Additional file 13: of HOTAIR and its surrogate DNA methylation signature indicate carboplatin resistance in ovarian cancer

Expression analyses for the GRONINGEN set. Of the 175 samples from the GRONINGEN set, 114 samples had matched array expression profiles (Operon Human v3 ~ 35 K 70-mer two-color oligonucleotide arrays, GSE13876, Crijns et al. [23 ]) and HOTAIR expression (36 HOTAIR -ve, 78 HOTAIR +  ve). We correlated the expression of genes on the array to HOTAIR expression and selected genes with a t-statistic P value < 0.05 (1147 genes). From these we then selected those genes which are PRC2 targets in MDAMB231 breast cancer cell lines (PRC2-MDAMB231; Gupta et al. [10]) or in human embryonic fibroblasts (PRC2-hEF; Bracken et al. 2006). There were 42 and 97 such PRC2-MDAMB231 and PRC2-hEF genes, respectively. The average expression (AvExp) over these enriched PRC2-MDAMB231 and PRC2-hEF genes was then computed for each sample separately and these values are compared between HOTAIR-ve and HOTAIR + ve samples. Wilcoxon rank sum test P value is given. (PDF 5 kb)