Identification of Reference Genes in Chordoma Cells Allows Cross-Comparison of Expression Studies Across Subtypes.

AIM: To present the best housekeeping genes including clival/sacral based chordoma, and the nucleus pulposus cells. MATERIAL AND METHODS: We investigated 13 candidate reference genes in public chordoma array transcriptome datasets, validated these genes by using RT-PCR, and evaluated their stability with NormFinder, geNorm, and Bestkeeper. RESULTS: YWHAZ, TBP and PGK1 genes were identified as the most stable reference genes as confirmed with three different approaches. Conversely, KRT8, KRT19 and GAPDH genes are less stable and not appropriate for use in chordoma research. CONCLUSION: For normalization of RT-PCR experiments in gene profiling of chordoma, we recommend the use of the stable genes YWHAZ, TBP and PGK1.