Adrenal gland tissue sections showing intense immunoreactivity for P gp, were used as positive controls. The negative control consisted on the omission of the primary antibody. Assess ment of antibody expression was performed by a pathologist blinded to molecular analyses data. Imunohisto chemistry results were categorized according product info to stain in tensity as 2, 1, and 0. Chromatin immunoprecipitation Assay EZ Magna ChIP G Chromatin Immunoprecipitation Kit and the Magna Grip Rack were used to perform ChIP assay according to the man ufacturers instruction. For each chromatin immunopre cipitation, 5 ug of anti AcH3, anti H3K4me2, anti H3K4me3, anti AcH3K9, anti AcH4 and 1 uL of the negative control provided with the kit were used.

Quantification of DNA was performed in a 7000 Real Time PCR System, using Power SYBR Green PCR Master Mix and gene specific primers for gene promoter of MDR1 upstream Inhibitors,Modulators,Libraries Transcription Start Site ]. The relative amount of promoter Inhibitors,Modulators,Libraries DNA was normalized using Input Percent Method. Western blot For mock and treated LNCaP, DU145 and PC3 cell lines, protein extract concentrations were determined using Pierce BCA Protein Assay Kit. Subsequently, 30 ug of total protein were loaded in each well, and separated by SDS PAGE, transferred to nitrocellulose membranes and probed with antibodies against P glycoprotein or the endogenous control B actin. Secondary antibodies, conjugated with horseradish peroxidase, were incubated at a dilution of 1 3000. Finally, blots were developed Inhibitors,Modulators,Libraries using Immun Star WesternC Kit according to manufacturers indications and exposed to Amersham Hyperfilm.

Experiments were done with biological triplicates. Relative optical density determin ation was performed using QuantityOne Software version 4. 6. 6. Statistical analysis As the analyzed variables did not follow a normal distribu tion, nonparametric tests were used. In each group of samples, frequencies of MDR1 methylation Inhibitors,Modulators,Libraries were com pared using the Chi square test for trend. Median and interquartile range of MDR1 methylation levels were also determined, and then compared using Kruskall Wallis test or the Mann Whitney U test, depending on the number of categories in each group. Likewise, the rela tionship between methylation Inhibitors,Modulators,Libraries ratios and standard clinico pathological variables, were evaluated using the Kruskall Wallis or Mann Whitney tests.

A Spearman nonparametric correl ation test was additionally performed to compare age and methylation levels. Frequencies of immunoexpression along sample groups were compared using the Chi square test, and the direc tional measure Somersd was additionally computed. Som ers statistic varies from ?1 selleck chemicals Tubacin to 1 and assesses the association between two ordinal variables, with a value of 1 indicating a strong positive association, and a value of ?1 indicating a strong negative one.