Wilms' tumor gene (WT1) expression in lung cancer, colon cancer and glioblastoma cell lines compared to freshly isolated tumor specimens

The Wilms' tumor gene (WT1) encodes a transcriptional regulator involved in growth and differentiation of various tissue types. A continuous over-expr ession of WT1 was found in leukemic blasts, thus suggesting an oncogenic fu nction. Solid cancer entities have also been described as expressing WT1. W e systematically analyzed WT1 expression in small-cell and non-small-cell l ung cancer, colon cancer and glioblastoma patients and in the respective tu mor cell lines. Using reverse transcription/polymerase chain reaction, we f ound WT1 expression in glioblastoma (5 of 8), lung (5 of 11), and colon can cer (5 of 15) cell lines. While WT1 was expressed in only 1 of 12 lung canc er and 1 of 5 glioblastoma specimens, it was not detected in colon cancer o r macroscopically tumor-free colon and lung tissue. In addition, HT29 colon cancer cells showed a loss of WT1 expression when grown to confluence or i nduced to differentiate by sodium butyrate. From this evidence, testing for WT1 expression is not clinically relevant for colon cancer, lung cancer, o r glioblastoma patients. WT1 expression in cancer cell lines can probably b e attributed to optimized in vitro growth conditions.