Erythroblasts negative for WRN immunostaining were only observed in two patients, both of whom were diagnosed with WS: one with concomitant myelodysplastic syndrome and the other with erythroleukemia with overexpression of TP53.
Moreover, Friend virus-induced erythroleukemia requires maintenance of PU.1 expression and the disruption of p53 function greatly accelerates disease progression.
In conclusion, persistently active STAT5 can recruit normal p53, like in the case of MPN cells, but also p53 mutants, such as p53M133K in human erythroleukemia cells, leading to pathologic gene expression that differs from canonical STAT5 or p53 transcriptional programs.
These three MDS patients with p53 gene mutations and an MDS-derived erythroleukemia cell line that we had previously reported to carry a p53 gene mutation showed no N-ras gene mutations, suggesting heterogeneity in the oncogenic mechanism of MDS.