Figure 6. miR-31 functions as an oncomir in lung cancer cells.

A/B) Direct cell count assays depicting in-vitro proliferation of Calu-6 and H841 lung cancer cells exhibiting over-expression or knock-down of miR-31. Constitutive over-expression of miR-31 increased proliferation, whereas knock-down of miR-31 diminished proliferation of Calu-6 (a) as well as H841 (b) cells relative to vector controls. C) Growth of H358 and Calu-6 tumor xenografts in nude mice. Calu-6 and H358 cells constitutively over-expressing miR-31 and vector controls (1×10⁶) were inoculated subcutaneously in the right and left flanks of athymic nude mice. Tumor volumes were determined every five days. The mean tumor volumes are shown. Volumes of xenografts derived from Calu-6 or H358 cells over-expressing miR-31 were significantly larger than vector controls (P<0.01). D) Tumor masses from H358 and Calu-6 xenografts. MiR-31 expression significantly increased average mass of H358 as well as Calu-6 xenografts (p<0.001).