Mapping of transcription start sites of human retina expressed genes.

Background: The proper assembly of the transcriptional initiation machinery is a key regulatory step in the execution of the correct program of mRNA synthesis. The use of alternative transcription start sites (TSSs) provides a mechanism for cell and tissue specific gene regulation. Our knowledge of transcriptional initiation sequences in the human genome is limited despite the availability of the complete genome sequence.

Identification of genes selectively regulated by IFNs in endothelial cells.

IFNs are highly pleiotropic cytokines also endowed with marked antiangiogenic activity. In this study, the mRNA expression profiles of endothelial cells (EC) exposed in vitro to IFN-alpha, IFN-beta, or IFN-gamma were determined. We found that in HUVEC as well as in other EC types 175 genes were up-regulated (>2-fold increase) by IFNs, including genes involved in the host response to RNA viruses, inflammation, and apoptosis.

Recruitment of human umbilical vein endothelial cells and human primary fibroblasts into experimental tumors growing in SCID mice.

Generation of a vascular network is a hallmark of solid tumor growth, and attempts to switch off the tumor angiogenic phenotype are promising. However, this angiogenic potential might also be exploited to obtain incorporation into tumor vessels of genetically modified third-party cells, which could behave as targets of immunologic or pharmacologic attack. With this in mind, we addressed the efficiency and selectivity of third-party cell recruitment into experimental tumors generated in severe combined immunodeficiency mice.

Expression from cell type-specific enhancer-modified retroviral vectors after transduction: influence of marker gene stability.

The enhanced green fluorescent protein (EGFP) is increasingly used as a reporter gene in viral vectors for a number of applications. To establish a system to study the activity of cis-acting cellular regulatory sequences, we deleted the viral enhancer in EGFP-carrying retroviral vectors and replaced it with cell type-specific elements. In this study, we use this system to demonstrate the activity of the human CD2 lymphoid-specific and the Tie2 endothelial cell type-specific enhancers in cell lines and in primary cells transduced by retroviral vectors.