Human cyclin D1 is expressed as two isoforms derived by alternate RNA splicing, termed D1a and D1b, which differ for the inclusion of intron 4 in the D1b mRNA. Both isoforms are frequently upregulated in human cancers, but cyclin D1b displays relatively higher oncogenic potential. The splicing factors that regulate alternative splicing of cyclin D1b remain unknown despite the likelihood that they contribute to cyclin D1 oncogenicity. In this study, we report that Sam68, an RNA-binding protein frequently overexpressed in prostate cancer cells, enhances splicing of cyclin D1b and supports its expression in prostate cancer cells. Chromatin immunoprecipitation and RNA coimmunoprecipitation experiments showed that Sam68 is recruited to the human CCND1 gene encoding cyclin D1 and that it binds to cyclin D1 mRNA. Transient overexpression and RNAi knockdown experiments indicated that Sam68 acts to enhance endogenous expression of cyclin D1b. Minigene reporter assays showed that Sam68 directly affected alternative splicing of CCND1 message, with a preference for the A870 allele that is known to favor cyclin D1b splicing. Sam68 interacted with the proximal region of intron 4, and its binding correlated inversely with recruitment of the spliceosomal component U1-70K. Sam68-mediated splicing was modulated by signal transduction pathways that elicit phosphorylation of Sam68 and regulate its affinity for CCND1 intron 4. Notably, Sam68 expression positively correlates with levels of cyclin D1b, but not D1a, in human prostate carcinomas. Our results identify Sam68 as the first splicing factor to affect CCND1 alternative splicing in prostate cancer cells, and suggest that increased levels of Sam68 may stimulate cyclin D1b expression in human prostate cancers.

We show for the first time that necroptosis is strongly associated with intestinal inflammation in children with IBD and contributes to strengthen the inflammatory process. We believe that RIP3 and MLKL could represent attractive targets for the management of human IBD.

The Finite element technique is applied for studying the very complex stre:;s-strain Field of thin hard coatings subjected to a hast:indentation process. Berkovich indentation experiments were simulated with the ABAQUS Finite element software package. The investigated system was titanium nitride on high speed sleel as an exampfc or a hard film on a softer st.bstrate. The tmmerical analysis allowed the plastic deformation history dtning intle,ltati(m to be I'nlh~wed. in particular, it was possible to correlate the onset of plastic deformation in the substrate with the shape of the loading curve, The system was ~imulaled by ;.m axisyn)tnetric nlotlel in which tile conical indenter has the same contau't area its the Berkovich indenter, A six-fold symmetric three-dimensional model was also defined for testing the suitability of the previous model. Tile indenler was modeled either as a rigid surface or as a delkwmable tliamotld tip. Comparison between the experimental data and nttmerical resulls demonstrated that tile I'inile elemet)l approach in capable of reproducing the loading-unloading behavior of a nanoindentation test. The film hardness of TiN/HSS specimens was numerically calculated for different indentation depths. It was shown thai the presence of the substrate affected Ih¢ hal'thtess IlteaStlt'eltletit l~)t" relative indentation depths greater than about t5q-of tile filrn ihickliess. ,O 199g Elsevier Science S.A.

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It was shown for the first time in our study that HMGB1 is secreted by human inflamed intestinal tissues and abundantly found in the stools of IBD patients. Hence, it can be considered as a novel marker for intestinal inflammation. We can also suggest that the presence of HMGB1 in large amounts in the fecal stream of IBD patients is mainly due to active secretion of the protein stored in the nucleus rather than a "de novo" synthesis.

This is the first study showing the presence of adhesive-invasive bacteria strains in the inflamed tissues of children with IBD. Collective features of these strains indicate that they belong to the AIEC spectrum, suggesting their possible role in disease pathogenesis.

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