RNA analysis indicates tight correlation between the expression of a long non coding RNA and the TG2 mRNA levels

The long non-coding RNAs (lncRNAs) are matter of intense investigation as potential regulators of gene expression, but their mechanism of action, activity and eventual therapeutic utility are not fully understood. In the case of the tranglutaminase 2 gene (TGM2) the databases of genome sequence indicate location of a lncRNA (LOC107987281) within the first intron. This lncRNA is 588 nt long, arises from 2 exons and starts few nucleotides (nt) 3’ of the first splicing site of TGM2 gene. In this study we looked for correlations between expression of LOC107987281 lncRNA and TGM2 mRNA by real time PCR in K562 cell line untreated or treated with the anticancer drugs TPA (12-O-Tetradecanoylphorbol-13-acetate), Docetaxel and Doxorubicin. According to our data the drugs increase the transcript levels of both TGM2 mRNA and lncRNA. To validate this finding we used HumanExon1_0ST Affymetrix; data were chip background-adjusted, quantile-normalized and summarized using RMA robust multiarray analysis implemented in the R package. The probesets recognize sequences inside each exon, near intronic splicing sites and others located in the untraslated regions of TGM2 gene The analysis of total RNA samples from K562, HL60, THP-1 and U937 cell lines, untreated or treated with TPA in replicated experiments confirmed our earlier results. Results demonstrate correlation between LOC107987281 and TGM2 mRNA variant 1 in the cell lines (K562, HL60 and THP-1) where increased levels of TGM mRNA are produced. Additional array study on 358 samples of several normal and tumor tissues leads to the same conclusions, indicating a correlation between TGM2 variant 1 mRNA and LOC107987281 lncRNA in relation to development of several tumors