Overexpression of pvt1 in CML patients positive for t(9; 22) translocation

The ENCODE project results revealed that only < 3% of the human genome encodes proteins, while 87.3% of it, is transcribed. These results cause scientists to be familiar with new regulatory factors beyond protein functions in cells. Noncoding transcripts include two general categories: short noncoding RNAs and long noncoding RNAs. Progressing researches have uncovered the roles of lncRNAs in different cellular processes such as stress response, alternative splicing and cell cycle, but many questions about precise molecular mechanisms of them are remained to be answered. The lncRNA pvt1 gene -located in downstream of myc oncogene- shows dysregulation in many cancers. It is reported that pvt1 binds to oncoproteins, stabilizes them and causes to uncontrolled proliferation of cells. For example, pvt1 binds to myc protein and protects it from degradation by phosphorylation. Material and methods: We have studied the expression of pvt1 and myc in CML By using qRT-PCR. This study includes 35 blood samples positive for t(9; 22) translocation with MRD> 1% and 43 blood samples negative for the Philadelphia chromosome. Results: Our results show almost 2.8-fold overexpression of lncRNA pvt1 levels in positive samples compared to negative ones (p-value= 0.067), while there is no significant difference of myc expression between positive and negative groups. Discussion: These results suggest that overexpression of pvt1 without an increase in oncoprotein levels can operate its own oncogenic function in cells. To our best knowledge, this is the first time that the pvt1 expression in CML is studied, but the mechanism of its function in this cancer needs more researches.