Ring chromosome 17 syndrome is a rare disease that arises from the breakage and reunion of the short and long arms of chromosome 17. Usually this abnormality results in deletion of genetic material, which explains the clinical features of the syndrome. Moreover, similar phenotypic features have been observed in cases with complete or partial loss of the telomeric repeats and conservation of the euchromatic regions. We studied two different cases of ring 17 syndrome, firstly, to clarify, by analyzing gene expression analysis using real-time qPCR, the role of the telomere absence in relationship with the clinical symptoms, and secondly, to look for a new model of the mechanism of ring chromosome transmission in a rare case of familial mosaicism, through cytomolecular and quantitative fluorescence in-situ hybridization (Q-FISH) investigations.

The advent of next generation sequencing revealed that a fraction of transcribed RNAs (short and long RNAs) is non-coding. Long non-coding RNAs (lncRNAs) have a crucial role in regulating gene expression and in epigenetics (chromatin and histones remodeling). LncRNAs may have different roles: gene activators (signaling), repressors (decoy), cis and trans gene expression regulators (guides) and chromatin modificators (scaffolds) without the need to be mutually exclusive. LncRNAs are also implicated in a number of diseases. The huge amount of inhomogeneous data produced so far poses several bioinformatics challenges spanning from the simple annotation to the more complex functional annotation. In this review, we report and discuss several bioinformatics resources freely available and dealing with the study of lncRNAs. To our knowledge, this is the first review summarizing all the available bioinformatics resources on lncRNAs appeared in the literature after the completion of the human genome project. Therefore, the aim of this review is to provide a little guide for biologists and bioinformaticians looking for dedicated resources, public repositories and other tools for lncRNAs functional analysis.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression through the binding of the 3' untranslated region (3'UTR) of specific mRNAs. MiRNAs are post-transcriptional regulators and determine the repression of translation processes or the degradation of mRNA targets. Recently, another kind of miRNA-mediated regulation of translation (repression or activation) involving the binding of miRNA to the 5'UTR of target gene has been reported. The possible interactions and the mechanism of action have been reported in many works that we reviewed here. Moreover, we discussed also the available bioinformatics tools for predicting the miRNA binding sites in the 5'UTR and public databases collecting this information.

Chitin and chitosan are natural polysaccharide polymers. These polymers have been used in several agricultural, food protection and nutraceutical applications. Moreover, chitin and chitosan have been also used in biomedical and biotechnological applications as drug delivery systems or in pharmaceutical formulations. So far, there are only few studies dealing with arsenic (As) removal from groundwater using chitin or chitosan and no evidence of the use of these natural polymers for arsenic trioxide (As₂O₃) delivery in tumor therapy. Here we suggest that chitin and/or chitosan might have the right properties to be employed as efficient polymers for such applications. Besides, nanotechnology offers suitable tools for the fabrication of novel nanostructured materials of natural origin. Since different nanostructured materials have already been employed successfully in various multidisciplinary fields, we expect that the integration of nanotechnology and natural polymer chemistry will further lead to innovative applications for environment and medicine.

MicroRNAs (miRs) are an abundant class of small non-coding RNAs (~22 nt) that reprogram gene expression by targeting mRNA degradation and translational disruption. An emerging concept implicates miR coupling with transcription factors in myeloid cell development and function, thus contributing to host defense and inflammation. The important role that these molecules play in the pathogenesis of HIV-1 is only now emerging. We provide evidence that exposure of monocyte-derived dendritic cells (MDDCs) to recombinant HIV-1 R5 gp120, but not to CCR5 natural ligand CCL4, influences the expression of a panel of miRs (i.e., miR-21, miR-155 and miR-181b) regulated by STAT3 and potentially targeting genes belonging to the STAT3 signaling pathway. The blockage of gp120-induced STAT3 activation impairs gp120 capacity to modulate the expression level of above mentioned miRs. Predictive analysis of miR putative targets emphasizes that these miRs share common target genes. Furthermore, gene ontology and pathway enrichment analysis outline that these genes mainly belong to biological processes related to regulation of transcription, in a complex network of interactions involving pathways relevant to HIV-DC interaction. Overall, these results point to gp120-triggered modulation of miR expression via STAT3 activation as a novel molecular mechanism exploited by HIV-1 to affect DC biology and thus modulate the immune response through complex regulatory loops involving, at the same time, miRs and transcription factors.

Rhabdomyosarcoma (RMS) is a pediatric tumor that originates from skeletal muscle precursors. Therapeutic strategies aimed at restoring the differentiation potential of RMS tumor cells are accepted as anti-cancer approaches. Therefore, pathways involved in skeletal muscle determination are good potential targets. We have recently demonstrated that Notch3 signaling is over-activated in RMS cell lines of both embryonal and alveolar subtype. Down-regulation of Notch3 expression resulted in cell cycle inhibition of RMS alveolar and embryonal cell lines that showed the appearance of multinucleated structures indicative of skeletal muscle-like myotubes in vitro. Moreover, Notch3 knockdown impaired tumor growth in vivo. Here we expand this study evaluating, through microarrays profiling, the expression of microRNAs 48 hours after Notch3 siRNA treatment compared to that of control siRNA. Several up- or down-regulated microRNAs were detected in both RH30 alveolar and RD embryonal cells. The up-regulation of muscle-specific microRNAs such as miR-1, miR-133 and miR-206 was confirmed 24 and 48 hours post-Notch3 depletion by RT-qPCR. Moreover, non-muscle-specific microRNAs such as miR-26a and miR-214 that cooperate to myogenesis were up-regulated as well. Altogether, these preliminary results indicate that Notch3 prevents the differentiation of RMS cells also through down-regulation of pro-myogenic microRNAs. More deep studies are in course to dissect the Notch3-dependent modulation of these small non-coding RNAs in this soft tissue sarcoma. Citation Format: Rossella Rota, Sr., Roberta Ciarapica, Jr., Letizia Da Sacco, Jr., Maria De Salvo, Jr., Andrea Masotti, Sr., Lucio Miele, Sr., Franco Locatelli, Sr. Notch-dependent modulation of microRNAs in rhabdomyosarcoma [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer; 2012 Jan 8-11; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(2 Suppl):Abstract nr A29.