Quantitive expression of proliferating cell nuclear antigen by western blot (PCNAWB) in peripheral blasts correlates with remission induciton in patients with acute myelogenous leukemia

Proliferating cell nuclear antigen (PCNA) is a 36-kD nuclear protein that functions BS a cofactor of delta DNA polymerase which is regulated in a cell cycle-depcndent fashion. PCNA expression also increases when cells are actively engaged in DNA repair. We used Western blotting (WB) to measure the level of expression of PCNA in peripheral blasts of 36 adult acute myrlogenous leukemia (AML) paticnts treated with Ara-C based induction regimens. PCNA levelscorrclated positively with the percentage of cells in S + GIM of the cell cycle. Logistic regression analysis revcaled PCNA (B = 4.5162; p = 0.0260) together with age (B = 0.1777; p = 0.0364) as independent variables for remission induction: high PCNA levels were associated with poor response to induction therapy. PCNA expression was not, however. a predictor of survival in this subset of patients. We conclude that PCNA levels in this disease may be important for predicting response to Ara-C based remission induction chemotherapy.