A High-Throughput Arrayed Lentiviral RNAi Screen To Identify Novel Oncogenes in Multiple Myeloma.

Karyotypic complexity is one of the hallmarks of multiple myeloma, complicating efforts to identify the specific genetic alterations involved in the development of multiple myeloma. To identify genes essential for myeloma proliferation, we used a high-throughput loss-of-function approach using lentivirally delivered short hairpin RNA (shRNA) library targeting human kinases as part of a Multiple Myeloma Research Foundation sponsored pilot project. Three myeloma cell lines, MM.1S, RPMI8226 and INA6, were infected in an arrayed 384-well format. All infections were performed in quadruplicate; two replicates were treated with puromycin to select for infected cells and two were left untreated. Wells in which more than 25% of the cells survived puromycin treatment, as determined by a cell viability assay, were included in future analysis. Genes in which 2 or more hairpins scored below a defined threshold were considered as ‘hits’. To identify physiologically relevant hits, we have integrated these findings with whole genome analysis of copy number and gene expression of multiple myeloma. We have identified a number of genes that are both amplified in and required for multiple myeloma cell viability. These observations suggest potential new targets for therapeutic targeting in myeloma.