The mouse strains for all the transgenic lines are C57black background and established after nearly 2 years of cross-breeding between the floxed alleles and the MCM strain. ?MHC-floxed-HRas-v12/MKK3bE/MKK7D transgenic mice were established as reported previously(19, 20, 36, 37, 40). They were bred with ?MHC-Mer-Cre-Mer (MCM) mice (from Dr. J. Molkentin, Cincinnati Children’s Hospital)(32) to generate double transgenic animals harboring both floxed transgenes and Mer-Cre-Mer transgene. At 12 weeks of age the double transgenic mice and non-transgenic littermate controls were treated via i.p. injection of tamoxifen at a dosage of 20mg/kgBW once a day for 3 consecutive days as reported. The hearts were harvested at an early (4-7 days post first tamoxifen injection) and a late (2-4 weeks) time point. Left ventricles were dissected and rapidly frozen in liquid nitrogen and stored at -80?C prior to protein and RNA analysis.
Data processing
Affymetrix MAS5.0 gene expressions are normalized with median invariant method. To filter out significant genes, we adapted two approaches. A primary filtering method we used the standard two samples t-test in pair-wise comparisons involving gender (male or female), animal types (control, JNK, RAS, p38) and different time points (0, 1, 3, 4, 5, 9, 14). The selection criteria are as follows: |the fold change >2, |difference|>100, and p-value < 0.05