No abstract

In Europe, multiple waves of infections with SARS-CoV-2 (COVID-19) have been observed. Here, we have investigated whether common patterns of cytokines could be detected in individuals with mild and severe forms of COVID-19 in two pandemic waves, and whether machine learning approach could be useful to identify the best predictors. An increasing trend of multiple cytokines was observed in patients with mild or severe/critical symptoms of COVID-19, compared with healthy volunteers. Linear Discriminant Analysis (LDA) clearly recognized the three groups based on cytokine patterns. Classification and Regression Tree (CART) further indicated that IL-6 discriminated controls and COVID-19 patients, whilst IL-8 defined disease severity. During the second wave of pandemics, a less intense cytokine storm was observed, as compared with the first. IL-6 was the most robust predictor of infection and discriminated moderate COVID-19 patients from healthy controls, regardless of epidemic peak curve. Thus, serum cytokine patterns provide biomarkers useful for COVID-19 diagnosis and prognosis. Further definition of individual cytokines may allow to envision novel therapeutic options and pave the way to set up innovative diagnostic tools.

-isopentenyladenosine (i6A) is a modified nucleoside with a pentaatomic isopentenyl derived from mevalonate that induces inhibition of tumor cell proliferation and apoptosis in several tumor cell lines. In this study, we reported that N 6 -isopentenyladenosine inhibited the proliferation and promotes apoptosis in DLD1 human colon cancer cells. It suppressed the proliferation of cells through inhibition of DNA synthesis, causing a cell cycle arrest that correlated with a decrease in the levels of cyclin E, cyclin A and cyclin D1 and with a concomitant increase in the levels of cyclin-dependent kinase inhibitor p21waf and p27kip1. Moreover, it induced apoptosis through an increase in the number of annexin V-positive cells, a downregulation of antiapoptotic products and caspase-3 activation. The apoptotic effects of N 6 -isopentenyladenosine were accompanied by sustained phosphorylation and activation of c-jun N-terminal kinase (JNK) that induced phosphorylation of c-jun. Overall, our data show that JNK, could play an important role in i6A-mediated apoptosis in DLD1 human colon cancer cells ' 2008 Wiley-Liss, Inc. -Isopentenyladenosine (i6A) is a modified nucleoside (Fig. 1) found in transfer RNA (tRNA) of many eukaryotic and prokaryotic cells. i6A is the only known cytokinin existing in animal tRNAs and is specifically found next to the 3 0 of the tRNA anticodon that binds codons containing uracile as first base (tRNAleu, tRNAphe, tRNAser, tRNAtrp, tRNAtyr), this site suggests a role in the process of transduction.1-3 Many biological effects, both in plants and animal systems, also including antitumor effects on human and murine cells, can be attributed to i6A. Recently we demonstrated that i6A influences cAMP dependent organization of the microfilaments in a thyroid cell line, FRTL-5 cells. We described that i6A decreased cAMP levels, subsequently reduced DNA synthesis and iodium uptake, and inhibited microfilament disassembling. i6A is the only nitrogen-6-substituted adenosine which have physiologic relevance. 4 Moreover, we investigated the antiproliferative effects of i6A in a thyroid cell system, FRTL-5 wild-type, and K-ras transformed KiMol cells. Addition of i6A to FRTL-5 cells caused a dose-dependent arrest of cell growth that was much more evident in KiMol cells. It was due to the inhibition of farnesyl diphosphate synthase (FPPS), an enzyme of mevalonate pathway. Indeed the blockade of cell growth was completely prevented and/or reversed by farnesol, the substrate of FPPS. i6A reduced of prenylated signaling proteins that contribute to cell growth as Lamin B and GTPase proteins. We evaluated the i6A antiproliferative effect in vivo in a nude mouse xenograft model, where KiMol cells were implanted subcutaneously. Mice treated with i6A showed a drastic reduction in tumor volume.5 Previous studies have shown the capacity of the modified ribonucleotides to induce apoptosis in several human cell lines and it was observed that i6A was the most active cytokinin. 6 The cancer cell lines Caco-2 (human colonic ad...

N(6)-isopentenyladenosine (i6A) inhibits the tumor cell growth by inducing cell apoptosis in various cancer cell lines. However, little is known regarding the mechanisms by which the drug induces cell apoptosis. In this study, we further explored the molecular mechanisms of i6A as an anticancer agent on a human breast cancer cell line MDA MB 231. Treatment with i6A decreased the cell proliferation of MDA MB 231 cells in a dose-dependent manner by arresting the cells at G(0)/G(1) phase. This effect was strongly associated with concomitant decrease in the level of cyclin D1, cyclin E, cdk2, and increase of p21waf1 and p27kip. In addition i6A also induced apoptotic cell death by increasing the expression of Bax, and decreasing the levels of Bcl-2 and Bcl-xL, and subsequently triggered mitochondria apoptotic pathway (release of cytochrome c and activation of caspase-3). We observed that i6A suppressed the nuclear factor kappaB (NF-κB) pathway and inhibited the Akt activation. The results of this study indicate that i6A decreases cell proliferation and induces apoptotic cell death in human breast cancer cells, possibly by decreasing signal transduction through the Akt/NF-κB cell survival pathway.

Cell adhesion to extracellular matrix regulates proliferation and survival of several cell types including epithelial thyroid cells. Activation of integrin receptors by binding to extracellular matrix generates a complex cell type-dependent signaling. Adhesion to extracellular matrix induces proliferation and survival in primary cultures of thyroid cells and induces survival in immortalized human thyrocytes. In this study we demonstrate that in immortalized human thyrocyte cells, adhesion to immobilized fibronectin (FN) stimulates DNA synthesis and proliferation through the p21Ras/MAPK pathway, whereas cell survival is mediated by phosphatidylinositol 3-kinase (PI3K) signal pathway. Integrin activation by immobilized FN induced phosphorylation of pp125 focal adhesion kinase and paxillin and induced the formation of focal adhesion kinase/Grb-2/Sos complex. Western blot and in vitro kinase assay demonstrated the activation of Ras and the p44/p42 MAPK/ERK1/2. Inhibition of p21Ras activity and inhibition of MAPK enzymatic activity completely arrested cell growth but did not induce cell death. Integrin activation by cell adhesion to FN also induced activation of PI3K. Inhibition of PI3K enzymatic activity induced apoptosis demonstrated by annexin V-binding assay and loss of cellular DNA content. These results demonstrate that in thyroid cells adhesion to FN regulates proliferation through the p21Ras/MAPK signal pathway, whereas integrin-mediated cell survival is mediated by PI3K.

Our previous studies indicated that millimolar doses of aspirin induced growth arrest and resistance to anticancer drug treatment in Caco-2 cells. The present study was designed to better elucidate at the molecular level the effect of aspirin treatment on pathways that regulate cell death during serum withdrawal. Caco-2 cells were cultured under serum deprivation in the presence or absence of aspirin. Effects on cell cycle, phosphatidylinositol 3-kinase (PI3-kinase) and mitogen-activated protein (MAP) kinase pathways were investigated. We found that aspirin, but not the selective cyclooxygenase-2 inhibitor N-[2-(cyclohexyloxyl)-4-nitrophenyl]-methane sulfonamide (NS-398); prevented apoptosis and G 2 /M transition after prolonged Caco-2 cells serum deprivation. Aspirin-dependent inhibition of apoptosis and G 2 /M transition was prevented by treatment with the PI3-kinase inhibitor 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), but not with the MAP kinase kinase inhibitor 2Ј-amino-3Ј-methoxyflavone (PD98059). The effects of aspirin were mediated at molecular levels, through activation of PI3-kinase/AKT pathway and increase in the p21Cip/WAF1 level. The ability of aspirin to activate AKT protein was observed also in presence of etoposide cotreatment. Our data indicate a new intracellular target of aspirin with potential clinical impact for treatment schedules involving both anticancer agents and aspirin in malignancies.

In normal epithelial cells, impaired cell-matrix contact leads to induction of programmed cell death, a process that has been termed`anoikis'. We investigated the role of p53 and other apoptotic proteins in anoikis in thyroid epithelial cells. Western blot analysis demonstrated that neither p53 nor Bcl-2, Bcl-XL and Bax protein expression changed during anoikis. However, loss of endogenous p53 activity in cells transfected with a dominant-negative mutated p53 inhibited anoikis demonstrating the involvement of p53-dependent processes. The phosphatase inhibitor sodium orthovanadate opposed anoikis when added to the cells within 6 h, suggesting a role for phosphorylated proteins.z 1999 Federation of European Biochemical Societies.

This study showed that the administration of DFO for 5 d a wk in combination with daily administration of DFP at 75 mg/Kg seemed to be the most efficacy and rapid method for reducing iron overload at liver and heart level. Furthermore, the use of different schedules of combined DFO and DFP administration was not associated with different incidence of adverse effects between the groups.