Thesis (Ph.D.) - Cairo University - Faculty of Medicine - Department of Pathology

Background:Wilms{u2019} tumour gene product (WT1) is an embryonic zinc-finger transcription factor, which was originally identified as a tumor suppressor gene and documented as a target for gene therapy of many solid tumors including astrocytic tumors. Aim of work: The aim of this study is the assessment of immunohistochemical expression of WT1 protein, in different histologic types and grades of astrocytic tumors. WT1 protein expression will be correlated with various clinical data (such as age, sex).Material and Methods: The material of this study consisted of 80 paraffin blocks of astrocytoma cases collected from Nasser Institute for Research and Treatment from January 2012 toDecember 2013.Results: WT1 was expressed in (25/28) grade I astrocytomas, all grade II astrocytomas (14/14), (13/16) grade III astrocytomas and (21/22) grade IV with highly significant relationship (P-value<0.001) between grade I and grade IV, grade III and grade IV. Expression was the highest in older ages (significantp-value = 0.034),in male cases (insignificantp-value = 0.298) and in areas of perivascular proliferation and the astrocytic tumors subtypes (gemistocytic astrocytoma, pleomorphic xanthoastrocytoma, protoplasmic astrocytoma and glioblastoma). Conclusion:Many factors affect the expression of WT1 in astrocytomas, rather than the tumor grade, which include tumor vasculature, patient age and the tumor subtype. Recommendations:Further studies are recommended for assessment of WT1 expression in astrocytomas in relation to other brain tumors for detection of its specificity and sensitivity for astrocytic tumors and correlation of WT1 expression with the extent of tumor vasculature and each of astrocytoma histologic subtype and patients{u2019} age.

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