(E) Invasive properties were analyzed using Falcon cell culture inserts covered with 50 μg of Matrigel per filter. For both assays, the lower chambers contained conditioned media from NIH/3T3 cells cultured for 24 h, which

was used as a chemoattractant. After incubation for 24 h, the cells invading the lower surface were counted microscopically. The results are representative of 5 independent experiments. Inhibitory effect of statins on lung metastasis in B16BL6 cells Mice injected with tumor cells following a 3-d pretreatment with 0.05 μM fluvastatin or 0.1 μM simvastatin displayed visible lung nodules at 14 d after the injection. The numbers of pulmonary nodules following pretreatment with 0.1% DMSO (control cells), 0.1 μM simvastatin, and 0.05 μM fluvastatin were 452.6 ± 40.8, 257.6 ± 45.6, and 256.0 ± 33.9, respectively selleck products (P < 0.01, Figure 1C). Statins inhibit tumor cell migration and invasion Cell migration and invasion are critical processes in tumor metastasis. We investigated the effects of statins on B16BL6 cell migration and invasion by the Boyden chamber and Matrigel invasion chamber assays, selleck inhibitor respectively. The number of B16BL6 cells migrating and invading through the chambers was significantly decreased by pretreatment of the cells with statins (P < 0.01, Figure 1D, E). Inhibitory effect of statins on the expressions of MMP-1,

MMP-2, MMP-9, and MMP-14 in B16BL6 cells We found that statins had an inhibitory effect on invasion; this prompted us to examine its effects on the expression of MMP-1, MMP-2, MMP-9, and

MMP-14. First, we examined whether statins could inhibit the expression of these MMP mRNAs. Administration of statins markedly inhibited the MMP mRNA expression of all the MMPs (Figure 2A). Next, we investigated whether type I and type IV collagenase activities and MMP-14 protein production were inhibited in B16BL6 cells that were pretreated with statins. After statins were administered, the type I and type IV collagenase activities, as well as the level of MMP-14 protein, were Bumetanide markedly reduced in B16BL6 cells (Figure 2B-D). Figure 2 Inhibitory effects of statins on the mRNA expressions and protein activities of MMPs. B16BL6 cells were treated with 0.05 μM fluvastatin or 0.1 μM simvastatin for 3 d. (A) Equal amounts of total RNA were reverse-transcribed to generate cDNAs that were used for PCR analysis of the mRNA expressions of MMPs in B16BL6 cells. (B, C) Activities of (B) type I collagenase (MMP-1) and (C) type IV collagenases (MMP-2 and MMP-9) in B16BL6 cells. Conditioned media were harvested, and the type I and type IV collagenase activities were measured by FITC-conjugated type I and type IV collagen breakdown assays, respectively. The results are representative of 5 independent experiments. (D) Image showing a western blot of the MT1-MMP protein expression.