Histone Hyperacetylation in Mitosis Prevents Sister Chromatid Separation and Produces Chromosome Segregation Defects

Posttranslational modifications of core histones contribute to driving changes in chromatin conformation and compaction. Herein, we investigated the role of histone deacetylation on the mitotic process by inhibiting histone deacetylases shortly before mitosis in human primary fibroblasts. Cells entering mitosis with hyperacetylated histones displayed altered chromatin conformation associated with decreased reactivity to the anti-Ser 10 phospho H3 antibody, increased recruitment of protein phosphatase 1-δ on mitotic chromosomes, and depletion of heterochromatin protein 1 from the centromeric heterochromatin. Inhibition of histone deacetylation before mitosis produced defective chromosome condensation and impaired mitotic progression in living cells, suggesting that improper chromosome condensation may induce mitotic checkpoint activation. In situ hybridization analysis on anaphase cells demonstrated the presence of chromatin bridges, which were caused by persisting cohesion along sister chromatid arms after centromere separation. Thus, the presence of hyperacetylated chromatin during mitosis impairs proper chromosome condensation during the pre-anaphase stages, resulting in poor sister chromatid resolution. Lagging chromosomes consisting of single or paired sisters were also induced by the presence of hyperacetylated histones, indicating that the less constrained centromeric organization associated with heterochromatin protein 1 depletion may promote the attachment of kinetochores to microtubules coming from both poles

Merotelic kinetochore orientation versus chromosome mono-orientation in the origin of lagging chromosomes in human primary cells

Defects in chromosome segregation play a critical role in producing genomic instability and aneuploidy, which are associated with congenital diseases and carcinogenesis. We recently provided evidence from immunofluorescence and electron microscopy studies that merotelic kinetochore orientation is a major mechanism for lagging chromosomes during mitosis in PtK1 cells. Here we investigate whether human primary fibroblasts exhibit similar errors in chromosome segregation and if at least part of lagging chromosomes may arise in cells entering anaphase in the presence of mono-oriented chromosomes. By using in situ hybridization with alphoid probes to chromosome 7 and 11 we showed that loss of a single sister is much more frequent than loss of both sisters from the same chromosome in anatelophases from human primary fibroblasts released from a nocodazole-induced mitotic arrest, as predicted from merotelic orientation of single kinetochores. Furthermore, the lagging of pairs of separated sisters was higher than expected from random chance indicating that merotelic orientation of one sister may promote merotelic orientation of the other. Kinetochores of lagging chromosomes in anaphase human cells were found to be devoid of the mitotic checkpoint phosphoepitopes recognized by the 3F3/2 antibody, suggesting that they attached kinetochore microtubules prior to anaphase onset. Live cell imaging of H2B histone-GFP-transfected cells showed that cells with mono-oriented chromosomes never enter anaphase and that lagging chromosomes appear during anaphase after chromosome alignment occurs during metaphase. Thus, our results demonstrate that the mitotic checkpoint efficiently prevents the possible aneuploid burden due to mono-oriented chromosomes and that merotelic kinetochore orientation is a major limitation for accurate chromosome segregation and a potentially important mechanism of aneuploidy in human cells

Is there a role for tumor volume in prediction of prognosis for oral cancer?

Purpose: New prognostic factors in oral squamous cell carcinoma (OSCC) (tumor-, host-, and environment-related) have been introduced recently to complete those traditionally considered. Among them, tumor volume (TV) could be the most interesting and applicable in clinical practice, considering the routine use of computed tomography in tumor staging. In this retrospective study we aimed to investigate whether a correlation exists among these new prognostic factors and survival outcomes. Meterials and methods: We collected data about 140 patients affected by OSCC who underwent primary surgery. Prognostic factors were collected and Overall Survival (OS), Disease Specific Survival (DSS) and Disease Free Survival (DFS) were estimated using Kaplan-Meier method; the Log-Rank test (Mantel-Cox) and Cox regression models were applied to investigate predictors of survival. Results: The 5-year OS, DSS and DFS were 73.6 %, 89.2 % and 75.2 % respectively. Nodal metastasis (pN+), relapse and American Society of Anesthesiologists ASA-II were found independent prognostic factors for OS, and significantly associated to worst DSS (p < 0.001). TV significantly correlated with higher relapse occurrence (p = 0.03). Conclusions: In our experience, lymph-node status, ASA classification and relapse significantly influenced DSS on univariate analysis. TV could represent an interesting additional parameter, since it significantly influenced DFS. However, prospective studies with standardized TV measurements and a greater number of patients are needed to validate this result

Pharmacological targeting of CBP/p300 drives a redox/autophagy axis leading to senescence-induced growth arrest in non-small cell lung cancer cells

p300/CBP histone acetyltransferases (HAT) are critical transcription coactivators involved in multiple cellular activities. They act at multiple levels in non-small cell lung carcinoma (NSCLC) and appear, therefore, as promising druggable targets. Herein, we investigated the biological effects of A-485, the first selective (potent) drug-like HAT catalytic inhibitor of p300/CBP, in human NSCLC cell lines. A-485 treatment specifically reduced p300/CBP-mediated histone acetylation marks and caused growth arrest of lung cancer cells via activation of the autophagic pathway. Indeed, A-485 growth-arrested cells displayed phenotypic markers of cell senescence and failed to form colonies. Notably, disruption of autophagy by genetic and pharmacological approaches triggered apoptotic cell death. Mechanistically, A-485-induced senescence occurred through the accumulation of reactive oxygen species (ROS), which in turn resulted in DNA damage and activation of the autophagic pathway. Interestingly, ROS scavengers were able to revert senescence phenotype and restore cell viability, suggesting that ROS production had a key role in upstream events leading to growth arrest commitment. Altogether, our data provide new insights into the biological effects of the A-485 and uncover the importance of the autophagic/apoptotic response to design a new combinatorial anticancer strategy

Testing supersymmetry at the LHC through gluon-fusion production of a slepton pair

Renormalizable quartic couplings among new particles are typical of supersymmetric models. Their detection could provide a test for supersymmetry, discriminating it from other extensions of the Standard Model. Quartic couplings among squarks and sleptons, together with the SU(3) gauge couplings for squarks, allow a new realization of the gluon-fusion mechanism for pair-production of sleptons at the one-loop level. The corresponding production cross section, however, is at most of ${\cal O}(1)$fb for slepton and squark masses of ${\cal O}(100)$GeV. We then extend our investigation to the gluon-fusion production of sleptons through the exchange of Higgs bosons. The cross section is even smaller, of ${\cal O}(0.1)$fb, if the exchanged Higgs boson is considerably below the slepton-pair threshold, but it is enhanced when it is resonant. It can reach ${\cal O}(10)$fb for the production of sleptons of same-chirality, exceeding these values for $\widetilde{\tau}$'s of opposite-chirality, even when chirality-mixing terms in the squark sector are vanishing. The cross section can be further enhanced if these mixing terms are nonnegligible, providing a potentially interesting probe of the Higgs sector, in particular of parameters such as $A$, $\mu$, and $\tan\beta$.Comment: 28 pages, 11 figure

Soft Yukawa couplings in supersymmetric theories

The possibility of radiatively generated fermion masses arising from chiral flavor violation in soft supersymmetry-breaking terms is explored. Vacuum stability constraints are considered in various classes of models, and allow in principle all of the first- and second-generation quarks and leptons and the $b$-quark to obtain masses radiatively. Radiatively induced Higgs-fermion couplings have non-trivial momentum-dependent form factors, which at low momentum are enhanced with respect to the case of tree-level Yukawa couplings. These form factors may be probed by various sum rules and relations among Higgs boson decay widths and branching ratios to fermion final states. An apparent, large, hard violation of supersymmetry also results for Higgsino couplings. Mixing between left- and right-handed scalar superpartners is enhanced. A radiative muon mass is shown to lead to a relatively large and potentially measurable contribution to the muon anomalous magnetic moment. If the light-quark masses arise radiatively, the neutron electric dipole moment is suppressed by a natural phase alignment between the masses and dipole moment, and is below the current experimental bound. The possibility of neutrino masses arising from softly broken lepton number, and concomitant enhanced sneutrino-antisneutrino oscillations, is briefly discussed.Comment: 66 pages. LaTex + RevTex. 16 figures (included). Published version (minor changes and typos corrected

INTERKULTURALNI ODGOJ U PROGRAMIMA DJEČJIH VRTIĆA

La tesina di laurea intitolata “L’educazione interculturale nei programmi della scuola d’infanzia’” comprende due parti: la parte teorica e quella pratica. La parte teorica attraverso cinque capitoli elabora gli argomenti e i concetti più significativi come cultura, mulicultura, intercultura, educazione interculturale, educazione alla cittadinnza attiva, educazione civica e il loro rapporto con l’educazione interculturale, ed infine la competenza interculturale e il ruolo dell’ educatore nella promozione dell’educazione interculturale nella scuola d’infanzia. La parte pratica analizza quattro progetti svolti nella scuola d’infanzia durante l’anno pedagogico 2020/2021. Lo scopo dell’analisi era di determinare la presenza delle dimensioni della competenza interculturale in ognuno di loro. La competenza interculturale comprende cinque dimensioni: (cognitiva (conoscenza), affettiva (motivazione), comportamentale (forme di comportamento in un particolare contesto temporale e spaziale), comunicativa (comunicazione verbale e non verbale) e etico/valoriale dimensione costituita da: valori personali (valori morali); professionali (deontologia); valori di gruppo (sociali, culturali, organizzativi); valori universali (rispetto dei diritti umani). Secondo l’analisi svolta si conclude che ogni progetto comprende due o più dimensioni della competenza interculturale. Dunque, i progetti analizzati sono solo una testimonianza come si possono implementare valori non soltanto dell’educazione interculturale ma anche quelli dell’ educazione civica e dei diritti dell’infanzia nella programmazione pedagogica in collaborazione con tutti gli adetti dell’asilo, dalla diretrice, pedagoga, incluso tutte le educatrici dei vari gruppi educativi, come pure i genitori.Završni rad “Interkulturalni odgoj u programima dječjih vrtića” obuhvaća dva dijela: teorijski i praktični. Teorijski dio rada sastoji se od poglavlja u kojima se obrađuju temeljni pojmovi kao što su kultura, multikultura, interkultura, interkulturalni odgoj te odgoj za aktivno građanstvo i građanski odgoj kao i njihov međusobni odnos. Posebna pažnja posvećuje se i ulozi odgojitelja u promicanju interkulturalnog odgoja u predškolskim ustanovama. Praktični dio rada analizira četiri projekta koji su realizirani u dječjem vrtiću tijekom pedagoške 2020./2021. godine. Cilj analize bio je utvrditi jesu li i koje dimenzije interkulturalne kompetencije prisutne u odabranim projektima. Interkulturalna kompetencija obuhvaća pet dimenzija: kognitivna (znanje), afektivna (motivacija), ponašajna (oblici ponašanja u određenom vremenskom i prostornom kontekstu), komunikacijska (verbalna i neverbalna komunikacija) i etičko/vrijednosna dimenzija koju čine: osobne vrijednosti (moralne vrijednosti); profesionalne (deontologija); grupne vrijednosti (društvene, kulturne, organizacijske); univerzalne vrijednosti (poštivanje ljudskih prava). Na temelju provedene analize može se zaključiti da su u svakom projektu prisutne dvije ili više dimenzija interkulturalne kompetencije. Dakle, analizirani projekti samo nam potvrđuju kako je moguće u pedagoški program dječjeg vrtića implementirati vrijednosti ne samo interkulturalnog odgoja, nego i građanskog odgoja i prava djece u suradnji sa svim djelatnicima vrtića, od ravnatelja, pedagoga, odgojitelja raznih odgojnih skupina, ali i roditelja te drugih dionika lokalne zajednice

INTERKULTURALNI ODGOJ U PROGRAMIMA DJEČJIH VRTIĆA

La tesina di laurea intitolata “L’educazione interculturale nei programmi della scuola d’infanzia’” comprende due parti: la parte teorica e quella pratica. La parte teorica attraverso cinque capitoli elabora gli argomenti e i concetti più significativi come cultura, mulicultura, intercultura, educazione interculturale, educazione alla cittadinnza attiva, educazione civica e il loro rapporto con l’educazione interculturale, ed infine la competenza interculturale e il ruolo dell’ educatore nella promozione dell’educazione interculturale nella scuola d’infanzia. La parte pratica analizza quattro progetti svolti nella scuola d’infanzia durante l’anno pedagogico 2020/2021. Lo scopo dell’analisi era di determinare la presenza delle dimensioni della competenza interculturale in ognuno di loro. La competenza interculturale comprende cinque dimensioni: (cognitiva (conoscenza), affettiva (motivazione), comportamentale (forme di comportamento in un particolare contesto temporale e spaziale), comunicativa (comunicazione verbale e non verbale) e etico/valoriale dimensione costituita da: valori personali (valori morali); professionali (deontologia); valori di gruppo (sociali, culturali, organizzativi); valori universali (rispetto dei diritti umani). Secondo l’analisi svolta si conclude che ogni progetto comprende due o più dimensioni della competenza interculturale. Dunque, i progetti analizzati sono solo una testimonianza come si possono implementare valori non soltanto dell’educazione interculturale ma anche quelli dell’ educazione civica e dei diritti dell’infanzia nella programmazione pedagogica in collaborazione con tutti gli adetti dell’asilo, dalla diretrice, pedagoga, incluso tutte le educatrici dei vari gruppi educativi, come pure i genitori.Završni rad “Interkulturalni odgoj u programima dječjih vrtića” obuhvaća dva dijela: teorijski i praktični. Teorijski dio rada sastoji se od poglavlja u kojima se obrađuju temeljni pojmovi kao što su kultura, multikultura, interkultura, interkulturalni odgoj te odgoj za aktivno građanstvo i građanski odgoj kao i njihov međusobni odnos. Posebna pažnja posvećuje se i ulozi odgojitelja u promicanju interkulturalnog odgoja u predškolskim ustanovama. Praktični dio rada analizira četiri projekta koji su realizirani u dječjem vrtiću tijekom pedagoške 2020./2021. godine. Cilj analize bio je utvrditi jesu li i koje dimenzije interkulturalne kompetencije prisutne u odabranim projektima. Interkulturalna kompetencija obuhvaća pet dimenzija: kognitivna (znanje), afektivna (motivacija), ponašajna (oblici ponašanja u određenom vremenskom i prostornom kontekstu), komunikacijska (verbalna i neverbalna komunikacija) i etičko/vrijednosna dimenzija koju čine: osobne vrijednosti (moralne vrijednosti); profesionalne (deontologija); grupne vrijednosti (društvene, kulturne, organizacijske); univerzalne vrijednosti (poštivanje ljudskih prava). Na temelju provedene analize može se zaključiti da su u svakom projektu prisutne dvije ili više dimenzija interkulturalne kompetencije. Dakle, analizirani projekti samo nam potvrđuju kako je moguće u pedagoški program dječjeg vrtića implementirati vrijednosti ne samo interkulturalnog odgoja, nego i građanskog odgoja i prava djece u suradnji sa svim djelatnicima vrtića, od ravnatelja, pedagoga, odgojitelja raznih odgojnih skupina, ali i roditelja te drugih dionika lokalne zajednice