62 research outputs found
Genotype of Immunologically Hot or Cold Tumors Determines the Antitumor Immune Response and Efficacy by Fully Virulent Retargeted oHSV
We report on the efficacy of the non-attenuated HER2-retargeted oHSV named R-337 against the immunologically hot CT26-HER2 tumor, and an insight into the basis of the immune protection. Preliminarily, we conducted an RNA immune profiling and immune cell content characterization of CT26-HER2 tumor in comparison to the immunologically cold LLC1-HER2 tumor. CT26-HER2 tumor was implanted into HER2-transgenic BALB/c mice. Hallmarks of R-337 effects were the protection from primary tumor, long-term adaptive vaccination directed to both HER2 and CT26-wt cell neoantigens. The latter effect differentiated R-337 from OncoVEXGM-CSF. As to the basis of the immune protection, R-337 orchestrated several changes to the tumor immune profile, which cumulatively reversed the immunosuppression typical of this tumor (graphical abstract). Thus, Ido1 (inhibitor of T cell anticancer immunity) levels and T regulatory cell infiltration were decreased; Cd40 and Cd27 co-immunostimulatory markers were increased; the IFNγ cascade was activated. Of note was the dampening of IFN-I response, which we attribute to the fact that R-337 is fully equipped with genes that contrast the host innate response. The IFN-I shut-down likely favored viral replication and the expression of the mIL-12 payload, which, in turn, boosted the antitumor response. The results call for a characterization of tumor immune markers to employ oncolytic herpesviruses more precisely
Targeting the liver kinaseB1/AMP-activated protein kinasepathway as a therapeutic strategyfor hematological malignancies
Cytotoxic activity of the novel Akt inhibitor, MK-2206, in T-cell acute lymphoblastic leukemia.
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder arising from T-cell progenitors. T-ALL accounts for
15% of newly diagnosed ALL cases in children and 25% in adults. Although the prognosis of T-ALL has improved, due to the use of
polychemotherapy schemes, the outcome of relapsed/chemoresistant T-ALL cases is still poor. A signaling pathway that is
frequently upregulated in T-ALL, is the phosphatidylinositol 3-kinase/Akt/mTOR network. To explore whether Akt could represent a
target for therapeutic intervention in T-ALL, we evaluated the effects of the novel allosteric Akt inhibitor, MK-2206, on a panel of
human T-ALL cell lines and primary cells from T-ALL patients. MK-2206 decreased T-ALL cell line viability by blocking leukemic cells
in the G0/G1 phase of the cell cycle and inducing apoptosis. MK-2206 also induced autophagy, as demonstrated by an increase in
the 14-kDa form of LC3A/B. Western blotting analysis documented a concentration-dependent dephosphorylation of Akt and its
downstream targets, GSK-3a/b and FOXO3A, in response to MK-2206. MK-2206 was cytotoxic to primary T-ALL cells and induced
apoptosis in a T-ALL patient cell subset (CD34þ/CD4/CD7), which is enriched in leukemia-initiating cells. Taken together, our
findings indicate that Akt inhibition may represent a potential therapeutic strategy in T-ALL
The foliar application of a mixture of semisynthetic chitosan derivatives induces tolerance to water deficit in maize, improving the antioxidant system and increasing photosynthesis and grain yield.
Research has shown that chitosan induces plant stress tolerance and protection, but few studies have explored chemical modifications of chitosan and their effects on plants under water stress. Chitosan and its derivatives were applied (isolated or in mixture) to maize hybrids sensitive to water deficit under greenhouse conditions through foliar spraying at the pre-flowering stage. After the application, water deficit was induced for 15 days. Analyses of leaves and biochemical gas exchange in the ear leaf were performed on the first and fifteenth days of the stress period. Production attributes were also analysed at the end of the experiment. In general, the application of the two chitosan derivatives or their mixture potentiated the activities of the antioxidant enzymes superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and guaiacol peroxidase at the beginning of the stress period, in addition to reducing lipid peroxidation (malonaldehyde content) and increasing gas exchange and proline contents at the end of the stress period. The derivatives also increased the content of phenolic compounds and the activity of enzymes involved in their production (phenylalanine ammonia lyase and tyrosine ammonia lyase). Dehydroascorbate reductase and compounds such as total soluble sugars, total amino acids, starch, grain yield and harvest index increased for both the derivatives and chitosan. However, the mixture of derivatives was the treatment that led to the higher increase in grain yield and harvest index compared to the other treatments. The application of semisynthetic molecules derived from chitosan yielded greater leaf gas exchange and a higher incidence of the biochemical conditions that relieve plant stress
Shine-Dalgarno sequence enhances the efficiency of lacZ repression by artificial anti-lac antisense RNAs in Escherichia coli.
Silencing of the lacZ gene in Escherichia coli was attempted by means of the expression of antisense RNAs (asRNAs) in vivo. A short fragment of lacZ was cloned into the pBAD expression vector, in reverse orientation, using the EcoRI and PstI restriction sites. This construct (pBAD-Zcal1) was used to transform E. coli cells, and the antisense transcription was induced simply by adding arabinose to the culture medium. We demonstrated that the Zcal1 asRNA effectively silenced lacZ using β-galactosidase activity determinations, SDS\u2013PAGE, and Western blotting. Because the concentration of the lac mRNA was always high in cells that expressed Zcal1, we hypothesize that this antisense acts by inhibiting messenger translation. Similar analyses, performed with a series of site-specific Zcal1 mutants, showed that the Shine-Dalgarno sequence, which is conferred by the pBAD vector, is an essential requisite for silencing competence. Indeed, the presence of the intact Shine-Dalgarno sequence positively affects asRNA stability and, hence, silencing effectiveness. Our observations will contribute to the understanding of the main determinants of silencing as exerted by asRNAs as well as provide useful support for the design of robust and efficient prokaryotic gene silencers
Stipsi cronica idiopatica e morbo di Hirschprung dell'adulto: diagnostica per immagini
In extens
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