Effect of t10,c12 CLA on the global gene expression shows significant changes in critical genes from the ER stress pathway.

<p>A2780 cells were treated with 7 μM t10,c12 CLA for 72 h. Control cells were treated with vehicle under identical conditions. RNA was isolated from the t10,c12 CLA-treated cells and the vehicle controls. After quality check of the RNA, the gene expression was determined using the Illumina HT12V4 expression bead chip array. (A) A volcano plot of the differentially expressed genes is shown. Genes that were either up- or down-regulated at or above a 1.5-fold threshold were considered for further analysis. Results shown are mean of three independent experiments. (B) The Gene Ontology (GO) analysis was conducted on the genes that were differentially expressed by at least 1.5-fold (with p<0.02) in t10,c12 CLA-treated A2780 cells. The analysis shows that genes in several critical processes are affected. The numbers in parenthesis denote the percentage of the total differentially expressed genes that belong to the individual cellular processes. (C) The fold-change in expression of the most prominent genes detected in the t10,c12 CLA-treated A2780 cells is shown. Significantly, based on the fold change, top 7 differentially expressed genes (ATF4, CHOP (DDIT3), EDEM2, HSPH1, HSPA4L, HSP90AA1, PPP1R15A, and MAP2K2) shown in this bar plot belong to the ER stress pathway (green bars). (D) Independent validation of the differential expression of ER stress-related genes, ATF4, GADD34, Hsp90 and CHOP (DDIT3) in t10,c12 CLA treated ovarian cancer cells was monitored by real-time quantitative PCR. The A2780 cells were treated with t10,c12 CLA (7 μM) for 72 h. Mean readings from three separate experiments is plotted. Expression of the genes is normalized to the housekeeping gene, S27.