DNA polymerase delta (POLD1 and POLD2) gene expression in pediatric acute lymphoblastic leukemia patients and its relationship with prognosis

Purpose: This study aimed to investigate the status of DNA polymerase delta (POLD1 and POLD2) gene expression at the time of diagnosis in pediatric acute lymphoblastic leukemia (ALL) patients, compared with the normal population, and its relationship with prognosis and other clinical findings. Materials and Methods: Seventy-three patients diagnosed with ALL between January 2008 and November 2015 and 29 healthy control subjects were included in the study. Gene expression profiling of peripheral blood samples was performed using Real-time PCR. Results: The mean value of POLD1 gene expression was found to be significantly higher in ALL patients at the time of diagnosis than the control group (376.5± 685.8 and 17.9± 19.8, respectively), but there was no difference in POLD2 gene expression (511.5± 898.1 and 125.4± 132.7, respectively). POLD1 and POLD2 gene expressions were found to be low in patients with relapse and exitus, but the results were not statistically significant. Patients with low levels of POLD1 expression had lower survival rates in the 5th year than those with high levels of expression (54% and 68%, respectively), and similarly, patients with low levels of POLD2 expression had lower survival rates in the 5th year compared to those with high levels of expression (58% and 68%, respectively). Conclusion: Lower POLD1 and POLD2 expressions at the time of diagnosis in ALL patients may adversely affects the prognosis.