Overexpression of the Wilms' tumor gene WT1 in de novo lung cancers

Expression of the Wilms' tumor gene WTI in de novo lung cancer was examined using quantitative real-time RT-PCR and immunohistochemistry. Overexpression of the WTI gene was detected by RT-PCR in 54/56 (96%) de novo non-small cell lung cancers examined and confirmed by detection of WTI protein with an anti-WTI antibody. Overexpression of the WTI gene was also demonstrated in 516 (83%) de novo small cell lung cancers by immunohistochemistry. Furthermore, when the WTI gene was examined for mutations by direct sequencing of genomic DNA in 7 lung cancers, no mutations were found. These results suggest that the non-mutated, wild-type WTI gene plays an important role in tumorigenesis of de novo lung cancers and may provide us with the rationale for new therapeutic strategies for lung cancer targeting the WTI gene and its products. (C) 2002 Wiley-Liss, Inc.