Adiponectin and Breast Cancer Figure 3. Accelerated mammary tumor development in adiponectin haplodeficient MMTV-PyVT mice. Tumor growth in PyVT(+/2)/ ADN(+/+) and PyVT(+/2)/ADN(+/2) mice were monitored starting from 6 and 11 wks, up to 14 and 28 wks for female (left panel) and male (right panel) mice respectively. Tumor sizes were measured using vernier calipers and tumor volume calculated as described in Methods. Each group contained 13–20 mice, and the mean tumor volume 6SD was presented. doi:10.1371/journal.pone.0004968.g003 assays (Figure 7A). Inappropriate Akt activation can occur through PI3K. We found that the protein levels of the p110alpha subunits of PI3K, the main isoform involved in oncogenesis, were slightly increased in PyVT(+/2)/ADN(+/2) tumor cells (data not shown). Both general (LY294002) and selective pharmacological antago- nists against different isoforms of p110 catalytic subunits (p110alpha-selective inhibitor PIK75, p110beta-selective inhibitor TGX221 and p110delta-selective inhibitor IC8714) [34] were then used for testing their effects in cells isolated from PyVT(+/2)/ ADN(+/2) tumors. Treatment with either LY294002 or PIK75 led to significantly attenuated phosphorylations of Akt and GSK3beta and more than 50% reductions of nuclear beta-catenin activities, whereas treatment with IC8714 and TGX221 did not have much impacts (Figure 7B). Similarly, treatment with a specific inhibitor of Akt1 and Akt2 (Akti-1/2) significantly reduced beta-catenin and cyclin-D1 expression levels and caused about 11- fold decrease of nuclear beta-catenin activities (Figure 7C). To further verify the involvement of PI3K and Akt in the accelerated Table 1. Total wet weights of tumor and lung tissues collected from PyVT(+/2)/ADN(+/+) and PyVT(+/2)/ADN(+/2) mice in FVB/N and C57BL/6J background. FVB/N Female (14 weeks) ADN(+/2) ADN(+/+) (n = 20) (n = 20) Male (22 Weeks) ADN(+/2) ADN(+/+) (n = 13) (n = 18) C57BL/6J Female (16 weeks) ADN(+/2) ADN(+/+) (n = 13) (n = 19) Male (26 Weeks) ADN(+/2) ADN(+/+) (n = 18) (n = 18) Tumor Lung 4.48361.645 0.20360.041 9.88963.189* 0.21360.0309 3.68761.483 0.25260.005 6.85761.262* 0.28660.028 3.60961.846 0.22560.085 8.70462.742* 0.21960.026 2.13461.253 0.26660.018 5.07962.51* 0.29260.029 *p,0.05 vs the corresponding PyVT(+/2)/ADN(+/+) mice group. doi:10.1371/journal.pone.0004968.t001 PLoS ONE | www.plosone.org 5 March 2009 | Volume 4 | Issue 3 | e4968