liferation, connective tis sue development and function, cell cycle, and cell death. Genes demonstrating altered expression included those expressing kinases, phosphatases and transcrip tional regulators but not growth factors. When compar ing expression levels Tipifarnib IC50 at 35 versus 7 days for transcriptional coregulators, CREBBP, RNPC2, PRRX1, Nrip1 and NMI were upregulated by 2 to 3. 98 fold while Tgif, Lmcd1, Ankrd1 and Ankrd2 were downregu lated from 2. 75 to 23. 81 fold. There were 24 other transcriptional regulators for which expression changed between 7 and 35 Inhibitors,Modulators,Libraries days, with alterations in expression ranging from a 3. 28 fold increase to 6. 85 fold decrease. The largest increases in expres sion were for TSC22D4, BHLHB3, and DBP, while the greatest decreases in expression were observed for BTG2, Egr2, and RCAN1.

Seventeen kinases demonstrated significant changes in expression ranging from a 4. 08 fold increase to a 2. 84 fold decrease. Kinases with the most highly increased expression included ERBB2, NTRK2, and PIK3C2B, while those with the greatest decrease in expression included MPP6, TRIB1, and UCK2. Seven Inhibitors,Modulators,Libraries phosphatases demonstrated altered expression, with 6 being decreased by 1. 54 to 3. 62 fold and one being increased by 6. 96 fold. Verification of selected microarray data by real time PCR The results of the microarray analysis were confirmed for selected genes by real time PCR. A com parison of findings from microarray and real time PCR analysis revealed that the direction and magnitude of change in expression were similar.

As compared to 7 days, expression at 35 days was significantly different for the transcriptional coregulators Ankrd1, Ankrd2, and CREBBP, as well as for the transcription factors Atf5 and LIMCD 1. Correlation between gene expression changes Inhibitors,Modulators,Libraries and nandrolone response To gain insights into physiological significance of gene expression changes, we analyzed the relationship between gastrocnemius muscle size at 35 days and magnitude of gene expression change induced by nandrolone. For this analysis we chose the two genes for which nandrolone had the largest effect on mRNA levels as determined by real time PCR, RCAN2 and ApoD. There was a signifi cant negative correlation Inhibitors,Modulators,Libraries between RCAN2 mRNA levels and gastrocnemius muscle weight. A positive correlation was observed between ApoD mRNA and weights of denervated gastrocnemius.

Discussion Nandrolone effects on gene expression over time This study sought insights into the molecular basis for the observation that administration of nandrolone GSK-3 for 7 LDK378 days slowed denervation atrophy when begun at day 29 after nerve transection, but had no effect on atrophy when initiated at the time the nerve was severed. The findings indicated that nandrolone regu lated an almost entirely different set of genes at 7 days compared to 35 days. A marked change in the expres sion in denervated muscle of genes involved in the con trol of transcription and intracellular signaling was observed between 7 and 35 days. Am