The remarkable suppression of ES xenograft tumor growth by miR-34a-5p prodrug, revealed in current study, was associated with a lower degree of tumoral cell proliferation and greater extent of apoptosis, as well as a relatively increased level of p53 expression, providing a good molecular explanation for the effectiveness of miR-34a-5p prodrug in xenograft mouse models. This evidence concerns the gene TP53 and neoplasm.