Identification of differentially expressed genes associated with prognosis of B acute lymphoblastic leukemia.

BACKGROUND

Acute lymphoblastic leukemia type B (B-ALL) is a neoplastic disorder with high mortality rates. The aim of this study was to validate the expression profile of 45 genes associated with signaling pathways involved in leukemia and to evaluate their association with the prognosis of B-ALL.

METHODS

219 samples of peripheral blood mononuclear cells obtained from 73 B-ALL patients were studied at diagnosis, four, and eight weeks after starting treatment. Gene expression was analyzed by quantitative real-time polymerase chain reaction.

RESULTS

Normalized delta Cq values of 23 genes showed differences between B-ALL and controls at diagnosis time (P values < 0.05). There were significant associations between B-ALL patients relapse/death and the expression levels of IL2RA, SORT1, DEFA1, and FLT3 genes at least in one of the times evaluated (P values < 0.05 and odds ratio ranges: 3.73-27). The association between FLT3 deregulation and relapse/death was a constant in the times studied and their overexpression significantly increased the odds of relapse/death in a range of 3.73 and 6.05 among study population (P values < 0.05).

CONCLUSIONS

Overexpression of FLT3 and DEFA1 genes retained independent prognostic significance for B-ALL outcome, reflected as increased risks of relapse/death among the study population.