Investigation of the expression of P-element-induced wimpy testis-interacting RNAs in human acute myeloid leukemia

P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a newly known class of small non-coding RNAs with 24–31 nucleotides in length. There are more than 20,000 piRNA genes in the human genome and some of them have a role in cancer. In this study, we investigated the expression of piRNAs in acute myeloid leukemia (AML). We used publicly available small RNA sequencing data derived from the peripheral blood of patients with AML and control samples to be re-analyzed for investigation of piRNA expression pattern and then was validated via the real-time polymerase chain reaction (PCR). Differential expression analysis showed that four upregulated piRNAs and six downregulated piRNAs in AML samples, among which, the piR-32,877 and piR-33,195 were the top two upregulated piRNAs. Real-time PCR was performed to validate the increased expression of these two piRNAs in AML compared to controls. Pathway analysis was also performed. The results provide evidence that piR-32,877 and piR-33,195 may serve as a new diagnostic and prognostic biomarker in AML.