Ween two mouse lines at any time point observed. When we looked at the prostate size, there were no detectible differences in the average corrected prostate weights between CCX168 biological activity TRAMPMIC+/+ and TRAMPMIC-/- mouse lines at week 8 and 17. At week 25 and 33, TRAMPMIC-/- mice had a 6.9 and 8 fold increase in corrected average prostate 6 / 12 MIC-1/GDF15 and Prostate Cancer Fig 2. TRAMPMIC-/- mice have comparatively larger prostate tumor than TRAMPMIC+/+ mice. The corrected tumor weights of GU and prostates were compared in TRAMPMIC+/+ and TRAMPMIC-/- mice sacrificed at 8, 17, 25 and 33 weeks of age. Results were analyzed using a 2 way ANOVA and are presented as mean SEM. p values are shown as , p< 0.05. doi:10.1371/journal.pone.0115189.g002 tumor weight respectively, as compared to TRAMPMIC+/+ mice and this difference was statistically significant at week 33. MIC-1/GDF15 gene deletion has no effect on metastases Since metastasis is the major cause of death in patients with human PCa, we evaluated the effect of MIC-1/GDF15 gene deletion on the incidence and extent of metastasis in TRAMP mice. We examined a separate cohort of 63 TRAMPMIC+/+, 63 TRAMPMIC-/- and 63 MIC-1/GDF15 overexpressing TRAMP mice, which were followed until death or ethical end point. The latter group was included as a positive control, as our previous study had indicated TRAMPfmsmic-1 mice have more metastases but survive longer. Kaplan-Meier survival analysis reconfirmed that TRAMPMIC-/- mice die significantly Scutellarin site earlier than TRAMPMIC+/+ mice, consistent with data in the survival group. Further, TRAMPfmsmic-1 mice died at significantly slower rate than TRAMPMIC+/+ mice confirming data from our previous publication. In this cohort 19 of the TRAMPMIC+/+ mice developed macroscopically detectible distant organ metastasis PubMed ID:http://jpet.aspetjournals.org/content/124/2/165 in the surveyed organs, which was not significantly different to that of 14.2 in TRAMPMIC-/mice. The incidence of metastases in these two mouse lines was significantly less that in TRAMPfmsmic-1 mice, 59 of which developed metastases. These data show that although TRAMPMIC-/- mice die significantly earlier than TRAMPMIC+/+ mice there were no significant differences in the incidence of distant organ metastasis between the two mouse lines. In contrast, as previously reported, a significantly higher proportion of TRAMPfmsmic-1 mice showed distant organ metastasis compared with TRAMPMIC+/+ or TRAMPMIC-/- mice. Multivariate logistic regression analysis confirmed that the increased proportion of TRAMPfmsmic-1 mice with metastases was 7 / 12 MIC-1/GDF15 and Prostate Cancer Fig 3. Effect of MIC-1/GDF15 gene modification on metastases. Survival data for TRAMPMIC+/+, TRAMPMIC-/- and TRAMPfmsmic-1 mice is presented as a Kaplan-Meier plot and the log-rank statistic for median survival time is shown. Comparison between number of TRAMPMIC+/+, TRAMPMIC-/- and TRAMPfmsmic-1 mice having distant organ metastases at the time of death has been 
analyzed using the Chi-squared test. doi:10.1371/journal.pone.0115189.g003 independent of their longer survival times and only dependent on genotype. Further, using a similar approach, the lack of difference in the proportion of TRAMPMIC-/- compared with TRAMPMIC+/+ mice with metastases, could not be accounted for by their shorter survival. Discussion This study clearly indicates that germline deletion of the MIC-1/GDF15 leads to increased local primary tumor growth resulting in earlier death of TRAMP PCa prone mice. These data 8 / 12 MIC-1/GDF.Ween two mouse lines at any time point observed. When we looked at the prostate size, there were no detectible differences in the average corrected prostate weights between TRAMPMIC+/+ and TRAMPMIC-/- mouse lines at week 8 and 17. At week 25 and 33, TRAMPMIC-/- mice had a 6.9 and 8 fold increase in corrected average prostate 6 / 12 MIC-1/GDF15 and Prostate Cancer Fig 2. TRAMPMIC-/- mice have comparatively larger prostate tumor than TRAMPMIC+/+ mice. The corrected tumor weights of GU and prostates were compared in TRAMPMIC+/+ and TRAMPMIC-/- mice sacrificed at 8, 17, 25 and 33 weeks 
of age. Results were analyzed using a 2 way ANOVA and are presented as mean SEM. p values are shown as , p< 0.05. doi:10.1371/journal.pone.0115189.g002 tumor weight respectively, as compared to TRAMPMIC+/+ mice and this difference was statistically significant at week 33. MIC-1/GDF15 gene deletion has no effect on metastases Since metastasis is the major cause of death in patients with human PCa, we evaluated the effect of MIC-1/GDF15 gene deletion on the incidence and extent of metastasis in TRAMP mice. We examined a separate cohort of 63 TRAMPMIC+/+, 63 TRAMPMIC-/- and 63 MIC-1/GDF15 overexpressing TRAMP mice, which were followed until death or ethical end point. The latter group was included as a positive control, as our previous study had indicated TRAMPfmsmic-1 mice have more metastases but survive longer. Kaplan-Meier survival analysis reconfirmed that TRAMPMIC-/- mice die significantly earlier than TRAMPMIC+/+ mice, consistent with data in the survival group. Further, TRAMPfmsmic-1 mice died at significantly slower rate than TRAMPMIC+/+ mice confirming data from our previous publication. In this cohort 19 of the TRAMPMIC+/+ mice developed macroscopically detectible distant organ metastasis PubMed ID:http://jpet.aspetjournals.org/content/124/2/165 in the surveyed organs, which was not significantly different to that of 14.2 in TRAMPMIC-/mice. The incidence of metastases in these two mouse lines was significantly less that in TRAMPfmsmic-1 mice, 59 of which developed metastases. These data show that although TRAMPMIC-/- mice die significantly earlier than TRAMPMIC+/+ mice there were no significant differences in the incidence of distant organ metastasis between the two mouse lines. In contrast, as previously reported, a significantly higher proportion of TRAMPfmsmic-1 mice showed distant organ metastasis compared with TRAMPMIC+/+ or TRAMPMIC-/- mice. Multivariate logistic regression analysis confirmed that the increased proportion of TRAMPfmsmic-1 mice with metastases was 7 / 12 MIC-1/GDF15 and Prostate Cancer Fig 3. Effect of MIC-1/GDF15 gene modification on metastases. Survival data for TRAMPMIC+/+, TRAMPMIC-/- and TRAMPfmsmic-1 mice is presented as a Kaplan-Meier plot and the log-rank statistic for median survival time is shown. Comparison between number of TRAMPMIC+/+, TRAMPMIC-/- and TRAMPfmsmic-1 mice having distant organ metastases at the time of death has been analyzed using the Chi-squared test. doi:10.1371/journal.pone.0115189.g003 independent of their longer survival times and only dependent on genotype. Further, using a similar approach, the lack of difference in the proportion of TRAMPMIC-/- compared with TRAMPMIC+/+ mice with metastases, could not be accounted for by their shorter survival. Discussion This study clearly indicates that germline deletion of the MIC-1/GDF15 leads to increased local primary tumor growth resulting in earlier death of TRAMP PCa prone mice. These data 8 / 12 MIC-1/GDF.