Physical interactions between genetic elements located throughout the genome play important roles in gene regulation and can be identified with the Chromosome Conformation Capture (3C) methodology. 3C converts physical chromatin interactions into specific ligation products, which are quantified individually by PCR. Here we present a high-throughput 3C approach, 3C-Carbon Copy (5C), that employs microarrays or quantitative DNA sequencing using 454-technology as detection methods. We applied 5C to analyze a 400-kb region containing the human ␤-globin locus and a 100-kb conserved gene desert region. We validated 5C by detection of several previously identified looping interactions in the ␤-globin locus. We also identified a new looping interaction in K562 cells between the ␤-globin Locus Control Region and the ␥-␦-globin intergenic region. Interestingly, this region has been implicated in the control of developmental globin gene switching. 5C should be widely applicable for large-scale mapping of cis-and trans-interaction networks of genomic elements and for the study of higher-order chromosome structure.

Cohesin is required to prevent premature dissociation of sister chromatids after DNA replication. Although its role in chromatid cohesion is well established, the functional significance of cohesin's association with interphase chromatin is not clear. Using a quantitative proteomics approach, we show that the STAG1 (Scc3/ SA1) subunit of cohesin interacts with the CCTC-binding factor CTCF bound to the c-myc insulator element. Both allele-specific binding of CTCF and Scc3/SA1 at the imprinted IGF2/H19 gene locus and our analyses of human DM1 alleles containing base substitutions at CTCF-binding motifs indicate that cohesin recruitment to chromosomal sites depends on the presence of CTCF. A large-scale genomic survey using ChIP-Chip demonstrates that Scc3/SA1 binding strongly correlates with the CTCF-binding site distribution in chromosomal arms. However, some chromosomal sites interact exclusively with CTCF, whereas others interact with Scc3/SA1 only. Furthermore, immunofluorescence microscopy and ChIP-Chip experiments demonstrate that CTCF associates with both centromeres and chromosomal arms during metaphase. These results link cohesin to gene regulatory functions and suggest an essential role for CTCF during sister chromatid cohesion. These results have implications for the functional role of cohesin subunits in the pathogenesis of Cornelia de Lange syndrome and Roberts syndromes.cohesion ͉ transcription ͉ insulator ͉ centromere ͉ metaphase

The (15)(16)(17). These factors include acidic fibroblast growth factor, basic fibroblast growth factor (bFGF), epidermal growth factor, transforming growth factors a and 13, tumor necrosis factor a, and vascular endothelial growth factor (VEGF). VEGF is secreted by a number of tumors and is normally expressed in the kidney, brain, and other tissues (18-22).VEGF is also markedly elevated in both VHL-associated and sporadic central nervous system hemangioblastomas (23, 24) and renal carcinomas (25,26). In addition to having mitogenic activity on endothelial cells, VEGF also induces vascular permeability, which may lead to extravasation of plasma proteins and deposition of fibrin, providing an extracellular support for tumor cell and endothelial cell growth.In the present study the effects of retroviral transduction of the VHL cDNA into renal carcinoma cell lines was evaluated. ITo whom reprint requests should be addressed