BioProject

Recently, the p53-miR-34a network was identified to play an important role in tumorigenesis. More...

Recently, the p53-miR-34a network was identified to play an important role in tumorigenesis. As in acute myeloid leukemia with complex karyotype (CK-AML) TP53 alterations are the most common known molecular lesion, we further analyzed the p53-miR-34a axis in CK-AML with known TP53 status. Clinically, low miR-34a expression and TP53 alterations predicted for chemotherapy resistance and inferior outcome. Notably, in TP53unaltered CK-AML high miR-34a expression predicted for inferior overall survival (OS), whereas in TP53biallelic altered CK-AML high miR-34a expression pointed to better OS. To further investigate miR-34a-associated gene expression patterns, we analyzed distinct subgroups defined by TP53 alteration and miR-34a expression status. Exemplary samples from TP53unaltered (n=6) and TP53biallelic altered (n=6) CK-AML characterized by either high (CK+/miR-34ahigh expression, above median miR-34a expression of the entire cohort), or low (CK+/miR-34alow expression, below median miR-34a expression of the entire cohort) miR-34a expression (n=3 in each group), were analyzed. This molecular profiling linked impaired p53 to decreased miR-34a expression but also identified p53-independent miR-34a induction mechanisms, as shown in TP53biallelic altered cell lines treated with 15-deoxy-∆12,14-prostaglandin (PGJ2). An improved understanding of this mechanism might provide novel therapeutic options to restore miR-34a function and thereby induce cell cycle arrest and apoptosis in TP53altered CK-AML. Overall design: All samples were obtained from untreated patients at the time of diagnosis. Cells used for microarray analysis were collected from the purified fraction of mononuclear cells after Ficoll density centrifugation. Routine diagnostic algorithms, including the characterization of molecular markers are performed. Less...