Human and murine hematopoietic cells express miR-142. (A) Endogenous expression of miR-142 in CD11c DC subsets: basal expression levels of miRNA-142-3p and 142-5p was analyzed by in purified FACS sorted CD11c⁺/CD8⁺ DC and CD11c⁺/CD8⁻ DC subsets with quantitative RT-PCR. Data shown are from 1 of 3 similar experiments (mean ± SEM). (B) miR-142s are specific for hematopoietic cells in mice. miR-142 expression was analyzed in the brain, whole splenocytes, DCs harvested from spleen, and the T and B lymphocytes harvested from the spleen or lymphoid nodes of naive mice. Data were obtained from 1 of 2 experiments with n = 3/group. (C) The miR-142-3p target sequence in the 3′UTR of IL-6 mRNA is conserved across several mammalian species. Seed sequence pairing is indicated by lines. (D) miR-142-3p and miR-142-5p are highly expressed in human hematopoietic cells: DCs and T lymphocytes were harvested from the PBMCs that were freshly isolated from normal healthy human volunteers (n = 3). The human cell lines—such as the endothelial cells, fibroblasts, and some cancers cells such as MCF7 and PC3—were used for controls as the nonhematopoietic cells. miR-142-3p and miR-142-5p expression was analyzed by quantitative RT-PCR. Results shown are from 1 of 2 experiments. (E) Control miR expression analyses in human cells: The above cells were also concomitantly analyzed for expression of miR-744, 668, and 720 as additional controls. miR-744 was extensively expressed in hematopoietic, nonhematopoietic, and cancer cells. Both miR-668 and miR-720 were expressed in nonhematopoietic and cancer cells but not in hematopoietic cells.