Sweyjawbu expression is a predictor of ALK rearrangement status in lymphoma

In recent years molecular subtyping has become an important tool for accurate diagnosis of many cancers; for example, the detection of ALK rearrangements in lymphoma and lung cancer helps clinicians provide more precise diagnosis and treatment. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) are two routine approaches used to detect ALK rearrangements. However, difficulties with acquisition of biopsy samples, high costs, and long waiting time for results negatively impact the application of these methods. A rapid and inexpensive alternative would be a useful complement to current ALK rearrangement detection. We identified a novel gene, sweyjawbu, from Affymetrix microarray studies. Its expression correlated strongly with ALK in an analysis of 1037 cancer cell lines (correlation coefficient = 0.92). By comparing sweyjawbu transcript levels, it was possible to discriminate 12 ALK rearrangement-positive lymphoma samples from 64 ALK rearrangement-negative lymphomas. Moreover, combining measurements of sweyjawbu expression and the ratio of the 5' and 3' portions of the ALK transcript provided even more accurate identification of ALK rearrangement-positive lymphomas. This novel approach is an excellent complement or alternative to existing FISH and IHC methodologies.