Folic acid treatment of colorectal cancer cell lines

Folic acid is involved in DNA methylation, thereby it can potentially induce gene silencing. We used microarrays to detect the transcripts that are showing different expressions after short-term folic acid (FA) treatment. Colorectal cancer (CRC) cells were kept in FA-free medium or treated with 10000 ng/mL folic acid, then harvested for gene expression analysis following 72 hours incubation period. HTA 2.0 microarray experiments were performed according to the manufacturer’s instructions. Firstly, 100 ng input total RNA samples were applied as starting material. For sscDNA synthesis 15 µg cRNA was used and 5.5 µg fragmented and labeled sscDNA sample was hybridized to HTA 2.0 microarrays (Affymetrix) for 16 hours at 45°C with 60 rpm rotation in the Hybridization Oven (Affymetrix). Microarrays were washed and stained with GeneChip® Hybridization, Wash, and Stain Kit reagents according to FS450_0001 protocol using the Fluidics Station 450 instrument (Affymetrix). Scanning was performed with GeneChip Scanner 3000 (Affymetrix).