Previous studies have shown that increased levels of chemokine receptor CXCR7 are associated with the increased invasiveness of prostate cancer cells. We now show that CXCR7 expression is upregulated in VCaP and C4‐2B cells after enzalutamide (ENZ) treatment. ENZ treatment induced apoptosis (sub‐G1) in VCaP and C4‐2B cells, and this effect was further increased after combination treatment with ENZ and CCX771, a specific CXCR7 inhibitor. The levels of p‐EGFR (Y1068), p‐AKT (T308) and VEGFR2 were reduced after ENZ and CCX771 combination treatment compared to single agent treatment. In addition, significantly greater reductions in migration were shown after combination treatment compared to those of single agents or vehicle controls, and importantly, similar reductions in the levels of secreted VEGF were also demonstrated. Orthotopic VCaP xenograft growth and subcutaneous MDA133‐4 patient‐derived xenograft (PDX) tumor growth was reduced by single agent treatment, but significantly greater suppression was observed in the combination treatment group. Although overall microvessel densities in the tumor tissues were not different among the different treatment groups, a significant reduction in large blood vessels (>100 μm2) was observed in tumors following combination treatment. Apoptotic indices in tumor tissues were significantly increased following combination treatment compared with vehicle control‐treated tumor tissues. Our results demonstrate that significant tumor suppression mediated by ENZ and CXCR7 combination treatment may be due, in part, to reductions in proangiogenic signaling and in the formation of large blood vessels in prostate cancer tumors.

Abstract.Marital status is an independent prognostic factor for survival in several types of cancer, but has not been fully studied in prostate cancer (PCa). A total of 95,846 men diagnosed with PCa were treated with radical prostatectomy (RP) between 2004 and 2009 within 18 Surveillance, Epidemiology and End Results registries. Survival curves were generated using Kaplan-Meier estimates and differences in survival were assessed using the log-rank test. Cox regression models were used to assess the impact of marital status on survival outcomes. The results demonstrated that the 8-year cancer-cause specific survival (CSS) rate of married men was higher than unmarried individuals. Further analyses revealed that divorced/separated men had a higher proportion of high Gleason scores (GS) PCa at diagnosis [hazard ratio (HR), 1.12; P=0.007] and those patients had the worst survival outcomes independent of age, ethnicity, grade, stage and sequence number [HR, 1.61; 95% confidence interval (CI), 1.34-1.93]. Interestingly, it was observed that CSS among divorced/separated men decreased as the GS increased (GS≤6: HR, 2.5; GS=7: HR, 1.71; GS≥8: HR, 1.50; all P<0.05). Apart from that, no significant differences in CSS were observed in those who had never been married (HR, 1.20) or were widowed (HR, 1.13) relative to the married group. The results of the present study support the hypothesis that marital status is an independent prognostic factor among men with PCa who underwent RP. It was demonstrated that the mortality rates of divorced or separated men with PCa were significantly greater compared with the other groups. A further understanding of the potential associations among marital status, psychosocial factors and survival outcomes may help in developing novel, more effective methods of treating different groups of patients with PCa.

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In present study, a novel four-lncRNA signature that is useful in survival prediction in PCa patients was developed. If validated, this lncRNA signature might assist in selecting high-risk subpopulation who need more aggressive therapeutic intervention. The clinical implications and the mechanism of these four lncRNAs deserve further investigation in future studies.