ADAM9 is highly expressed in renal cell cancer and is associated with tumour progression

108 renal cancer cases were immunostained for ADAM9 on a tissue-micro-array. For 30 additional cases, ADAM9 mRNA of microdissected tumour and normal tissue was analyzed via quantitative RT-PCR. SPSS 14.0 was used to apply crosstables (Fisher's exact test and χ2-test), correlations and univariate as well as multivariate survival analyses.ADAM9 was significantly up-regulated in renal cancer in comparison to the adjacent normal tissue on mRNA level. On protein level, ADAM9 was significantly associated with higher tumour grade, positive nodal status and distant metastasis. Furthermore, ADAM9 protein expression was significantly associated with shortened patient survival in the univariate analysis.ADAM9 is strongly expressed in a large proportion of renal cell cancers, concordant with findings in other tumour entities. Additionally, ADAM9 expression is significantly associated with markers of unfavourable prognosis. Whether the demonstrated prognostic value of ADAM9 is independent from other tumour parameters will have to be verified in larger study cohorts.Renal cell cancer (RCC) is thought to cause 12.890 deaths in 2007 in the USA [1] and accounts for around 2–3% of cancers worldwide [2,3]. It is one of the most lethal urologic malignancies. Nodal and systemic metastasis as well as vascular invasion are important prognostic factors in this tumour entity [4]. New molecular markers are warranted to improve the classification of RCC, to provide further prognostic and predictive information and eventually to allow for an individualized cancer therapy [5-8].In this study, we focused on ADAM9 (synonyms: MDC9, meltrin-γ), a member of the "A Disintegrin And Metalloprotease" family. Functionally, ADAMs participate in spermatogenesis, cell adhesion, myo- and neurogenesis, inflammation, cell migration and tissue remodelling [9,10]. ADAMs are membrane-anchored cell surface glycoproteins with a protease domain in addition to an adhesion domain. The structure of ADAMs was found to b