title: The clinical utility of miR-21 as a diagnostic and prognostic marker for renal cell carcinoma.
abstract: Renal cell carcinoma (RCC) is the most common neoplasm of the kidney. Increasing evidence suggests that microRNAs are dysregulated in RCC and are important factors in RCC pathogenesis. miR-21 is a known oncogene with tumor-promoting effects in many types of cancer. In this study, we analyzed miR-21 in 121 cases of healthy kidney and different RCC subtypes, including clear cell (ccRCC), papillary (pRCC), chromophobe (chRCC), and oncocytoma. Total RNA was extracted, and the expression of miR-21 was measured with real-time quantitative RT-PCR using miR-21-specific probes. The expression of miR-21 was significantly up-regulated in RCC compared with healthy kidney. There was a significant difference in the expression levels between RCC subtypes, with the highest levels of expression in ccRCC and pRCC subtypes. miR-21 expression distinguished ccRCC and pRCC from chRCC and oncocytoma with 90% specificity (95% CI, 63.9% to 98.1%) and 83% sensitivity (95% CI, 53.5% to 97.6%). Significantly higher miR-21 levels were associated with higher stage and grade. Patients who were miR-21 positive had statistically significant shorter disease-free and overall survival rates. Thus, miR-21 is up-regulated in RCC, and its expression levels can be used as a diagnostic marker to distinguish ccRCC and pRCC from chRCC and oncocytoma. Moreover, it has potential as a prognostic marker in RCC, although it is not independent of tumor stage and grade.
authors.affiliation: Department of Laboratory Medicine, and the Keenan Research Center in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Hala
authors.initials: H
authors.lastname: Faragalla
authors.forename: Youssef M
authors.initials: YM
authors.lastname: Youssef
authors.forename: Andreas
authors.initials: A
authors.lastname: Scorilas
authors.forename: Bishoy
authors.initials: B
authors.lastname: Khalil
authors.forename: Nicole M A
authors.initials: NM
authors.lastname: White
authors.forename: Salvador
authors.initials: S
authors.lastname: Mejia-Guerrero
authors.forename: Heba
authors.initials: H
authors.lastname: Khella
authors.forename: Michael A S
authors.initials: MA
authors.lastname: Jewett
authors.forename: Andrew
authors.initials: A
authors.lastname: Evans
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Lichner
authors.forename: Georg
authors.initials: G
authors.lastname: Bjarnason
authors.forename: Linda
authors.initials: L
authors.lastname: Sugar
authors.forename: Magdy I
authors.initials: MI
authors.lastname: Attalah
authors.forename: George M
authors.initials: GM
authors.lastname: Yousef
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D002292:Carcinoma, Renal Cell / Q000235:genetics*; D019295:Computational Biology; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs