DJ-1 mRNA expression in cells from healthy donors (n = 13), and patients with low-grade or advanced MDS (n = 58). (A) There was a statistically significant difference between the mRNA from healthy donors and patients with untreated MDS (P < .001) *Statistical significance as determined by Student t test compared with healthy control patients. (B) In comparison, patients with advanced MDS showed increased levels of DJ-1 (P < .019). The difference between low-grade MDS (refractory anemia, refractory anemia with ringed sideroblasts, and refractory cytopenia with multilineage dysplasia) and healthy controls was not significant. **Statistical significance as determined by ANOVA, comparison of healthy versus advanced MDS and healthy controls versus low-grade MDS. (C) Expression of p53 and DJ-1 as determined by RT-PCR in CD34⁺ cells from healthy donors (normal controls [NC]) and patients with MDS CD34 cells. In CD34⁺ cells from healthy donors (NCD34⁺; left), p53 and DJ-1 levels did not differ with and without stroma-contact. In clonal cells (MDSCD34⁺), the expression of p53 after stroma contact (CC) showed prominent p53 up-regulation; the inverse correlation was found for levels of DJ-1, which declined. (D) DJ-1 and p53 mRNA expression in cells for healthy donors (n = 13), and patients with low-grade (n = 30) and advanced MDS (n = 28). The ratio of DJ-1 and p53 expression was assessed by subgroup. A ratio greater than 1.01 would indicate inhibition of p53 expression. *Statistical significance as determined by ANOVA, comparison of DJ-1/p53 ratios of healthy versus advanced MDS healthy controls versus low-grade MDS and low-grade versus advanced MDS (P < .014). (E) DJ-1/p53 mRNA ratio in patients with MDS. There was a statistically significant difference between DJ-1/p53 ratios in low-grade (mean = 1.029; variance = 0.060064) and advanced (mean = 1.176468, variance = 0.137022) MDS patients (P = .014). *Statistical significance as determined by ANOVA compared low-grade with advanced MDS (P < .014).