Coexpression of an unusual form of the EWS-WT1 fusion transcript and interleukin 2/15 receptor βmRNA in a desmoplastic small round cell tumour

Abstract

Background: The β chain of the interleukin 2/15 receptor (IL-2/15Rβ) is induced by the expression of the EWS-WT1. A case of desmoplastic small round cell tumour (DSRCT) expressing only an unusual EWS-WT1 treated by us is reported here. Aim: To characterise an unusual form of EWS-WT1. Methods: Frozen tissue sections of the axillary tumour were examined using a laser-assisted microdissection technique and reverse transcriptase polymerase chain reaction. Results: The novel fusion of exon 8 of EWS and the defective exon 10 of WT1 (-KTS) was detected. Although it was an unusual form, the coexpression of the present EWS-WT1, IL-2/15Rβ and Janus kinase (JAK1) mRNA was detected in the tumour cells. IL-2 and signal transducers and activators of transcription (STAT5) mRNA were detected in both tumour and stromal cells. Conclusion: The induction of the IL-2/15 receptor signalling pathway may contribute to tumorigenesis in DSRCT through a paracrine or an autocrine system, even though the EWS-WT1 was an unusual form.