity. Moreover, SNP significantly activated gene expression for 12/15-LOX in all types of investigated cells. Inhibitors of all LOX isoforms and specific inhibitor of 12-LOX enhanced the survival of cells that were subjected to SNP. We conclude that the LOX pathways may play a role in Aβ toxicity and in nitrosative-stress-induced cell death and that inhibition of these pathways offers novel protective strategies

The Effect of the CO32- to Ca2+ Ion activity ratio on calcite precipitation kinetics and Sr2+ partitioning

<p>Abstract</p> <p>Background</p> <p>A proposed strategy for immobilizing trace metals in the subsurface is to stimulate calcium carbonate precipitation and incorporate contaminants by co-precipitation. Such an approach will require injecting chemical amendments into the subsurface to generate supersaturated conditions that promote mineral precipitation. However, the formation of reactant mixing zones will create gradients in both the saturation state and ion activity ratios (i.e., <inline-formula><m:math name="1467-4866-13-1-i1" xmlns:m="http://www.w3.org/1998/Math/MathML"><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:msub><m:mrow><m:mi>O</m:mi></m:mrow><m:mrow><m:mn>3</m:mn></m:mrow></m:msub></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msup></m:mrow></m:msub><m:mo class="MathClass-bin">/</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">+</m:mo></m:mrow></m:msup></m:mrow></m:msub></m:math></inline-formula>). To better understand the effect of ion activity ratios on CaCO₃precipitation kinetics and Sr²⁺co-precipitation, experiments were conducted under constant composition conditions where the supersaturation state (Ω) for calcite was held constant at 9.4, but the ion activity ratio <inline-formula><m:math name="1467-4866-13-1-i2" xmlns:m="http://www.w3.org/1998/Math/MathML"><m:mrow><m:mo class="MathClass-open">(</m:mo><m:mrow><m:mi>r</m:mi><m:mo class="MathClass-rel">=</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:msub><m:mrow><m:mi>O</m:mi></m:mrow><m:mrow><m:mn>3</m:mn></m:mrow></m:msub></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msup></m:mrow></m:msub><m:mo class="MathClass-bin">/</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">+</m:mo></m:mrow></m:msup></m:mrow></m:msub></m:mrow><m:mo class="MathClass-close">)</m:mo></m:mrow></m:math></inline-formula> was varied between 0.0032 and 4.15.</p> <p>Results</p> <p>Calcite was the only phase observed, by XRD, at the end of the experiments. Precipitation rates increased from 41.3 ± 3.4 μmol m^-2min^-1at <it>r = </it>0.0315 to a maximum rate of 74.5 ± 4.8 μmol m^-2min^-1at <it>r = </it>0.306 followed by a decrease to 46.3 ± 9.6 μmol m^-2min^-1at <it>r </it>= 1.822. The trend was simulated using a simple mass transfer model for solute uptake at the calcite surface. However, precipitation rates at fixed saturation states also evolved with time. Precipitation rates accelerated for low <it>r </it>values but slowed for high <it>r </it>values. These trends may be related to changes in effective reactive surface area. The <inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" name="1467-4866-13-1-i1"><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:msub><m:mrow><m:mi>O</m:mi></m:mrow><m:mrow><m:mn>3</m:mn></m:mrow></m:msub></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msup></m:mrow></m:msub><m:mo class="MathClass-bin">/</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">+</m:mo></m:mrow></m:msup></m:mrow></m:msub></m:math></inline-formula> ratios did not affect the distribution coefficient for Sr in calcite (D^P_Sr²⁺), apart from the indirect effect associated with the established positive correlation between D^P_Sr²⁺and calcite precipitation rate.</p> <p>Conclusion</p> <p>At a constant supersaturation state (Ω = 9.4), varying the ion activity ratio affects the calcite precipitation rate. This behavior is not predicted by affinity-based rate models. Furthermore, at the highest ion ratio tested, no precipitation was observed, while at the lowest ion ratio precipitation occurred immediately and valid rate measurements could not be made. The maximum measured precipitation rate was 2-fold greater than the minima, and occurred at a carbonate to calcium ion activity ratio of 0.306. These findings have implications for predicting the progress and cost of remediation operations involving enhanced calcite precipitation where mineral precipitation rates, and the spatial/temporal distribution of those rates, can have significant impacts on the mobility of contaminants.</p

Global chemical effects of the microbiome include new bile-acid conjugations

A mosaic of cross-phylum chemical interactions occurs between all metazoans and their microbiomes. A number of molecular families that are known to be produced by the microbiome have a marked effect on the balance between health and disease. Considering the diversity of the human microbiome (which numbers over 40,000 operational taxonomic units), the effect of the microbiome on the chemistry of an entire animal remains underexplored. Here we use mass spectrometry informatics and data visualization approaches to provide an assessment of the effects of the microbiome on the chemistry of an entire mammal by comparing metabolomics data from germ-free and specific-pathogen-free mice. We found that the microbiota affects the chemistry of all organs. This included the amino acid conjugations of host bile acids that were used to produce phenylalanocholic acid, tyrosocholic acid and leucocholic acid, which have not previously been characterized despite extensive research on bile-acid chemistry. These bile-acid conjugates were also found in humans, and were enriched in patients with inflammatory bowel disease or cystic fibrosis. These compounds agonized the farnesoid X receptor in vitro, and mice gavaged with the compounds showed reduced expression of bile-acid synthesis genes in vivo. Further studies are required to confirm whether these compounds have a physiological role in the host, and whether they contribute to gut diseases that are associated with microbiome dysbiosis

Phenotype and genotype of 87 patients with Mowat-Wilson syndrome and recommendations for care

Mowat-Wilson syndrome (MWS) is a rare intellectual disability/multiple congenital anomalies syndrome caused by heterozygous mutation of the ZEB2 gene. It is generally underestimated because its rarity and phenotypic variability sometimes make it difficult to recognize. Here, we aimed to better delineate the phenotype, natural history, and genotype-phenotype correlations of MWS.MethodsIn a collaborative study, we analyzed clinical data for 87 patients with molecularly confirmed diagnosis. We described the prevalence of all clinical aspects, including attainment of neurodevelopmental milestones, and compared the data with the various types of underlying ZEB2 pathogenic variations.ResultsAll anthropometric, somatic, and behavioral features reported here outline a variable but highly consistent phenotype. By presenting the most comprehensive evaluation of MWS to date, we define its clinical evolution occurring with age and derive suggestions for patient management. Furthermore, we observe that its severity correlates with the kind of ZEB2 variation involved, ranging from ZEB2 locus deletions, associated with severe phenotypes, to rare nonmissense intragenic mutations predicted to preserve some ZEB2 protein functionality, accompanying milder clinical presentations.ConclusionKnowledge of the phenotypic spectrum of MWS and its correlation with the genotype will improve its detection rate and the prediction of its features, thus improving patient care.GENETICS in MEDICINE advance online publication, 4 January 2018; doi:10.1038/gim.2017.221

Phenotype and genotype of 87 patients with Mowat–Wilson syndrome and recommendations for care

Purpose: Mowat–Wilson syndrome (MWS) is a rare intellectual disability/multiple congenital anomalies syndrome caused by heterozygous mutation of the ZEB2 gene. It is generally underestimated because its rarity and phenotypic variability sometimes make it difficult to recognize. Here, we aimed to better delineate the phenotype, natural history, and genotype–phenotype correlations of MWS. Methods: In a collaborative study, we analyzed clinical data for 87 patients with molecularly confirmed diagnosis. We described the prevalence of all clinical aspects, including attainment of neurodevelopmental milestones, and compared the data with the various types of underlying ZEB2 pathogenic variations. Results: All anthropometric, somatic, and behavioral features reported here outline a variable but highly consistent phenotype. By presenting the most comprehensive evaluati

Strains, Mechanism, and Perspective: Salmonella-Based Cancer Therapy

Recently, investigation of bacterial-based tumor therapy has regained focus due to progress in molecular, cellular, and microbial biology. Many bacteria such as Salmonella, Listeria, Escherichia, and Clostridium have proved to have tumor targeting and in some cases even tumor-destroying phenotypes. Furthermore, bacterial clinical treatments for cancer have been improved by combination with other therapeutic methods such as chemotherapeutic drugs and radioactive agents. Synthetic biology techniques have also driven the development of new bacterial-based cancer therapies. However, basic questions about the mechanisms of bacterial-mediated tumor targeting and destruction are still being elucidated. In this review, we focus on three tumor-therapeutic Salmonella models, the most intensively studied bacterial genus in this field. One of these Salmonella models is our Salmonella enterica serovar Typhimurium LT2 derived strain CRC2631, engineered to minimize toxicity but maximize tumor-targeting and destruction effects. The other two are VNP20009 and A1-R. We compare the means by which these therapeutic candidate strain models were selected for study, their tumor targeting and tumor destruction phenotypes in vitro and in vivo, and what is currently known about the mechanisms by which they target and destroy tumors