The Expression of CCAT2, a Novel Long Noncoding RNA Transcript, and rs6983267 Single-Nucleotide Polymorphism Genotypes in Colorectal Cancers

Colon cancer-associated transcription 2 (CCAT2) was recently identified as a novel long noncoding RNA transcript encompassing the single-nucleotide polymorphism rs6983267. CCAT2 is overexpressed in colorectal cancer (CRC) where it promotes tumor growth, metastasis, and chromosomal instability, although the clinical relevance of this enhanced expression is unknown. In this retrospective study, CCAT2 expression was evaluated using real-time polymerase chain reaction in 149 CRC patients, and its associations with clinicopathological characteristics, outcome, rs6983267 genotypes, microsatellite status, DNA ploidy, and BubR1 expression were analyzed. CCAT2 expression in cancer tissue was significantly higher than in noncancer tissue (p < 0.001), particularly in cases of metastatic cancer (p < 0.001). However, relative CCAT2 expression levels and rs6983267 genotypes were not correlated with clinicopathological features or patient prognosis. CRC cases demonstrating high CCAT2 expression were all microsatellite stable (p < 0.005). Together, this indicates that CCAT2 expression was associated with microsatellite-stable CRC.