The association of increased p14ARF/p16INK4a and p15INK4a gene expression with proliferative activity and the clinical course of multiple myeloma.

p14/p16 and p15 gene expression was assessed by quantitative polymerase chain reaction in purified plasma cells (PC) from 52 patients with symptomatic multiple myeloma (MM) and seven with smoldering MM in order to clarify the impact of these genes on the proliferative activity of tumor cells and patients' outcome. p15 expression was lower in symptomatic MM than in smoldering SMM (-1.80 vs.1.51,p=0.026); similar results were observed for p14/p16. MM patients whose PC displayed high p15 and/or p14/p16 expression had a lower percentage of S-phase PC than the remaining cases (1.79%+/-1.35 vs. 3.04%+/-1.42, p=0.028), favorable prognostic factors and longer survival (100% vs. 49%at 2.5 years; p=0.007).