Strategies for Gene Expression Imaging

Direct approaches depend on probes of various types that either accumulate in tissues by binding directly to the DNA, to the RNA message, to the gene product itself (e.g., when that product is a receptor), or are trapped intraceUularly as they are modified by the gene product (e.g., when that product is an enzyme). 

Endogenous gene expression can also be monitored using radiolabeled probes that bind directiy to the gene product. This strategy has the advantage 

The use of imaging to monitor reporter gene expression can theoretically overcome the disadvantages associated with tissue-based techniques. The concepts 

To date, the optimal PRG-PRP system is still a matter of debate, and may differ depending on the tissue or process under study. Even so, the use of PET imaging to monitor exogenous gene transfer in pulmonary tissue by measuring the expression of a suitable enzyme is already proving to be a fruitful experimental strategy (41-43). 

However, this particular strategy has not yet been evaluated with imaging methods (16,53). 

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