? The overall goal of the proposed research program is to develop a gene activation technology that can be applied to spatially discrete tissue subsites in the adult animal. The importance of this technology is that it should furnish a direct means to examine the biological consequences of gene expression within the context of specific tissue microenvironments. For example, the growth and progression of breast and prostate tumors are dependent upon the microenvironment in which they develop. However, it is not yet feasible to correlate the activity (or lack thereof) of a particular protein with oncogenic potential as a function of tissue microenvironment. Our strategy is based upon the ecdysteroid-driven gene expression system developed by Evans and his colleagues and further refined at the Albert Einstein College of Medicine by Pestell and his coworkers. We have prepared a light-activatable form of ecdysone that, in combination with spot illumination, can drive protein expression in any desired subset of cells present in a multicellular environment. We wilt prepare caged ecdysteroids that can be photochemically unleashed using two-photon illumination. The gene activation properties of these light-activatable agents will be evaluated both in cell-free and cell-based model systems and in the presence or absence of two-photon illumination. The latter technology furnishes deeper tissue penetration and a significantly reduced phototoxic load compared to single photon irradiation. Consequently, it is uniquely applicable to whole animal systems. We will evaluate the efficacy of light-induced protein expression in two distinct, but commonly employed, animal models. The first model consists of ectopically expressed tumors in Fischer 344 rats routinely employed in the Condeelis group. The second model is a previously described triply transgenic mouse line developed in the Pestell group. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21GM068993-01
Application #
6686108
Study Section
Special Emphasis Panel (ZRG1-SSS-U (10))
Program Officer
Deatherage, James F
Project Start
2003-08-01
Project End
2005-07-31
Budget Start
2003-08-01
Budget End
2004-07-31
Support Year
1
Fiscal Year
2003
Total Cost
$125,250
Indirect Cost
Name
Albert Einstein College of Medicine
Department
Biochemistry
Type
Schools of Medicine
DUNS #
071036636
City
Bronx
State
NY
Country
United States
Zip Code
10461
Singer, Robert H; Lawrence, David S; Ovryn, Ben et al. (2005) Imaging of gene expression in living cells and tissues. J Biomed Opt 10:051406