Background-MicroRNAs (miRNAs) are involved in cancer pathogenesis, apoptosis and cell growth, thereby functioning as either tumor suppressors or oncogenes. However, expression alterations and roles of these miRNAs in pancreatic cancer are largely unknown. We hypothesize that pancreatic cancer may have a unique miRNA profile, which may play a critical role in pancreatic cancer development, progression, diagnosis and prognosis.

Insertional mutagenesis and genotoxicity, which usually manifest as hematopoietic malignancy, represent major barriers to realizing the promise of gene therapy. Although insulator sequences that block transcriptional enhancers could mitigate or eliminate these risks, so far no human insulators with high functional potency have been identified. Here we describe a genomic approach for the identification of compact sequence elements that function as insulators. These elements are highly occupied by the insulator protein CTCF, are DNase I hypersensitive and represent only a small minority of the CTCF recognition sequences in the human genome. We show that the elements identified acted as potent enhancer blockers and substantially decreased the risk of tumor formation in a cancer-prone animal model. The elements are small, can be efficiently accommodated by viral vectors and have no detrimental effects on viral titers. The insulators we describe here are expected to increase the safety of gene therapy for genetic diseases.

BackgroundThe SBP-box gene family is specific to plants and encodes a class of zinc finger-containing transcription factors with a broad range of functions. Although SBP-box genes have been identified in numerous plants including green algae, moss, silver birch, snapdragon, Arabidopsis, rice and maize, there is little information concerning SBP-box genes, or the corresponding miR156/157, function in grapevine.Methodology/Principal FindingsEighteen SBP-box gene family members were identified in Vitis vinifera, twelve of which bore sequences that were complementary to miRNA156/157. Phylogenetic reconstruction demonstrated that plant SBP-domain proteins could be classified into seven subgroups, with the V. vinifera SBP-domain proteins being more closely related to SBP-domain proteins from dicotyledonous angiosperms than those from monocotyledonous angiosperms. In addition, synteny analysis between grape and Arabidopsis demonstrated that homologs of several grape SBP genes were found in corresponding syntenic blocks of Arabidopsis. Expression analysis of the grape SBP-box genes in various organs and at different stages of fruit development in V. quinquangularis ‘Shang-24’ revealed distinct spatiotemporal patterns. While the majority of the grape SBP-box genes lacking a miR156/157 target site were expressed ubiquitously and constitutively, most genes bearing a miR156/157 target site exhibited distinct expression patterns, possibly due to the inhibitory role of the microRNA. Furthermore, microarray data mining and quantitative real-time RT-PCR analysis identified several grape SBP-box genes that are potentially involved in the defense against biotic and abiotic stresses.ConclusionThe results presented here provide a further understanding of SBP-box gene function in plants, and yields additional insights into the mechanism of stress management in grape, which may have important implications for the future success of this crop.