Determine genes differentially expressed between Raji cells and a subline which is resistant to APTO-253 (Raji/253R)

To obtain further insight into the resistance mechanism, RNA-seq analysis was carried out on 3 independent samples of both the sensitive Raji and resistant Raji/253R cells. A gene-level differential expression analysis was performed by removing all genes with less than 50 reads across all 6 samples as genes with only low level expression can cause irregularities in differential expression analysis. Genes were considered to be differentially expressed if their adjusted p-value was less than the 0.05 level and their fold change was >2 in either direction. Among the 13,791 evaluable genes there were 1,012 that were significantly up-regulated in the Raji/253R cells and 704 genes that were significantly down regulated relative to the parental sensitive Raji cells. The ATP-binding cassette sub-family member ABCG2 was the most up-regulated gene with more than a thousand-fold increase in transcript level. Genes were considered to be differentially expressed if their adjusted p-value was less than the 0.05 level and their fold change was >2 in either direction. Total cellular RNA was isolated using the RNeasy mini kit (QIAGEN, Valencia, CA) from 3 independent samples for each cell line. Total RNA was polyA selected and libraries were contructed using the Iluumina Tru-seq kit.