Antibody detection of translocations (ADOT) in Ewing Sarcoma

We developed a new approach called antibody detection of translocations (ADOT) which combines a transcriptional microarray-based approach with a novel antibody-based detection method to detect translocations in cancer. ADOT allows for the accurate and sensitive identification of translocations and provides exon-level information about the fusion transcript. ADOT can detect translocations in poor quality unprocessed total RNA. We demonstrate the feasibility of ADOT by examples in which both known and unknown Ewing sarcoma translocations are identified from cell lines, tumor xenografts, and FFPE primary tumors. These results demonstrate that ADOT may be an effective approach for translocation analysis in clinical specimens with significant RNA degradation and may offer a novel diagnostic tool for translocation-based cancers. We designed oligonucleotide probes for each possible exon-exon combination between potential fusion partners and printed the DNA oligonucleotides on custom-designed microarrays. Total RNA from tumor cells or tissues was hybridized on the array. Bound RNA was detected with the S9.6 monoclonal antibody that recognizes RNA-DNA duplexes in a sequence-independent fashion,and detected with Cy3-labeled anti-mouse IgG.