New tool for spreading proteins to the environment: Cry1Ab toxin immobilized to bioplastics

A new tool to provide an environmentally friendly way to deliver active proteins to the environment has been developed, based on the use of polyhydroxyalkanoate (PHA, bioplastic) granules. To illustrate this novel approach, a derived Cry1Ab insect-specific toxin protein was in vivo immobilized into PHA granules through the polypeptide tag BioF. The new toxin, named Fk-Bt1, was shown to be active against Sesamia nonagrioides (Lepidoptera: Noctuidae). The dose–mortality responses of the new toxin granule formulation (PFk-Bt1) and purified Cry1Ab have been compared, demonstrating the effectiveness of PFk-Bt1 and suggesting a common mode of action.     

Positive correlation between the expression of X-chromosome RBM genes (RBMX, RBM3, RBM10) and the proapoptotic Bax gene in human breast cancer

In a recent report, it has been postulated that the ubiquitous RBM proteins might constitute a novel family of apoptosis modulators. We measured the expression of the X-chromosome RBM genes (RBMX, RBM3, and RBM10) in 122 breast cancers by means of differential RT-PCR. Using the same method, we also studied the expression of the apoptosis-related genes Bcl-2 and Bax. Markers of hormone dependence (estrogen and progesterone receptors), proliferation (Ki67 and DNA-ploidy), angiogenesis (VEGF and CD105), as well as oncogene (c-erb-B2), and tumor suppressor gene (p53) expression were also analyzed. The expression of all X-chromosome RBM genes was significantly associated with the expression of the proapoptotic Bax gene (RBMX, P=0.039; RBM3, P<0.001; RBM10 large variant, P<0.001; RBM10 small variant, P<0.001). Furthermore, the expression of both RBM10 variants was significantly associated with the expression of the VEGF gene (large variant, P=0.004; small variant, P=0.003). We also found an association of borderline significance (P=0.05) between the expression of RBM3, the large variant of RBM10 and wild-type p53. Expression of the small RBM10 variant, finally, was associated with high proliferation of the tumors (Ki67>or=20%; P=0.037). The expression of both RBM10 variants seems to be interdependent to a significant degree (r=0.26, P=0.006). From these results, it seems that the X-chromosome, through its RBM genes, plays a formerly unknown role in the regulation of programmed cell death (apoptosis) in breast cancer.     

Role of LrpC from Bacillus subtilis in DNA transactions during DNA repair and recombination

Bacillus subtilis LrpC is a sequence-independent DNA-binding and DNA-bending protein, which binds both single-stranded (ss) and double-stranded (ds) DNA and facilitates the formation of higher order protein–DNA complexes in vitro. LrpC binds at different sites within the same DNA molecule promoting intramolecular ligation. When bound to separate molecules, it promotes intermolecular ligation, and joint molecule formation between a circular ssDNA and a homologous ssDNA-tailed linear dsDNA. LrpC binding showed a higher affinity for 4-way (Holliday) junctions in their open conformation, when compared with curved dsDNA. Consistent with these biochemical activities, an lrpC null mutant strain rendered cells sensitive to DNA damaging agents such as methyl methanesulfonate and 4-nitroquinoline-1-oxide, and showed a segregation defect. These findings collectively suggest that LrpC may be involved in DNA transactions during DNA repair and recombination.     

Histone deacetylase inhibition results in a common metabolic profile associated with HT29 differentiation

Cell differentiation is an orderly process that begins with modifications in gene expression. This process is regulated by the acetylation state of histones. Removal of the acetyl groups of histones by specific enzymes (histone deacetylases, HDAC) usually downregulates expression of genes that can cause cells to differentiate, and pharmacological inhibitors of these enzymes have been shown to induce differentiation in several colon cancer cell lines. Butyrate at high (mM) concentration is both a precursor for acetyl-CoA and a known HDAC inhibitor that induces cell differentiation in colon cells. The dual role of butyrate raises the question whether its effects on HT29 cell differentiation are due to butyrate metabolism or to its HDAC inhibitor activity. To distinguish between these two possibilities, we used a tracer-based metabolomics approach to compare the metabolic changes induced by two different types of HDAC inhibitors (butyrate and the non-metabolic agent trichostatin A) and those induced by other acetyl-CoA precursors that do not inhibit HDAC (caprylic and capric acids). [1,2-¹³C₂]-d-glucose was used as a tracer and its redistribution among metabolic intermediates was measured to estimate the contribution of glycolysis, the pentose phosphate pathway and the Krebs cycle to the metabolic profile of HT29 cells under the different treatments. The results demonstrate that both HDAC inhibitors (trichostatin A and butyrate) induce a common metabolic profile that is associated with histone deacetylase inhibition and differentiation of HT29 cells whereas the metabolic effects of acetyl-CoA precursors are different from those of butyrate. The experimental findings support the concept of crosstalk between metabolic and cell signalling events, and provide an experimental approach for the rational design of new combined therapies that exploit the potential synergism between metabolic adaptation and cell differentiation processes through modification of HDAC activity.     

Anti-CCR7 therapy exerts a potent anti-tumor activity in a xenograft model of human mantle cell lymphoma

Background

The chemokine receptor CCR7 mediates lymphoid dissemination of many cancers, including lymphomas and epithelial carcinomas, thus representing an attractive therapeutic target. Previous results have highlighted the potential of the anti-CCR7 monoclonal antibodies to inhibit migration in transwell assays. The present study aimed to evaluate the in vivo therapeutic efficacy of an anti-CCR7 antibody in a xenografted human mantle cell lymphoma model.

Methods

NOD/SCID mice were either subcutaneously or intravenously inoculated with Granta-519 cells, a human cell line derived from a leukemic mantle cell lymphoma. The anti-CCR7 mAb treatment (3 × 200 μg) was started on day 2 or 7 to target lymphoma cells in either a peri-implantation or a post-implantation stage, respectively.

Results

The anti-CCR7 therapy significantly delayed the tumor appearance and also reduced the volumes of tumors in the subcutaneous model. Moreover, an increased number of apoptotic tumor cells was detected in mice treated with the anti-CCR7 mAb compared to the untreated animals. In addition, significantly reduced number of Granta-519 cells migrated from subcutaneous tumors to distant lymphoid organs, such as bone marrow and spleen in the anti-CCR7 treated mice. In the intravenous models, the anti-CCR7 mAb drastically increased survival of the mice. Accordingly, dissemination and infiltration of tumor cells in lymphoid and non-lymphoid organs, including lungs and central nervous system, was almost abrogated.

Conclusions

The anti-CCR7 mAb exerts a potent anti-tumor activity and might represent an interesting therapeutic alternative to conventional therapies.

     

A non‐aquatic otter (Mammalia,Carnivora, Mustelidae) from the Late Miocene (Vallesian,MN 10) of La Roma 2 (Alfambra,Teruel, Spain): systematics and functional anatomy

A new genus and species of otter‐like mustelid, Teruelictis riparius, is created on the basis of a partial skeleton from the Late Miocene (Vallesian age, MN 10) locality of La Roma 2 (Teruel, Spain), including several postcranial elements, the skull, and the mandible. The combination of a typically lutrine dentition, similar to that of other fossil otters such as Paralutra jaegeri, with a very slender postcranial skeleton, including a long back and gracile long bones and metacarpals, thus lacking any aquatic adaptations, was previously unknown in the fossil record. This mosaic of features strongly suggests the possibility that the aquatic lifestyle of otters could have appeared after the initial development of the distinctive dental morphology of this specialized group of mustelids. © 2013 The Linnean Society of London     

Urinary iodine and thyroid function in a population of healthy pregnant women in the North of Spain

BackgroundIodine is an essential trace element for the synthesis of thyroid hormones, which are keys in maternal metabolism during pregnancy as well as in neurological development during fetal and postnatal life. This was a prospective study on iodine status and thyroid function in women during pregnancy in the Basque country to assess whether there was any relationship among maternal urinary iodine, maternal thyroid function and thyrotropin (TSH) in newborns, and to explore any difference in women experiencing miscarriages.MethodsWe analyzed TSH, free T₄ (FT₄), free T₃ (FT₃), thyroid peroxidase antibody (TPO-Ab) titers in serum and urinary iodine concentrations (UIC) in 2104 women in the first trimester of pregnancy and in 1322 of them in their second trimester. We obtained neonatal TSH levels in 1868 cases.ResultsIn the first (T1) and second trimesters (T2), the median UICs were 88.5 μg/L and 140 μg/L, respectively. No relationship was found between UIC and FT₄, or maternal and neonatal TSH. In T1 and T2, 9.7% and 7.5% of women were TPO-Ab positive, respectively. The total miscarriage rate was 10%. The percentage of miscarriages in healthy women was 8.9%, lower than in women with overt hypothyroidism (21.2%; p < 0.001) and than in women with subclinical hypothyroidism (15.6%; p < 0.025). The miscarriage rate was not higher in TPO-Ab-positive women.ConclusionsIn this study most women had iodine deficiency during pregnancy. Neonatal TSH is not correlated with maternal UIC during pregnancy. Pregnant women with hypothyroidism have a higher rate of miscarriages.