Fig. 2

Ectopic expression of miR-130a & miR-145 reduced tumor metastases. a Top panel: the construct of miR-130a or miR-145 expressions under control of a CD11b promoter, with GFP and WPRE (Woodchuck hepatitis virus posttranscriptional regulatory element) in 3′-UTR. * indicates transcription starting site (TSS); numbers indicate CD11b promoter sequence relative to TSS. Lower panels: microscopy (left), flow cytometry analysis of CD11b⁺ myeloid cells differentiated from HS/PCs with the lentiviral expression vector in the culture with 4T1 tumor supernatant (right). b flow cytometry of GFP expression in CD11b⁺ myeloid cells (left), and CD11b⁺Ly6C⁺ monocytic and CD11b⁺ Ly6G⁺ granulocytic subsets in GFP⁺ myeloid cells (middle) with quantitative data (right). c Fold changes of miR-130a (left), and miR-145 (middle) as well as TβRII (right) in sorted GFP⁺ and GFP^– myeloid cells by qRT-PCR, with HS/PCs as a negative control. Data in (b-c) are from ex vivo culture as illustrated in (a). d TβRII fold changes by qRT-PCR from sorted peripheral blood Gr-1⁺CD11b⁺ myeloid cells of tumor-bearing mice that received miR-130a, miR-145, and TβRII shRNA-engineered bone marrow transplantation. e Lung metastasis of 4T1 cells in mice that received miR-engineered bone marrow transplantation as noted above. 4T1 cells were injected in MFP number 2 and metastatic nodules in the lung were assessed 28 days later (n = 5–13 mice). The data are represented as mean±SEM, and Student’s t test was performed. *p < 0.05, **p < 0.01, ***p < 0.001