miRNA profiling of sacral chordoma and nucleus pulposus cells

Next-generation RNA sequencing (NGS) was used for the combinatorial analysis of mRNA-miRNA gene expression profiles in sacral chordoma and nucleus pulposus samples, and to predict miRNA-mRNA regulatory networks with altered activity in chordoma. We identified a gene set including key regulators of the Hippo pathway, which is targeted by differently expressed miRNAs, and validated their altered expression by RT-qPCR. These newly identified miRNA/RNA interactions are predicted to have a role in the self-renewal process of chordoma stem cells, which might sustain the high rate of recurrence for this tumor. Overall design: 8 chordoma (CH) and 8 nucleus pulposus (NP) tissue samples were collected from surgically treated Caucasian patients. The chordoma samples were frozen in lN2 immediately after removal and stored at -80 ºC until processing. NP tissues were surgically removed from patients diagnosed with degenerative disc disease (Pfirrmann grade III), undergoing lumbar intervertebral fusion surgery. We established primary NP cell cultures from the NP tissue samples, applying the explantation method without any enzymatic digestions.