Expression of PIM-2 and NF-κB genes is increased in patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) and is associated with complete remission rate and overall survival.

Introduction: PIM-2 is a proto-oncogene that encodes for a serine/threonine kinase that interacts with various signaling molecules. PIM-2 is highly expressed in neoplastic tissues and in leukemic and lymphoma cell lines, which is consistent with its role during oncogenic transformation. The nuclear factor kappa B (NF-κB) pathway appears to be deregulated in a variety of tumors, with sustained activity of NF-κB leading to apoptotic resistance in tumor cells. The aim of this study was to investigate whether expression of PIM-2 and NF-κB is altered in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL).

Patients And Methods: One hundred forty-three patients were included: 91 with AML and 52 with ALL, aged 18-84 (median 46.7). Eighty-three patients (51 AML and 32 ALL) reached complete remission (CR). Bone marrow samples were collected at the time of diagnosis. Control samples were obtained from 24 healthy donors. We analyzed PIM-2 and NF-κB expression by RQ-PCR analysis.

Results: Expression of both PIM-2 and NF-κB in all leukemia patients and subgroups was significantly higher than in controls. AML patients who reached CR expressed PIM-2 and NF-κB at significantly lower levels than did patients with primary resistance to chemotherapy and who did not reach CR (NCR). Survival analysis revealed that in AML patients with higher expression of PIM-2 the overall survival (OS) was significantly shorter than in patients with lower expression.

Conclusion: Our data indicate that PIM-2 and NF-κB gene expression is increased in patients with AML and ALL. Moreover, high PIM-2 expression is associated with CR rate and OS in AML patients.