Transient ectopic expression as a method to detect genes conferring drug resistance

Ectopic expression provides an alternative to RNAi to conduct functional genomic screens. We have determined whether transient expression can be used to identify genes which confer drug resistance. We constructed a bigenic vector that allows high throughput cloning and which also encodes a red fluorescent protein to monitor transfection. Assay conditions were optimized to allow detection of changes in sensitivity to carboplatin or paclitaxel. Following transient expression of MDR-1 and MCJ, changes in the sensitivity of Sk-Ov-3 cells to paclitaxel were detected whereas expression of Src, Bcl-2 and Bcl-X-L decreased the sensitivity of Sk-Ov-3 cells to carboplatin. This approach may potentially be used as an independent screen or as a method to help rank hit identified in screens utilizing methods such as RNAi (c) 2008 Wiley-Liss, Inc.