Mir-21 Expression in Wilms’ Tumor

Background and objective: wilms’ tumor (wt) is the most common genitourinary tract tumor in children. micrornas (mirnas) are small non-coding rnas; their role in the pathogenesis of many types of human cancers has been identified. we aimed to evaluate the expression of mir-21, a well-known oncomir, in wt tissue samples which is a very common urinary tract malignancy in children. methods: we performed chromogenic in situ hybridization (cish) to detect the sub-cellular localization of mir-21 in 25 formalin-fixed, paraffin-embedded (ffpe) samples of wt. we also evaluated mir-21 expression in 24 of these blocks and 6 normal kidneys as controls using quantitative real-time pcr technique. results: while our real-time pcr analysis showed mir-21 significant overexpression in 4 tumors compared to the normal kidney samples, we could not detect significant ish signal in any of these samples. conclusion: low expression of mir-21 in wt might pinpoint the weak involvement of this mirna in the pathogenesis of this cancer.