Cancer-associated rs6983267 SNP and its accompanying long noncoding RNACCAT2induce myeloid malignancies via unique SNP-specific RNA mutations

The cancer-risk-associated rs6983267 single nucleotide polymorphism (SNP) and the accompanying long noncoding RNACCAT2in the highly amplified 8q24.21 region have been implicated in cancer predisposition, although causality has not been established. Here, using allele-specificCCAT2transgenic mice, we demonstrate thatCCAT2overexpression leads to spontaneous myeloid malignancies. We further identified thatCCAT2is overexpressed in bone marrow and peripheral blood of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) patients.CCAT2induces global deregulation of gene expression by down-regulating EZH2 in vitro and in vivo in an allele-specific manner. We also identified a novel non-APOBEC, non-ADAR, RNA editing at the SNP locus in MDS/MPN patients andCCAT2-transgenic mice. The RNA transcribed from the SNP locus in malignant hematopoietic cells have different allelic composition from the corresponding genomic DNA, a phenomenon rarely observed in normal cells. Our findings provide fundamental insights into the functional role of rs6983267 SNP andCCAT2in myeloid malignancies.