miR-26a protects hematopoiesis from chemotherapeutic agent–induced myelosuppression. The mice received IV injection of 670 pmol per 20g of miR-26a or control (ctrl) chimera daily for 3 days. On day 2 of chimera treatment, 5-FU 150 mg/kg was injected. (A) The numbers of WBCs, red blood cells (RBCs), and platelets (PLTs) 10 days after 5-FU treatment. Data (mean ± SD) were pooled from 2 experiments involving a total of 6 mice per group. (B) The number of bone marrow (BM) cells 10 days after 5-FU treatment. Data (mean ± SD) were pooled from 2 experiments involving a total of 6 mice per group. (C) Representative picture of LSK population 5 days after 5-FU treatment with or without miR-26a chimera treatment (left). Percentages of LSK population (right). Data (mean ± SD) were pooled from 2 experiments involving a total of 6 mice per group. (D) Apoptosis. Representative picture of annexin V⁺ in LSK population 5 days after 5-FU treatment (left). Percentages of annexin V⁺ in the LSK population (right). Data (mean ± SD) were pooled from 2 experiments involving a total of 6 mice per group. *P < .05, **P < .01. Error bars indicate SD.