F79 aptamer exerts synthetic lethality in acute leukemias displaying epigenetic BRCA-deficient phenotype. (A) AML (n = 15), (B) BCR-ABL1 -negative B-ALL (n = 18), and (C) T-ALL (n = 10) xenograft cells and CD34⁺ (n = 3), B-cells (n = 11) and T-cells (n = 17) from healthy donors were employed here. (mRNA) Microarray detection of mRNA for BRCA1 and BRCA2; each circle represents an individual patient; BRCA1 and/or BRCA2 high (red) and low (blue) samples were used for further studies. Green circles represent cells from healthy donors. (BRCA1 and Ki67) Immunofluorescent quantitation of BRCA1 protein levels in Ki67-positive cells and percentage of Ki67-positive cells. Representative cells highlighting the differences of BRCA1 (red) levels in Ki67-positive cells (green) are shown; nuclei are counterstained with 4,6 diamidino-2-phenylindole. (F79) Xenograft cells were incubated in vitro with 5 μM F79 aptamer. (DNR+F79) Xenograft cells were treated in vitro with daunorubicin (0.2 μM for AML, 0.1 μM for B-ALL and T-ALL) and 5 μM F79 aptamer. Results represent percentage of surviving cells; *P < .05 in comparison with BRCAhigh patients.