To investigate the relationship between P15INK4B gene promoter methylation degree and different types of MDS and prognosis

Abstract

Objective To determine the methylation level of P15INK4B gene promoter in different types of myelodysplastic syndromes (MDS) and its correlation with its prognosis. Methods Methylation frequency of the P15INK4B gene promoter in 44 cases of MDS were determined by methylation-specific polymerase chain reaction (PCR) and pyrosequencing, and its correlation with clinical classification and characteristics of MDS were statistically analyzed. Results Frequency of P15INK4B gene promoter methylation in myelodysplastic syndromes-refractory anemia with excess blasts Ⅱ (MDS-RAEB Ⅱ) patients was (46.89±15.41)%, significantly higher than that in other types of MDS (P 0.05); frequency of P15INK4B gene promoter methylation was found to be correlated with decline in platelet upon diagnosis (t=9.02, P 0.05). As for the correlation between P15INK4B gene promoter methylation and MDS risk stratification, no significant difference was detected between the low-risk and very low-risk groups (P> 0.05), but significant differences were detected among the medium-risk, high-risk, and very high-risk groups (P< 0.05). In addition, frequency of P15INK4B gene promoter methylation was (49.21±8.78)% in MDS patients that developed leukemia in the following two year, significantly higher than that in MDS patients who didn't (19.64±6.24)% (P<0.05). Conclusions P15INK4B gene promoter methylation frequency is a valuable indicator of prognosis of MDS patients. Key words: Tumor suppressor proteins/GE; Methylation; Myelodysplastic syndromes/GE; Prognosis