Low Epression of MiR-18a Distinguishes Pediatric and Adult Acute Lymphoblastic Leukemia from Each Other

In several adult solid cancers the presence or absence of an inflammatory microenvironment has turned out to be an important prognostic factor. Acute lymphoblastic leukemia (ALL) is seen in both adults and children but the response to chemotherapy and survival is significantly worse in adults than children. Therefore, we wanted to study whether the expression of immune system associated molecular markers would be different in adult and pediatric ALL patients at the time of diagnosis. IDO and FOXP3 were studied from paraffin embedded tissue samples by immunohistochemistry in 12 pediatric and 10 adult bone marrow samples. Inflammation associated miRNA analysis were performed in 19 adult and 79 pediatric ALL patients and involved miR-10, miR-15, miR-16, miR-17-92 cluster, miR-33, miR-146a, miR-150, miR-155, miR-181a, miR-222, miR-223, and miR-339. miRNAs were first analysed by Agilent9s miRNA microarray and thereafter validated by qRT-PCR. miRNAs not expressed in at least 75% of one group of samples were excluded. Significance (p Disclosures No relevant conflicts of interest to declare.