Abstract 5321: An informative clinical applicable serum miRNAs 371-3 and 302/367 test for (germ cell) cancer patients

Expression of microRNAs (miR) can be unique and specific for malignant cells, as shown for human germ cell cancers (GCC), i.e., seminomas (SE) and nonseminomas (NS). GCC are the most frequent malignancy in Caucasian young males. They show high expression of the embryonic stem cell miR clusters 371-3 and 302/367, related to their cancer stem cell component. No recurrent DNA copy number changes of these miR and mutation in DICER was found in more than 250 primary GCC samples. Current clinically used serum markers for GCC are the proteins AFP and hCG, which are informative in a selection of patients (minority with a SE, and majority of those with a NS: i.p. yolk sac tumor and/or choriocarcinoma). Although the fore-mentioned miR have been suggested as serum markers for GCC, no robust protocol is available so far. A novel, sensitive and specific pipeline for miRNA profiling in body fluids is developed based on a magnetic anti-probe bead purification step (ABC miRNA purification kit, Life Technologies). This method shows stable recovery based on multiple synthetic non-human spike-ins, allowing calibration. Out of a set of 9 potential serum-specific controls, two were identified by Normfinder and geNorm as most stable (miR-20a and 93), therefore used for normalization. This TSmiR test was applied to five series of serum samples for independent learning and validation, including 47 controls (N), 80 GCC (adult and pediatric) (T), 11 matched pre- and post-orchidectomy samples, and 12 no-GCC testicular tumors (no-GCC). TSmiR demonstrated a consistent, significant increase (p