Upregulation of Wilms' tumour gene 1 (WT1) in uterine sarcomas

Aim: Overexpression of Wilms' tumour gene (WT1) has been proven in several tumours. Previous research of our group on the cell cycle of uterine leiomyosarcoma (LMS) and carcinosarcoma (CS) suggested a possible role for WT1. We therefore intended to further explore the expression pattern of \WT1 in uterine sarcomas. Methods: 27 CS, 38 LMS, 15 endometrial stromal sarcomas (ESS) and seven undifferentiated sarcomas (US) were collected. WT1 expression was evaluated by immunohistochemistry (IHC) in 87 samples, by RT-PCR (m-RNA expression) in 23 random selected samples and by Western blotting in 12 samples, separating cytoplasmic and nuclear proteins. A pilot study to detect mutations (exons 7-10) was performed on eight samples. Results: IHC showed WT1 positivity in 12/27 CS, 29/38 LMS, 7115 ESS and 4/7 US. All-but-one sample had a positive RT-PCR. All Western blottings were positive with more cytoplasmic expression in 9/12 cases. No mutations were found. Conclusions: WT1 is overexpressed in uterine sarcomas. Since increased levels of mRNA determine the biological role, WT1 might contribute to uterine sarcoma tumour biology. (C) 2007 Elsevier Ltd. All rights reserved.