Validation of Suitable Endogenous Control Genes for Expression Studies of Mirna in Prostate Cancer Tissues Short Title: Mirna Control Genes Prostate Cancer

When performing qPCR analysis, there is a need for correction of technical variation between experiments. This correction is most commonly performed by using endogenous control genes, which are stably expressed across samples, as reference genes for normal expression in a specific tissue. In microRNA (miRNA) studies, two types of control genes are commonly used and these are small nuclear RNAs and small nucleolar RNAs. In this study, six different endogenous control genes for miRNA studies were investigated in a prostate tissue material from the Swedish Watchful Waiting cohort. The stability of the controls was investigated using two different software applications, NormFinder and BestKeeper. The results denote RNU24 as the most suitable endogenous control gene for miRNA studies in prostate tissue materials.