DNA methylation and expression profiling study for prostate cancer

ABSTRACT: Microarray-based DNA methylation and gene expression profiling was carried out using a panel of prostate cancer cell lines (LNCaP-FGC, DU-145, and PC-3) and the control normal prostate RWPE1 cell line. The identification of prostate cancer-specific methylation markers was based on the following criteria: a difference in DNA methylation level (β) of at least 0.5, and at least a 2-fold difference in expression level between cancer and control cells. Using highly stringent selection criteria, we identified novel hypermethylated genes whose expression was silenced in prostate cancer cells. Genomic DNA was extracted by standard methods using the Wizard Genomic DNA Purification System (Promega, Madison, WI). Total RNA was extracted with TRIzol reagent (Life Technologies, NY) according to the manufacturer’s protocol. Methylation patterns were assayed using the genome-wide Illumina Infinium HumanMethylation27 BeadChip array (Illumina Inc., San Diego, CA). Methylation assays were carried out according to the manufacturer’s protocol. Bisulfite conversion of genomic DNA was performed using the EZ DNA Methylation Kit (Zymo Research, Orange, CA). Fluorescence signals corresponding to C or T nucleotides were measured and the data were used to assign a quantitative measure of methylation level (β value). The β value is a quantitative measure of DNA methylation levels of specific CpGs and ranges from 0 for completely unmethylated to 1 for completely methylated. For the integrated analysis of global methylation status and gene expression levels, we used the genome-wide HumanHT-12 Gene Expression BeadChip (Illumina Inc., San Diego, CA). Gene expression analysis was performed according to the manufacturer’s protocol. Five hundred nanograms of total RNA were used for labeling hybridization according to the manufacturer’s protocol. Arrays were scanned with an Illumina Bead Array Reader confocal scanner (BeadStation 500GXDW; Illumina Inc., San Diego, CA), according to the manufacturer's instructions. Initial microarray gene expression data were obtained using the gene expression analysis module of Bead Studio software (version 3.1.3, Illumina Inc., San Diego, CA).

ORGANISM(S): Homo sapiens

SUBMITTER: Seon-Kyu Kim 

PROVIDER: E-GEOD-23388 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress